diff --git a/.cargo/config.toml b/.cargo/config.toml
index 65635d8134..4781cd1929 100644
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -4,6 +4,12 @@
 xtask = "run --package xtask --"
 
 [build]
+# An explicit RUSTFLAGS environment variable replaces these flags, so callers that set it must
+# also enable the NuTachyon cfg.
+rustflags = [
+    '--cfg',
+    'zcash_unstable="nutachyon"',
+]
 rustdocflags = [
     # Keep shared rustdoc lint levels synchronized with the book and lint
     # workflows.
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 59db3faf69..909e7e9657 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -134,6 +134,10 @@ jobs:
       # coverage. `zakura-watchdog` is excluded: it depends on `sentry`, which
       # requires a newer rustc than the workspace library MSRV.
       - run: cargo check --workspace --bins --exclude zakura-watchdog
+        env:
+          # NuTachyon's Tachyon dependency requires Rust 1.97. Clear the repository-level
+          # opt-in cfg so this job continues to check the supported cfg-off build on 1.91.
+          RUSTFLAGS: ""
 
   docs:
     name: docs
diff --git a/.github/workflows/semver-checks.yml b/.github/workflows/semver-checks.yml
index b7c6aab92f..df2b4a63a6 100644
--- a/.github/workflows/semver-checks.yml
+++ b/.github/workflows/semver-checks.yml
@@ -269,7 +269,7 @@ jobs:
         run: |
           # cargo-public-api builds both the current and published crate with
           # nightly. Nightly-only warnings are evidence, not the lint gate.
-          RUSTFLAGS='' cargo public-api diff latest -p "$PACKAGE" -sss
+          RUSTFLAGS='--cfg zcash_unstable="nutachyon"' cargo public-api diff latest -p "$PACKAGE" -sss
 
   warm-baselines:
     name: Warm semver baselines
diff --git a/.github/workflows/test-crates.yml b/.github/workflows/test-crates.yml
index d7556a3b32..8cc9dff3c0 100644
--- a/.github/workflows/test-crates.yml
+++ b/.github/workflows/test-crates.yml
@@ -101,8 +101,8 @@ jobs:
           cargo hack check --workspace
           cargo hack check --workspace --no-default-features
         env:
-          # Treat warnings as errors, preserving the old `features` job behavior.
-          RUSTFLAGS: -D warnings
+          # Treat warnings as errors while preserving the workspace NuTachyon cfg.
+          RUSTFLAGS: '--cfg zcash_unstable="nutachyon" -D warnings'
 
       - name: Check publishable crate packaging
         run: ./scripts/check-crate-packaging.sh
diff --git a/Cargo.lock b/Cargo.lock
index a9b1e5a727..c76f2b2c91 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1669,8 +1669,7 @@ dependencies = [
 [[package]]
 name = "f4jumble"
 version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d42773cb15447644d170be20231a3268600e0c4cea8987d013b93ac973d3cf7"
+source = "git+https://github.com/zcash/librustzcash.git?rev=c7235b1fc4b4296b8af2e26bf2f6adb24f873f56#c7235b1fc4b4296b8af2e26bf2f6adb24f873f56"
 dependencies = [
  "blake2b_simd",
 ]
@@ -3369,6 +3368,15 @@ dependencies = [
  "rayon",
 ]
 
+[[package]]
+name = "maybe-rayon"
+version = "0.1.1"
+source = "git+https://github.com/tachyon-zcash/maybe-rayon.git?rev=5c37ee0dd448e8c1edc4529d0b8897ecaff5aad1#5c37ee0dd448e8c1edc4529d0b8897ecaff5aad1"
+dependencies = [
+ "cfg-if",
+ "rayon",
+]
+
 [[package]]
 name = "md5"
 version = "0.7.0"
@@ -4716,6 +4724,100 @@ version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dc33ff2d4973d518d823d61aa239014831e521c75da58e3df4840d3f47749d09"
 
+[[package]]
+name = "ragu"
+version = "0.0.0"
+source = "git+https://github.com/tachyon-zcash/ragu?rev=f4f6315b10ed96944c40b2bbdbca0fe06af66ce0#f4f6315b10ed96944c40b2bbdbca0fe06af66ce0"
+dependencies = [
+ "blake2b_simd",
+ "ragu_arithmetic",
+ "ragu_circuits",
+ "ragu_core",
+ "ragu_pasta",
+ "ragu_pcd",
+ "ragu_primitives",
+]
+
+[[package]]
+name = "ragu_arithmetic"
+version = "0.0.0"
+source = "git+https://github.com/tachyon-zcash/ragu?rev=f4f6315b10ed96944c40b2bbdbca0fe06af66ce0#f4f6315b10ed96944c40b2bbdbca0fe06af66ce0"
+dependencies = [
+ "ff",
+ "group",
+ "maybe-rayon 0.1.1 (git+https://github.com/tachyon-zcash/maybe-rayon.git?rev=5c37ee0dd448e8c1edc4529d0b8897ecaff5aad1)",
+ "ragu_macros",
+ "rand 0.10.2",
+ "zakura-pasta-curves",
+]
+
+[[package]]
+name = "ragu_circuits"
+version = "0.0.0"
+source = "git+https://github.com/tachyon-zcash/ragu?rev=f4f6315b10ed96944c40b2bbdbca0fe06af66ce0#f4f6315b10ed96944c40b2bbdbca0fe06af66ce0"
+dependencies = [
+ "blake2b_simd",
+ "maybe-rayon 0.1.1 (git+https://github.com/tachyon-zcash/maybe-rayon.git?rev=5c37ee0dd448e8c1edc4529d0b8897ecaff5aad1)",
+ "ragu_arithmetic",
+ "ragu_core",
+ "ragu_primitives",
+]
+
+[[package]]
+name = "ragu_core"
+version = "0.0.0"
+source = "git+https://github.com/tachyon-zcash/ragu?rev=f4f6315b10ed96944c40b2bbdbca0fe06af66ce0#f4f6315b10ed96944c40b2bbdbca0fe06af66ce0"
+dependencies = [
+ "ragu_arithmetic",
+ "ragu_macros",
+ "thiserror 2.0.18",
+]
+
+[[package]]
+name = "ragu_macros"
+version = "0.0.0"
+source = "git+https://github.com/tachyon-zcash/ragu?rev=f4f6315b10ed96944c40b2bbdbca0fe06af66ce0#f4f6315b10ed96944c40b2bbdbca0fe06af66ce0"
+dependencies = [
+ "num-bigint",
+ "num-traits",
+ "proc-macro-crate",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.118",
+]
+
+[[package]]
+name = "ragu_pasta"
+version = "0.0.0"
+source = "git+https://github.com/tachyon-zcash/ragu?rev=f4f6315b10ed96944c40b2bbdbca0fe06af66ce0#f4f6315b10ed96944c40b2bbdbca0fe06af66ce0"
+dependencies = [
+ "lazy_static",
+ "ragu_arithmetic",
+]
+
+[[package]]
+name = "ragu_pcd"
+version = "0.0.0"
+source = "git+https://github.com/tachyon-zcash/ragu?rev=f4f6315b10ed96944c40b2bbdbca0fe06af66ce0#f4f6315b10ed96944c40b2bbdbca0fe06af66ce0"
+dependencies = [
+ "maybe-rayon 0.1.1 (git+https://github.com/tachyon-zcash/maybe-rayon.git?rev=5c37ee0dd448e8c1edc4529d0b8897ecaff5aad1)",
+ "ragu_arithmetic",
+ "ragu_circuits",
+ "ragu_core",
+ "ragu_primitives",
+]
+
+[[package]]
+name = "ragu_primitives"
+version = "0.0.0"
+source = "git+https://github.com/tachyon-zcash/ragu?rev=f4f6315b10ed96944c40b2bbdbca0fe06af66ce0#f4f6315b10ed96944c40b2bbdbca0fe06af66ce0"
+dependencies = [
+ "ragu_arithmetic",
+ "ragu_core",
+ "ragu_macros",
+ "thiserror 2.0.18",
+]
+
 [[package]]
 name = "rand"
 version = "0.8.6"
@@ -7697,8 +7799,7 @@ checksum = "cdad84f915d23f50eeb7389fd1ffc2385b35c57c68ceb2df20c73b7724621a30"
 [[package]]
 name = "zakura-bellman"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a6b7239d41621cc0c39349882001442d49bbc8dc46390c4826feb85a55a8d47"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "bitvec",
  "blake2s_simd",
@@ -7714,8 +7815,7 @@ dependencies = [
 [[package]]
 name = "zakura-bls12-381"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d2c114620056f8c97ecc17d7333add6c818ff376434943c7ff4974320426887"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "ff",
  "group",
@@ -7754,6 +7854,7 @@ dependencies = [
  "primitive-types",
  "proptest",
  "proptest-derive",
+ "ragu",
  "rand 0.10.2",
  "rand 0.8.6",
  "rand_chacha 0.10.0",
@@ -7777,6 +7878,7 @@ dependencies = [
  "uint 0.10.0",
  "x25519-dalek",
  "zakura-halo2-proofs",
+ "zakura-history",
  "zakura-jubjub",
  "zakura-orchard",
  "zakura-primitives",
@@ -7786,10 +7888,10 @@ dependencies = [
  "zakura-sinsemilla",
  "zakura-test",
  "zcash_address",
- "zcash_history",
  "zcash_note_encryption",
  "zcash_protocol",
  "zcash_script",
+ "zcash_tachyon",
  "zcash_transparent",
 ]
 
@@ -7812,6 +7914,7 @@ dependencies = [
  "once_cell",
  "proptest",
  "proptest-derive",
+ "ragu",
  "rand 0.10.2",
  "rand 0.8.6",
  "rayon",
@@ -7839,14 +7942,14 @@ dependencies = [
  "zakura-tower-fallback",
  "zcash_protocol",
  "zcash_script",
+ "zcash_tachyon",
  "zcash_transparent",
 ]
 
 [[package]]
 name = "zakura-halo2-gadgets"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af79f971003d67f4a198985469834c083f37354d604bf93f892c9c9f5a129ae0"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "arrayvec",
  "ff",
@@ -7861,14 +7964,12 @@ dependencies = [
 [[package]]
 name = "zakura-halo2-legacy-pdqsort"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2c91d2f5fd4fc95a9c42d43744fa9512b2d7d996ea454f3b21faac6fb36a9806"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 
 [[package]]
 name = "zakura-halo2-poseidon"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cdac6fc73528451edc4ee8cff55946ff2c75359c47937eb42e6d31b83b542d39"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "bitvec",
  "ff",
@@ -7879,13 +7980,12 @@ dependencies = [
 [[package]]
 name = "zakura-halo2-proofs"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5875a590a7d9175fdb47286ca0e5073a1e9ee78775b70ca4309353cf19a6b6ed"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "blake2b_simd",
  "ff",
  "group",
- "maybe-rayon",
+ "maybe-rayon 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.10.2",
  "rand_core 0.10.1",
  "tracing",
@@ -7908,6 +8008,17 @@ dependencies = [
  "zakura-test",
 ]
 
+[[package]]
+name = "zakura-history"
+version = "1.0.0"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
+dependencies = [
+ "blake2b_simd",
+ "corez",
+ "primitive-types",
+ "zcash_encoding 0.5.0",
+]
+
 [[package]]
 name = "zakura-jsonl-trace"
 version = "1.2.0"
@@ -7923,8 +8034,7 @@ dependencies = [
 [[package]]
 name = "zakura-jubjub"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d9915c2c7f2c021379453608c91548f2811d1ba59b7e8505bb8ba32f51e494db"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "bitvec",
  "ff",
@@ -7937,8 +8047,7 @@ dependencies = [
 [[package]]
 name = "zakura-keys"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "df47ed252741a6fcefc2b92aa773034c602eca361c5f974ffbb4f67a49fe2c78"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "bech32",
  "blake2b_simd",
@@ -7953,7 +8062,7 @@ dependencies = [
  "zakura-orchard",
  "zakura-sapling-crypto",
  "zcash_address",
- "zcash_encoding",
+ "zcash_encoding 0.4.0",
  "zcash_protocol",
  "zcash_transparent",
  "zip32",
@@ -8022,8 +8131,7 @@ dependencies = [
 [[package]]
 name = "zakura-orchard"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fd7edaa754f9bafb4965559e38af6d337eb001f76de666fe20e510fb8e1cf631"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "aes",
  "bitvec",
@@ -8035,7 +8143,7 @@ dependencies = [
  "group",
  "hex",
  "incrementalmerkletree",
- "maybe-rayon",
+ "maybe-rayon 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "memuse",
  "nonempty",
  "once_cell",
@@ -8059,8 +8167,7 @@ dependencies = [
 [[package]]
 name = "zakura-pairing"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "59445f1cb78bef29da023f8ecdba607ed00f2df51c245e1d50964af2a3e7b800"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "group",
 ]
@@ -8068,14 +8175,13 @@ dependencies = [
 [[package]]
 name = "zakura-pasta-curves"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e878bab2110a70ed4496e377b4b3f3039d6a227c5d79e171b316f334857531b9"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "blake2b_simd",
  "cc",
  "ff",
  "group",
- "maybe-rayon",
+ "maybe-rayon 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "once_cell",
  "rand 0.10.2",
  "static_assertions",
@@ -8085,8 +8191,7 @@ dependencies = [
 [[package]]
 name = "zakura-primitives"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "799de508ecd41846dd0dfd06490e30ec6ee918008ceba19155e09f2545f3df73"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "blake2b_simd",
  "block-buffer 0.11.0-rc.3",
@@ -8106,18 +8211,18 @@ dependencies = [
  "zakura-orchard",
  "zakura-redjubjub",
  "zakura-sapling-crypto",
- "zcash_encoding",
+ "zcash_encoding 0.4.0",
  "zcash_note_encryption",
  "zcash_protocol",
  "zcash_script",
+ "zcash_tachyon",
  "zcash_transparent",
 ]
 
 [[package]]
 name = "zakura-proofs"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "506fc870df35b86053fa50a24f3f02c50189a3a609c62478bbd1b7c94943d188"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "blake2b_simd",
  "document-features",
@@ -8136,8 +8241,7 @@ dependencies = [
 [[package]]
 name = "zakura-reddsa"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3391ff6c3e6222f5176c046e1d3645748be5b211880747e279d0f17860d51526"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "blake2b_simd",
  "frost-rerandomized",
@@ -8154,8 +8258,7 @@ dependencies = [
 [[package]]
 name = "zakura-redjubjub"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "174ffd325c22f5dbb4c4dfe6f825bd82c3ca88a91bbe603b5cdf0dd7590d0a9c"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "rand_core 0.10.1",
  "serde",
@@ -8170,6 +8273,7 @@ version = "9.0.0"
 dependencies = [
  "anyhow",
  "base64 0.22.1",
+ "blake2b_simd",
  "bytes",
  "chrono",
  "color-eyre",
@@ -8193,6 +8297,7 @@ dependencies = [
  "phf",
  "proptest",
  "prost",
+ "ragu",
  "rand 0.10.2",
  "rand 0.8.6",
  "reqwest 0.12.28",
@@ -8230,14 +8335,14 @@ dependencies = [
  "zcash_address",
  "zcash_protocol",
  "zcash_script",
+ "zcash_tachyon",
  "zcash_transparent",
 ]
 
 [[package]]
 name = "zakura-sapling-crypto"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eadf81594078e0e18f6c1744d978a9ee418fce988c293567131bc4870247ee85"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "aes",
  "bitvec",
@@ -8288,8 +8393,7 @@ dependencies = [
 [[package]]
 name = "zakura-sinsemilla"
 version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "582ec66fe58b717034b8f5c8b54834d93abd515fc20a0ce2ab769d522432b8ca"
+source = "git+https://github.com/zakura-core/common.git?rev=88473230387865b2b5c6770c0cfbcd943f56cbce#88473230387865b2b5c6770c0cfbcd943f56cbce"
 dependencies = [
  "group",
  "once_cell",
@@ -8345,6 +8449,7 @@ dependencies = [
  "zakura-orchard",
  "zakura-sapling-crypto",
  "zakura-test",
+ "zcash_tachyon",
 ]
 
 [[package]]
@@ -8445,14 +8550,13 @@ dependencies = [
 [[package]]
 name = "zcash_address"
 version = "0.13.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a854b28c07dba372f4410ea8ad62b4bf7d5c2bf8be32fc4b31bc0db6521a975"
+source = "git+https://github.com/zcash/librustzcash.git?rev=c7235b1fc4b4296b8af2e26bf2f6adb24f873f56#c7235b1fc4b4296b8af2e26bf2f6adb24f873f56"
 dependencies = [
  "bech32",
  "bs58",
  "corez",
  "f4jumble",
- "zcash_encoding",
+ "zcash_encoding 0.4.0",
  "zcash_protocol",
 ]
 
@@ -8468,14 +8572,14 @@ dependencies = [
 ]
 
 [[package]]
-name = "zcash_history"
+name = "zcash_encoding"
 version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "69d2ed9a9fa7b466a7adedab1ad5a21f8330e4943756912fc776cf7f3beae32b"
+checksum = "b2871fd3c37eaeb635c815a9c97495553bf8237a481b9f8b37eba661764bf937"
 dependencies = [
- "blake2b_simd",
- "byteorder",
- "primitive-types",
+ "corez",
+ "hex",
+ "nonempty",
 ]
 
 [[package]]
@@ -8494,14 +8598,13 @@ dependencies = [
 [[package]]
 name = "zcash_protocol"
 version = "0.10.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "314329b91ec4bbb517441840e47d0b2029bf0b946f086980c96c889c2d92dc5d"
+source = "git+https://github.com/zcash/librustzcash.git?rev=c7235b1fc4b4296b8af2e26bf2f6adb24f873f56#c7235b1fc4b4296b8af2e26bf2f6adb24f873f56"
 dependencies = [
  "corez",
  "document-features",
  "hex",
  "memuse",
- "zcash_encoding",
+ "zcash_encoding 0.4.0",
 ]
 
 [[package]]
@@ -8530,11 +8633,27 @@ dependencies = [
  "blake2b_simd",
 ]
 
+[[package]]
+name = "zcash_tachyon"
+version = "0.0.0"
+source = "git+https://github.com/tachyon-zcash/tachyon?rev=2dc7010c3e7771c539fd1c03a06bc6be1a7316c7#2dc7010c3e7771c539fd1c03a06bc6be1a7316c7"
+dependencies = [
+ "blake2b_simd",
+ "corez",
+ "derive_more 2.1.1",
+ "ff",
+ "group",
+ "lazy_static",
+ "ragu",
+ "rand_core 0.10.1",
+ "zakura-pasta-curves",
+ "zakura-reddsa",
+]
+
 [[package]]
 name = "zcash_transparent"
 version = "0.10.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "547c012778bae17f58007731af074d638aa146ab0ecfc120adebf23d049aff6c"
+source = "git+https://github.com/zcash/librustzcash.git?rev=c7235b1fc4b4296b8af2e26bf2f6adb24f873f56#c7235b1fc4b4296b8af2e26bf2f6adb24f873f56"
 dependencies = [
  "bip32",
  "bs58",
@@ -8548,7 +8667,7 @@ dependencies = [
  "sha2 0.10.9",
  "subtle",
  "zcash_address",
- "zcash_encoding",
+ "zcash_encoding 0.4.0",
  "zcash_protocol",
  "zcash_script",
  "zcash_spec",
diff --git a/Cargo.toml b/Cargo.toml
index 79a50cd20c..c97f32b4dc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -49,26 +49,28 @@ edition = "2021"
 # gate refers to `zakura-assets` and nothing else.
 zakura-assets = { version = "=0.3466571.0" }
 incrementalmerkletree = { version = "0.8.2", features = ["legacy-api"] }
-orchard = { version = "1.1.0", package = "zakura-orchard" }
-sapling-crypto = { version = "1.1.0", package = "zakura-sapling-crypto" }
-zcash_address = "0.13.0"
-zcash_history = "0.5.0"
-zcash_keys = { version = "1.1.0", package = "zakura-keys" }
-zcash_primitives = { version = "1.1.0", package = "zakura-primitives" }
-zcash_proofs = { version = "1.1.0", package = "zakura-proofs" }
-zcash_transparent = "0.10.0"
-zcash_protocol = "0.10.1"
+orchard = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-orchard" }
+sapling-crypto = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-sapling-crypto" }
+zcash_address = { git = "https://github.com/zcash/librustzcash.git", rev = "c7235b1fc4b4296b8af2e26bf2f6adb24f873f56" }
+zcash_history = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-history" }
+zcash_keys = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-keys" }
+zcash_primitives = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-primitives" }
+zcash_proofs = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-proofs" }
+zcash_transparent = { git = "https://github.com/zcash/librustzcash.git", rev = "c7235b1fc4b4296b8af2e26bf2f6adb24f873f56" }
+zcash_protocol = { git = "https://github.com/zcash/librustzcash.git", rev = "c7235b1fc4b4296b8af2e26bf2f6adb24f873f56" }
+zcash_tachyon = { git = "https://github.com/tachyon-zcash/tachyon", rev = "2dc7010c3e7771c539fd1c03a06bc6be1a7316c7", version = "0.0.0", default-features = false }
+ragu = { git = "https://github.com/tachyon-zcash/ragu", rev = "f4f6315b10ed96944c40b2bbdbca0fe06af66ce0", default-features = false, features = ["mock"] }
 abscissa_core = { version = "0.7", default-features = false }
 base64 = "0.22.1"
 bech32 = "0.11.0"
-bellman = { version = "1.1.0", package = "zakura-bellman" }
+bellman = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-bellman" }
 bincode = "1.3"
 bitflags = "2.9"
 bitflags-serde-legacy = "0.1.1"
 bitvec = "1.0"
 blake2b_simd = "1.0"
 blake2s_simd = "1.0"
-bls12_381 = { version = "1.1.0", package = "zakura-bls12-381" }
+bls12_381 = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-bls12-381" }
 bs58 = "0.5"
 byteorder = "1.5"
 bytes = "1.10"
@@ -87,7 +89,7 @@ futures = "0.3.31"
 futures-core = "0.3.31"
 futures-util = "0.3.31"
 group = "0.14"
-halo2 = { version = "1.1.0", package = "zakura-halo2-proofs" }
+halo2 = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-halo2-proofs" }
 hex = "0.4.3"
 hex-literal = "0.4"
 howudoin = "0.1"
@@ -106,7 +108,7 @@ itertools = "0.14"
 jsonrpsee = "0.24.8"
 jsonrpsee-proc-macros = "0.24.9"
 jsonrpsee-types = "0.24.9"
-jubjub = { version = "1.1.0", package = "zakura-jubjub" }
+jubjub = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-jubjub" }
 lazy_static = "1.4"
 libzcash_script = "0.1"
 log = "0.4.27"
@@ -129,8 +131,8 @@ rand_10 = { package = "rand", version = "0.10" }
 rand_chacha_10 = { package = "rand_chacha", version = "0.10" }
 rand_core_10 = { package = "rand_core", version = "0.10" }
 rayon = "1.10"
-reddsa = { version = "1.1.0", package = "zakura-reddsa" }
-redjubjub = { version = "1.1.0", package = "zakura-redjubjub" }
+reddsa = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-reddsa" }
+redjubjub = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-redjubjub" }
 regex = "1.11"
 reqwest = { version = "0.12", default-features = false }
 ripemd = "0.1"
@@ -145,7 +147,7 @@ serde_json = "1.0.140"
 serde_with = "3.12"
 sha2 = "0.10"
 schemars = "1"
-sinsemilla = { version = "1.1.0", package = "zakura-sinsemilla" }
+sinsemilla = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce", package = "zakura-sinsemilla" }
 spandoc = "0.2"
 anyhow = "1.0"
 strum = "0.27"
@@ -183,6 +185,10 @@ zcash_note_encryption = "0.4.1"
 zcash_script = "0.4.5"
 config = { version = "0.15.14", default-features = false, features = ["toml"] }
 
+[patch.crates-io]
+zakura-pasta-curves = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce" }
+zakura-reddsa = { git = "https://github.com/zakura-core/common.git", rev = "88473230387865b2b5c6770c0cfbcd943f56cbce" }
+
 # All cargo-release configuration lives in this table. Do not add a root
 # release.toml: it would silently shadow every setting here (cargo-release
 # reads a workspace release.toml in preference to this metadata table).
@@ -380,7 +386,7 @@ lto = "off"
 # The linter should ignore these expected config flags/values
 unexpected_cfgs = { level = "warn", check-cfg = [
     'cfg(tokio_unstable)', # Used by tokio-console
-    'cfg(zcash_unstable, values("zfuture", "nu6.1", "nu7"))', # Used in Zakura and librustzcash
+    'cfg(zcash_unstable, values("zfuture", "nu6.1", "nu7", "nutachyon"))', # Used in Zakura and librustzcash
 ] }
 
 # High-risk code
diff --git a/crates/zakura-chain/Cargo.toml b/crates/zakura-chain/Cargo.toml
index 97fd8c83e3..52d0df6cd6 100644
--- a/crates/zakura-chain/Cargo.toml
+++ b/crates/zakura-chain/Cargo.toml
@@ -129,6 +129,9 @@ proptest-derive = { workspace = true, optional = true }
 zakura-test = { path = "../zakura-test/", version = "2.1.0", optional = true }
 bounded-vec = { version = "0.9.0", features = ["serde"] }
 
+[target.'cfg(zcash_unstable = "nutachyon")'.dependencies]
+zcash_tachyon = { workspace = true }
+
 [dev-dependencies]
 # Benchmarks
 criterion = { workspace = true, features = ["html_reports"] }
@@ -150,6 +153,9 @@ tokio = { workspace = true, features = ["full", "tracing", "test-util"] }
 
 zakura-test = { path = "../zakura-test/", version = "2.1.0" }
 
+[target.'cfg(zcash_unstable = "nutachyon")'.dev-dependencies]
+ragu = { workspace = true }
+
 [[bench]]
 name = "block"
 harness = false
diff --git a/crates/zakura-chain/src/block.rs b/crates/zakura-chain/src/block.rs
index 56b0026d66..9a79d2d479 100644
--- a/crates/zakura-chain/src/block.rs
+++ b/crates/zakura-chain/src/block.rs
@@ -269,6 +269,18 @@ impl Block {
             .expect("number of transactions must fit u64")
     }
 
+    /// Count how many Tachyon transactions exist in a block,
+    /// i.e. transactions carrying a tachyon bundle (NuTachyon).
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_transactions_count(&self) -> u64 {
+        self.transactions
+            .iter()
+            .filter(|tx| tx.has_tachyon_shielded_data())
+            .count()
+            .try_into()
+            .expect("number of transactions must fit u64")
+    }
+
     /// Returns the overall chain value pool change in this block---the negative sum of the
     /// transaction value balances in this block.
     ///
diff --git a/crates/zakura-chain/src/block/arbitrary.rs b/crates/zakura-chain/src/block/arbitrary.rs
index 9a29304b42..42ab0bc0ba 100644
--- a/crates/zakura-chain/src/block/arbitrary.rs
+++ b/crates/zakura-chain/src/block/arbitrary.rs
@@ -430,6 +430,8 @@ impl Block {
             let mut sapling_tree = sapling::tree::NoteCommitmentTree::default();
             let mut orchard_tree = orchard::tree::NoteCommitmentTree::default();
             let mut ironwood_tree = ironwood::tree::NoteCommitmentTree::default();
+            #[cfg(zcash_unstable = "nutachyon")]
+            let mut tachyon_anchor = crate::tachyon::Anchor::default();
             // The history tree usually takes care of "creating itself". But this
             // only works when blocks are pushed into it starting from genesis
             // (or at least pre-Heartwood, where the tree is not required).
@@ -481,6 +483,16 @@ impl Block {
                 // delete invalid transactions
                 block.transactions = new_transactions;
 
+                #[cfg(zcash_unstable = "nutachyon")]
+                if let Some(pool_height) =
+                    crate::tachyon::pool_height(&current.network, block.coinbase_height().unwrap())
+                {
+                    tachyon_anchor = tachyon_anchor
+                        .advance_with_block(pool_height, block)
+                        .expect("generated Tachyon stamps have valid anchor transitions")
+                        .post_block;
+                }
+
                 // fix commitment (must be done after finishing changing the block)
                 if generate_valid_commitments {
                     let current_height = block.coinbase_height().unwrap();
@@ -537,6 +549,8 @@ impl Block {
                                 &sapling_tree.root(),
                                 &orchard_tree.root(),
                                 &ironwood_tree.root(),
+                                #[cfg(zcash_unstable = "nutachyon")]
+                                &tachyon_anchor,
                             )
                             .unwrap();
                     } else {
@@ -547,6 +561,8 @@ impl Block {
                                 &sapling_tree.root(),
                                 &orchard_tree.root(),
                                 &ironwood_tree.root(),
+                                #[cfg(zcash_unstable = "nutachyon")]
+                                &tachyon_anchor,
                             )
                             .unwrap(),
                         );
@@ -609,6 +625,11 @@ where
                 sapling_shielded_data,
                 ..
             } => *sapling_shielded_data = None,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data,
+                ..
+            } => *sapling_shielded_data = None,
             Transaction::V1 { .. } | Transaction::V2 { .. } | Transaction::V3 { .. } => {}
         }
     }
diff --git a/crates/zakura-chain/src/block/commitment.rs b/crates/zakura-chain/src/block/commitment.rs
index 4141e6d37e..77560a84a5 100644
--- a/crates/zakura-chain/src/block/commitment.rs
+++ b/crates/zakura-chain/src/block/commitment.rs
@@ -142,6 +142,10 @@ impl Commitment {
             (Nu5 | Nu6 | Nu6_1 | Nu6_2 | Nu6_3 | Nu7, _) => Ok(ChainHistoryBlockTxAuthCommitment(
                 ChainHistoryBlockTxAuthCommitmentHash(bytes),
             )),
+            #[cfg(zcash_unstable = "nutachyon")]
+            (NuTachyon, _) => Ok(ChainHistoryBlockTxAuthCommitment(
+                ChainHistoryBlockTxAuthCommitmentHash(bytes),
+            )),
 
             #[cfg(zcash_unstable = "zfuture")]
             (ZFuture, _) => Ok(ChainHistoryBlockTxAuthCommitment(
diff --git a/crates/zakura-chain/src/history_tree.rs b/crates/zakura-chain/src/history_tree.rs
index 71ab524507..79f1e18ca2 100644
--- a/crates/zakura-chain/src/history_tree.rs
+++ b/crates/zakura-chain/src/history_tree.rs
@@ -24,6 +24,8 @@ use crate::{
     },
     sapling,
 };
+#[cfg(zcash_unstable = "nutachyon")]
+use crate::{primitives::zcash_history::V4 as TachyonOnward, tachyon};
 
 /// An error describing why a history tree operation failed.
 #[derive(Debug, Error)]
@@ -60,6 +62,9 @@ enum InnerHistoryTree {
     OrchardOnward(Tree<OrchardOnward>),
     /// An Ironwood-onward tree.
     IronwoodOnward(Tree<IronwoodOnward>),
+    /// A Tachyon-onward tree.
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonOnward(Tree<TachyonOnward>),
 }
 
 /// History tree (Merkle mountain range) structure that contains information about
@@ -142,6 +147,17 @@ impl NonEmptyHistoryTree {
                 )?;
                 InnerHistoryTree::IronwoodOnward(tree)
             }
+            #[cfg(zcash_unstable = "nutachyon")]
+            NetworkUpgrade::NuTachyon => {
+                let tree = Tree::<TachyonOnward>::new_from_cache(
+                    network,
+                    network_upgrade,
+                    size,
+                    &peaks,
+                    &Default::default(),
+                )?;
+                InnerHistoryTree::TachyonOnward(tree)
+            }
 
             #[cfg(zcash_unstable = "zfuture")]
             NetworkUpgrade::ZFuture => {
@@ -179,10 +195,18 @@ impl NonEmptyHistoryTree {
         sapling_root: &sapling::tree::Root,
         orchard_root: &orchard::tree::Root,
         ironwood_root: &ironwood::tree::Root,
+        #[cfg(zcash_unstable = "nutachyon")] tachyon_anchor: &tachyon::Anchor,
     ) -> Result<Self, HistoryTreeError> {
         Self::from_parts(
             network,
-            HistoryTreeBlockParts::from_block(&block, sapling_root, orchard_root, ironwood_root),
+            HistoryTreeBlockParts::from_block(
+                &block,
+                sapling_root,
+                orchard_root,
+                ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_anchor,
+            ),
         )
     }
 
@@ -230,6 +254,11 @@ impl NonEmptyHistoryTree {
                 let (tree, entry) = Tree::<IronwoodOnward>::new_from_parts(network, parts)?;
                 (InnerHistoryTree::IronwoodOnward(tree), entry)
             }
+            #[cfg(zcash_unstable = "nutachyon")]
+            NetworkUpgrade::NuTachyon => {
+                let (tree, entry) = Tree::<TachyonOnward>::new_from_parts(network, parts)?;
+                (InnerHistoryTree::TachyonOnward(tree), entry)
+            }
 
             #[cfg(zcash_unstable = "zfuture")]
             NetworkUpgrade::ZFuture => {
@@ -267,12 +296,15 @@ impl NonEmptyHistoryTree {
         sapling_root: &sapling::tree::Root,
         orchard_root: &orchard::tree::Root,
         ironwood_root: &ironwood::tree::Root,
+        #[cfg(zcash_unstable = "nutachyon")] tachyon_anchor: &tachyon::Anchor,
     ) -> Result<(), HistoryTreeError> {
         self.push_from_parts(HistoryTreeBlockParts::from_block(
             &block,
             sapling_root,
             orchard_root,
             ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_anchor,
         ))
     }
 
@@ -326,6 +358,10 @@ impl NonEmptyHistoryTree {
             InnerHistoryTree::IronwoodOnward(tree) => tree
                 .append_leaf_parts(parts)
                 .map_err(|e| HistoryTreeError::InnerError { inner: e })?,
+            #[cfg(zcash_unstable = "nutachyon")]
+            InnerHistoryTree::TachyonOnward(tree) => tree
+                .append_leaf_parts(parts)
+                .map_err(|e| HistoryTreeError::InnerError { inner: e })?,
         };
         for entry in new_entries {
             // Not every entry is a peak; those will be trimmed later
@@ -338,6 +374,36 @@ impl NonEmptyHistoryTree {
     }
 
     /// Extend the history tree with the given blocks.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn try_extend<
+        'a,
+        T: IntoIterator<
+            Item = (
+                Arc<Block>,
+                &'a sapling::tree::Root,
+                &'a orchard::tree::Root,
+                &'a ironwood::tree::Root,
+                &'a tachyon::Anchor,
+            ),
+        >,
+    >(
+        &mut self,
+        iter: T,
+    ) -> Result<(), HistoryTreeError> {
+        for (block, sapling_root, orchard_root, ironwood_root, tachyon_anchor) in iter {
+            self.push(
+                block,
+                sapling_root,
+                orchard_root,
+                ironwood_root,
+                tachyon_anchor,
+            )?;
+        }
+        Ok(())
+    }
+
+    /// Extend the history tree with the given blocks.
+    #[cfg(not(zcash_unstable = "nutachyon"))]
     pub fn try_extend<
         'a,
         T: IntoIterator<
@@ -460,6 +526,16 @@ impl NonEmptyHistoryTree {
                     &Default::default(),
                 )?)
             }
+            #[cfg(zcash_unstable = "nutachyon")]
+            InnerHistoryTree::TachyonOnward(_) => {
+                InnerHistoryTree::TachyonOnward(Tree::<TachyonOnward>::new_from_cache(
+                    &self.network,
+                    self.network_upgrade,
+                    self.size,
+                    &self.peaks,
+                    &Default::default(),
+                )?)
+            }
         };
         Ok(())
     }
@@ -470,6 +546,8 @@ impl NonEmptyHistoryTree {
             InnerHistoryTree::PreOrchard(tree) => tree.hash(),
             InnerHistoryTree::OrchardOnward(tree) => tree.hash(),
             InnerHistoryTree::IronwoodOnward(tree) => tree.hash(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            InnerHistoryTree::TachyonOnward(tree) => tree.hash(),
         }
     }
 
@@ -527,6 +605,17 @@ impl Clone for NonEmptyHistoryTree {
                 )
                 .expect("rebuilding an existing tree should always work"),
             ),
+            #[cfg(zcash_unstable = "nutachyon")]
+            InnerHistoryTree::TachyonOnward(_) => InnerHistoryTree::TachyonOnward(
+                Tree::<TachyonOnward>::new_from_cache(
+                    &self.network,
+                    self.network_upgrade,
+                    self.size,
+                    &self.peaks,
+                    &Default::default(),
+                )
+                .expect("rebuilding an existing tree should always work"),
+            ),
         };
         NonEmptyHistoryTree {
             network: self.network.clone(),
@@ -555,10 +644,18 @@ impl HistoryTree {
         sapling_root: &sapling::tree::Root,
         orchard_root: &orchard::tree::Root,
         ironwood_root: &ironwood::tree::Root,
+        #[cfg(zcash_unstable = "nutachyon")] tachyon_anchor: &tachyon::Anchor,
     ) -> Result<Self, HistoryTreeError> {
         Self::from_parts(
             network,
-            HistoryTreeBlockParts::from_block(&block, sapling_root, orchard_root, ironwood_root),
+            HistoryTreeBlockParts::from_block(
+                &block,
+                sapling_root,
+                orchard_root,
+                ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_anchor,
+            ),
         )
     }
 
@@ -593,10 +690,18 @@ impl HistoryTree {
         sapling_root: &sapling::tree::Root,
         orchard_root: &orchard::tree::Root,
         ironwood_root: &ironwood::tree::Root,
+        #[cfg(zcash_unstable = "nutachyon")] tachyon_anchor: &tachyon::Anchor,
     ) -> Result<(), HistoryTreeError> {
         self.push_from_parts(
             network,
-            HistoryTreeBlockParts::from_block(&block, sapling_root, orchard_root, ironwood_root),
+            HistoryTreeBlockParts::from_block(
+                &block,
+                sapling_root,
+                orchard_root,
+                ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_anchor,
+            ),
         )
     }
 
diff --git a/crates/zakura-chain/src/history_tree/tests/vectors.rs b/crates/zakura-chain/src/history_tree/tests/vectors.rs
index 09ca1c8e5a..b1b9d09e8c 100644
--- a/crates/zakura-chain/src/history_tree/tests/vectors.rs
+++ b/crates/zakura-chain/src/history_tree/tests/vectors.rs
@@ -16,6 +16,9 @@ use crate::{
     serialization::ZcashDeserializeInto,
 };
 
+#[cfg(zcash_unstable = "nutachyon")]
+const DEFAULT_TACHYON_ANCHOR: crate::tachyon::Anchor = crate::tachyon::Anchor([0; 32]);
+
 use color_eyre::eyre;
 use eyre::Result;
 
@@ -69,6 +72,8 @@ fn push_and_prune_for_network_upgrade(
         &first_sapling_root,
         &Default::default(),
         &Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
 
     assert_eq!(tree.size(), 1);
@@ -102,6 +107,8 @@ fn push_and_prune_for_network_upgrade(
         &second_sapling_root,
         &Default::default(),
         &Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )
     .unwrap();
 
@@ -176,6 +183,8 @@ fn parts_api_matches_block_api_for_network(network: Network) -> Result<()> {
         &Default::default(),
         &Default::default(),
         &Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     parts_tree.push_from_parts(
         &network,
@@ -184,6 +193,8 @@ fn parts_api_matches_block_api_for_network(network: Network) -> Result<()> {
             &Default::default(),
             &Default::default(),
             &Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            &Default::default(),
         ),
     )?;
 
@@ -196,6 +207,8 @@ fn parts_api_matches_block_api_for_network(network: Network) -> Result<()> {
         &first_sapling_root,
         &Default::default(),
         &Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     parts_tree.push_from_parts(
         &network,
@@ -204,6 +217,8 @@ fn parts_api_matches_block_api_for_network(network: Network) -> Result<()> {
             &first_sapling_root,
             &Default::default(),
             &Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            &Default::default(),
         ),
     )?;
 
@@ -226,6 +241,8 @@ fn parts_api_matches_block_api_for_network(network: Network) -> Result<()> {
         &second_sapling_root,
         &Default::default(),
         &Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     parts_tree.push_from_parts(
         &network,
@@ -234,6 +251,8 @@ fn parts_api_matches_block_api_for_network(network: Network) -> Result<()> {
             &second_sapling_root,
             &Default::default(),
             &Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            &Default::default(),
         ),
     )?;
 
@@ -278,9 +297,13 @@ fn from_cache_preserves_ironwood_history_version() -> Result<()> {
                 sapling_root: &Default::default(),
                 orchard_root: &Default::default(),
                 ironwood_root: &ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_anchor: &DEFAULT_TACHYON_ANCHOR,
                 sapling_tx: 0,
                 orchard_tx: 0,
                 ironwood_tx: 1,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_tx: 0,
             },
         )?;
         // Decoding the same peaks as V2 succeeds, because the serialized V3
@@ -361,6 +384,8 @@ fn from_block_delegation_preserves_all_history_versions() -> Result<()> {
             &sapling_root,
             &orchard_root,
             &ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            &Default::default(),
         )?;
         let parts_tree = NonEmptyHistoryTree::from_parts(
             &network,
@@ -370,9 +395,13 @@ fn from_block_delegation_preserves_all_history_versions() -> Result<()> {
                 sapling_root: &sapling_root,
                 orchard_root: &orchard_root,
                 ironwood_root: &ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_anchor: &DEFAULT_TACHYON_ANCHOR,
                 sapling_tx: block.sapling_transactions_count(),
                 orchard_tx: block.orchard_transactions_count(),
                 ironwood_tx: block.ironwood_transactions_count(),
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_tx: block.tachyon_transactions_count(),
             },
         )?;
 
@@ -431,9 +460,13 @@ fn from_parts_selects_epoch_version_and_ignores_future_fields() -> Result<()> {
         sapling_root: &sapling_root,
         orchard_root,
         ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        tachyon_anchor: &DEFAULT_TACHYON_ANCHOR,
         sapling_tx: 1,
         orchard_tx,
         ironwood_tx,
+        #[cfg(zcash_unstable = "nutachyon")]
+        tachyon_tx: 0,
     };
 
     assert_eq!(
@@ -551,6 +584,8 @@ fn push_wrapper_matches_parts_across_nu6_3_activation() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     let mut parts_tree = NonEmptyHistoryTree::from_parts(
         &network,
@@ -559,6 +594,8 @@ fn push_wrapper_matches_parts_across_nu6_3_activation() -> Result<()> {
             &sapling_root,
             &orchard_root,
             &ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            &Default::default(),
         ),
     )?;
 
@@ -567,12 +604,16 @@ fn push_wrapper_matches_parts_across_nu6_3_activation() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     parts_tree.push_from_parts(HistoryTreeBlockParts::from_block(
         &activation_block,
         &sapling_root,
         &orchard_root,
         &ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     ))?;
     let activation_tree = NonEmptyHistoryTree::from_block(
         &network,
@@ -580,6 +621,8 @@ fn push_wrapper_matches_parts_across_nu6_3_activation() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     let activation_without_ironwood = NonEmptyHistoryTree::from_block(
         &network,
@@ -587,6 +630,8 @@ fn push_wrapper_matches_parts_across_nu6_3_activation() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
 
     assert_eq!(block_tree.hash(), parts_tree.hash());
@@ -664,9 +709,13 @@ fn push_from_parts_routes_each_history_version() -> Result<()> {
             sapling_root,
             orchard_root,
             ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_anchor: &DEFAULT_TACHYON_ANCHOR,
             sapling_tx: 1,
             orchard_tx,
             ironwood_tx,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_tx: 0,
         }
     }
     let two_leaf_tree = |network: &Network,
@@ -765,18 +814,24 @@ fn try_extend_forwards_ironwood_roots_in_order() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &first_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     sequential.push(
         second_block.clone(),
         &sapling_root,
         &orchard_root,
         &second_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     sequential.push(
         third_block.clone(),
         &sapling_root,
         &orchard_root,
         &third_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
 
     let mut extended = NonEmptyHistoryTree::from_block(
@@ -785,7 +840,27 @@ fn try_extend_forwards_ironwood_roots_in_order() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &first_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
+    #[cfg(zcash_unstable = "nutachyon")]
+    extended.try_extend([
+        (
+            second_block.clone(),
+            &sapling_root,
+            &orchard_root,
+            &second_ironwood_root,
+            &DEFAULT_TACHYON_ANCHOR,
+        ),
+        (
+            third_block.clone(),
+            &sapling_root,
+            &orchard_root,
+            &third_ironwood_root,
+            &DEFAULT_TACHYON_ANCHOR,
+        ),
+    ])?;
+    #[cfg(not(zcash_unstable = "nutachyon"))]
     extended.try_extend([
         (
             second_block.clone(),
@@ -807,7 +882,27 @@ fn try_extend_forwards_ironwood_roots_in_order() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &first_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
+    #[cfg(zcash_unstable = "nutachyon")]
+    wrong_last_root.try_extend([
+        (
+            second_block,
+            &sapling_root,
+            &orchard_root,
+            &second_ironwood_root,
+            &DEFAULT_TACHYON_ANCHOR,
+        ),
+        (
+            third_block,
+            &sapling_root,
+            &orchard_root,
+            &Default::default(),
+            &DEFAULT_TACHYON_ANCHOR,
+        ),
+    ])?;
+    #[cfg(not(zcash_unstable = "nutachyon"))]
     wrong_last_root.try_extend([
         (
             second_block,
@@ -873,9 +968,13 @@ fn v3_pruning_and_hash_dispatch_match_unpruned_tree() -> Result<()> {
             sapling_root,
             orchard_root,
             ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_anchor: &DEFAULT_TACHYON_ANCHOR,
             sapling_tx: u64::from(height),
             orchard_tx: u64::from(height + 1),
             ironwood_tx: u64::from(height + 2),
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_tx: 0,
         }
     }
 
@@ -987,14 +1086,25 @@ fn v3_clone_preserves_root_and_future_append() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &first_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     original.push(
         block(2),
         &sapling_root,
         &orchard_root,
         &second_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
+    )?;
+    original.push(
+        block(3),
+        &sapling_root,
+        &orchard_root,
+        &third_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
-    original.push(block(3), &sapling_root, &orchard_root, &third_ironwood_root)?;
     assert_eq!(original.peaks().len(), 2, "three leaves have two MMR peaks");
 
     let mut cloned = original.clone();
@@ -1013,12 +1123,16 @@ fn v3_clone_preserves_root_and_future_append() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &fourth_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     cloned.push(
         fourth_block,
         &sapling_root,
         &orchard_root,
         &fourth_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
 
     assert_eq!(cloned.hash(), original.hash());
@@ -1081,10 +1195,19 @@ fn history_tree_from_block_matches_parts_across_history_versions() -> Result<()>
             &sapling_root,
             &orchard_root,
             &ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            &Default::default(),
         )?;
         let parts_tree = HistoryTree::from_parts(
             &network,
-            HistoryTreeBlockParts::from_block(&block, &sapling_root, &orchard_root, &ironwood_root),
+            HistoryTreeBlockParts::from_block(
+                &block,
+                &sapling_root,
+                &orchard_root,
+                &ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                &Default::default(),
+            ),
         )?;
 
         assert_eq!(block_tree.is_some(), should_exist);
@@ -1138,6 +1261,8 @@ fn history_tree_push_wrapper_matches_parts_across_nu6_3_activation() -> Result<(
         &sapling_root,
         &orchard_root,
         &ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     parts_tree.push_from_parts(
         &network,
@@ -1146,6 +1271,8 @@ fn history_tree_push_wrapper_matches_parts_across_nu6_3_activation() -> Result<(
             &sapling_root,
             &orchard_root,
             &ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            &Default::default(),
         ),
     )?;
     assert_eq!(block_tree.hash(), parts_tree.hash());
@@ -1156,6 +1283,8 @@ fn history_tree_push_wrapper_matches_parts_across_nu6_3_activation() -> Result<(
         &sapling_root,
         &orchard_root,
         &ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     parts_tree.push_from_parts(
         &network,
@@ -1164,6 +1293,8 @@ fn history_tree_push_wrapper_matches_parts_across_nu6_3_activation() -> Result<(
             &sapling_root,
             &orchard_root,
             &ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            &Default::default(),
         ),
     )?;
     let activation_tree = HistoryTree::from_block(
@@ -1172,6 +1303,8 @@ fn history_tree_push_wrapper_matches_parts_across_nu6_3_activation() -> Result<(
         &sapling_root,
         &orchard_root,
         &ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
     let activation_without_ironwood = HistoryTree::from_block(
         &network,
@@ -1179,6 +1312,8 @@ fn history_tree_push_wrapper_matches_parts_across_nu6_3_activation() -> Result<(
         &sapling_root,
         &orchard_root,
         &Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
 
     assert_eq!(block_tree.hash(), parts_tree.hash());
@@ -1233,6 +1368,8 @@ fn upgrade_for_network_upgrade(network: Network, network_upgrade: NetworkUpgrade
         &sapling_root_prev,
         &Default::default(),
         &Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
 
     assert_eq!(tree.size(), 1);
@@ -1260,6 +1397,8 @@ fn upgrade_for_network_upgrade(network: Network, network_upgrade: NetworkUpgrade
         &activation_sapling_root,
         &Default::default(),
         &Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )
     .unwrap();
 
diff --git a/crates/zakura-chain/src/lib.rs b/crates/zakura-chain/src/lib.rs
index aa2d5104ee..00645c19bd 100644
--- a/crates/zakura-chain/src/lib.rs
+++ b/crates/zakura-chain/src/lib.rs
@@ -44,6 +44,8 @@ pub mod shutdown;
 pub mod sprout;
 pub mod subtree;
 pub mod subtree_verify;
+#[cfg(zcash_unstable = "nutachyon")]
+pub mod tachyon;
 pub mod transaction;
 pub mod transparent;
 pub mod value_balance;
diff --git a/crates/zakura-chain/src/local_genesis.rs b/crates/zakura-chain/src/local_genesis.rs
index c699a3d30c..7b3d38446e 100644
--- a/crates/zakura-chain/src/local_genesis.rs
+++ b/crates/zakura-chain/src/local_genesis.rs
@@ -439,6 +439,8 @@ fn configured_activation_heights(
         nu6_2: (latest_network_upgrade >= Nu6_2).then_some(activation_height),
         nu6_3: (latest_network_upgrade >= Nu6_3).then_some(activation_height),
         nu7: (latest_network_upgrade >= Nu7).then_some(activation_height),
+        #[cfg(zcash_unstable = "nutachyon")]
+        nu_tachyon: (latest_network_upgrade >= NuTachyon).then_some(activation_height),
     })
 }
 
diff --git a/crates/zakura-chain/src/parallel/commitment_aux_verify.rs b/crates/zakura-chain/src/parallel/commitment_aux_verify.rs
index 015661ecac..ad187b8b2b 100644
--- a/crates/zakura-chain/src/parallel/commitment_aux_verify.rs
+++ b/crates/zakura-chain/src/parallel/commitment_aux_verify.rs
@@ -102,6 +102,11 @@ impl VerifiedHeaderCommitmentRoots {
 /// A supplied-root verification failure.
 #[derive(Debug, Error)]
 pub enum SuppliedRootsError {
+    /// The roots-only auxiliary format cannot reconstruct Tachyon history state.
+    #[error("Tachyon history commitments require block bodies")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonDataUnavailable,
+
     /// A header commitment did not match its supplied auxiliary data.
     #[error("invalid header commitment: {0}")]
     InvalidHeaderCommitment(#[from] CommitmentError),
@@ -143,6 +148,11 @@ where
     for (index, (header, roots)) in items.iter().enumerate() {
         let height = roots.height;
 
+        #[cfg(zcash_unstable = "nutachyon")]
+        if NetworkUpgrade::current(network, height) >= NetworkUpgrade::NuTachyon {
+            return Err((height, SuppliedRootsError::TachyonDataUnavailable));
+        }
+
         header_commitment_is_valid_for_chain_history(
             header,
             height,
@@ -183,9 +193,13 @@ where
                 sapling_root: &roots.sapling_root,
                 orchard_root: &roots.orchard_root,
                 ironwood_root: &roots.ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_anchor: &Default::default(),
                 sapling_tx: roots.sapling_tx,
                 orchard_tx: roots.orchard_tx,
                 ironwood_tx: roots.ironwood_tx,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_tx: 0,
             },
         )
         .map_err(Arc::new)
@@ -480,6 +494,8 @@ mod tests {
             &Default::default(),
             &Default::default(),
             &Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            &Default::default(),
         )
         .expect("empty history tree for a pre-Heartwood block")
     }
@@ -914,6 +930,8 @@ mod tests {
                 &act_root,
                 &empty_orchard_root,
                 &empty_ironwood_root(),
+                #[cfg(zcash_unstable = "nutachyon")]
+                &Default::default(),
             )
             .expect("activation block builds a history tree")
             .hash(),
@@ -940,6 +958,8 @@ mod tests {
             &empty_sapling_root,
             &empty_orchard_root,
             &empty_ironwood_root(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            &Default::default(),
         )
         .expect("the parent history tree builds");
         let witness_roots =
diff --git a/crates/zakura-chain/src/parallel/tree.rs b/crates/zakura-chain/src/parallel/tree.rs
index 8d5c5e8138..09d7c25c0f 100644
--- a/crates/zakura-chain/src/parallel/tree.rs
+++ b/crates/zakura-chain/src/parallel/tree.rs
@@ -4,6 +4,8 @@ use std::sync::Arc;
 
 use thiserror::Error;
 
+#[cfg(zcash_unstable = "nutachyon")]
+use crate::tachyon;
 use crate::{
     block::Block,
     ironwood, orchard, sapling, sprout,
@@ -35,6 +37,14 @@ pub struct NoteCommitmentTrees {
 
     /// The Ironwood note commitment subtree.
     pub ironwood_subtree: Option<NoteCommitmentSubtree<ironwood::tree::Node>>,
+
+    /// The Tachyon pool anchor after this block.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub tachyon_anchor: tachyon::Anchor,
+
+    /// The epoch-boundary anchor if this block starts a Tachyon epoch.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub tachyon_epoch_anchor: Option<tachyon::Anchor>,
 }
 
 /// Note commitment tree errors.
diff --git a/crates/zakura-chain/src/parameters/network/testnet.rs b/crates/zakura-chain/src/parameters/network/testnet.rs
index 09c8146b56..ed8c69f1a3 100644
--- a/crates/zakura-chain/src/parameters/network/testnet.rs
+++ b/crates/zakura-chain/src/parameters/network/testnet.rs
@@ -194,6 +194,8 @@ impl From<&BTreeMap<Height, NetworkUpgrade>> for ConfiguredActivationHeights {
                 NetworkUpgrade::Nu6_2 => &mut configured_activation_heights.nu6_2,
                 NetworkUpgrade::Nu6_3 => &mut configured_activation_heights.nu6_3,
                 NetworkUpgrade::Nu7 => &mut configured_activation_heights.nu7,
+                #[cfg(zcash_unstable = "nutachyon")]
+                NetworkUpgrade::NuTachyon => &mut configured_activation_heights.nu_tachyon,
                 #[cfg(zcash_unstable = "zfuture")]
                 NetworkUpgrade::ZFuture => &mut configured_activation_heights.zfuture,
                 NetworkUpgrade::Genesis => continue,
@@ -514,6 +516,9 @@ pub struct ConfiguredActivationHeights {
     /// Activation height for `NU7` network upgrade.
     #[serde(rename = "NU7")]
     pub nu7: Option<u32>,
+    /// Activation height for `NuTachyon` network upgrade.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub nu_tachyon: Option<u32>,
     /// Activation height for `ZFuture` network upgrade.
     #[serde(rename = "ZFuture")]
     #[cfg(zcash_unstable = "zfuture")]
@@ -537,6 +542,8 @@ impl ConfiguredActivationHeights {
             nu6_2,
             nu6_3,
             nu7,
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon,
             #[cfg(zcash_unstable = "zfuture")]
             zfuture,
         } = self;
@@ -560,6 +567,8 @@ impl ConfiguredActivationHeights {
             nu6_2,
             nu6_3,
             nu7,
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon,
             #[cfg(zcash_unstable = "zfuture")]
             zfuture,
         }
@@ -757,6 +766,8 @@ impl ParametersBuilder {
             nu6_2,
             nu6_3,
             nu7,
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon,
             #[cfg(zcash_unstable = "zfuture")]
             zfuture,
         }: ConfiguredActivationHeights,
@@ -787,6 +798,10 @@ impl ParametersBuilder {
                 .chain(nu6_3.into_iter().map(|h| (h, Nu6_3)))
                 .chain(nu7.into_iter().map(|h| (h, Nu7)));
 
+            #[cfg(zcash_unstable = "nutachyon")]
+            let activation_heights =
+                activation_heights.chain(nu_tachyon.into_iter().map(|h| (h, NuTachyon)));
+
             #[cfg(zcash_unstable = "zfuture")]
             let activation_heights =
                 activation_heights.chain(zfuture.into_iter().map(|h| (h, ZFuture)));
diff --git a/crates/zakura-chain/src/parameters/network/tests/vectors.rs b/crates/zakura-chain/src/parameters/network/tests/vectors.rs
index 5cfb2d9e11..0bf3e4ac47 100644
--- a/crates/zakura-chain/src/parameters/network/tests/vectors.rs
+++ b/crates/zakura-chain/src/parameters/network/tests/vectors.rs
@@ -222,10 +222,14 @@ fn bip70_network_names_are_stable_for_every_network_kind() {
 fn activates_network_upgrades_correctly() {
     let expected_nu6_3_activation_height = 1;
     let expected_nu7_activation_height = 2;
+    #[cfg(zcash_unstable = "nutachyon")]
+    let expected_nu_tachyon_activation_height = 3;
     let network = testnet::Parameters::build()
         .with_activation_heights(ConfiguredActivationHeights {
             nu6_3: Some(expected_nu6_3_activation_height),
             nu7: Some(expected_nu7_activation_height),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: Some(expected_nu_tachyon_activation_height),
             ..Default::default()
         })
         .expect("failed to set activation heights")
@@ -246,6 +250,8 @@ fn activates_network_upgrades_correctly() {
     for nu in NetworkUpgrade::iter().skip(1) {
         let expected_activation_height = match nu {
             NetworkUpgrade::Nu7 => expected_nu7_activation_height,
+            #[cfg(zcash_unstable = "nutachyon")]
+            NetworkUpgrade::NuTachyon => expected_nu_tachyon_activation_height,
             _ => expected_nu6_3_activation_height,
         };
 
@@ -340,6 +346,26 @@ fn configured_nu6_3_activation_preserves_upgrade_order() {
         "an overwritten NU6.3 activation must remain implicit at the NU7 height"
     );
 
+    #[cfg(zcash_unstable = "nutachyon")]
+    {
+        let nu_tachyon_network = testnet::Parameters::build()
+            .with_activation_heights(ConfiguredActivationHeights {
+                nu7: Some(activation_height.0),
+                nu_tachyon: Some(activation_height.0),
+                ..Default::default()
+            })
+            .expect("same-height upgrades are valid")
+            .clear_funding_streams()
+            .to_network()
+            .expect("valid configured network");
+
+        assert_eq!(
+            NetworkUpgrade::current(&nu_tachyon_network, activation_height),
+            NetworkUpgrade::NuTachyon,
+            "NuTachyon must overwrite NU7 when both activate at the same height"
+        );
+    }
+
     let out_of_order = testnet::Parameters::build()
         .with_activation_heights(ConfiguredActivationHeights {
             nu6_2: Some(activation_height.0 + 1),
diff --git a/crates/zakura-chain/src/parameters/network_upgrade.rs b/crates/zakura-chain/src/parameters/network_upgrade.rs
index 8fb7601f3b..a9968ef639 100644
--- a/crates/zakura-chain/src/parameters/network_upgrade.rs
+++ b/crates/zakura-chain/src/parameters/network_upgrade.rs
@@ -67,6 +67,9 @@ pub enum NetworkUpgrade {
     /// The Zcash protocol after the NU7 upgrade.
     #[serde(rename = "NU7")]
     Nu7,
+    /// The Zcash protocol after the NuTachyon upgrade.
+    #[cfg(zcash_unstable = "nutachyon")]
+    NuTachyon,
 
     #[cfg(zcash_unstable = "zfuture")]
     ZFuture,
@@ -241,6 +244,8 @@ pub(crate) const CONSENSUS_BRANCH_IDS: &[(NetworkUpgrade, ConsensusBranchId)] =
     // TODO: set below to (Nu7, ConsensusBranchId(0x77190ad8)), once the same value is set in librustzcash
     #[cfg(any(test, feature = "zakura-test"))]
     (Nu7, ConsensusBranchId(0xfffffffe)),
+    #[cfg(zcash_unstable = "nutachyon")]
+    (NuTachyon, ConsensusBranchId(0xfffffffc)),
     #[cfg(zcash_unstable = "zfuture")]
     (ZFuture, ConsensusBranchId(0xfffffffd)),
 ];
@@ -406,6 +411,9 @@ impl NetworkUpgrade {
                 POST_BLOSSOM_POW_TARGET_SPACING.into()
             }
 
+            #[cfg(zcash_unstable = "nutachyon")]
+            NuTachyon => POST_BLOSSOM_POW_TARGET_SPACING.into(),
+
             #[cfg(zcash_unstable = "zfuture")]
             ZFuture => POST_BLOSSOM_POW_TARGET_SPACING.into(),
         };
@@ -531,6 +539,8 @@ impl From<zcash_protocol::consensus::NetworkUpgrade> for NetworkUpgrade {
             zcash_protocol::consensus::NetworkUpgrade::Nu6_3 => Self::Nu6_3,
             #[cfg(zcash_unstable = "nu7")]
             zcash_protocol::consensus::NetworkUpgrade::Nu7 => Self::Nu7,
+            #[cfg(zcash_unstable = "nutachyon")]
+            zcash_protocol::consensus::NetworkUpgrade::NuTachyon => Self::NuTachyon,
             #[cfg(zcash_unstable = "zfuture")]
             zcash_protocol::consensus::NetworkUpgrade::ZFuture => Self::ZFuture,
         }
diff --git a/crates/zakura-chain/src/parameters/tests.rs b/crates/zakura-chain/src/parameters/tests.rs
index 6d5ec15a65..71f8c804e7 100644
--- a/crates/zakura-chain/src/parameters/tests.rs
+++ b/crates/zakura-chain/src/parameters/tests.rs
@@ -274,6 +274,8 @@ const NETWORK_UPGRADES_IN_ORDER: &[NetworkUpgrade] = &[
     #[cfg(any(test, feature = "zakura-test"))]
     Nu6_3,
     Nu7,
+    #[cfg(zcash_unstable = "nutachyon")]
+    NuTachyon,
 ];
 
 #[test]
@@ -289,7 +291,9 @@ fn full_activation_list_contains_all_upgrades() {
     let network = Network::Mainnet;
     let full_list = network.full_activation_list();
 
-    // NU7 is unscheduled on Mainnet (no activation height committed), so it is absent from the
-    // full activation list even though it is always present in the iter.
+    // Unscheduled upgrades are absent from the full activation list.
+    #[cfg(zcash_unstable = "nutachyon")]
+    assert_eq!(full_list.len(), NetworkUpgrade::iter().count() - 2);
+    #[cfg(not(zcash_unstable = "nutachyon"))]
     assert_eq!(full_list.len(), NetworkUpgrade::iter().count() - 1);
 }
diff --git a/crates/zakura-chain/src/parameters/transaction.rs b/crates/zakura-chain/src/parameters/transaction.rs
index b3342d380a..193703dfe9 100644
--- a/crates/zakura-chain/src/parameters/transaction.rs
+++ b/crates/zakura-chain/src/parameters/transaction.rs
@@ -14,3 +14,7 @@ pub const TX_V5_VERSION_GROUP_ID: u32 = 0x26A7_270A;
 
 /// The version group ID for version 6 transactions.
 pub const TX_V6_VERSION_GROUP_ID: u32 = 0xD884_B698;
+
+/// The placeholder version group ID for version 7 transactions ("tach" in ASCII).
+#[cfg(zcash_unstable = "nutachyon")]
+pub const TX_V7_VERSION_GROUP_ID: u32 = 0x7461_6368;
diff --git a/crates/zakura-chain/src/primitives/zcash_history.rs b/crates/zakura-chain/src/primitives/zcash_history.rs
index bc0d32c503..09f3789ed0 100644
--- a/crates/zakura-chain/src/primitives/zcash_history.rs
+++ b/crates/zakura-chain/src/primitives/zcash_history.rs
@@ -9,8 +9,12 @@ mod tests;
 use std::{collections::BTreeMap, io, sync::Arc};
 
 use serde_big_array::BigArray;
-pub use zcash_history::{V1, V2, V3};
+#[cfg(zcash_unstable = "nutachyon")]
+pub use zcash_history::V4;
+pub use zcash_history::{MAX_ENTRY_SIZE, V1, V2, V3};
 
+#[cfg(zcash_unstable = "nutachyon")]
+use crate::tachyon;
 use crate::{
     block::{Block, ChainHistoryMmrRootHash, Header, Height},
     ironwood, orchard,
@@ -31,12 +35,18 @@ pub struct HistoryTreeBlockParts<'a> {
     pub orchard_root: &'a orchard::tree::Root,
     /// The block's Ironwood note commitment tree root.
     pub ironwood_root: &'a ironwood::tree::Root,
+    /// The Tachyon pool anchor after the block.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub tachyon_anchor: &'a tachyon::Anchor,
     /// The number of Sapling transactions in the block.
     pub sapling_tx: u64,
     /// The number of Orchard transactions in the block.
     pub orchard_tx: u64,
     /// The number of Ironwood transactions in the block.
     pub ironwood_tx: u64,
+    /// The number of Tachyon transactions in the block.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub tachyon_tx: u64,
 }
 
 impl<'a> HistoryTreeBlockParts<'a> {
@@ -46,6 +56,7 @@ impl<'a> HistoryTreeBlockParts<'a> {
         sapling_root: &'a sapling::tree::Root,
         orchard_root: &'a orchard::tree::Root,
         ironwood_root: &'a ironwood::tree::Root,
+        #[cfg(zcash_unstable = "nutachyon")] tachyon_anchor: &'a tachyon::Anchor,
     ) -> Self {
         let height = block
             .coinbase_height()
@@ -57,9 +68,13 @@ impl<'a> HistoryTreeBlockParts<'a> {
             sapling_root,
             orchard_root,
             ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_anchor,
             sapling_tx: block.sapling_transactions_count(),
             orchard_tx: block.orchard_transactions_count(),
             ironwood_tx: block.ironwood_transactions_count(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_tx: block.tachyon_transactions_count(),
         }
     }
 }
@@ -73,9 +88,17 @@ pub trait Version: zcash_history::Version {
         sapling_root: &sapling::tree::Root,
         orchard_root: &orchard::tree::Root,
         ironwood_root: &ironwood::tree::Root,
+        #[cfg(zcash_unstable = "nutachyon")] tachyon_anchor: &tachyon::Anchor,
     ) -> Self::NodeData {
         Self::parts_to_history_node(
-            HistoryTreeBlockParts::from_block(&block, sapling_root, orchard_root, ironwood_root),
+            HistoryTreeBlockParts::from_block(
+                &block,
+                sapling_root,
+                orchard_root,
+                ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_anchor,
+            ),
             network,
         )
     }
@@ -146,9 +169,17 @@ impl Entry {
         sapling_root: &sapling::tree::Root,
         orchard_root: &orchard::tree::Root,
         ironwood_root: &ironwood::tree::Root,
+        #[cfg(zcash_unstable = "nutachyon")] tachyon_anchor: &tachyon::Anchor,
     ) -> Self {
-        let node_data =
-            V::block_to_history_node(block, network, sapling_root, orchard_root, ironwood_root);
+        let node_data = V::block_to_history_node(
+            block,
+            network,
+            sapling_root,
+            orchard_root,
+            ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_anchor,
+        );
         Self::from_node_data::<V>(node_data)
     }
 
@@ -227,13 +258,21 @@ impl<V: Version> Tree<V> {
         sapling_root: &sapling::tree::Root,
         orchard_root: &orchard::tree::Root,
         ironwood_root: &ironwood::tree::Root,
+        #[cfg(zcash_unstable = "nutachyon")] tachyon_anchor: &tachyon::Anchor,
     ) -> Result<(Self, Entry), io::Error> {
         let height = block
             .coinbase_height()
             .expect("block must have coinbase height during contextual verification");
         let network_upgrade = NetworkUpgrade::current(network, height);
-        let entry0 =
-            Entry::new_leaf::<V>(block, network, sapling_root, orchard_root, ironwood_root);
+        let entry0 = Entry::new_leaf::<V>(
+            block,
+            network,
+            sapling_root,
+            orchard_root,
+            ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_anchor,
+        );
         let mut peaks = BTreeMap::new();
         peaks.insert(0u32, entry0);
         Ok((
@@ -283,6 +322,7 @@ impl<V: Version> Tree<V> {
         sapling_root: &sapling::tree::Root,
         orchard_root: &orchard::tree::Root,
         ironwood_root: &ironwood::tree::Root,
+        #[cfg(zcash_unstable = "nutachyon")] tachyon_anchor: &tachyon::Anchor,
     ) -> Result<Vec<Entry>, zcash_history::Error> {
         let height = block
             .coinbase_height()
@@ -302,6 +342,8 @@ impl<V: Version> Tree<V> {
             sapling_root,
             orchard_root,
             ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_anchor,
         );
         let appended = self.inner.append_leaf(node_data)?;
 
@@ -423,6 +465,8 @@ impl Version for zcash_history::V1 {
             | NetworkUpgrade::Nu6_2
             | NetworkUpgrade::Nu6_3
             | NetworkUpgrade::Nu7 => {}
+            #[cfg(zcash_unstable = "nutachyon")]
+            NetworkUpgrade::NuTachyon => {}
             #[cfg(zcash_unstable = "zfuture")]
             NetworkUpgrade::ZFuture => {}
         };
@@ -485,3 +529,20 @@ impl Version for V3 {
         }
     }
 }
+
+#[cfg(zcash_unstable = "nutachyon")]
+impl Version for V4 {
+    fn parts_to_history_node(
+        parts: HistoryTreeBlockParts<'_>,
+        network: &Network,
+    ) -> Self::NodeData {
+        let node_data_v3 = V3::parts_to_history_node(parts, network);
+        let tachyon_anchor: [u8; 32] = parts.tachyon_anchor.into();
+        Self::NodeData {
+            v3: node_data_v3,
+            start_tachyon_anchor: tachyon_anchor,
+            end_tachyon_anchor: tachyon_anchor,
+            tachyon_tx: parts.tachyon_tx,
+        }
+    }
+}
diff --git a/crates/zakura-chain/src/primitives/zcash_history/tests/vectors.rs b/crates/zakura-chain/src/primitives/zcash_history/tests/vectors.rs
index 09220f5b43..95c2f8af34 100644
--- a/crates/zakura-chain/src/primitives/zcash_history/tests/vectors.rs
+++ b/crates/zakura-chain/src/primitives/zcash_history/tests/vectors.rs
@@ -14,6 +14,8 @@ const U32_SIZE: usize = 4;
 const V1_FIXED_NODE_DATA_SIZE: usize = HISTORY_HASH_SIZE + U32_SIZE * 4 + HISTORY_HASH_SIZE * 3;
 const V2_EXTRA_FIXED_NODE_DATA_SIZE: usize = HISTORY_HASH_SIZE * 2;
 const V3_EXTRA_FIXED_NODE_DATA_SIZE: usize = HISTORY_HASH_SIZE * 2;
+#[cfg(zcash_unstable = "nutachyon")]
+const V4_EXTRA_FIXED_NODE_DATA_SIZE: usize = HISTORY_HASH_SIZE * 2;
 
 /// Test the MMR tree using the activation block of a network upgrade
 /// and its next block.
@@ -58,6 +60,8 @@ fn tree_for_network_upgrade(network: &Network, network_upgrade: NetworkUpgrade)
         &sapling_root0,
         &Default::default(),
         &Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )?;
 
     // Compute root hash of the MMR tree, which will be included in the next block
@@ -88,6 +92,8 @@ fn tree_for_network_upgrade(network: &Network, network_upgrade: NetworkUpgrade)
             &sapling_root1,
             &Default::default(),
             &Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            &Default::default(),
         )
         .unwrap();
 
@@ -114,6 +120,8 @@ fn old_history_versions_ignore_ironwood_root() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &default_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     );
     let v1_non_default = <V1 as ZebraHistoryVersion>::block_to_history_node(
         block.clone(),
@@ -121,6 +129,8 @@ fn old_history_versions_ignore_ironwood_root() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &non_default_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     );
 
     assert_eq!(
@@ -138,6 +148,8 @@ fn old_history_versions_ignore_ironwood_root() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &default_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     );
     let v2_non_default = <V2 as ZebraHistoryVersion>::block_to_history_node(
         block,
@@ -145,6 +157,8 @@ fn old_history_versions_ignore_ironwood_root() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &non_default_ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     );
 
     assert_eq!(
@@ -173,6 +187,8 @@ fn v3_history_node_hash_input_has_exact_serialized_size() -> Result<()> {
         &sapling_root,
         &orchard_root,
         &ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     );
 
     assert_eq!(node_data.start_ironwood_root, ironwood_root_bytes);
@@ -186,11 +202,48 @@ fn v3_history_node_hash_input_has_exact_serialized_size() -> Result<()> {
     // value in a V3 node.
     assert_eq!(encoded.len(), serialized_v3_node_data_size(&node_data));
     assert_eq!(encoded.last(), Some(&1));
+    #[cfg(zcash_unstable = "nutachyon")]
+    assert_eq!(::zcash_history::MAX_NODE_DATA_SIZE, 390);
+    #[cfg(not(zcash_unstable = "nutachyon"))]
     assert_eq!(::zcash_history::MAX_NODE_DATA_SIZE, 317);
 
     Ok(())
 }
 
+#[test]
+#[cfg(zcash_unstable = "nutachyon")]
+fn v4_history_node_commits_to_tachyon_state() -> Result<()> {
+    let network = Network::Mainnet;
+    let (block, sapling_root) = block_and_sapling_root(&network, NetworkUpgrade::Canopy)?;
+    let orchard_root = orchard::tree::Root::default();
+    let ironwood_root = non_default_ironwood_root();
+    let tachyon_anchor = crate::tachyon::Anchor([1; 32]);
+
+    let mut node_data = <V4 as ZebraHistoryVersion>::block_to_history_node(
+        block,
+        &network,
+        &sapling_root,
+        &orchard_root,
+        &ironwood_root,
+        &tachyon_anchor,
+    );
+
+    assert_eq!(node_data.start_tachyon_anchor, tachyon_anchor.0);
+    assert_eq!(node_data.end_tachyon_anchor, tachyon_anchor.0);
+
+    let without_tachyon_transaction = <V4 as ZcashHistoryVersion>::hash(&node_data);
+    node_data.tachyon_tx = 1;
+    let with_tachyon_transaction = <V4 as ZcashHistoryVersion>::hash(&node_data);
+    assert_ne!(without_tachyon_transaction, with_tachyon_transaction);
+
+    let encoded = <V4 as ZcashHistoryVersion>::to_bytes(&node_data);
+    assert_eq!(encoded.len(), serialized_v4_node_data_size(&node_data));
+    assert_eq!(encoded.last(), Some(&1));
+    assert_eq!(::zcash_history::MAX_NODE_DATA_SIZE, 390);
+
+    Ok(())
+}
+
 fn block_and_sapling_root(
     network: &Network,
     network_upgrade: NetworkUpgrade,
@@ -231,6 +284,13 @@ fn serialized_v3_node_data_size(data: &::zcash_history::NodeDataV3) -> usize {
         + compact_size(data.ironwood_tx)
 }
 
+#[cfg(zcash_unstable = "nutachyon")]
+fn serialized_v4_node_data_size(data: &::zcash_history::NodeDataV4) -> usize {
+    serialized_v3_node_data_size(&data.v3)
+        + V4_EXTRA_FIXED_NODE_DATA_SIZE
+        + compact_size(data.tachyon_tx)
+}
+
 fn serialized_v2_node_data_size(data: &::zcash_history::NodeDataV2) -> usize {
     serialized_v1_node_data_size(&data.v1)
         + V2_EXTRA_FIXED_NODE_DATA_SIZE
diff --git a/crates/zakura-chain/src/tachyon.rs b/crates/zakura-chain/src/tachyon.rs
new file mode 100644
index 0000000000..de88e95539
--- /dev/null
+++ b/crates/zakura-chain/src/tachyon.rs
@@ -0,0 +1,215 @@
+//! Tachyon shielded-pool chain-state types.
+
+use std::{fmt, io};
+
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    block::Block,
+    parameters::{Network, NetworkUpgrade},
+    serialization::{ReadZcashExt, SerializationError, ZcashDeserialize, ZcashSerialize},
+};
+
+/// The number of blocks in a Tachyon epoch.
+pub const EPOCH_LENGTH: u32 = zcash_tachyon::constants::EPOCH_SIZE;
+
+/// Returns the zero-based Tachyon pool height at `height`.
+pub fn pool_height(network: &Network, height: crate::block::Height) -> Option<u32> {
+    let activation_height = NetworkUpgrade::NuTachyon.activation_height(network)?;
+    height.0.checked_sub(activation_height.0)
+}
+
+/// Returns the Tachyon epoch containing `pool_height`.
+pub fn epoch_of_pool_height(pool_height: u32) -> u32 {
+    pool_height / EPOCH_LENGTH
+}
+
+/// Returns `true` if `pool_height` is the first block in its epoch.
+pub fn is_epoch_first(pool_height: u32) -> bool {
+    pool_height.is_multiple_of(EPOCH_LENGTH)
+}
+
+/// Returns the Tachyon epoch containing `height`, if the pool is active.
+pub fn epoch(network: &Network, height: crate::block::Height) -> Option<u32> {
+    pool_height(network, height).map(epoch_of_pool_height)
+}
+
+/// Returns `true` if `earlier` is in `later`'s two-epoch consensus scan window.
+pub fn within_scan_window(
+    network: &Network,
+    earlier: crate::block::Height,
+    later: crate::block::Height,
+) -> bool {
+    match (epoch(network, earlier), epoch(network, later)) {
+        (Some(earlier_epoch), Some(later_epoch)) => earlier_epoch + 1 >= later_epoch,
+        _ => false,
+    }
+}
+
+/// The running Tachyon pool anchor after a block.
+#[derive(Clone, Copy, Default, Eq, PartialEq, Hash, PartialOrd, Ord, Serialize, Deserialize)]
+pub struct Anchor(pub [u8; 32]);
+
+impl fmt::Debug for Anchor {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("tachyon::Anchor")
+            .field(&hex::encode(self.0))
+            .finish()
+    }
+}
+
+impl From<[u8; 32]> for Anchor {
+    fn from(bytes: [u8; 32]) -> Self {
+        Self(bytes)
+    }
+}
+
+impl From<Anchor> for [u8; 32] {
+    fn from(anchor: Anchor) -> Self {
+        anchor.0
+    }
+}
+
+impl From<&Anchor> for [u8; 32] {
+    fn from(anchor: &Anchor) -> Self {
+        anchor.0
+    }
+}
+
+impl ZcashSerialize for Anchor {
+    fn zcash_serialize<W: io::Write>(&self, mut writer: W) -> Result<(), io::Error> {
+        writer.write_all(&self.0)
+    }
+}
+
+impl ZcashDeserialize for Anchor {
+    fn zcash_deserialize<R: io::Read>(mut reader: R) -> Result<Self, SerializationError> {
+        Ok(Self(reader.read_32_bytes()?))
+    }
+}
+
+impl From<zcash_tachyon::Anchor> for Anchor {
+    fn from(anchor: zcash_tachyon::Anchor) -> Self {
+        let mut bytes = Vec::with_capacity(32);
+        anchor
+            .write(&mut bytes)
+            .expect("serializing a Tachyon anchor into a Vec is infallible");
+        Self(
+            bytes
+                .try_into()
+                .expect("Tachyon anchors always encode as 32 bytes"),
+        )
+    }
+}
+
+/// A nullifier or note commitment revealed by a Tachyon proof stamp.
+#[derive(Clone, Copy, Eq, PartialEq, Hash, PartialOrd, Ord, Serialize, Deserialize)]
+pub struct Tachygram(pub [u8; 32]);
+
+impl fmt::Debug for Tachygram {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("tachyon::Tachygram")
+            .field(&hex::encode(self.0))
+            .finish()
+    }
+}
+
+impl From<[u8; 32]> for Tachygram {
+    fn from(bytes: [u8; 32]) -> Self {
+        Self(bytes)
+    }
+}
+
+impl From<Tachygram> for [u8; 32] {
+    fn from(tachygram: Tachygram) -> Self {
+        tachygram.0
+    }
+}
+
+impl From<&Tachygram> for [u8; 32] {
+    fn from(tachygram: &Tachygram) -> Self {
+        tachygram.0
+    }
+}
+
+impl From<zcash_tachyon::Tachygram> for Tachygram {
+    fn from(tachygram: zcash_tachyon::Tachygram) -> Self {
+        let field: halo2::pasta::pallas::Base = tachygram.into();
+        Self(field.into())
+    }
+}
+
+impl Anchor {
+    fn to_tachyon(self) -> zcash_tachyon::Anchor {
+        zcash_tachyon::Anchor::read(&self.0[..])
+            .expect("stored Tachyon anchors are canonical field-element encodings")
+    }
+
+    /// Computes the Tachyon pool anchor after `block`.
+    pub fn advance_with_block(
+        &self,
+        pool_height: u32,
+        block: &Block,
+    ) -> Result<AnchorAdvance, zcash_tachyon::AnchorError> {
+        use zcash_tachyon::TachyonBundle;
+
+        let epoch = zcash_tachyon::EpochIndex(epoch_of_pool_height(pool_height));
+        let mut anchor = if pool_height == 0 {
+            zcash_tachyon::Anchor::default()
+        } else {
+            self.to_tachyon()
+        };
+        let epoch_boundary = if pool_height == 0 {
+            Some(Anchor::from(anchor))
+        } else if is_epoch_first(pool_height) {
+            anchor = anchor.next_epoch(epoch)?;
+            Some(Anchor::from(anchor))
+        } else {
+            None
+        };
+
+        for transaction in &block.transactions {
+            let Some(shielded_data) = transaction.tachyon_shielded_data() else {
+                continue;
+            };
+            if let TachyonBundle::Proven(bundle) = &shielded_data.0 {
+                anchor = anchor.next_stamp(epoch, &bundle.stamp.tachygram_set)?;
+            }
+        }
+
+        Ok(AnchorAdvance {
+            post_block: Anchor::from(anchor),
+            epoch_boundary,
+        })
+    }
+}
+
+/// The result of advancing the Tachyon anchor through a block.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub struct AnchorAdvance {
+    /// The anchor after the block.
+    pub post_block: Anchor,
+    /// The anchor immediately after an epoch lift, if this block starts an epoch.
+    pub epoch_boundary: Option<Anchor>,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn anchor_serialization_round_trip() {
+        let anchor = Anchor([42; 32]);
+        let mut bytes = Vec::new();
+        anchor.zcash_serialize(&mut bytes).unwrap();
+        assert_eq!(Anchor::zcash_deserialize(&bytes[..]).unwrap(), anchor);
+    }
+
+    #[test]
+    fn epoch_helpers_follow_epoch_length() {
+        assert_eq!(epoch_of_pool_height(0), 0);
+        assert_eq!(epoch_of_pool_height(EPOCH_LENGTH), 1);
+        assert!(is_epoch_first(0));
+        assert!(is_epoch_first(EPOCH_LENGTH));
+    }
+}
diff --git a/crates/zakura-chain/src/transaction.rs b/crates/zakura-chain/src/transaction.rs
index 53d518a6d3..8f803a2102 100644
--- a/crates/zakura-chain/src/transaction.rs
+++ b/crates/zakura-chain/src/transaction.rs
@@ -11,6 +11,8 @@ mod lock_time;
 mod memo;
 mod serialize;
 mod sighash;
+#[cfg(zcash_unstable = "nutachyon")]
+mod tachyon_shielded;
 mod txid;
 mod unmined;
 pub(crate) mod zip244;
@@ -33,12 +35,16 @@ pub use serialize::{
     MIN_TRANSPARENT_TX_V5_SIZE,
 };
 pub use sighash::{HashType, SigHash, SigHasher};
+#[cfg(zcash_unstable = "nutachyon")]
+pub use tachyon_shielded::TachyonShieldedData;
 pub use unmined::{
     zip317, UnminedTx, UnminedTxId, VerifiedUnminedTx, MEMPOOL_TRANSACTION_COST_THRESHOLD,
 };
 use zcash_protocol::consensus;
 
 use crate::parameters::TX_V6_VERSION_GROUP_ID;
+#[cfg(zcash_unstable = "nutachyon")]
+use crate::parameters::TX_V7_VERSION_GROUP_ID;
 use crate::{
     amount::{Amount, Error as AmountError, NegativeAllowed, NonNegative},
     block, ironwood,
@@ -169,6 +175,30 @@ pub enum Transaction {
         /// The Ironwood data for this transaction, if any.
         ironwood_shielded_data: Option<ironwood::ShieldedData>,
     },
+    /// A `version = 7` transaction enabled by NuTachyon.
+    #[cfg(zcash_unstable = "nutachyon")]
+    V7 {
+        /// The Network Upgrade for this transaction.
+        ///
+        /// Derived from the ConsensusBranchId field.
+        network_upgrade: NetworkUpgrade,
+        /// The earliest time or block height that this transaction can be added to the chain.
+        lock_time: LockTime,
+        /// The latest block height that this transaction can be added to the chain.
+        expiry_height: block::Height,
+        /// The transparent inputs to the transaction.
+        inputs: Vec<transparent::Input>,
+        /// The transparent outputs from the transaction.
+        outputs: Vec<transparent::Output>,
+        /// The sapling shielded data for this transaction, if any.
+        sapling_shielded_data: Option<sapling::ShieldedData<sapling::SharedAnchor>>,
+        /// The orchard data for this transaction, if any.
+        orchard_shielded_data: Option<orchard::ShieldedData>,
+        /// The Ironwood data for this transaction, if any.
+        ironwood_shielded_data: Option<ironwood::ShieldedData>,
+        /// The Tachyon data for this transaction, if any.
+        tachyon_shielded_data: Option<TachyonShieldedData>,
+    },
 }
 
 impl AttributedMemorySize for Transaction {
@@ -257,6 +287,37 @@ impl AttributedMemorySize for Transaction {
                             .map_or(0, AttributedMemorySize::attributed_memory_size_bytes),
                     ),
             ),
+            #[cfg(zcash_unstable = "nutachyon")]
+            V7 {
+                inputs,
+                outputs,
+                sapling_shielded_data,
+                orchard_shielded_data,
+                ironwood_shielded_data,
+                tachyon_shielded_data,
+                ..
+            } => (
+                inputs,
+                outputs,
+                sapling_shielded_data
+                    .as_ref()
+                    .map_or(0, AttributedMemorySize::attributed_memory_size_bytes)
+                    .saturating_add(
+                        orchard_shielded_data
+                            .as_ref()
+                            .map_or(0, AttributedMemorySize::attributed_memory_size_bytes),
+                    )
+                    .saturating_add(
+                        ironwood_shielded_data
+                            .as_ref()
+                            .map_or(0, AttributedMemorySize::attributed_memory_size_bytes),
+                    )
+                    .saturating_add(
+                        tachyon_shielded_data
+                            .as_ref()
+                            .map_or(0, AttributedMemorySize::attributed_memory_size_bytes),
+                    ),
+            ),
         };
 
         vec_capacity_bytes(inputs)
@@ -389,6 +450,8 @@ impl Transaction {
             | Transaction::V4 { .. } => None,
             Transaction::V5 { .. } => Some(AuthDigest::from(self)),
             Transaction::V6 { .. } => Some(AuthDigest::from(self)),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => Some(AuthDigest::from(self)),
         }
     }
 
@@ -413,6 +476,12 @@ impl Transaction {
                     crate::primitives::zcash_primitives::txid_and_auth_digest(self);
                 (txid, Some(auth_digest))
             }
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => {
+                let (txid, auth_digest) =
+                    crate::primitives::zcash_primitives::txid_and_auth_digest(self);
+                (txid, Some(auth_digest))
+            }
         }
     }
 
@@ -454,6 +523,7 @@ impl Transaction {
                     .ironwood_flags()
                     .unwrap_or_else(ironwood::Flags::empty)
                     .contains(ironwood::Flags::ENABLE_SPENDS))
+            || self.has_tachyon_actions()
     }
 
     /// Does this transaction have shielded outputs?
@@ -472,6 +542,7 @@ impl Transaction {
                     .ironwood_flags()
                     .unwrap_or_else(ironwood::Flags::empty)
                     .contains(ironwood::Flags::ENABLE_OUTPUTS))
+            || self.has_tachyon_actions()
     }
 
     /// Does this transaction have transparent or shielded outputs?
@@ -524,6 +595,8 @@ impl Transaction {
             Transaction::V1 { .. } | Transaction::V2 { .. } => false,
             Transaction::V3 { .. } | Transaction::V4 { .. } | Transaction::V5 { .. } => true,
             Transaction::V6 { .. } => true,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => true,
         }
     }
 
@@ -546,6 +619,8 @@ impl Transaction {
             Transaction::V4 { .. } => 4,
             Transaction::V5 { .. } => 5,
             Transaction::V6 { .. } => 6,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => 7,
         }
     }
 
@@ -558,6 +633,8 @@ impl Transaction {
             | Transaction::V4 { lock_time, .. }
             | Transaction::V5 { lock_time, .. } => *lock_time,
             Transaction::V6 { lock_time, .. } => *lock_time,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { lock_time, .. } => *lock_time,
         };
 
         // `zcashd` checks that the block height is greater than the lock height.
@@ -606,6 +683,8 @@ impl Transaction {
             | Transaction::V4 { lock_time, .. }
             | Transaction::V5 { lock_time, .. } => *lock_time,
             Transaction::V6 { lock_time, .. } => *lock_time,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { lock_time, .. } => *lock_time,
         };
         let mut lock_time_bytes = Vec::new();
         lock_time
@@ -642,11 +721,18 @@ impl Transaction {
                 block::Height(0) => None,
                 block::Height(expiry_height) => Some(block::Height(*expiry_height)),
             },
-            Transaction::V6 { expiry_height, .. } => match expiry_height {
-                // # Consensus
-                //
-                // > No limit: To set no limit on transactions (so that they do not expire), nExpiryHeight should be set to 0.
-                // https://zips.z.cash/zip-0203#specification
+            Transaction::V6 { expiry_height, .. } => {
+                match expiry_height {
+                    // # Consensus
+                    //
+                    // > No limit: To set no limit on transactions (so that they do not expire), nExpiryHeight should be set to 0.
+                    // https://zips.z.cash/zip-0203#specification
+                    block::Height(0) => None,
+                    block::Height(expiry_height) => Some(block::Height(*expiry_height)),
+                }
+            }
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { expiry_height, .. } => match expiry_height {
                 block::Height(0) => None,
                 block::Height(expiry_height) => Some(block::Height(*expiry_height)),
             },
@@ -669,6 +755,10 @@ impl Transaction {
             Transaction::V6 {
                 network_upgrade, ..
             } => Some(*network_upgrade),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                network_upgrade, ..
+            } => Some(*network_upgrade),
         }
     }
 
@@ -683,6 +773,8 @@ impl Transaction {
             Transaction::V4 { ref inputs, .. } => inputs,
             Transaction::V5 { ref inputs, .. } => inputs,
             Transaction::V6 { ref inputs, .. } => inputs,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { ref inputs, .. } => inputs,
         }
     }
 
@@ -702,6 +794,8 @@ impl Transaction {
             Transaction::V4 { ref outputs, .. } => outputs,
             Transaction::V5 { ref outputs, .. } => outputs,
             Transaction::V6 { ref outputs, .. } => outputs,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { ref outputs, .. } => outputs,
         }
     }
 
@@ -751,6 +845,8 @@ impl Transaction {
             }
             | Transaction::V5 { .. } => Box::new(std::iter::empty()),
             Transaction::V6 { .. } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => Box::new(std::iter::empty()),
         }
     }
 
@@ -787,6 +883,8 @@ impl Transaction {
             }
             | Transaction::V5 { .. } => Box::new(std::iter::empty()),
             Transaction::V6 { .. } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => Box::new(std::iter::empty()),
         }
     }
 
@@ -823,6 +921,8 @@ impl Transaction {
             }
             | Transaction::V5 { .. } => 0,
             Transaction::V6 { .. } => 0,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => 0,
         }
     }
 
@@ -863,6 +963,8 @@ impl Transaction {
             }
             | Transaction::V5 { .. } => Box::new(std::iter::empty()),
             Transaction::V6 { .. } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => Box::new(std::iter::empty()),
         }
     }
 
@@ -900,6 +1002,8 @@ impl Transaction {
             }
             | Transaction::V5 { .. } => None,
             Transaction::V6 { .. } => None,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => None,
         }
     }
 
@@ -909,6 +1013,8 @@ impl Transaction {
             // No JoinSplits
             Transaction::V1 { .. } | Transaction::V5 { .. } => false,
             Transaction::V6 { .. } => false,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => false,
 
             // JoinSplits-on-BCTV14
             Transaction::V2 { joinsplit_data, .. } | Transaction::V3 { joinsplit_data, .. } => {
@@ -957,6 +1063,8 @@ impl Transaction {
             | Transaction::V1 { .. }
             | Transaction::V5 { .. } => Box::new(std::iter::empty()),
             Transaction::V6 { .. } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => Box::new(std::iter::empty()),
         }
     }
 
@@ -974,6 +1082,11 @@ impl Transaction {
                 sapling_shielded_data,
                 ..
             } => sapling_shielded_data.as_ref(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data,
+                ..
+            } => sapling_shielded_data.as_ref(),
             _ => None,
         }
     }
@@ -998,6 +1111,11 @@ impl Transaction {
                 sapling_shielded_data: Some(sapling_shielded_data),
                 ..
             } => Box::new(sapling_shielded_data.anchors()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: Some(sapling_shielded_data),
+                ..
+            } => Box::new(sapling_shielded_data.anchors()),
 
             // No Spends
             Transaction::V1 { .. }
@@ -1015,6 +1133,11 @@ impl Transaction {
                 sapling_shielded_data: None,
                 ..
             } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: None,
+                ..
+            } => Box::new(std::iter::empty()),
         }
     }
 
@@ -1044,6 +1167,11 @@ impl Transaction {
                 sapling_shielded_data: Some(sapling_shielded_data),
                 ..
             } => Box::new(sapling_shielded_data.spends_per_anchor()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: Some(sapling_shielded_data),
+                ..
+            } => Box::new(sapling_shielded_data.spends_per_anchor()),
 
             // No Spends
             Transaction::V1 { .. }
@@ -1061,6 +1189,11 @@ impl Transaction {
                 sapling_shielded_data: None,
                 ..
             } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: None,
+                ..
+            } => Box::new(std::iter::empty()),
         }
     }
 
@@ -1080,6 +1213,11 @@ impl Transaction {
                 sapling_shielded_data: Some(sapling_shielded_data),
                 ..
             } => Box::new(sapling_shielded_data.outputs()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: Some(sapling_shielded_data),
+                ..
+            } => Box::new(sapling_shielded_data.outputs()),
 
             // No Outputs
             Transaction::V1 { .. }
@@ -1097,6 +1235,11 @@ impl Transaction {
                 sapling_shielded_data: None,
                 ..
             } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: None,
+                ..
+            } => Box::new(std::iter::empty()),
         }
     }
 
@@ -1118,6 +1261,11 @@ impl Transaction {
                 sapling_shielded_data: Some(sapling_shielded_data),
                 ..
             } => Box::new(sapling_shielded_data.nullifiers()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: Some(sapling_shielded_data),
+                ..
+            } => Box::new(sapling_shielded_data.nullifiers()),
 
             // No Spends
             Transaction::V1 { .. }
@@ -1135,6 +1283,11 @@ impl Transaction {
                 sapling_shielded_data: None,
                 ..
             } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: None,
+                ..
+            } => Box::new(std::iter::empty()),
         }
     }
 
@@ -1158,6 +1311,11 @@ impl Transaction {
                 sapling_shielded_data: Some(sapling_shielded_data),
                 ..
             } => Box::new(sapling_shielded_data.note_commitments()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: Some(sapling_shielded_data),
+                ..
+            } => Box::new(sapling_shielded_data.note_commitments()),
 
             // No Spends
             Transaction::V1 { .. }
@@ -1175,6 +1333,11 @@ impl Transaction {
                 sapling_shielded_data: None,
                 ..
             } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: None,
+                ..
+            } => Box::new(std::iter::empty()),
         }
     }
 
@@ -1194,6 +1357,11 @@ impl Transaction {
                 sapling_shielded_data,
                 ..
             } => sapling_shielded_data.is_some(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data,
+                ..
+            } => sapling_shielded_data.is_some(),
         }
     }
 
@@ -1219,6 +1387,11 @@ impl Transaction {
                 sapling_shielded_data: Some(sapling_shielded_data),
                 ..
             } => sapling_shielded_data.point_encodings_are_valid(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: Some(sapling_shielded_data),
+                ..
+            } => sapling_shielded_data.point_encodings_are_valid(),
             _ => true,
         }
     }
@@ -1238,6 +1411,11 @@ impl Transaction {
                 orchard_shielded_data,
                 ..
             } => orchard_shielded_data.as_ref(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                orchard_shielded_data,
+                ..
+            } => orchard_shielded_data.as_ref(),
 
             // No Orchard shielded data
             Transaction::V1 { .. }
@@ -1294,6 +1472,11 @@ impl Transaction {
                 ironwood_shielded_data,
                 ..
             } => ironwood_shielded_data.as_ref(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                ironwood_shielded_data,
+                ..
+            } => ironwood_shielded_data.as_ref(),
 
             Transaction::V1 { .. }
             | Transaction::V2 { .. }
@@ -1340,6 +1523,57 @@ impl Transaction {
         self.ironwood_shielded_data().is_some()
     }
 
+    // Tachyon
+
+    /// Access the Tachyon shielded data in this transaction, if present.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_shielded_data(&self) -> Option<&TachyonShieldedData> {
+        match self {
+            Transaction::V7 {
+                tachyon_shielded_data,
+                ..
+            } => tachyon_shielded_data.as_ref(),
+            _ => None,
+        }
+    }
+
+    /// Returns `true` if this transaction carries a Tachyon bundle.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn has_tachyon_shielded_data(&self) -> bool {
+        self.tachyon_shielded_data().is_some()
+    }
+
+    /// Returns the tachygrams revealed by this transaction's proof stamp.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_tachygrams(&self) -> Vec<crate::tachyon::Tachygram> {
+        match self.tachyon_shielded_data() {
+            Some(shielded_data) => match &shielded_data.0 {
+                zcash_tachyon::TachyonBundle::Proven(bundle) => bundle
+                    .stamp
+                    .tachygrams
+                    .iter()
+                    .copied()
+                    .map(crate::tachyon::Tachygram::from)
+                    .collect(),
+                zcash_tachyon::TachyonBundle::NoBundle
+                | zcash_tachyon::TachyonBundle::Adjunct(_) => Vec::new(),
+            },
+            None => Vec::new(),
+        }
+    }
+
+    /// Returns `true` if this transaction has any Tachyon actions.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn has_tachyon_actions(&self) -> bool {
+        self.tachyon_shielded_data()
+            .is_some_and(|data| !data.actions().is_empty())
+    }
+
+    #[cfg(not(zcash_unstable = "nutachyon"))]
+    fn has_tachyon_actions(&self) -> bool {
+        false
+    }
+
     // value balances
 
     /// Return the transparent value balance,
@@ -1452,6 +1686,8 @@ impl Transaction {
             }
             | Transaction::V5 { .. } => Box::new(std::iter::empty()),
             Transaction::V6 { .. } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => Box::new(std::iter::empty()),
         }
     }
 
@@ -1500,6 +1736,8 @@ impl Transaction {
             }
             | Transaction::V5 { .. } => Box::new(std::iter::empty()),
             Transaction::V6 { .. } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => Box::new(std::iter::empty()),
         }
     }
 
@@ -1542,6 +1780,8 @@ impl Transaction {
             }
             | Transaction::V5 { .. } => Box::new(iter::empty()),
             Transaction::V6 { .. } => Box::new(iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => Box::new(iter::empty()),
         };
 
         joinsplit_value_balances.map(ValueBalance::from_sprout_amount)
@@ -1587,6 +1827,11 @@ impl Transaction {
                 sapling_shielded_data: Some(sapling_shielded_data),
                 ..
             } => sapling_shielded_data.value_balance,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: Some(sapling_shielded_data),
+                ..
+            } => sapling_shielded_data.value_balance,
 
             Transaction::V1 { .. }
             | Transaction::V2 { .. }
@@ -1603,6 +1848,11 @@ impl Transaction {
                 sapling_shielded_data: None,
                 ..
             } => Amount::zero(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: None,
+                ..
+            } => Amount::zero(),
         };
 
         ValueBalance::from_sapling_amount(sapling_value_balance)
@@ -1626,6 +1876,11 @@ impl Transaction {
                 sapling_shielded_data: Some(sapling_shielded_data),
                 ..
             } => Some(sapling_shielded_data.binding_sig),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: Some(sapling_shielded_data),
+                ..
+            } => Some(sapling_shielded_data.binding_sig),
             _ => None,
         }
     }
@@ -1713,6 +1968,26 @@ impl Transaction {
         ValueBalance::from_ironwood_amount(ironwood_value_balance)
     }
 
+    /// Return the Tachyon value balance, the change in the transaction value pool due to
+    /// Tachyon actions.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_value_balance(&self) -> ValueBalance<NegativeAllowed> {
+        let tachyon_value_balance = self
+            .tachyon_shielded_data()
+            .map(|shielded_data| {
+                Amount::try_from(i64::from(shielded_data.value_balance()))
+                    .expect("Tachyon value balances are range-checked when the bundle is parsed")
+            })
+            .unwrap_or_else(Amount::zero);
+
+        ValueBalance::from_tachyon_amount(tachyon_value_balance)
+    }
+
+    #[cfg(not(zcash_unstable = "nutachyon"))]
+    fn tachyon_value_balance(&self) -> ValueBalance<NegativeAllowed> {
+        ValueBalance::zero()
+    }
+
     /// Returns the value balances for this transaction using the provided transparent outputs.
     #[cfg(any(test, feature = "proptest-impl"))]
     pub(crate) fn value_balance_from_outputs(
@@ -1724,6 +1999,7 @@ impl Transaction {
             + self.sapling_value_balance()
             + self.orchard_value_balance()
             + self.ironwood_value_balance()
+            + self.tachyon_value_balance()
     }
 
     /// Returns the value balances for this transaction.
@@ -1782,6 +2058,7 @@ impl Transaction {
             + self.sapling_value_balance()
             + self.orchard_value_balance()
             + self.ironwood_value_balance()
+            + self.tachyon_value_balance()
     }
 
     /// Converts [`Transaction`] to [`zcash_primitives::transaction::Transaction`].
@@ -1829,6 +2106,8 @@ impl Transaction {
             Transaction::V4 { .. } => Some(SAPLING_VERSION_GROUP_ID),
             Transaction::V5 { .. } => Some(TX_V5_VERSION_GROUP_ID),
             Transaction::V6 { .. } => Some(TX_V6_VERSION_GROUP_ID),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => Some(TX_V7_VERSION_GROUP_ID),
         }
     }
 }
@@ -1862,6 +2141,14 @@ impl Transaction {
                 *network_upgrade = nu;
                 Ok(())
             }
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                ref mut network_upgrade,
+                ..
+            } => {
+                *network_upgrade = nu;
+                Ok(())
+            }
         }
     }
 
@@ -1891,6 +2178,11 @@ impl Transaction {
                 ref mut expiry_height,
                 ..
             } => expiry_height,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                ref mut expiry_height,
+                ..
+            } => expiry_height,
         }
     }
 
@@ -1903,6 +2195,8 @@ impl Transaction {
             Transaction::V4 { ref mut inputs, .. } => inputs,
             Transaction::V5 { ref mut inputs, .. } => inputs,
             Transaction::V6 { ref mut inputs, .. } => inputs,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { ref mut inputs, .. } => inputs,
         }
     }
 
@@ -1933,6 +2227,11 @@ impl Transaction {
                 sapling_shielded_data: Some(sapling_shielded_data),
                 ..
             } => Some(&mut sapling_shielded_data.value_balance),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: Some(sapling_shielded_data),
+                ..
+            } => Some(&mut sapling_shielded_data.value_balance),
             Transaction::V1 { .. }
             | Transaction::V2 { .. }
             | Transaction::V3 { .. }
@@ -1948,6 +2247,11 @@ impl Transaction {
                 sapling_shielded_data: None,
                 ..
             } => None,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                sapling_shielded_data: None,
+                ..
+            } => None,
         }
     }
 
@@ -1997,6 +2301,8 @@ impl Transaction {
             }
             | Transaction::V5 { .. } => Box::new(std::iter::empty()),
             Transaction::V6 { .. } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => Box::new(std::iter::empty()),
         }
     }
 
@@ -2046,6 +2352,8 @@ impl Transaction {
             }
             | Transaction::V5 { .. } => Box::new(std::iter::empty()),
             Transaction::V6 { .. } => Box::new(std::iter::empty()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => Box::new(std::iter::empty()),
         }
     }
 
@@ -2068,6 +2376,11 @@ impl Transaction {
                 orchard_shielded_data: Some(orchard_shielded_data),
                 ..
             } => Some(orchard_shielded_data),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                orchard_shielded_data: Some(orchard_shielded_data),
+                ..
+            } => Some(orchard_shielded_data),
 
             Transaction::V1 { .. }
             | Transaction::V2 { .. }
@@ -2081,6 +2394,11 @@ impl Transaction {
                 orchard_shielded_data: None,
                 ..
             } => None,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                orchard_shielded_data: None,
+                ..
+            } => None,
         }
     }
 
@@ -2105,6 +2423,10 @@ impl Transaction {
             Transaction::V6 {
                 ref mut outputs, ..
             } => outputs,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                ref mut outputs, ..
+            } => outputs,
         }
     }
 }
diff --git a/crates/zakura-chain/src/transaction/arbitrary.rs b/crates/zakura-chain/src/transaction/arbitrary.rs
index ec3a8b0b8f..4b20cca4ed 100644
--- a/crates/zakura-chain/src/transaction/arbitrary.rs
+++ b/crates/zakura-chain/src/transaction/arbitrary.rs
@@ -806,6 +806,8 @@ impl Arbitrary for Transaction {
             ]
             .boxed(),
             NetworkUpgrade::Nu7 => Self::v5_strategy(ledger_state),
+            #[cfg(zcash_unstable = "nutachyon")]
+            NetworkUpgrade::NuTachyon => Self::v5_strategy(ledger_state),
 
             #[cfg(zcash_unstable = "zfuture")]
             NetworkUpgrade::ZFuture => Self::v5_strategy(ledger_state),
@@ -955,6 +957,8 @@ pub fn transaction_to_fake_v5(
         },
         v5 @ V5 { .. } => v5.clone(),
         v6 @ V6 { .. } => v6.clone(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        v7 @ V7 { .. } => v7.clone(),
     }
 }
 
@@ -1040,6 +1044,8 @@ pub fn v5_transactions<'b>(
         | Transaction::V4 { .. } => None,
         ref tx @ Transaction::V5 { .. } => Some(tx.clone()),
         ref tx @ Transaction::V6 { .. } => Some(tx.clone()),
+        #[cfg(zcash_unstable = "nutachyon")]
+        ref tx @ Transaction::V7 { .. } => Some(tx.clone()),
     })
 }
 
diff --git a/crates/zakura-chain/src/transaction/hash.rs b/crates/zakura-chain/src/transaction/hash.rs
index 75fe43fea5..259fe812d1 100644
--- a/crates/zakura-chain/src/transaction/hash.rs
+++ b/crates/zakura-chain/src/transaction/hash.rs
@@ -6,10 +6,10 @@
 //! * [`WtxId`]: a 64-byte witnessed transaction ID, which uniquely identifies unmined transactions
 //!   (transactions that are sent by wallets or stored in node mempools).
 //!
-//! Transaction versions 5 and 6 use both these unique identifiers:
-//! * [`struct@Hash`] uniquely identifies the effects of a v5 or v6 transaction (spends and outputs),
+//! Transaction versions 5 and later use both these unique identifiers:
+//! * [`struct@Hash`] uniquely identifies the effects of a v5+ transaction (spends and outputs),
 //!   so it uniquely identifies the transaction's data after it has been mined into a block;
-//! * [`WtxId`] uniquely identifies the effects and authorizing data of a v5 or v6 transaction
+//! * [`WtxId`] uniquely identifies the effects and authorizing data of a v5+ transaction
 //!   (signatures, proofs, and scripts), so it uniquely identifies the transaction's data
 //!   outside a block. (For example, transactions produced by Zcash wallets, or in node mempools.)
 //!
@@ -42,7 +42,7 @@ use crate::serialization::{
 
 use super::{txid::TxIdBuilder, AuthDigest, Transaction};
 
-/// A transaction ID, which uniquely identifies mined v5 and v6 transactions,
+/// A transaction ID, which uniquely identifies mined v5+ transactions,
 /// and all v1-v4 transactions.
 ///
 /// Note: Zebra displays transaction and block hashes in big-endian byte-order,
@@ -195,7 +195,7 @@ impl ZcashDeserialize for Hash {
     }
 }
 
-/// A witnessed transaction ID, which uniquely identifies unmined v5 and v6 transactions.
+/// A witnessed transaction ID, which uniquely identifies unmined v5+ transactions.
 ///
 /// Witnessed transaction IDs are not used for transaction versions 1-4.
 ///
diff --git a/crates/zakura-chain/src/transaction/serialize.rs b/crates/zakura-chain/src/transaction/serialize.rs
index 0e5f9ad582..9cb246913a 100644
--- a/crates/zakura-chain/src/transaction/serialize.rs
+++ b/crates/zakura-chain/src/transaction/serialize.rs
@@ -22,6 +22,8 @@ use crate::{
 };
 
 use crate::parameters::TX_V6_VERSION_GROUP_ID;
+#[cfg(zcash_unstable = "nutachyon")]
+use crate::parameters::TX_V7_VERSION_GROUP_ID;
 
 use super::*;
 use crate::sapling;
@@ -199,7 +201,7 @@ impl ZcashDeserialize for Option<sapling::ShieldedData<sapling::SharedAnchor>> {
     }
 }
 
-/// Deserialize V5/V6 Sapling shielded data with an optional early coinbase
+/// Deserialize V5+ Sapling shielded data with an optional early coinbase
 /// rejection.
 ///
 /// When `is_coinbase` is true, a non-zero `nSpendsSapling` count is rejected
@@ -875,6 +877,54 @@ impl ZcashSerialize for Transaction {
                     ALLOW_CROSS_ADDRESS_BIT,
                 )?;
             }
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 {
+                network_upgrade,
+                lock_time,
+                expiry_height,
+                inputs,
+                outputs,
+                sapling_shielded_data,
+                orchard_shielded_data,
+                ironwood_shielded_data,
+                tachyon_shielded_data,
+            } => {
+                if *network_upgrade < NetworkUpgrade::NuTachyon {
+                    return Err(io::Error::new(
+                        io::ErrorKind::InvalidData,
+                        "v7 transaction must have a NuTachyon or later consensus branch ID",
+                    ));
+                }
+
+                writer.write_u32::<LittleEndian>(TX_V7_VERSION_GROUP_ID)?;
+                writer.write_u32::<LittleEndian>(u32::from(
+                    network_upgrade
+                        .branch_id()
+                        .expect("valid transactions must have a network upgrade with a branch id"),
+                ))?;
+                lock_time.zcash_serialize(&mut writer)?;
+                writer.write_u32::<LittleEndian>(expiry_height.0)?;
+                inputs.zcash_serialize(&mut writer)?;
+                outputs.zcash_serialize(&mut writer)?;
+                sapling_shielded_data.zcash_serialize(&mut writer)?;
+                serialize_optional_orchard_shielded_data_with_flags(
+                    orchard_shielded_data,
+                    &mut writer,
+                    !ALLOW_CROSS_ADDRESS_BIT,
+                )?;
+                serialize_optional_orchard_shielded_data_with_flags(
+                    ironwood_shielded_data,
+                    &mut writer,
+                    ALLOW_CROSS_ADDRESS_BIT,
+                )?;
+                let tachyon_bundle = tachyon_shielded_data
+                    .as_ref()
+                    .map_or(&zcash_tachyon::TachyonBundle::NoBundle, |bundle| &bundle.0);
+                zcash_primitives::transaction::components::tachyon::write_v7_bundle(
+                    tachyon_bundle,
+                    &mut writer,
+                )?;
+            }
         }
         Ok(())
     }
@@ -1235,6 +1285,57 @@ impl ZcashDeserialize for Transaction {
                     ironwood_shielded_data,
                 })
             }
+            #[cfg(zcash_unstable = "nutachyon")]
+            (7, true) => {
+                let id = limited_reader.read_u32::<LittleEndian>()?;
+                if id != TX_V7_VERSION_GROUP_ID {
+                    return Err(SerializationError::Parse("expected TX_V7_VERSION_GROUP_ID"));
+                }
+
+                let network_upgrade =
+                    NetworkUpgrade::try_from(limited_reader.read_u32::<LittleEndian>()?)?;
+                if network_upgrade < NetworkUpgrade::NuTachyon {
+                    return Err(SerializationError::Parse(
+                        "v7 transaction must have a NuTachyon or later consensus branch ID",
+                    ));
+                }
+
+                let lock_time = LockTime::zcash_deserialize(&mut limited_reader)?;
+                let expiry_height = block::Height(limited_reader.read_u32::<LittleEndian>()?);
+                let inputs: Vec<transparent::Input> = Vec::zcash_deserialize(&mut limited_reader)?;
+                let outputs = Vec::zcash_deserialize(&mut limited_reader)?;
+
+                let is_coinbase = inputs.len() == 1
+                    && matches!(inputs.first(), Some(transparent::Input::Coinbase { .. }));
+                let sapling_shielded_data =
+                    deserialize_v5_sapling_shielded_data(&mut limited_reader, is_coinbase)?;
+                let orchard_shielded_data = deserialize_orchard_shielded_data_with_flags(
+                    &mut limited_reader,
+                    !ALLOW_CROSS_ADDRESS_BIT,
+                )?;
+                let ironwood_shielded_data = deserialize_orchard_shielded_data_with_flags(
+                    &mut limited_reader,
+                    ALLOW_CROSS_ADDRESS_BIT,
+                )?;
+                let tachyon_shielded_data =
+                    match zcash_primitives::transaction::components::tachyon::read_v7_bundle(
+                        &mut limited_reader,
+                    )? {
+                        zcash_tachyon::TachyonBundle::NoBundle => None,
+                        bundle => Some(TachyonShieldedData::from(bundle)),
+                    };
+                Ok(Transaction::V7 {
+                    network_upgrade,
+                    lock_time,
+                    expiry_height,
+                    inputs,
+                    outputs,
+                    sapling_shielded_data,
+                    orchard_shielded_data,
+                    ironwood_shielded_data,
+                    tachyon_shielded_data,
+                })
+            }
             (_, _) => Err(SerializationError::Parse("bad tx header")),
         }
     }
diff --git a/crates/zakura-chain/src/transaction/tachyon_shielded.rs b/crates/zakura-chain/src/transaction/tachyon_shielded.rs
new file mode 100644
index 0000000000..fc034cc58e
--- /dev/null
+++ b/crates/zakura-chain/src/transaction/tachyon_shielded.rs
@@ -0,0 +1,90 @@
+//! The Tachyon shielded data carried by V7 transactions.
+
+use zcash_tachyon::TachyonBundle;
+
+use crate::memory::{inline_size_bytes, vec_capacity_bytes, AttributedMemorySize};
+
+/// A non-empty Tachyon bundle.
+///
+/// `TachyonBundle::NoBundle` is represented by `None` on [`super::Transaction::V7`].
+#[derive(Clone, Debug)]
+pub struct TachyonShieldedData(pub TachyonBundle);
+
+impl TachyonShieldedData {
+    /// Returns the bundle's actions.
+    pub fn actions(&self) -> &[zcash_tachyon::Action] {
+        match &self.0 {
+            TachyonBundle::NoBundle => &[],
+            TachyonBundle::Proven(bundle) => &bundle.actions,
+            TachyonBundle::Adjunct(bundle) => &bundle.actions,
+        }
+    }
+
+    /// Returns the bundle's value balance.
+    pub fn value_balance(&self) -> zcash_tachyon::value::Balance {
+        match &self.0 {
+            TachyonBundle::NoBundle => zcash_tachyon::value::Balance::ZERO,
+            TachyonBundle::Proven(bundle) => bundle.value_balance,
+            TachyonBundle::Adjunct(bundle) => bundle.value_balance,
+        }
+    }
+}
+
+impl From<TachyonBundle> for TachyonShieldedData {
+    fn from(bundle: TachyonBundle) -> Self {
+        Self(bundle)
+    }
+}
+
+impl PartialEq for TachyonShieldedData {
+    fn eq(&self, other: &Self) -> bool {
+        let mut self_bytes = Vec::new();
+        let mut other_bytes = Vec::new();
+        self.0
+            .write(&mut self_bytes)
+            .expect("serializing a Tachyon bundle into a Vec is infallible");
+        other
+            .0
+            .write(&mut other_bytes)
+            .expect("serializing a Tachyon bundle into a Vec is infallible");
+        self_bytes == other_bytes
+    }
+}
+
+impl Eq for TachyonShieldedData {}
+
+impl AttributedMemorySize for TachyonShieldedData {
+    fn attributed_memory_size_bytes(&self) -> u64 {
+        let bundle = match &self.0 {
+            TachyonBundle::NoBundle => return 0,
+            TachyonBundle::Proven(bundle) => bundle,
+            TachyonBundle::Adjunct(bundle) => {
+                return vec_capacity_bytes(&bundle.actions)
+                    .saturating_add(vec_capacity_bytes(&bundle.memo));
+            }
+        };
+
+        vec_capacity_bytes(&bundle.actions)
+            .saturating_add(vec_capacity_bytes(&bundle.memo))
+            .saturating_add(
+                u64::try_from(bundle.stamp.tachygrams.len())
+                    .unwrap_or(u64::MAX)
+                    .saturating_mul(inline_size_bytes::<zcash_tachyon::Tachygram>()),
+            )
+            .saturating_add(
+                u64::try_from(std::mem::size_of_val(bundle.stamp.proof.as_ref()))
+                    .unwrap_or(u64::MAX),
+            )
+    }
+}
+
+#[cfg(any(test, feature = "proptest-impl"))]
+impl serde::Serialize for TachyonShieldedData {
+    fn serialize<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        use serde::ser::Error as _;
+
+        let mut bytes = Vec::new();
+        self.0.write(&mut bytes).map_err(S::Error::custom)?;
+        serde::Serialize::serialize(&bytes, serializer)
+    }
+}
diff --git a/crates/zakura-chain/src/transaction/tests.rs b/crates/zakura-chain/src/transaction/tests.rs
index ccb1591e09..83d84a24d8 100644
--- a/crates/zakura-chain/src/transaction/tests.rs
+++ b/crates/zakura-chain/src/transaction/tests.rs
@@ -3,4 +3,6 @@
 mod ironwood_v6_tx_hash;
 mod preallocate;
 mod prop;
+#[cfg(zcash_unstable = "nutachyon")]
+mod v7_vectors;
 mod vectors;
diff --git a/crates/zakura-chain/src/transaction/tests/v7_vectors.rs b/crates/zakura-chain/src/transaction/tests/v7_vectors.rs
new file mode 100644
index 0000000000..82a4e5f2a0
--- /dev/null
+++ b/crates/zakura-chain/src/transaction/tests/v7_vectors.rs
@@ -0,0 +1,255 @@
+//! V7 transaction fixtures and cross-implementation serialization vectors.
+
+use group::{
+    ff::{FromUniformBytes, PrimeField},
+    CurveAffine, GroupEncoding,
+};
+use halo2::pasta::pallas;
+use reddsa::{orchard::SpendAuth, SigningKey, VerificationKey};
+use zcash_tachyon::{
+    Action, Anchor, Bundle, PointerStamp, ProofStamp, Tachygram, TachygramSetPoly, TachyonBundle,
+};
+
+use crate::{
+    block::Height,
+    parameters::{NetworkUpgrade, TX_V7_VERSION_GROUP_ID},
+    serialization::{SerializationError, ZcashDeserialize, ZcashSerialize},
+    transaction::{LockTime, TachyonShieldedData, Transaction},
+};
+
+fn action_with_seed(seed: u8, signature_byte: u8) -> Action {
+    let signing_key = SigningKey::<SpendAuth>::try_from(
+        pallas::Scalar::from_uniform_bytes(&[seed; 64]).to_repr(),
+    )
+    .expect("the reduced scalar is a valid signing key");
+    let verification_key = VerificationKey::<SpendAuth>::from(&signing_key);
+    let verification_key = Option::<pallas::Affine>::from(pallas::Affine::from_bytes(
+        &<[u8; 32]>::from(verification_key),
+    ))
+    .expect("the verification key is a valid curve point");
+
+    Action {
+        cv: zcash_tachyon::value::Commitment::from(pallas::Affine::generator()),
+        rk: zcash_tachyon::keys::public::ActionVerificationKey::try_from(verification_key)
+            .expect("a non-identity verification key is valid"),
+        sig: zcash_tachyon::action::Signature::read(&[signature_byte; 64][..])
+            .expect("test signature bytes are canonical"),
+    }
+}
+
+fn default_anchor() -> Anchor {
+    Anchor::read(&[0; 64][..]).expect("64 zero bytes encode the default Tachyon anchor")
+}
+
+fn tachygram(seed: u8) -> Tachygram {
+    Tachygram::from(pallas::Base::from_uniform_bytes(&[seed; 64]))
+}
+
+fn transaction_with_tachyon_bundle(bundle: TachyonBundle) -> Transaction {
+    let tachyon_shielded_data = (!bundle.is_no_bundle()).then_some(TachyonShieldedData(bundle));
+
+    Transaction::V7 {
+        network_upgrade: NetworkUpgrade::NuTachyon,
+        lock_time: LockTime::unlocked(),
+        expiry_height: Height(0),
+        inputs: Vec::new(),
+        outputs: Vec::new(),
+        sapling_shielded_data: None,
+        orchard_shielded_data: None,
+        ironwood_shielded_data: None,
+        tachyon_shielded_data,
+    }
+}
+
+fn empty_transaction() -> Transaction {
+    transaction_with_tachyon_bundle(TachyonBundle::NoBundle)
+}
+
+fn adjunct_transaction() -> Transaction {
+    transaction_with_tachyon_bundle(TachyonBundle::Adjunct(Bundle {
+        actions: vec![action_with_seed(0x42, 0x01)],
+        value_balance: zcash_tachyon::value::Balance::ZERO,
+        binding_sig: zcash_tachyon::bundle::Signature::read(&[0x02; 64][..])
+            .expect("test signature bytes are canonical"),
+        memo: Vec::new(),
+        stamp: PointerStamp::try_from([0xEE; 64])
+            .expect("a 64-byte witnessed transaction ID is valid"),
+    }))
+}
+
+fn proven_transaction() -> Transaction {
+    let tachygram = tachygram(0xAA);
+
+    transaction_with_tachyon_bundle(TachyonBundle::Proven(Bundle {
+        actions: vec![action_with_seed(0x42, 0x01)],
+        value_balance: zcash_tachyon::value::Balance::try_from(100i64)
+            .expect("100 is a valid Tachyon value balance"),
+        binding_sig: zcash_tachyon::bundle::Signature::read(&[0x02; 64][..])
+            .expect("test signature bytes are canonical"),
+        memo: Vec::new(),
+        stamp: ProofStamp {
+            coverage: [0; 32],
+            tachygram_set: [tachygram]
+                .into_iter()
+                .collect::<TachygramSetPoly>()
+                .commit(),
+            tachygrams: [tachygram].into_iter().collect(),
+            anchor: default_anchor(),
+            proof: Box::new(ragu::Proof::trivial()),
+        },
+    }))
+}
+
+fn multi_action_proven_transaction() -> Transaction {
+    let tachygrams = [tachygram(0xAA), tachygram(0xCC), tachygram(0xDD)];
+
+    transaction_with_tachyon_bundle(TachyonBundle::Proven(Bundle {
+        actions: vec![action_with_seed(0x42, 0x01), action_with_seed(0x43, 0x03)],
+        value_balance: zcash_tachyon::value::Balance::try_from(300i64)
+            .expect("300 is a valid Tachyon value balance"),
+        binding_sig: zcash_tachyon::bundle::Signature::read(&[0x02; 64][..])
+            .expect("test signature bytes are canonical"),
+        memo: Vec::new(),
+        stamp: ProofStamp {
+            coverage: [0; 32],
+            tachygram_set: tachygrams
+                .into_iter()
+                .collect::<TachygramSetPoly>()
+                .commit(),
+            tachygrams: tachygrams.into_iter().collect(),
+            anchor: default_anchor(),
+            proof: Box::new(ragu::Proof::trivial()),
+        },
+    }))
+}
+
+fn fixtures() -> [(&'static str, Transaction); 4] {
+    [
+        ("V7_EMPTY", empty_transaction()),
+        ("V7_TACHYON_ADJUNCT", adjunct_transaction()),
+        ("V7_TACHYON_PROVEN", proven_transaction()),
+        (
+            "V7_TACHYON_MULTI_ACTION_PROVEN",
+            multi_action_proven_transaction(),
+        ),
+    ]
+}
+
+#[test]
+fn v7_is_nu_tachyon_gated_and_matches_zakura_primitives() {
+    let _init_guard = zakura_test::init();
+
+    assert_eq!(
+        TX_V7_VERSION_GROUP_ID,
+        zcash_protocol::constants::V7_VERSION_GROUP_ID,
+    );
+    assert_eq!(
+        TX_V7_VERSION_GROUP_ID,
+        zcash_primitives::transaction::TxVersion::V7.version_group_id(),
+    );
+
+    let pre_nu_tachyon = Transaction::V7 {
+        network_upgrade: NetworkUpgrade::Nu6_3,
+        lock_time: LockTime::unlocked(),
+        expiry_height: Height(0),
+        inputs: Vec::new(),
+        outputs: Vec::new(),
+        sapling_shielded_data: None,
+        orchard_shielded_data: None,
+        ironwood_shielded_data: None,
+        tachyon_shielded_data: None,
+    };
+    pre_nu_tachyon
+        .zcash_serialize_to_vec()
+        .expect_err("V7 must not serialize before NuTachyon");
+
+    let transaction = empty_transaction();
+    let bytes = transaction
+        .zcash_serialize_to_vec()
+        .expect("an empty NuTachyon V7 transaction has a valid wire encoding");
+    assert_eq!(&bytes[0..4], &[0x07, 0x00, 0x00, 0x80]);
+    assert_eq!(&bytes[4..8], &TX_V7_VERSION_GROUP_ID.to_le_bytes());
+    assert_eq!(&bytes[8..12], &0xffff_fffcu32.to_le_bytes());
+    assert_eq!(transaction.version_group_id(), Some(TX_V7_VERSION_GROUP_ID));
+
+    let decoded = Transaction::zcash_deserialize(&bytes[..])
+        .expect("Zakura must deserialize its NuTachyon V7 encoding");
+    assert_eq!(decoded, transaction);
+    let zakura_primitives_transaction = transaction
+        .to_librustzcash(NetworkUpgrade::NuTachyon)
+        .expect("zakura-primitives must accept Zakura's NuTachyon V7 encoding");
+    assert_eq!(
+        transaction.hash().0,
+        *zakura_primitives_transaction.txid().as_ref()
+    );
+    let zakura_primitives_auth_digest: [u8; 32] = zakura_primitives_transaction
+        .auth_commitment()
+        .as_ref()
+        .try_into()
+        .expect("the authorizing-data digest is 32 bytes");
+    assert_eq!(
+        transaction
+            .auth_digest()
+            .expect("V7 transactions have an authorizing-data digest")
+            .0,
+        zakura_primitives_auth_digest,
+    );
+
+    let mut pre_nu_tachyon_bytes = bytes;
+    let nu6_3_branch_id = u32::from(
+        NetworkUpgrade::Nu6_3
+            .branch_id()
+            .expect("NU6.3 has a branch ID"),
+    );
+    pre_nu_tachyon_bytes[8..12].copy_from_slice(&nu6_3_branch_id.to_le_bytes());
+    let error = Transaction::zcash_deserialize(&pre_nu_tachyon_bytes[..])
+        .expect_err("V7 must not deserialize with a pre-NuTachyon branch ID");
+    assert!(matches!(
+        error,
+        SerializationError::Parse(message) if message.contains("NuTachyon")
+    ));
+}
+
+#[test]
+fn v7_tachyon_fixtures_round_trip() {
+    let _init_guard = zakura_test::init();
+
+    for (name, transaction) in fixtures() {
+        let bytes = transaction
+            .zcash_serialize_to_vec()
+            .unwrap_or_else(|error| panic!("{name} serialization failed: {error}"));
+        let decoded = Transaction::zcash_deserialize(&bytes[..])
+            .unwrap_or_else(|error| panic!("{name} deserialization failed: {error}"));
+        let reencoded = decoded
+            .zcash_serialize_to_vec()
+            .unwrap_or_else(|error| panic!("{name} reserialization failed: {error}"));
+
+        assert_eq!(decoded, transaction, "{name} round-trip mismatch");
+        assert_eq!(reencoded, bytes, "{name} reserialization differs");
+        assert_eq!(decoded.hash(), transaction.hash(), "{name} txid differs");
+        assert_eq!(
+            decoded.auth_digest(),
+            transaction.auth_digest(),
+            "{name} authorization digest differs"
+        );
+    }
+}
+
+/// Prints the canonical encodings consumed by `zakura-primitives` tests.
+#[test]
+#[ignore = "prints V7 serialization vectors for zakura-primitives"]
+#[allow(clippy::print_stdout)]
+fn generate_v7_tachyon_serialization_vectors() {
+    let _init_guard = zakura_test::init();
+
+    for (name, transaction) in fixtures() {
+        let bytes = transaction
+            .zcash_serialize_to_vec()
+            .unwrap_or_else(|error| panic!("{name} serialization failed: {error}"));
+        let decoded = Transaction::zcash_deserialize(&bytes[..])
+            .unwrap_or_else(|error| panic!("{name} deserialization failed: {error}"));
+
+        assert_eq!(decoded, transaction, "{name} round-trip mismatch");
+        println!("{name}={}", hex::encode(bytes));
+    }
+}
diff --git a/crates/zakura-chain/src/transaction/tests/vectors.rs b/crates/zakura-chain/src/transaction/tests/vectors.rs
index 53e6407a2b..4834df0304 100644
--- a/crates/zakura-chain/src/transaction/tests/vectors.rs
+++ b/crates/zakura-chain/src/transaction/tests/vectors.rs
@@ -1745,6 +1745,38 @@ fn binding_signatures() {
                             )
                             .expect("a valid redjubjub::VerificationKey");
 
+                            bvk.verify(sighash.as_ref(), &sapling_shielded_data.binding_sig)
+                                .expect("verification passes");
+                        }
+                    }
+                    #[cfg(zcash_unstable = "nutachyon")]
+                    Transaction::V7 {
+                        sapling_shielded_data,
+                        ..
+                    } => {
+                        if let Some(sapling_shielded_data) = sapling_shielded_data {
+                            // V6 txs have the outputs spent by their transparent inputs hashed into
+                            // their SIGHASH, so we need to exclude txs with transparent inputs.
+                            //
+                            // References:
+                            //
+                            // <https://zips.z.cash/zip-0244#s-2c-amounts-sig-digest>
+                            // <https://zips.z.cash/zip-0244#s-2d-scriptpubkeys-sig-digest>
+                            if tx.has_transparent_inputs() {
+                                continue;
+                            }
+
+                            let sighash = tx
+                                .sighash(nu, HashType::ALL, Arc::new(Vec::new()), None)
+                                .expect("network upgrade is valid for tx");
+
+                            let bvk = redjubjub::VerificationKey::try_from(
+                                sapling_shielded_data
+                                    .binding_verification_key()
+                                    .expect("test transaction has valid value commitments"),
+                            )
+                            .expect("a valid redjubjub::VerificationKey");
+
                             bvk.verify(sighash.as_ref(), &sapling_shielded_data.binding_sig)
                                 .expect("verification passes");
                         }
diff --git a/crates/zakura-chain/src/transaction/txid.rs b/crates/zakura-chain/src/transaction/txid.rs
index 1b7033dae4..ad1b3ffbe5 100644
--- a/crates/zakura-chain/src/transaction/txid.rs
+++ b/crates/zakura-chain/src/transaction/txid.rs
@@ -6,7 +6,7 @@ use crate::serialization::{sha256d, ZcashSerialize};
 
 /// A Transaction ID builder. It computes the transaction ID by hashing
 /// different parts of the transaction, depending on the transaction version.
-/// For V5 and V6 transactions, it follows [ZIP-244] and [ZIP-225].
+/// For V5 and later transactions, it follows [ZIP-244] and [ZIP-225].
 ///
 /// [ZIP-244]: https://zips.z.cash/zip-0244
 /// [ZIP-225]: https://zips.z.cash/zip-0225
@@ -29,6 +29,8 @@ impl<'a> TxIdBuilder<'a> {
             | Transaction::V4 { .. } => self.txid_v1_to_v4(),
             Transaction::V5 { .. } => self.txid_v5(),
             Transaction::V6 { .. } => self.txid_v6(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => self.txid_v6(),
         }
     }
 
@@ -40,7 +42,7 @@ impl<'a> TxIdBuilder<'a> {
         Some(Hash(hash_writer.finish()))
     }
 
-    /// Compute the Transaction ID for a V5 or V6 transaction.
+    /// Compute the Transaction ID for a V5 or later transaction.
     /// In this case it's the hash of a tree of hashes of specific parts of the
     /// transaction, as specified in ZIP-244 and ZIP-225.
     fn txid_v5(self) -> Option<Hash> {
@@ -56,7 +58,7 @@ impl<'a> TxIdBuilder<'a> {
         Some(Hash(*self.trans.to_librustzcash(nu).ok()?.txid().as_ref()))
     }
 
-    /// Passthrough to the ZIP-244 txid path for V6 transactions.
+    /// Passthrough to the ZIP-244 txid path for V6 and V7 transactions.
     fn txid_v6(self) -> Option<Hash> {
         self.txid_v5()
     }
diff --git a/crates/zakura-chain/src/transaction/unmined.rs b/crates/zakura-chain/src/transaction/unmined.rs
index a899963484..e3acc4cc0f 100644
--- a/crates/zakura-chain/src/transaction/unmined.rs
+++ b/crates/zakura-chain/src/transaction/unmined.rs
@@ -1,8 +1,8 @@
 //! Unmined Zcash transaction identifiers and transactions.
 //!
-//! Transaction versions 5 and 6 are uniquely identified by [`WtxId`] when
+//! Transaction versions 5 and later are uniquely identified by [`WtxId`] when
 //! unmined, and [`struct@Hash`] in the blockchain. The effects of a v5 or
-//! v6 transaction (spends and outputs) are uniquely identified by the same
+//! v5+ transaction (spends and outputs) are uniquely identified by the same
 //! [`struct@Hash`] in both cases.
 //!
 //! Transaction versions 1-4 are uniquely identified by legacy
@@ -98,8 +98,8 @@ pub enum UnminedTxId {
 
     /// A witnessed unmined transaction identifier.
     ///
-    /// Used to uniquely identify unmined version 5 and 6 transactions.
-    /// (After v5 and v6 transactions are mined, they can be uniquely identified
+    /// Used to uniquely identify unmined version 5+ transactions.
+    /// (After v5+ transactions are mined, they can be uniquely identified
     /// using only the [`struct@Hash`] in their `WtxId.id`.)
     ///
     /// For more details, see [`WtxId`].
@@ -142,6 +142,8 @@ impl From<&Transaction> for UnminedTxId {
             V1 { .. } | V2 { .. } | V3 { .. } | V4 { .. } => Legacy(transaction.into()),
             V5 { .. } => Witnessed(transaction.into()),
             V6 { .. } => Witnessed(transaction.into()),
+            #[cfg(zcash_unstable = "nutachyon")]
+            V7 { .. } => Witnessed(transaction.into()),
         }
     }
 }
diff --git a/crates/zakura-chain/src/value_balance.rs b/crates/zakura-chain/src/value_balance.rs
index b01e8f6449..c82b32af3b 100644
--- a/crates/zakura-chain/src/value_balance.rs
+++ b/crates/zakura-chain/src/value_balance.rs
@@ -18,6 +18,11 @@ mod tests;
 
 use ValueBalanceError::*;
 
+#[cfg(not(zcash_unstable = "nutachyon"))]
+const VALUE_BALANCE_BYTES: usize = 48;
+#[cfg(zcash_unstable = "nutachyon")]
+const VALUE_BALANCE_BYTES: usize = 56;
+
 /// A balance in each chain value pool or transaction value pool.
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Default)]
 pub struct ValueBalance<C> {
@@ -27,6 +32,8 @@ pub struct ValueBalance<C> {
     orchard: Amount<C>,
     deferred: Amount<C>,
     ironwood: Amount<C>,
+    #[cfg(zcash_unstable = "nutachyon")]
+    tachyon: Amount<C>,
 }
 
 impl<C> ValueBalance<C>
@@ -73,6 +80,15 @@ where
         }
     }
 
+    /// Creates a [`ValueBalance`] from the given Tachyon amount.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn from_tachyon_amount(tachyon_amount: Amount<C>) -> Self {
+        ValueBalance {
+            tachyon: tachyon_amount,
+            ..ValueBalance::zero()
+        }
+    }
+
     /// Get the transparent amount from the [`ValueBalance`].
     pub fn transparent_amount(&self) -> Amount<C> {
         self.transparent
@@ -147,6 +163,19 @@ where
         self
     }
 
+    /// Get the Tachyon amount from the [`ValueBalance`].
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_amount(&self) -> Amount<C> {
+        self.tachyon
+    }
+
+    /// Insert a Tachyon value balance without changing the other pools.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn set_tachyon_value_balance(&mut self, tachyon_value_balance: ValueBalance<C>) -> &Self {
+        self.tachyon = tachyon_value_balance.tachyon;
+        self
+    }
+
     /// Creates a [`ValueBalance`] where all the pools are zero.
     pub fn zero() -> Self {
         let zero = Amount::zero();
@@ -157,6 +186,8 @@ where
             orchard: zero,
             deferred: zero,
             ironwood: zero,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon: zero,
         }
     }
 
@@ -173,6 +204,8 @@ where
             orchard: self.orchard.constrain().map_err(Orchard)?,
             deferred: self.deferred.constrain().map_err(Deferred)?,
             ironwood: self.ironwood.constrain().map_err(Ironwood)?,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon: self.tachyon.constrain().map_err(Tachyon)?,
         })
     }
 }
@@ -199,8 +232,12 @@ impl ValueBalance<NegativeAllowed> {
         // like the orchard bundle; it is zero for transactions without an ironwood bundle.
         //
         // This will error if the remaining value in the transaction value pool is negative.
-        (self.transparent + self.sprout + self.sapling + self.orchard + self.ironwood)?
-            .constrain::<NonNegative>()
+        let remaining =
+            self.transparent + self.sprout + self.sapling + self.orchard + self.ironwood;
+        #[cfg(zcash_unstable = "nutachyon")]
+        let remaining = remaining? + self.tachyon;
+
+        remaining?.constrain::<NonNegative>()
     }
 }
 
@@ -350,10 +387,9 @@ impl ValueBalance<NonNegative> {
 
     /// To byte array
     ///
-    /// The `ironwood` pool (NU6.3 onward) is appended after `deferred`, so that records written by
-    /// earlier Zebra versions (32 bytes without `deferred`, or 40 bytes with it) remain parsable by
+    /// New pools are appended in activation order, so older records remain parsable by
     /// [`Self::from_bytes`].
-    pub fn to_bytes(self) -> [u8; 48] {
+    pub fn to_bytes(self) -> [u8; VALUE_BALANCE_BYTES] {
         match [
             self.transparent.to_bytes(),
             self.sprout.to_bytes(),
@@ -361,30 +397,33 @@ impl ValueBalance<NonNegative> {
             self.orchard.to_bytes(),
             self.deferred.to_bytes(),
             self.ironwood.to_bytes(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            self.tachyon.to_bytes(),
         ]
         .concat()
         .try_into()
         {
             Ok(bytes) => bytes,
             _ => unreachable!(
-                "six [u8; 8] should always concat with no error into a single [u8; 48]"
+                "the value balance fields should concat into the configured fixed-width array"
             ),
         }
     }
 
     /// From byte array
     ///
-    /// Accepts 32-byte (pre-`deferred`), 40-byte (pre-`ironwood`), and 48-byte records; missing
-    /// trailing pools default to zero.
+    /// Accepts 32-byte (pre-`deferred`), 40-byte (pre-`ironwood`), 48-byte (pre-`tachyon`),
+    /// and 56-byte records; missing trailing pools default to zero.
     #[allow(clippy::unwrap_in_result)]
     pub fn from_bytes(bytes: &[u8]) -> Result<ValueBalance<NonNegative>, ValueBalanceError> {
         let bytes_length = bytes.len();
 
         // Return an error early if bytes don't have the right length instead of panicking later.
-        match bytes_length {
-            32 | 40 | 48 => {}
-            _ => return Err(Unparsable),
-        };
+        let valid_length = matches!(bytes_length, 32 | 40 | 48)
+            || cfg!(zcash_unstable = "nutachyon") && bytes_length == 56;
+        if !valid_length {
+            return Err(Unparsable);
+        }
 
         let transparent = Amount::from_bytes(
             bytes[0..8]
@@ -416,7 +455,7 @@ impl ValueBalance<NonNegative> {
 
         let deferred = match bytes_length {
             32 => Amount::zero(),
-            40 | 48 => Amount::from_bytes(
+            40 | 48 | 56 => Amount::from_bytes(
                 bytes[32..40]
                     .try_into()
                     .expect("deferred amount should be parsable"),
@@ -427,7 +466,7 @@ impl ValueBalance<NonNegative> {
 
         let ironwood = match bytes_length {
             32 | 40 => Amount::zero(),
-            48 => Amount::from_bytes(
+            48 | 56 => Amount::from_bytes(
                 bytes[40..48]
                     .try_into()
                     .expect("ironwood amount should be parsable"),
@@ -436,6 +475,18 @@ impl ValueBalance<NonNegative> {
             _ => return Err(Unparsable),
         };
 
+        #[cfg(zcash_unstable = "nutachyon")]
+        let tachyon = match bytes_length {
+            32 | 40 | 48 => Amount::zero(),
+            56 => Amount::from_bytes(
+                bytes[48..56]
+                    .try_into()
+                    .expect("tachyon amount should be parsable"),
+            )
+            .map_err(Tachyon)?,
+            _ => return Err(Unparsable),
+        };
+
         Ok(ValueBalance {
             transparent,
             sprout,
@@ -443,6 +494,8 @@ impl ValueBalance<NonNegative> {
             orchard,
             deferred,
             ironwood,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon,
         })
     }
 }
@@ -468,6 +521,10 @@ pub enum ValueBalanceError {
     /// ironwood amount error {0}
     Ironwood(amount::Error),
 
+    /// Tachyon amount error {0}
+    #[cfg(zcash_unstable = "nutachyon")]
+    Tachyon(amount::Error),
+
     /// ValueBalance is unparsable
     Unparsable,
 }
@@ -481,6 +538,8 @@ impl fmt::Display for ValueBalanceError {
             Orchard(e) => format!("orchard amount err: {e}"),
             Deferred(e) => format!("deferred amount err: {e}"),
             Ironwood(e) => format!("ironwood amount err: {e}"),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Tachyon(e) => format!("tachyon amount err: {e}"),
             Unparsable => "value balance is unparsable".to_string(),
         })
     }
@@ -499,6 +558,8 @@ where
             orchard: (self.orchard + rhs.orchard).map_err(Orchard)?,
             deferred: (self.deferred + rhs.deferred).map_err(Deferred)?,
             ironwood: (self.ironwood + rhs.ironwood).map_err(Ironwood)?,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon: (self.tachyon + rhs.tachyon).map_err(Tachyon)?,
         })
     }
 }
@@ -549,6 +610,8 @@ where
             orchard: (self.orchard - rhs.orchard).map_err(Orchard)?,
             deferred: (self.deferred - rhs.deferred).map_err(Deferred)?,
             ironwood: (self.ironwood - rhs.ironwood).map_err(Ironwood)?,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon: (self.tachyon - rhs.tachyon).map_err(Tachyon)?,
         })
     }
 }
@@ -619,6 +682,8 @@ where
             orchard: self.orchard.neg(),
             deferred: self.deferred.neg(),
             ironwood: self.ironwood.neg(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon: self.tachyon.neg(),
         }
     }
 }
diff --git a/crates/zakura-chain/src/value_balance/arbitrary.rs b/crates/zakura-chain/src/value_balance/arbitrary.rs
index 9cbdbeb73a..14cf1c1550 100644
--- a/crates/zakura-chain/src/value_balance/arbitrary.rs
+++ b/crates/zakura-chain/src/value_balance/arbitrary.rs
@@ -1,6 +1,38 @@
 use crate::{amount::*, value_balance::*};
 use proptest::prelude::*;
 
+#[cfg(zcash_unstable = "nutachyon")]
+impl Arbitrary for ValueBalance<NegativeAllowed> {
+    type Parameters = ();
+
+    fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy {
+        (
+            any::<Amount<NegativeAllowed>>(),
+            any::<Amount<NegativeAllowed>>(),
+            any::<Amount<NegativeAllowed>>(),
+            any::<Amount<NegativeAllowed>>(),
+            any::<Amount<NegativeAllowed>>(),
+            any::<Amount<NegativeAllowed>>(),
+            any::<Amount<NegativeAllowed>>(),
+        )
+            .prop_map(
+                |(transparent, sprout, sapling, orchard, deferred, ironwood, tachyon)| Self {
+                    transparent,
+                    sprout,
+                    sapling,
+                    orchard,
+                    deferred,
+                    ironwood,
+                    tachyon,
+                },
+            )
+            .boxed()
+    }
+
+    type Strategy = BoxedStrategy<Self>;
+}
+
+#[cfg(not(zcash_unstable = "nutachyon"))]
 impl Arbitrary for ValueBalance<NegativeAllowed> {
     type Parameters = ();
 
@@ -29,6 +61,38 @@ impl Arbitrary for ValueBalance<NegativeAllowed> {
     type Strategy = BoxedStrategy<Self>;
 }
 
+#[cfg(zcash_unstable = "nutachyon")]
+impl Arbitrary for ValueBalance<NonNegative> {
+    type Parameters = ();
+
+    fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy {
+        (
+            any::<Amount<NonNegative>>(),
+            any::<Amount<NonNegative>>(),
+            any::<Amount<NonNegative>>(),
+            any::<Amount<NonNegative>>(),
+            any::<Amount<NonNegative>>(),
+            any::<Amount<NonNegative>>(),
+            any::<Amount<NonNegative>>(),
+        )
+            .prop_map(
+                |(transparent, sprout, sapling, orchard, deferred, ironwood, tachyon)| Self {
+                    transparent,
+                    sprout,
+                    sapling,
+                    orchard,
+                    deferred,
+                    ironwood,
+                    tachyon,
+                },
+            )
+            .boxed()
+    }
+
+    type Strategy = BoxedStrategy<Self>;
+}
+
+#[cfg(not(zcash_unstable = "nutachyon"))]
 impl Arbitrary for ValueBalance<NonNegative> {
     type Parameters = ();
 
diff --git a/crates/zakura-chain/src/value_balance/tests/prop.rs b/crates/zakura-chain/src/value_balance/tests/prop.rs
index 162721e023..b703daa1d9 100644
--- a/crates/zakura-chain/src/value_balance/tests/prop.rs
+++ b/crates/zakura-chain/src/value_balance/tests/prop.rs
@@ -6,6 +6,7 @@ use crate::{amount::*, value_balance::*};
 
 proptest! {
     #[test]
+    #[cfg(zcash_unstable = "nutachyon")]
     fn value_blance_add(
         value_balance1 in any::<ValueBalance<NegativeAllowed>>(),
         value_balance2 in any::<ValueBalance<NegativeAllowed>>())
@@ -18,9 +19,10 @@ proptest! {
         let orchard = value_balance1.orchard + value_balance2.orchard;
         let deferred = value_balance1.deferred + value_balance2.deferred;
         let ironwood = value_balance1.ironwood + value_balance2.ironwood;
+        let tachyon = value_balance1.tachyon + value_balance2.tachyon;
 
-        match (transparent, sprout, sapling, orchard, deferred, ironwood) {
-            (Ok(transparent), Ok(sprout), Ok(sapling), Ok(orchard), Ok(deferred), Ok(ironwood)) => prop_assert_eq!(
+        match (transparent, sprout, sapling, orchard, deferred, ironwood, tachyon) {
+            (Ok(transparent), Ok(sprout), Ok(sapling), Ok(orchard), Ok(deferred), Ok(ironwood), Ok(tachyon)) => prop_assert_eq!(
                 value_balance1 + value_balance2,
                 Ok(ValueBalance {
                     transparent,
@@ -28,7 +30,8 @@ proptest! {
                     sapling,
                     orchard,
                     deferred,
-                    ironwood
+                    ironwood,
+                    tachyon
                 })
             ),
             _ => prop_assert!(
@@ -39,12 +42,14 @@ proptest! {
                         | ValueBalanceError::Sapling(_)
                         | ValueBalanceError::Orchard(_)
                         | ValueBalanceError::Deferred(_)
-                        | ValueBalanceError::Ironwood(_))
+                        | ValueBalanceError::Ironwood(_)
+                        | ValueBalanceError::Tachyon(_))
                 )
             ),
         }
     }
     #[test]
+    #[cfg(zcash_unstable = "nutachyon")]
     fn value_balance_sub(
         value_balance1 in any::<ValueBalance<NegativeAllowed>>(),
         value_balance2 in any::<ValueBalance<NegativeAllowed>>())
@@ -57,9 +62,10 @@ proptest! {
         let orchard = value_balance1.orchard - value_balance2.orchard;
         let deferred = value_balance1.deferred - value_balance2.deferred;
         let ironwood = value_balance1.ironwood - value_balance2.ironwood;
+        let tachyon = value_balance1.tachyon - value_balance2.tachyon;
 
-        match (transparent, sprout, sapling, orchard, deferred, ironwood) {
-            (Ok(transparent), Ok(sprout), Ok(sapling), Ok(orchard), Ok(deferred), Ok(ironwood)) => prop_assert_eq!(
+        match (transparent, sprout, sapling, orchard, deferred, ironwood, tachyon) {
+            (Ok(transparent), Ok(sprout), Ok(sapling), Ok(orchard), Ok(deferred), Ok(ironwood), Ok(tachyon)) => prop_assert_eq!(
                 value_balance1 - value_balance2,
                 Ok(ValueBalance {
                     transparent,
@@ -67,7 +73,8 @@ proptest! {
                     sapling,
                     orchard,
                     deferred,
-                    ironwood
+                    ironwood,
+                    tachyon
                 })
             ),
             _ => prop_assert!(matches!(
@@ -77,12 +84,14 @@ proptest! {
                         | ValueBalanceError::Sapling(_)
                         | ValueBalanceError::Orchard(_)
                         | ValueBalanceError::Deferred(_)
-                        | ValueBalanceError::Ironwood(_))
+                        | ValueBalanceError::Ironwood(_)
+                        | ValueBalanceError::Tachyon(_))
                 )),
         }
     }
 
     #[test]
+    #[cfg(zcash_unstable = "nutachyon")]
     fn value_balance_sum(
         value_balance1 in any::<ValueBalance<NegativeAllowed>>(),
         value_balance2 in any::<ValueBalance<NegativeAllowed>>(),
@@ -97,9 +106,10 @@ proptest! {
         let orchard = value_balance1.orchard + value_balance2.orchard;
         let deferred = value_balance1.deferred + value_balance2.deferred;
         let ironwood = value_balance1.ironwood + value_balance2.ironwood;
+        let tachyon = value_balance1.tachyon + value_balance2.tachyon;
 
-        match (transparent, sprout, sapling, orchard, deferred, ironwood) {
-            (Ok(transparent), Ok(sprout), Ok(sapling), Ok(orchard), Ok(deferred), Ok(ironwood)) => prop_assert_eq!(
+        match (transparent, sprout, sapling, orchard, deferred, ironwood, tachyon) {
+            (Ok(transparent), Ok(sprout), Ok(sapling), Ok(orchard), Ok(deferred), Ok(ironwood), Ok(tachyon)) => prop_assert_eq!(
                 collection.iter().sum::<Result<ValueBalance<NegativeAllowed>, ValueBalanceError>>(),
                 Ok(ValueBalance {
                     transparent,
@@ -107,7 +117,8 @@ proptest! {
                     sapling,
                     orchard,
                     deferred,
-                    ironwood
+                    ironwood,
+                    tachyon
                 })
             ),
             _ => prop_assert!(matches!(
@@ -117,7 +128,8 @@ proptest! {
                         | ValueBalanceError::Sapling(_)
                         | ValueBalanceError::Orchard(_)
                         | ValueBalanceError::Deferred(_)
-                        | ValueBalanceError::Ironwood(_))
+                        | ValueBalanceError::Ironwood(_)
+                        | ValueBalanceError::Tachyon(_))
                  ))
         }
     }
@@ -132,7 +144,8 @@ proptest! {
     }
 
     #[test]
-    fn value_balance_deserialization(bytes in any::<[u8; 48]>()) {
+    #[cfg(zcash_unstable = "nutachyon")]
+    fn value_balance_deserialization(bytes in any::<[u8; 56]>()) {
         let _init_guard = zakura_test::init();
 
         if let Ok(deserialized) = ValueBalance::<NonNegative>::from_bytes(&bytes) {
@@ -140,7 +153,7 @@ proptest! {
         }
     }
 
-    /// The legacy version of [`ValueBalance`] had 32 bytes compared to the current 48 bytes,
+    /// The legacy version of [`ValueBalance`] had 32 bytes compared to the current 56 bytes,
     /// but it's possible to correctly instantiate the current version of [`ValueBalance`] from
     /// the legacy format, so we test if Zebra can still deserialize the legacy format.
     #[test]
@@ -149,7 +162,7 @@ proptest! {
 
         if let Ok(deserialized) = ValueBalance::<NonNegative>::from_bytes(&bytes) {
             let deserialized = deserialized.to_bytes();
-            let mut extended_bytes = [0u8; 48];
+            let mut extended_bytes = [0u8; VALUE_BALANCE_BYTES];
             extended_bytes[..32].copy_from_slice(&bytes);
             prop_assert_eq!(extended_bytes, deserialized);
         }
@@ -165,10 +178,24 @@ proptest! {
 
         if let Ok(deserialized) = ValueBalance::<NonNegative>::from_bytes(&bytes) {
             let deserialized = deserialized.to_bytes();
-            let mut extended_bytes = [0u8; 48];
+            let mut extended_bytes = [0u8; VALUE_BALANCE_BYTES];
             extended_bytes[..40].copy_from_slice(&bytes);
             prop_assert_eq!(extended_bytes, deserialized);
         }
     }
 
+    /// The pre-Tachyon value balance was a 48-byte prefix of the current format.
+    #[test]
+    #[cfg(zcash_unstable = "nutachyon")]
+    fn pre_tachyon_value_balance_deserialization(bytes in any::<[u8; 48]>()) {
+        let _init_guard = zakura_test::init();
+
+        if let Ok(deserialized) = ValueBalance::<NonNegative>::from_bytes(&bytes) {
+            let deserialized = deserialized.to_bytes();
+            let mut extended_bytes = [0u8; 56];
+            extended_bytes[..48].copy_from_slice(&bytes);
+            prop_assert_eq!(extended_bytes, deserialized);
+        }
+    }
+
 }
diff --git a/crates/zakura-consensus/Cargo.toml b/crates/zakura-consensus/Cargo.toml
index b79c398e01..a36b20df8a 100644
--- a/crates/zakura-consensus/Cargo.toml
+++ b/crates/zakura-consensus/Cargo.toml
@@ -82,6 +82,12 @@ howudoin = { workspace = true, optional = true }
 proptest = { workspace = true, optional = true }
 proptest-derive = { workspace = true, optional = true }
 
+[target.'cfg(zcash_unstable = "nutachyon")'.dependencies]
+zcash_tachyon.workspace = true
+
+[target.'cfg(zcash_unstable = "nutachyon")'.dev-dependencies]
+ragu = { workspace = true }
+
 [dev-dependencies]
 color-eyre = { workspace = true }
 
diff --git a/crates/zakura-consensus/src/block.rs b/crates/zakura-consensus/src/block.rs
index 565db91780..1b1a576edc 100644
--- a/crates/zakura-consensus/src/block.rs
+++ b/crates/zakura-consensus/src/block.rs
@@ -36,6 +36,8 @@ use crate::{error::*, primitives, transaction as tx, BoxError};
 pub mod check;
 pub mod request;
 pub mod subsidy;
+#[cfg(zcash_unstable = "nutachyon")]
+pub(crate) mod tachyon;
 
 pub use request::Request;
 
@@ -125,6 +127,22 @@ impl VerifyBlockError {
                     consensus("block.too_many_transparent_signature_operations")
                 }
                 BlockError::SummingMinerFees { .. } => consensus("block.summing_miner_fees"),
+                #[cfg(zcash_unstable = "nutachyon")]
+                BlockError::DuplicateTachygram => consensus("block.duplicate_tachygram"),
+                #[cfg(zcash_unstable = "nutachyon")]
+                BlockError::TachyonAggregateNotFound => {
+                    consensus("block.tachyon_aggregate_not_found")
+                }
+                #[cfg(zcash_unstable = "nutachyon")]
+                BlockError::TachyonCoverageMismatch => consensus("block.tachyon_coverage_mismatch"),
+                #[cfg(zcash_unstable = "nutachyon")]
+                BlockError::TachyonDuplicateAction => consensus("block.tachyon_duplicate_action"),
+                #[cfg(zcash_unstable = "nutachyon")]
+                BlockError::TachyonTachygramArityMismatch => {
+                    consensus("block.tachyon_tachygram_arity_mismatch")
+                }
+                #[cfg(zcash_unstable = "nutachyon")]
+                BlockError::TachyonProofInvalid(_) => consensus("block.tachyon_proof_invalid"),
                 BlockError::InvalidHeaderEncoding(_)
                 | BlockError::MissingHeight(_)
                 | BlockError::MaxHeight(_, _, _)
@@ -317,6 +335,12 @@ where
 
             check::merkle_root_validity(&network, &block, &transaction_hashes)?;
 
+            #[cfg(zcash_unstable = "nutachyon")]
+            let mut tachyon_checks = tachyon::coherence(&block)?
+                .into_iter()
+                .map(primitives::tachyon::verify_proof_stamp)
+                .collect::<FuturesUnordered<_>>();
+
             // Since errors cause an early exit, try to do the
             // quick checks first.
 
@@ -403,6 +427,11 @@ where
 
             // Check the summed block totals
 
+            #[cfg(zcash_unstable = "nutachyon")]
+            while let Some(result) = tachyon_checks.next().await {
+                result?;
+            }
+
             if sigops > MAX_BLOCK_SIGOPS {
                 Err(BlockError::TooManyTransparentSignatureOperations {
                     height,
diff --git a/crates/zakura-consensus/src/block/tachyon.rs b/crates/zakura-consensus/src/block/tachyon.rs
new file mode 100644
index 0000000000..b6c84021c5
--- /dev/null
+++ b/crates/zakura-consensus/src/block/tachyon.rs
@@ -0,0 +1,84 @@
+//! Block-level Tachyon consensus rules.
+
+use std::collections::{BTreeSet, HashMap};
+
+use zakura_chain::{block::Block, transaction::WtxId};
+use zcash_tachyon::{
+    stamp::StampState as _, Bundle, PointerStamp, ProofStamp, Tachygram, TachyonBundle,
+    VerifyCoverageError,
+};
+
+use crate::error::BlockError;
+
+#[cfg(test)]
+mod tests;
+
+/// A proof-stamped bundle and the pointer-stamped bundles it covers.
+#[derive(Debug)]
+pub(crate) struct AggregateCoverage {
+    pub bundle: Bundle<ProofStamp>,
+    pub adjuncts: Vec<Bundle<PointerStamp>>,
+}
+
+/// Checks block-wide Tachygram distinctness and aggregate coverage coherence.
+pub(crate) fn coherence(block: &Block) -> Result<Vec<AggregateCoverage>, BlockError> {
+    let mut seen_tachygrams = BTreeSet::<Tachygram>::new();
+    let mut aggregates = Vec::<AggregateCoverage>::new();
+    let mut aggregates_by_wtxid = HashMap::<[u8; 64], usize>::new();
+    let mut adjuncts = Vec::<([u8; 64], Bundle<PointerStamp>)>::new();
+
+    for transaction in &block.transactions {
+        let Some(tachyon_shielded_data) = transaction.tachyon_shielded_data() else {
+            continue;
+        };
+
+        match &tachyon_shielded_data.0 {
+            TachyonBundle::NoBundle => {}
+            TachyonBundle::Proven(bundle) => {
+                for &tachygram in &bundle.stamp.tachygrams {
+                    if !seen_tachygrams.insert(tachygram) {
+                        return Err(BlockError::DuplicateTachygram);
+                    }
+                }
+
+                let wtxid = WtxId::from(transaction.as_ref()).as_bytes();
+                aggregates_by_wtxid.insert(wtxid, aggregates.len());
+                aggregates.push(AggregateCoverage {
+                    bundle: bundle.clone(),
+                    adjuncts: Vec::new(),
+                });
+            }
+            TachyonBundle::Adjunct(bundle) => {
+                adjuncts.push((bundle.stamp.stamp_digest(), bundle.clone()));
+            }
+        }
+    }
+
+    for (target_wtxid, bundle) in adjuncts {
+        let Some(&aggregate_index) = aggregates_by_wtxid.get(&target_wtxid) else {
+            return Err(BlockError::TachyonAggregateNotFound);
+        };
+        aggregates[aggregate_index].adjuncts.push(bundle);
+    }
+
+    for aggregate in &aggregates {
+        let adjunct_refs: Vec<_> = aggregate
+            .adjuncts
+            .iter()
+            .map(|adjunct| adjunct.as_dyn())
+            .collect();
+
+        aggregate
+            .bundle
+            .verify_coverage(&adjunct_refs)
+            .map_err(|error| match error {
+                VerifyCoverageError::DuplicateActions => BlockError::TachyonDuplicateAction,
+                VerifyCoverageError::StampActionsMismatch => BlockError::TachyonCoverageMismatch,
+                VerifyCoverageError::TachygramArityMismatch => {
+                    BlockError::TachyonTachygramArityMismatch
+                }
+            })?;
+    }
+
+    Ok(aggregates)
+}
diff --git a/crates/zakura-consensus/src/block/tachyon/tests.rs b/crates/zakura-consensus/src/block/tachyon/tests.rs
new file mode 100644
index 0000000000..e0d538094d
--- /dev/null
+++ b/crates/zakura-consensus/src/block/tachyon/tests.rs
@@ -0,0 +1,368 @@
+//! Tests for the block-level tachyon consensus rules.
+
+use std::sync::Arc;
+
+use zakura_chain::{
+    block::{Block, Height},
+    parameters::NetworkUpgrade,
+    serialization::ZcashDeserialize,
+    transaction::{LockTime, Transaction, WtxId},
+};
+
+use zcash_tachyon::{
+    action, bundle, effect,
+    entropy::ActionEntropy,
+    keys::private,
+    note::{CommitmentTrapdoor, Note},
+    nullifier, value, Anchor, Bundle, PointerStamp, ProofStamp, Tachygram, TachygramSetPoly,
+    TachyonBundle,
+};
+
+use crate::error::BlockError;
+
+use super::{coherence, AggregateCoverage};
+
+/// Computes `hStampActionsTachyon` over descriptor bytes.
+///
+/// This duplicates tachyon's private `blake2b::action_descriptor_digest` (BLAKE2b-256,
+/// personalization `Tachyon-Actions`, over the sorted concatenated 64-byte descriptors). Tests
+/// using it self-validate via [`Bundle::verify_coverage`], so drift from the tachyon crate fails
+/// loudly instead of silently testing against the wrong digest.
+fn action_descriptor_digest(descriptors: &[action::Descriptor]) -> [u8; 32] {
+    // `Vec<[u8; 64]>: FromIterator<Descriptor>` is tachyon's public descriptor-bytes conversion.
+    let mut descriptor_bytes: Vec<[u8; 64]> = descriptors.iter().copied().collect();
+    descriptor_bytes.sort_unstable();
+
+    let mut state = blake2b_simd::Params::new()
+        .hash_length(32)
+        .personal(b"Tachyon-Actions")
+        .to_state();
+    for descriptor in &descriptor_bytes {
+        state.update(descriptor);
+    }
+    state
+        .finalize()
+        .as_bytes()
+        .try_into()
+        .expect("hash length is 32")
+}
+
+/// A structurally valid action with a random `rk` and dummy signature: block-level coherence
+/// never checks signatures.
+fn dummy_action() -> zcash_tachyon::Action {
+    use halo2::pasta::group::CurveAffine;
+
+    let mut rng = rand_10::rng();
+
+    let sk = private::SpendingKey::random(&mut rng);
+    let note = Note {
+        pk: sk.derive_payment_key(),
+        value: value::Positive::try_from(100u64).expect("valid value"),
+        psi: nullifier::Trapdoor::random(&mut rng),
+        rcm: CommitmentTrapdoor::random(&mut rng),
+    };
+    let alpha = ActionEntropy::random(&mut rng).randomizer::<effect::Output>(note.commitment());
+    let rk = private::ActionSigningKey::new(&alpha).derive_action_public();
+
+    zcash_tachyon::Action {
+        cv: value::Commitment::from(halo2::pasta::pallas::Affine::generator()),
+        rk,
+        sig: action::Signature::read(&[0x01u8; 64][..]).expect("64 bytes"),
+    }
+}
+
+/// The all-zero anchor.
+fn zero_anchor() -> Anchor {
+    Anchor::read(&[0u8; 32][..]).expect("zero anchor reads")
+}
+
+/// A proof-stamped bundle with the given actions, tachygrams, and covered-actions digest.
+fn proven_bundle(
+    actions: Vec<zcash_tachyon::Action>,
+    tachygrams: Vec<Tachygram>,
+    coverage: [u8; 32],
+) -> Bundle<ProofStamp> {
+    let tachygram_set = tachygrams.iter().copied().collect::<TachygramSetPoly>();
+    Bundle {
+        actions,
+        value_balance: value::Balance::ZERO,
+        binding_sig: bundle::Signature::read(&[0x02u8; 64][..]).expect("64 bytes"),
+        memo: Vec::new(),
+        stamp: ProofStamp {
+            coverage,
+            tachygram_set: tachygram_set.commit(),
+            tachygrams: tachygrams.into_iter().collect(),
+            anchor: zero_anchor(),
+            proof: Box::new(ragu::Proof::trivial()),
+        },
+    }
+}
+
+/// A pointer-stamped bundle with the given actions, naming `target` as its covering aggregate.
+fn adjunct_bundle(actions: Vec<zcash_tachyon::Action>, target: [u8; 64]) -> Bundle<PointerStamp> {
+    Bundle {
+        actions,
+        value_balance: value::Balance::ZERO,
+        binding_sig: bundle::Signature::read(&[0x02u8; 64][..]).expect("64 bytes"),
+        memo: Vec::new(),
+        stamp: PointerStamp::try_from(target).expect("nonzero wtxid"),
+    }
+}
+
+/// A V7 transaction carrying only the given tachyon bundle.
+fn v7_transaction(tachyon_bundle: TachyonBundle) -> Arc<Transaction> {
+    Arc::new(Transaction::V7 {
+        network_upgrade: NetworkUpgrade::NuTachyon,
+        lock_time: LockTime::min_lock_time_timestamp(),
+        expiry_height: Height(0),
+        inputs: Vec::new(),
+        outputs: Vec::new(),
+        sapling_shielded_data: None,
+        orchard_shielded_data: None,
+        ironwood_shielded_data: None,
+        tachyon_shielded_data: Some(tachyon_bundle.into()),
+    })
+}
+
+/// A block containing the given transactions (the header contents are irrelevant to coherence).
+fn block_with(transactions: Vec<Arc<Transaction>>) -> Block {
+    let template = Block::zcash_deserialize(&zakura_test::vectors::BLOCK_MAINNET_GENESIS_BYTES[..])
+        .expect("hardcoded test block deserializes");
+
+    Block {
+        header: template.header,
+        transactions,
+    }
+}
+
+fn tachygram(value: u64) -> Tachygram {
+    Tachygram::from(halo2::pasta::pallas::Base::from(value))
+}
+
+/// Rule 1: two proof stamps sharing a tachygram anywhere in the block are rejected.
+#[test]
+fn duplicate_tachygram_across_block_is_rejected() {
+    let _init_guard = zakura_test::init();
+
+    let action_a = dummy_action();
+    let action_b = dummy_action();
+    let digest_a = action_descriptor_digest(&[action_a.descriptor()]);
+    let digest_b = action_descriptor_digest(&[action_b.descriptor()]);
+
+    let block = block_with(vec![
+        v7_transaction(TachyonBundle::Proven(proven_bundle(
+            vec![action_a],
+            vec![tachygram(1), tachygram(2)],
+            digest_a,
+        ))),
+        v7_transaction(TachyonBundle::Proven(proven_bundle(
+            vec![action_b],
+            vec![tachygram(2), tachygram(3)],
+            digest_b,
+        ))),
+    ]);
+
+    assert_eq!(
+        coherence(&block).err(),
+        Some(BlockError::DuplicateTachygram)
+    );
+}
+
+/// Rule 2: a pointer stamp naming a wtxid with no proof-stamped transaction in the block is
+/// rejected.
+#[test]
+fn pointer_to_missing_aggregate_is_rejected() {
+    let _init_guard = zakura_test::init();
+
+    let block = block_with(vec![v7_transaction(TachyonBundle::Adjunct(
+        adjunct_bundle(vec![dummy_action()], [0xEEu8; 64]),
+    ))]);
+
+    assert_eq!(
+        coherence(&block).err(),
+        Some(BlockError::TachyonAggregateNotFound)
+    );
+}
+
+/// Rule 3: a proof stamp whose carried covered-actions digest doesn't match its actions is
+/// rejected.
+#[test]
+fn coverage_mismatch_is_rejected() {
+    let _init_guard = zakura_test::init();
+
+    let block = block_with(vec![v7_transaction(TachyonBundle::Proven(proven_bundle(
+        vec![dummy_action()],
+        vec![],
+        // Deliberately not the digest of the bundle's actions.
+        [0u8; 32],
+    )))]);
+
+    assert_eq!(
+        coherence(&block).err(),
+        Some(BlockError::TachyonCoverageMismatch)
+    );
+}
+
+/// Rule 3: the same action descriptor covered twice (in the aggregate and in an adjunct naming
+/// it) is rejected, even with a digest computed over the duplicated descriptor list.
+#[test]
+fn duplicate_covered_action_is_rejected() {
+    let _init_guard = zakura_test::init();
+
+    let action = dummy_action();
+    let covered_digest = action_descriptor_digest(&[action.descriptor(), action.descriptor()]);
+    let aggregate_tx = v7_transaction(TachyonBundle::Proven(proven_bundle(
+        vec![action],
+        vec![tachygram(1)],
+        covered_digest,
+    )));
+
+    let aggregate_wtxid = WtxId::from(aggregate_tx.as_ref()).as_bytes();
+    let adjunct_tx = v7_transaction(TachyonBundle::Adjunct(adjunct_bundle(
+        vec![action],
+        aggregate_wtxid,
+    )));
+
+    let block = block_with(vec![aggregate_tx, adjunct_tx]);
+
+    assert_eq!(
+        coherence(&block).err(),
+        Some(BlockError::TachyonDuplicateAction)
+    );
+}
+
+/// Rules 2-3 positive path: an aggregate covering its own actions plus a pointing adjunct's
+/// actions passes coherence, and the returned work item groups the adjunct with its aggregate.
+#[test]
+fn aggregate_with_adjunct_passes_coherence() {
+    let _init_guard = zakura_test::init();
+
+    let own_action = dummy_action();
+    let adjunct_action = dummy_action();
+
+    let covered_digest =
+        action_descriptor_digest(&[own_action.descriptor(), adjunct_action.descriptor()]);
+    // Two tachygrams per covered action (the aggregate's own and the adjunct's).
+    let aggregate_tx = v7_transaction(TachyonBundle::Proven(proven_bundle(
+        vec![own_action],
+        vec![tachygram(1), tachygram(2), tachygram(3), tachygram(4)],
+        covered_digest,
+    )));
+
+    let aggregate_wtxid = WtxId::from(aggregate_tx.as_ref()).as_bytes();
+    let adjunct_tx = v7_transaction(TachyonBundle::Adjunct(adjunct_bundle(
+        vec![adjunct_action],
+        aggregate_wtxid,
+    )));
+
+    // Self-validation: the hand-rolled digest must agree with tachyon's coverage check.
+    {
+        let Some(data) = aggregate_tx.tachyon_shielded_data() else {
+            panic!("aggregate transaction has a tachyon bundle");
+        };
+        let TachyonBundle::Proven(aggregate) = &data.0 else {
+            panic!("aggregate transaction bundle is proof-stamped");
+        };
+        let Some(data) = adjunct_tx.tachyon_shielded_data() else {
+            panic!("adjunct transaction has a tachyon bundle");
+        };
+        let TachyonBundle::Adjunct(adjunct) = &data.0 else {
+            panic!("adjunct transaction bundle is pointer-stamped");
+        };
+        aggregate
+            .verify_coverage(&[adjunct.as_dyn()])
+            .expect("hand-rolled action_descriptor_digest must not drift from the tachyon crate");
+    }
+
+    let block = block_with(vec![aggregate_tx, adjunct_tx]);
+
+    let aggregates = coherence(&block).expect("coherent block passes");
+    assert_eq!(aggregates.len(), 1, "one proof stamp to verify");
+    assert_eq!(
+        aggregates[0].adjuncts.len(),
+        1,
+        "the work item groups the pointing adjunct with its aggregate",
+    );
+}
+
+/// An autonome (proof-stamped bundle covering only its own actions) passes coherence by itself.
+#[test]
+fn autonome_passes_coherence() {
+    let _init_guard = zakura_test::init();
+
+    let action = dummy_action();
+    let digest = action_descriptor_digest(&[action.descriptor()]);
+
+    let block = block_with(vec![v7_transaction(TachyonBundle::Proven(proven_bundle(
+        vec![action],
+        vec![tachygram(7), tachygram(8)],
+        digest,
+    )))]);
+
+    let aggregates = coherence(&block).expect("coherent block passes");
+    assert_eq!(aggregates.len(), 1);
+    assert!(aggregates[0].adjuncts.is_empty());
+}
+
+/// Rule 4 negative path: a proof stamp with a correct covered-actions digest but an invalid
+/// (trivial mock) proof fails proof verification.
+#[tokio::test(flavor = "multi_thread")]
+async fn trivial_proof_fails_verification() {
+    let _init_guard = zakura_test::init();
+
+    let action = dummy_action();
+    let digest = action_descriptor_digest(&[action.descriptor()]);
+    let aggregate = AggregateCoverage {
+        bundle: proven_bundle(vec![action], vec![tachygram(1)], digest),
+        adjuncts: Vec::new(),
+    };
+
+    let result = crate::primitives::tachyon::verify_proof_stamp(aggregate).await;
+    assert!(
+        matches!(result, Err(BlockError::TachyonProofInvalid(_))),
+        "expected TachyonProofInvalid, got: {result:?}",
+    );
+}
+
+/// Rule 4 positive path: a genuinely proven (mock proof system) output stamp verifies.
+#[tokio::test(flavor = "multi_thread")]
+async fn real_mock_proof_passes_verification() {
+    let _init_guard = zakura_test::init();
+
+    let mut rng = rand_10::rng();
+
+    let sk = private::SpendingKey::random(&mut rng);
+    let note = Note {
+        pk: sk.derive_payment_key(),
+        value: value::Positive::try_from(100u64).expect("valid value"),
+        psi: nullifier::Trapdoor::random(&mut rng),
+        rcm: CommitmentTrapdoor::random(&mut rng),
+    };
+    let theta = ActionEntropy::random(&mut rng);
+    let rcv = value::Trapdoor::random(&mut rng);
+    let output_plan = action::Plan::output(note, theta, rcv);
+
+    let plan = bundle::Plan::new(vec![], vec![output_plan]);
+    let pak = sk.derive_proof_private();
+    let ask = sk.derive_auth_private();
+
+    let stamp = plan
+        .stamp_plan(zero_anchor())
+        .prove(&mut rng, &pak, vec![])
+        .expect("output-only stamp plan proves under the mock proof system");
+
+    // Proof verification never checks signatures, so the sighash is arbitrary here.
+    let bundle = plan
+        .sign(&mut rng, &[0u8; 32], &ask)
+        .expect("bundle plan signs")
+        .stamp(stamp);
+
+    let aggregate = AggregateCoverage {
+        bundle,
+        adjuncts: Vec::new(),
+    };
+
+    crate::primitives::tachyon::verify_proof_stamp(aggregate)
+        .await
+        .expect("a genuinely proven stamp verifies");
+}
diff --git a/crates/zakura-consensus/src/error.rs b/crates/zakura-consensus/src/error.rs
index 76e323712f..ff09f7ca20 100644
--- a/crates/zakura-consensus/src/error.rs
+++ b/crates/zakura-consensus/src/error.rs
@@ -290,6 +290,18 @@ pub enum TransactionError {
     #[error("Ironwood proof has a non-canonical size")]
     IronwoodProofSize,
 
+    #[error("Tachyon action value commitment and verification key must not be identity: {0}")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonIdentityAction(String),
+
+    #[error("Tachyon action and binding signatures must verify: {0}")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonSignatureInvalid(String),
+
+    #[error("the mempool only accepts autonome Tachyon transactions")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    NonAutonomeTachyon,
+
     #[error("unexpected error")]
     Other(String),
 }
@@ -492,6 +504,14 @@ impl TransactionError {
             Self::Balance(_) => consensus("transaction.balance"),
             Self::OrchardProofSize => consensus("transaction.orchard_proof_size"),
             Self::IronwoodProofSize => consensus("transaction.ironwood_proof_size"),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Self::TachyonIdentityAction(_) => consensus("transaction.tachyon_identity_action"),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Self::TachyonSignatureInvalid(_) => consensus("transaction.tachyon_signature_invalid"),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Self::NonAutonomeTachyon => {
+                BodyVerificationClass::Retryable(TransientBodyFailureKind::VerifierUnavailable)
+            }
             Self::ImmatureTransparentCoinbaseSpend { .. } => {
                 consensus("transaction.immature_transparent_coinbase_spend")
             }
@@ -550,6 +570,9 @@ impl TransactionError {
             | LockedUntilAfterBlockHeight(_)
             | LockedUntilAfterBlockTime(_) => 100,
 
+            #[cfg(zcash_unstable = "nutachyon")]
+            TachyonIdentityAction(_) | TachyonSignatureInvalid(_) => 100,
+
             // NU6.2 mempool transactions are invalid under NU6.3 rules, but
             // honest peers can relay them briefly while their chain tips converge.
             WrongConsensusBranchIdNu6_3GracePeriod => 0,
@@ -717,6 +740,30 @@ pub enum BlockError {
         source: amount::Error,
     },
 
+    #[error("all Tachygrams in a block must be distinct")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    DuplicateTachygram,
+
+    #[error("a Tachyon pointer stamp must refer to a proof-stamped transaction in the same block")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonAggregateNotFound,
+
+    #[error("a Tachyon proof stamp's covered-actions digest does not match its aggregate")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonCoverageMismatch,
+
+    #[error("action descriptors covered by a Tachyon proof stamp must be distinct")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonDuplicateAction,
+
+    #[error("a Tachyon proof stamp must publish exactly two Tachygrams per covered action")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonTachygramArityMismatch,
+
+    #[error("a Tachyon proof stamp must verify: {0}")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonProofInvalid(String),
+
     #[error("unexpected error occurred: {0}")]
     Other(String),
 }
@@ -755,6 +802,13 @@ impl BlockError {
             | BadMerkleRoot { .. }
             | WrongTransactionConsensusBranchId
             | TooManyTransparentSignatureOperations { .. } => 100,
+            #[cfg(zcash_unstable = "nutachyon")]
+            DuplicateTachygram
+            | TachyonAggregateNotFound
+            | TachyonCoverageMismatch
+            | TachyonDuplicateAction
+            | TachyonTachygramArityMismatch
+            | TachyonProofInvalid(_) => 100,
             Transaction(err) => err.mempool_misbehavior_score(),
             _other => 0,
         }
diff --git a/crates/zakura-consensus/src/primitives.rs b/crates/zakura-consensus/src/primitives.rs
index eeed3cd999..5d62eeef2d 100644
--- a/crates/zakura-consensus/src/primitives.rs
+++ b/crates/zakura-consensus/src/primitives.rs
@@ -17,6 +17,8 @@ pub mod halo2;
 pub mod redjubjub;
 pub mod redpallas;
 pub mod sapling;
+#[cfg(zcash_unstable = "nutachyon")]
+pub mod tachyon;
 
 /// The maximum batch size for any of the batch verifiers.
 const MAX_BATCH_SIZE: usize = 64;
diff --git a/crates/zakura-consensus/src/primitives/halo2.rs b/crates/zakura-consensus/src/primitives/halo2.rs
index 6d2094a4ac..5f83455ef5 100644
--- a/crates/zakura-consensus/src/primitives/halo2.rs
+++ b/crates/zakura-consensus/src/primitives/halo2.rs
@@ -404,6 +404,9 @@ fn lazy_verifier_for(network_upgrade: NetworkUpgrade) -> &'static Lazy<VerifierS
         // reject honest NU6.3 proofs and fail to enforce this constraint.
         Nu6_3 | Nu7 => &VERIFIER_NU6_3_ONWARD,
 
+        #[cfg(zcash_unstable = "nutachyon")]
+        NuTachyon => &VERIFIER_NU6_3_ONWARD,
+
         // `ZFuture` is post-NU6.3 and inherits the NU6.3 circuit. Keep the
         // cfg-gated arm explicit so a future upgrade cannot silently fall back
         // to an older or insecure verifier.
diff --git a/crates/zakura-consensus/src/primitives/tachyon.rs b/crates/zakura-consensus/src/primitives/tachyon.rs
new file mode 100644
index 0000000000..e82769b2cf
--- /dev/null
+++ b/crates/zakura-consensus/src/primitives/tachyon.rs
@@ -0,0 +1,34 @@
+//! Asynchronous verification of Tachyon proof stamps.
+
+use crate::{block::tachyon::AggregateCoverage, error::BlockError};
+
+use super::spawn_fifo;
+
+/// Verifies a Tachyon aggregate's proof stamp against all covered actions.
+pub async fn verify_proof_stamp(aggregate: AggregateCoverage) -> Result<(), BlockError> {
+    spawn_fifo(move || {
+        let adjunct_refs: Vec<_> = aggregate
+            .adjuncts
+            .iter()
+            .map(|adjunct| adjunct.as_dyn())
+            .collect();
+
+        match aggregate
+            .bundle
+            .verify_proof(&mut rand_10::rng(), &adjunct_refs)
+        {
+            Ok(true) => Ok(()),
+            Ok(false) => Err(BlockError::TachyonProofInvalid(
+                "proof stamp was disproved".to_string(),
+            )),
+            Err(error) => Err(BlockError::TachyonProofInvalid(error.to_string())),
+        }
+    })
+    .await
+    .map_err(|_| {
+        BlockError::Other(
+            "threadpool unexpectedly dropped response channel sender; is Zakura shutting down?"
+                .to_string(),
+        )
+    })?
+}
diff --git a/crates/zakura-consensus/src/transaction.rs b/crates/zakura-consensus/src/transaction.rs
index 14bc9f4db7..3b96b4acc5 100644
--- a/crates/zakura-consensus/src/transaction.rs
+++ b/crates/zakura-consensus/src/transaction.rs
@@ -486,6 +486,12 @@ where
             // Transaction parsing enforces the same rule. Repeat it here for
             // defense-in-depth and transactions constructed in memory.
             check::shielded_proof_size_is_canonical(&tx)?;
+            #[cfg(zcash_unstable = "nutachyon")]
+            check::tachyon_actions_have_valid_digests(&tx)?;
+            #[cfg(zcash_unstable = "nutachyon")]
+            if req.is_mempool() {
+                check::tachyon_bundle_is_autonome(&tx)?;
+            }
 
             // Validate the coinbase input consensus rules
             if req.is_mempool() && tx.is_coinbase() {
@@ -612,14 +618,22 @@ where
                     cached_ffi_transaction.clone(),
                     wtx_id.expect("a v5 transaction has a witnessed transaction ID"),
                 )?,
-                Transaction::V6 {
-                    ..
-                } => Self::verify_v6_transaction(
+                Transaction::V6 { .. } => {
+                    Self::verify_v6_or_v7_transaction(
+                        &req,
+                        &network,
+                        script_verifier,
+                        cached_ffi_transaction.clone(),
+                        wtx_id.expect("a v6 or v7 transaction has a witnessed transaction ID"),
+                    )?
+                }
+                #[cfg(zcash_unstable = "nutachyon")]
+                Transaction::V7 { .. } => Self::verify_v6_or_v7_transaction(
                     &req,
                     &network,
                     script_verifier,
                     cached_ffi_transaction.clone(),
-                    wtx_id.expect("a v6 transaction has a witnessed transaction ID"),
+                    wtx_id.expect("a v6 or v7 transaction has a witnessed transaction ID"),
                 )?,
             };
 
@@ -998,6 +1012,12 @@ where
                 transaction.version(),
                 network_upgrade,
             )),
+
+            #[cfg(zcash_unstable = "nutachyon")]
+            NetworkUpgrade::NuTachyon => Err(TransactionError::UnsupportedByNetworkUpgrade(
+                transaction.version(),
+                network_upgrade,
+            )),
         }
     }
 
@@ -1082,6 +1102,9 @@ where
             | NetworkUpgrade::Nu6_3
             | NetworkUpgrade::Nu7 => Ok(()),
 
+            #[cfg(zcash_unstable = "nutachyon")]
+            NetworkUpgrade::NuTachyon => Ok(()),
+
             #[cfg(zcash_unstable = "zfuture")]
             NetworkUpgrade::ZFuture => Ok(()),
 
@@ -1099,8 +1122,8 @@ where
         }
     }
 
-    /// Verify a V6 transaction.
-    fn verify_v6_transaction(
+    /// Verify a V6 or V7 transaction.
+    fn verify_v6_or_v7_transaction(
         request: &Request,
         network: &Network,
         script_verifier: script::Verifier,
@@ -1110,7 +1133,16 @@ where
         let transaction = request.transaction();
         let nu = request.upgrade(network);
 
-        Self::verify_v6_transaction_network_upgrade(&transaction, nu)?;
+        match transaction.as_ref() {
+            Transaction::V6 { .. } => {
+                Self::verify_v6_transaction_network_upgrade(&transaction, nu)?
+            }
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { .. } => {
+                Self::verify_v7_transaction_network_upgrade(&transaction, nu)?
+            }
+            _ => unreachable!("V6/V7 verification is only called for V6 or V7 transactions"),
+        }
 
         let sapling_bundle = cached_ffi_transaction.sighasher().sapling_bundle();
         let orchard_bundle = cached_ffi_transaction.sighasher().orchard_bundle();
@@ -1120,7 +1152,7 @@ where
             .sighasher()
             .sighash(HashType::ALL, None);
 
-        Ok(Self::verify_transparent_inputs_and_outputs(
+        let async_checks = Self::verify_transparent_inputs_and_outputs(
             request,
             script_verifier,
             cached_ffi_transaction,
@@ -1141,7 +1173,13 @@ where
             &sighash,
             nu,
             wtx_id,
-        )))
+        ));
+
+        #[cfg(zcash_unstable = "nutachyon")]
+        let async_checks =
+            async_checks.and(Self::verify_tachyon_signatures(&transaction, &sighash));
+
+        Ok(async_checks)
     }
 
     /// Verifies if a V6 `transaction` is supported by `network_upgrade`.
@@ -1159,6 +1197,46 @@ where
         Ok(())
     }
 
+    /// Verifies if a V7 `transaction` is supported by `network_upgrade`.
+    #[cfg(zcash_unstable = "nutachyon")]
+    fn verify_v7_transaction_network_upgrade(
+        transaction: &Transaction,
+        network_upgrade: NetworkUpgrade,
+    ) -> Result<(), TransactionError> {
+        if network_upgrade < NetworkUpgrade::NuTachyon {
+            return Err(TransactionError::UnsupportedByNetworkUpgrade(
+                transaction.version(),
+                network_upgrade,
+            ));
+        }
+
+        Ok(())
+    }
+
+    /// Queues verification of a V7 transaction's Tachyon action and binding signatures.
+    #[cfg(zcash_unstable = "nutachyon")]
+    fn verify_tachyon_signatures(tx: &Transaction, sighash: &SigHash) -> AsyncChecks {
+        use zcash_tachyon::TachyonBundle;
+
+        let mut async_checks = AsyncChecks::new();
+        let Some(tachyon_shielded_data) = tx.tachyon_shielded_data() else {
+            return async_checks;
+        };
+
+        let bundle = tachyon_shielded_data.0.clone();
+        let sighash_bytes = sighash.0;
+        async_checks.push(primitives::spawn_fifo_and_convert(move || {
+            match &bundle {
+                TachyonBundle::NoBundle => Ok(()),
+                TachyonBundle::Proven(bundle) => bundle.verify_signatures(&sighash_bytes),
+                TachyonBundle::Adjunct(bundle) => bundle.verify_signatures(&sighash_bytes),
+            }
+            .map_err(|error| TransactionError::TachyonSignatureInvalid(error.to_string()))
+        }));
+
+        async_checks
+    }
+
     /// Verifies if a transaction's transparent inputs are valid using the provided
     /// `script_verifier` and `cached_ffi_transaction`.
     ///
@@ -1346,7 +1424,7 @@ where
     ///
     /// `wtx_id` identifies the transaction containing `bundle`; the cache adds
     /// the bundle's value pool to distinguish the Orchard and Ironwood slots in
-    /// a v6 transaction.
+    /// a v6 or v7 transaction.
     fn verify_orchard_bundle(
         bundle: Option<::orchard::bundle::Bundle<::orchard::bundle::Authorized, ZatBalance>>,
         sighash: &SigHash,
diff --git a/crates/zakura-consensus/src/transaction/check.rs b/crates/zakura-consensus/src/transaction/check.rs
index 32550a6914..100da98a42 100644
--- a/crates/zakura-consensus/src/transaction/check.rs
+++ b/crates/zakura-consensus/src/transaction/check.rs
@@ -908,3 +908,35 @@ pub fn consensus_branch_id(
 
     Ok(())
 }
+
+/// Checks that no Tachyon action's value commitment or verification key is the identity point.
+#[cfg(zcash_unstable = "nutachyon")]
+pub fn tachyon_actions_have_valid_digests(tx: &Transaction) -> Result<(), TransactionError> {
+    let Some(tachyon_shielded_data) = tx.tachyon_shielded_data() else {
+        return Ok(());
+    };
+
+    for action in tachyon_shielded_data.actions() {
+        action
+            .digest()
+            .map_err(|error| TransactionError::TachyonIdentityAction(error.to_string()))?;
+    }
+
+    Ok(())
+}
+
+/// Checks that a Tachyon transaction is autonome before it enters the mempool.
+#[cfg(zcash_unstable = "nutachyon")]
+pub fn tachyon_bundle_is_autonome(tx: &Transaction) -> Result<(), TransactionError> {
+    let Some(tachyon_shielded_data) = tx.tachyon_shielded_data() else {
+        return Ok(());
+    };
+
+    match &tachyon_shielded_data.0 {
+        zcash_tachyon::TachyonBundle::Proven(bundle) if bundle.is_autonome() => Ok(()),
+        zcash_tachyon::TachyonBundle::NoBundle => Ok(()),
+        zcash_tachyon::TachyonBundle::Proven(_) | zcash_tachyon::TachyonBundle::Adjunct(_) => {
+            Err(TransactionError::NonAutonomeTachyon)
+        }
+    }
+}
diff --git a/crates/zakura-consensus/src/transaction/tests.rs b/crates/zakura-consensus/src/transaction/tests.rs
index 415f71a058..7c5b60a02d 100644
--- a/crates/zakura-consensus/src/transaction/tests.rs
+++ b/crates/zakura-consensus/src/transaction/tests.rs
@@ -54,6 +54,8 @@ use super::{check, Request, Verifier};
 
 #[cfg(test)]
 mod prop;
+#[cfg(all(test, zcash_unstable = "nutachyon"))]
+mod tachyon;
 
 /// Returns the timeout duration for tests, extended when running under coverage
 /// instrumentation to account for the performance overhead.
diff --git a/crates/zakura-consensus/src/transaction/tests/prop.rs b/crates/zakura-consensus/src/transaction/tests/prop.rs
index a2dc56bed9..10ae42fb7f 100644
--- a/crates/zakura-consensus/src/transaction/tests/prop.rs
+++ b/crates/zakura-consensus/src/transaction/tests/prop.rs
@@ -331,6 +331,18 @@ fn mock_transparent_transaction(
             ironwood_shielded_data: None,
             network_upgrade,
         },
+        #[cfg(zcash_unstable = "nutachyon")]
+        7 => Transaction::V7 {
+            inputs,
+            outputs,
+            lock_time,
+            expiry_height,
+            sapling_shielded_data: None,
+            orchard_shielded_data: None,
+            ironwood_shielded_data: None,
+            tachyon_shielded_data: None,
+            network_upgrade,
+        },
         invalid_version => unreachable!("invalid transaction version: {}", invalid_version),
     };
 
@@ -360,6 +372,8 @@ fn sanitize_transaction_version(
             Nu5 | Nu6 | Nu6_1 | Nu6_2 => (4, 5),
             Nu6_3 => (4, 6),
             Nu7 => (5, 5),
+            #[cfg(zcash_unstable = "nutachyon")]
+            NuTachyon => (5, 7),
 
             #[cfg(zcash_unstable = "zfuture")]
             NetworkUpgrade::ZFuture => (5, u8::MAX),
@@ -372,12 +386,14 @@ fn sanitize_transaction_version(
 }
 
 #[test]
-fn sanitize_transaction_version_handles_v6_at_nu6_3() {
+#[cfg(zcash_unstable = "nutachyon")]
+fn sanitize_transaction_version_handles_v6_and_v7_upgrades() {
     let network = zakura_chain::parameters::testnet::Parameters::build()
         .with_activation_heights(
             zakura_chain::parameters::testnet::ConfiguredActivationHeights {
                 nu6_3: Some(1),
                 nu7: Some(2),
+                nu_tachyon: Some(3),
                 ..Default::default()
             },
         )
@@ -402,6 +418,14 @@ fn sanitize_transaction_version_handles_v6_at_nu6_3() {
         sanitize_transaction_version(&network, 6, block::Height(2)),
         (5, NetworkUpgrade::Nu7)
     );
+    assert_eq!(
+        sanitize_transaction_version(&network, 6, block::Height(3)),
+        (6, NetworkUpgrade::NuTachyon)
+    );
+    assert_eq!(
+        sanitize_transaction_version(&network, 7, block::Height(3)),
+        (7, NetworkUpgrade::NuTachyon)
+    );
 }
 
 /// Create multiple mock transparent transfers.
diff --git a/crates/zakura-consensus/src/transaction/tests/tachyon.rs b/crates/zakura-consensus/src/transaction/tests/tachyon.rs
new file mode 100644
index 0000000000..fd0d372f72
--- /dev/null
+++ b/crates/zakura-consensus/src/transaction/tests/tachyon.rs
@@ -0,0 +1,406 @@
+//! Tests for V7 (tachyon) transaction verification.
+
+use std::{
+    collections::{HashMap, HashSet},
+    sync::Arc,
+};
+
+use chrono::Utc;
+use tower::{service_fn, ServiceExt};
+
+use zakura_chain::{
+    block::Height,
+    parameters::{testnet::ConfiguredActivationHeights, Network, NetworkUpgrade},
+    transaction::{HashType, LockTime, Transaction},
+};
+use zcash_tachyon::{
+    action, bundle, effect,
+    entropy::ActionEntropy,
+    keys::private,
+    note::{CommitmentTrapdoor, Note},
+    nullifier, value, PointerStamp, ProofStamp, Tachygram, TachygramSetPoly, TachyonBundle,
+};
+
+use crate::{
+    error::TransactionError,
+    transaction::{check, Request, Response, Verifier},
+};
+
+/// A regtest network with NuTachyon (tachyon) scheduled, and NuTachyon's activation height.
+fn nutachyon_network() -> (Network, Height) {
+    let network = Network::new_regtest(
+        ConfiguredActivationHeights {
+            canopy: Some(1),
+            nu5: Some(2),
+            nu6: Some(3),
+            nu6_1: Some(4),
+            nu6_2: Some(5),
+            nu6_3: Some(6),
+            nu7: Some(8),
+            nu_tachyon: Some(10),
+            ..Default::default()
+        }
+        .into(),
+    );
+    let height = NetworkUpgrade::NuTachyon
+        .activation_height(&network)
+        .expect("NuTachyon activation height is configured");
+    (network, height)
+}
+
+/// A V7 transaction with the given tachyon bundle and no other transfers.
+fn v7_transaction(
+    network_upgrade: NetworkUpgrade,
+    tachyon_bundle: Option<TachyonBundle>,
+) -> Transaction {
+    Transaction::V7 {
+        network_upgrade,
+        lock_time: LockTime::min_lock_time_timestamp(),
+        expiry_height: Height(0),
+        inputs: Vec::new(),
+        outputs: Vec::new(),
+        sapling_shielded_data: None,
+        orchard_shielded_data: None,
+        ironwood_shielded_data: None,
+        tachyon_shielded_data: tachyon_bundle.map(Into::into),
+    }
+}
+
+/// A proof stamp with an unasserted covered-actions digest and no proof: tx-level verification
+/// never checks the stamp's proof or coverage (those are block-level rules).
+fn mock_proof_stamp(tachygrams: Vec<Tachygram>) -> ProofStamp {
+    let tachygram_set = tachygrams.iter().copied().collect::<TachygramSetPoly>();
+    ProofStamp {
+        coverage: [0u8; 32],
+        tachygram_set: tachygram_set.commit(),
+        tachygrams: tachygrams.into_iter().collect(),
+        anchor: zcash_tachyon::Anchor::read(&[0u8; 64][..]).expect("zero anchor reads"),
+        proof: Box::new(ragu::Proof::trivial()),
+    }
+}
+
+/// Computes the covered-actions digest used by a proof stamp.
+fn action_descriptor_digest(actions: &[zcash_tachyon::Action]) -> [u8; 32] {
+    let mut descriptors: Vec<[u8; 64]> = actions.iter().map(|action| action.descriptor()).collect();
+    descriptors.sort_unstable();
+
+    let mut state = blake2b_simd::Params::new()
+        .hash_length(32)
+        .personal(b"Tachyon-Actions")
+        .to_state();
+    for descriptor in descriptors {
+        state.update(&descriptor);
+    }
+    state
+        .finalize()
+        .as_bytes()
+        .try_into()
+        .expect("hash length is 32")
+}
+
+/// A random note worth `value` zatoshis, with its spending key.
+fn random_note(rng: &mut impl rand_10::CryptoRng, value: u64) -> (private::SpendingKey, Note) {
+    let sk = private::SpendingKey::random(rng);
+    let note = Note {
+        pk: sk.derive_payment_key(),
+        value: value::Positive::try_from(value).expect("value is positive and below MAX_MONEY"),
+        psi: nullifier::Trapdoor::random(rng),
+        rcm: CommitmentTrapdoor::random(rng),
+    };
+    (sk, note)
+}
+
+/// A spend-only bundle plan worth `value`, with its spend authorizing key.
+///
+/// A spend contributes its value positively to the transaction value pool, so the resulting
+/// transaction has a valid (non-negative) miner fee.
+fn spend_bundle_plan(value: u64) -> (bundle::Plan, private::SpendAuthorizingKey) {
+    let mut rng = rand_10::rng();
+
+    let (sk, note) = random_note(&mut rng, value);
+    let ask = sk.derive_auth_private();
+
+    let theta = ActionEntropy::random(&mut rng);
+    let rcv = value::Trapdoor::random(&mut rng);
+    let spend_plan = action::Plan::spend(note, theta, rcv, |alpha| {
+        ask.derive_action_private(&alpha).derive_action_public()
+    });
+
+    (bundle::Plan::new(vec![spend_plan], vec![]), ask)
+}
+
+/// A properly-signed spend-only bundle over its own transaction's sighash, in the unproven state.
+///
+/// The V7 sighash commits to the bundle's effecting data (action descriptors and value balance)
+/// but not its signatures or stamp, so the sighash is computed from a draft bundle carrying
+/// placeholder signatures, and the returned bundle then signs over it. Attaching the returned
+/// bundle (under any stamp) to [`v7_transaction`] yields the same sighash the signatures commit
+/// to.
+fn signed_spend_bundle(value: u64) -> zcash_tachyon::Bundle<zcash_tachyon::Unproven> {
+    let mut rng = rand_10::rng();
+
+    let (plan, ask) = spend_bundle_plan(value);
+
+    let draft = plan
+        .sign(&mut rng, &[0u8; 32], &ask)
+        .expect("bundle plan has matching signatures and an in-range value balance");
+    let draft_tx = v7_transaction(
+        NetworkUpgrade::NuTachyon,
+        Some(TachyonBundle::Proven(draft.stamp(mock_proof_stamp(vec![])))),
+    );
+    let sighash = v7_sighash(&draft_tx);
+
+    plan.sign(&mut rng, &sighash, &ask)
+        .expect("bundle plan has matching signatures and an in-range value balance")
+}
+
+/// The sighash the tachyon bundle's signatures must commit to.
+///
+/// The V7 sighash commits to the tachyon bundle's effecting data (action descriptors and value
+/// balance), but not its signatures or stamp — so a bundle with placeholder signatures produces
+/// the same sighash as its properly-signed counterpart under any stamp.
+fn v7_sighash(tx: &Transaction) -> [u8; 32] {
+    tx.sighash(
+        NetworkUpgrade::NuTachyon,
+        HashType::ALL,
+        Arc::new(Vec::new()),
+        None,
+    )
+    .expect("sighash is computable for a V7 transaction with no transparent inputs")
+    .0
+}
+
+/// Verifies `tx` through the full transaction verifier with a block request at `height`.
+async fn verify_block_transaction(
+    network: &Network,
+    height: Height,
+    tx: Transaction,
+) -> Result<Response, TransactionError> {
+    // No transparent inputs anywhere in these tests, so the verifier never calls the state.
+    let state = service_fn(|_| async { unreachable!("state is not queried") });
+    let verifier = Verifier::new_for_tests(network, state);
+
+    verifier
+        .oneshot(Request::Block {
+            transaction_hash: tx.hash(),
+            transaction: Arc::new(tx),
+            known_utxos: Arc::new(HashMap::new()),
+            known_outpoint_hashes: Arc::new(HashSet::new()),
+            height,
+            time: Utc::now(),
+        })
+        .await
+}
+
+/// The mempool accepts only proof stamps that cover their own transaction's actions.
+#[test]
+fn mempool_accepts_only_autonome_tachyon_transactions() {
+    let bundle = signed_spend_bundle(100);
+    let mut stamp = mock_proof_stamp(vec![]);
+    stamp.coverage = action_descriptor_digest(&bundle.actions);
+    let autonome = bundle.stamp(stamp);
+
+    let autonome_tx = v7_transaction(
+        NetworkUpgrade::NuTachyon,
+        Some(TachyonBundle::Proven(autonome.clone())),
+    );
+    assert_eq!(check::tachyon_bundle_is_autonome(&autonome_tx), Ok(()));
+
+    let mut aggregate = autonome.clone();
+    aggregate.stamp.coverage = [0xAA; 32];
+    let aggregate_tx = v7_transaction(
+        NetworkUpgrade::NuTachyon,
+        Some(TachyonBundle::Proven(aggregate)),
+    );
+    assert_eq!(
+        check::tachyon_bundle_is_autonome(&aggregate_tx),
+        Err(TransactionError::NonAutonomeTachyon),
+    );
+
+    let adjunct_tx = v7_transaction(
+        NetworkUpgrade::NuTachyon,
+        Some(TachyonBundle::Adjunct(autonome.strip(
+            PointerStamp::try_from([0xEE; 64]).expect("nonzero wtxid"),
+        ))),
+    );
+    assert_eq!(
+        check::tachyon_bundle_is_autonome(&adjunct_tx),
+        Err(TransactionError::NonAutonomeTachyon),
+    );
+}
+
+/// The V7 sighash commits to the tachyon bundle's effecting data, but not its stamp.
+#[tokio::test(flavor = "multi_thread")]
+async fn v7_sighash_commits_to_tachyon_bundle() {
+    let _init_guard = zakura_test::init();
+
+    let mut rng = rand_10::rng();
+    let (plan, ask) = spend_bundle_plan(100);
+    let bundle = plan
+        .sign(&mut rng, &[0u8; 32], &ask)
+        .expect("bundle plan has matching signatures and an in-range value balance");
+
+    let no_bundle_sighash = v7_sighash(&v7_transaction(NetworkUpgrade::NuTachyon, None));
+    let proven_sighash = v7_sighash(&v7_transaction(
+        NetworkUpgrade::NuTachyon,
+        Some(TachyonBundle::Proven(
+            bundle.clone().stamp(mock_proof_stamp(vec![])),
+        )),
+    ));
+    let adjunct_sighash = v7_sighash(&v7_transaction(
+        NetworkUpgrade::NuTachyon,
+        Some(TachyonBundle::Adjunct(
+            bundle
+                .stamp(mock_proof_stamp(vec![]))
+                .strip(PointerStamp::try_from([0xEEu8; 64]).expect("nonzero wtxid")),
+        )),
+    ));
+    let other_bundle_sighash = v7_sighash(&v7_transaction(
+        NetworkUpgrade::NuTachyon,
+        Some(TachyonBundle::Proven(
+            signed_spend_bundle(100).stamp(mock_proof_stamp(vec![])),
+        )),
+    ));
+
+    // The sighash changes when a bundle is present, and differs between distinct action sets.
+    assert_ne!(no_bundle_sighash, proven_sighash);
+    assert_ne!(proven_sighash, other_bundle_sighash);
+
+    // The stamp is excluded, so the sighash is invariant across stamping and stripping.
+    assert_eq!(proven_sighash, adjunct_sighash);
+}
+
+/// A V7 transaction with a properly-signed tachyon bundle passes verification, whether
+/// proof-stamped or pointer-stamped: proof coverage is a block-level rule.
+#[tokio::test(flavor = "multi_thread")]
+async fn v7_with_signed_tachyon_bundle_is_accepted() {
+    let _init_guard = zakura_test::init();
+    let (network, height) = nutachyon_network();
+
+    // Proof-stamped: the tx-level rules don't verify the proof itself.
+    let proven = signed_spend_bundle(100).stamp(mock_proof_stamp(vec![]));
+    let tx = v7_transaction(
+        NetworkUpgrade::NuTachyon,
+        Some(TachyonBundle::Proven(proven)),
+    );
+    verify_block_transaction(&network, height, tx)
+        .await
+        .expect("a signed proof-stamped tachyon transaction should verify");
+
+    // Pointer-stamped: signature checks still run, proof coverage is deferred to the block.
+    // The sighash excludes the stamp, so stripping a signed bundle keeps its signatures valid.
+    let adjunct = signed_spend_bundle(100)
+        .stamp(mock_proof_stamp(vec![]))
+        .strip(PointerStamp::try_from([0xEEu8; 64]).expect("nonzero wtxid"));
+    let tx = v7_transaction(
+        NetworkUpgrade::NuTachyon,
+        Some(TachyonBundle::Adjunct(adjunct)),
+    );
+    verify_block_transaction(&network, height, tx)
+        .await
+        .expect("a signed pointer-stamped tachyon transaction should verify");
+}
+
+/// A tachyon bundle whose signatures don't commit to the transaction sighash is rejected.
+#[tokio::test(flavor = "multi_thread")]
+async fn v7_with_wrong_sighash_signatures_is_rejected() {
+    let _init_guard = zakura_test::init();
+    let (network, height) = nutachyon_network();
+
+    // Sign over a different message than the transaction's sighash.
+    let mut rng = rand_10::rng();
+    let (plan, ask) = spend_bundle_plan(100);
+    let bundle = plan
+        .sign(&mut rng, &[0x42u8; 32], &ask)
+        .expect("bundle plan has matching signatures and an in-range value balance")
+        .stamp(mock_proof_stamp(vec![]));
+    let tx = v7_transaction(
+        NetworkUpgrade::NuTachyon,
+        Some(TachyonBundle::Proven(bundle)),
+    );
+
+    let result = verify_block_transaction(&network, height, tx).await;
+    assert!(
+        matches!(result, Err(TransactionError::TachyonSignatureInvalid(_))),
+        "expected TachyonSignatureInvalid, got: {result:?}",
+    );
+}
+
+/// A tachyon action whose value commitment is the identity point is rejected.
+#[tokio::test(flavor = "multi_thread")]
+async fn v7_with_identity_cv_is_rejected() {
+    use halo2::pasta::group::CurveAffine;
+
+    let _init_guard = zakura_test::init();
+    let (network, height) = nutachyon_network();
+
+    let mut rng = rand_10::rng();
+
+    // A structurally valid action, except its cv is the identity point. The identity check runs
+    // before signature verification, so the dummy signature bytes are never checked.
+    let (_, note) = random_note(&mut rng, 100);
+    let theta = ActionEntropy::random(&mut rng);
+    let alpha = theta.randomizer::<effect::Output>(note.commitment());
+    let rk = private::ActionSigningKey::new(&alpha).derive_action_public();
+
+    let action = zcash_tachyon::Action {
+        cv: value::Commitment::from(halo2::pasta::pallas::Affine::identity()),
+        rk,
+        sig: action::Signature::read(&[0x01u8; 64][..]).expect("64 bytes"),
+    };
+
+    let bundle = zcash_tachyon::Bundle {
+        actions: vec![action],
+        value_balance: value::Balance::ZERO,
+        binding_sig: bundle::Signature::read(&[0x02u8; 64][..]).expect("64 bytes"),
+        memo: Vec::new(),
+        stamp: mock_proof_stamp(vec![]),
+    };
+    let tx = v7_transaction(
+        NetworkUpgrade::NuTachyon,
+        Some(TachyonBundle::Proven(bundle)),
+    );
+
+    let result = verify_block_transaction(&network, height, tx).await;
+    assert!(
+        matches!(result, Err(TransactionError::TachyonIdentityAction(_))),
+        "expected TachyonIdentityAction, got: {result:?}",
+    );
+}
+
+// Distinctness of the tachygrams within one proof stamp is enforced at parse time in
+// `zcash_tachyon`: they deserialize into a set, and the wire parser rejects duplicate or
+// unsorted entries. A duplicate-tachygram transaction is unrepresentable in Zebra, so there
+// is no transaction-level semantic check (or test) for it.
+
+/// V7 transactions are rejected before NuTachyon activation, including under NU7
+/// itself (the upstream v6-transaction upgrade).
+#[tokio::test(flavor = "multi_thread")]
+async fn v7_is_rejected_before_nu_tachyon() {
+    let _init_guard = zakura_test::init();
+    let (network, _) = nutachyon_network();
+
+    let nu7_height = NetworkUpgrade::Nu7
+        .activation_height(&network)
+        .expect("NU7 activation height is configured");
+
+    // The bundle's actions let the transaction pass the has-inputs-and-outputs check, so the
+    // network-upgrade gate is what rejects it. The gate errors before any signature check runs,
+    // so the signatures can be arbitrary.
+    let mut rng = rand_10::rng();
+    let (plan, ask) = spend_bundle_plan(100);
+    let bundle = plan
+        .sign(&mut rng, &[0u8; 32], &ask)
+        .expect("bundle plan has matching signatures and an in-range value balance")
+        .stamp(mock_proof_stamp(vec![]));
+    let tx = v7_transaction(
+        NetworkUpgrade::NuTachyon,
+        Some(TachyonBundle::Proven(bundle)),
+    );
+
+    let result = verify_block_transaction(&network, nu7_height, tx).await;
+    assert!(
+        matches!(result, Err(TransactionError::WrongConsensusBranchId)),
+        "expected WrongConsensusBranchId, got: {result:?}",
+    );
+}
diff --git a/crates/zakura-network/src/constants.rs b/crates/zakura-network/src/constants.rs
index e77a0a2697..0e766731e1 100644
--- a/crates/zakura-network/src/constants.rs
+++ b/crates/zakura-network/src/constants.rs
@@ -342,11 +342,11 @@ pub const MAX_ADDRS_IN_ADDRESS_BOOK: usize =
 /// messages from each of our peers.
 pub const TIMESTAMP_TRUNCATION_SECONDS: u32 = 30 * 60;
 
-// TODO: The NU7 protocol version is provisional. Update this constant and the mapping in
-// `Version::min_specified_for_upgrade` once NU7's deployment ZIP is published.
-// Next upgrade values, uncomment on activation:
-//   const CURRENT_NETWORK_PROTOCOL_VERSION_VALUE: u32 = 170_170; // NU7 Testnet.
-//   const CURRENT_NETWORK_PROTOCOL_VERSION_VALUE: u32 = 170_180; // NU7 Mainnet.
+// TODO: The NU7 and NuTachyon protocol versions are provisional. Update this constant and the
+// mapping in `Version::min_specified_for_upgrade` when their deployment ZIPs are published.
+#[cfg(zcash_unstable = "nutachyon")]
+const CURRENT_NETWORK_PROTOCOL_VERSION_VALUE: u32 = 170_190; // NuTachyon (Mainnet + Testnet).
+#[cfg(not(zcash_unstable = "nutachyon"))]
 const CURRENT_NETWORK_PROTOCOL_VERSION_VALUE: u32 = 170_160; // NU6.3 (Mainnet + Testnet).
 
 /// The Zcash network protocol version implemented by this crate, and advertised
diff --git a/crates/zakura-network/src/protocol/external/types.rs b/crates/zakura-network/src/protocol/external/types.rs
index c61b70704e..b9ee01d6b6 100644
--- a/crates/zakura-network/src/protocol/external/types.rs
+++ b/crates/zakura-network/src/protocol/external/types.rs
@@ -120,14 +120,20 @@ impl Version {
                 170_150
             }
             (Mainnet, Nu6_2) => 170_150,
-            // TODO: these NU6.3 (Ironwood) and Nu7 protocol versions are provisional, bumped above
-            // Nu6_2's 170_150. Update them when the real values are specified.
+            // TODO: these NU6.3, NU7, and NuTachyon protocol versions are provisional, bumped
+            // above Nu6_2's 170_150. Update them when the real values are specified.
             (Testnet(params), Nu6_3) if params.is_default_testnet() || params.is_regtest() => {
                 170_160
             }
             (Mainnet, Nu6_3) => 170_160,
             (Testnet(params), Nu7) if params.is_default_testnet() || params.is_regtest() => 170_170,
             (Mainnet, Nu7) => 170_180,
+            #[cfg(zcash_unstable = "nutachyon")]
+            (Testnet(params), NuTachyon) if params.is_default_testnet() || params.is_regtest() => {
+                170_190
+            }
+            #[cfg(zcash_unstable = "nutachyon")]
+            (Mainnet, NuTachyon) => 170_190,
 
             // It should be fine to reject peers with earlier network protocol versions on custom testnets for now.
             (Testnet(_), _) => CURRENT_NETWORK_PROTOCOL_VERSION.0,
@@ -219,11 +225,21 @@ mod test {
         let _init_guard = zakura_test::init();
 
         let highest_network_upgrade = NetworkUpgrade::current(network, block::Height::MAX);
+        #[cfg(not(zcash_unstable = "nutachyon"))]
         assert!(
             matches!(highest_network_upgrade, Nu6 | Nu6_1 | Nu6_2 | Nu6_3 | Nu7),
             "expected coverage of all network upgrades: \
             add the new network upgrade to the list in this test"
         );
+        #[cfg(zcash_unstable = "nutachyon")]
+        assert!(
+            matches!(
+                highest_network_upgrade,
+                Nu6 | Nu6_1 | Nu6_2 | Nu6_3 | Nu7 | NuTachyon
+            ),
+            "expected coverage of all network upgrades: \
+            add the new network upgrade to the list in this test"
+        );
 
         for &network_upgrade in &[
             BeforeOverwinter,
@@ -238,6 +254,8 @@ mod test {
             Nu6_2,
             Nu6_3,
             Nu7,
+            #[cfg(zcash_unstable = "nutachyon")]
+            NuTachyon,
         ] {
             let height = network_upgrade.activation_height(network);
             if let Some(height) = height {
@@ -250,19 +268,38 @@ mod test {
     }
 
     #[test]
-    fn nu63_protocol_versions_match_current_version() {
+    #[cfg(zcash_unstable = "nutachyon")]
+    fn nu_tachyon_protocol_versions_match_current_version() {
         let _init_guard = zakura_test::init();
 
         assert_eq!(
-            Version::min_specified_for_upgrade(&Mainnet, Nu6_3),
+            Version::min_specified_for_upgrade(&Mainnet, NuTachyon),
             CURRENT_NETWORK_PROTOCOL_VERSION
         );
         assert_eq!(
-            Version::min_specified_for_upgrade(&Network::new_default_testnet(), Nu6_3),
+            Version::min_specified_for_upgrade(&Network::new_default_testnet(), NuTachyon),
+            CURRENT_NETWORK_PROTOCOL_VERSION
+        );
+        assert_eq!(
+            Version::min_specified_for_upgrade(
+                &Network::new_regtest(Default::default()),
+                NuTachyon
+            ),
             CURRENT_NETWORK_PROTOCOL_VERSION
         );
+    }
+
+    #[test]
+    #[cfg(not(zcash_unstable = "nutachyon"))]
+    fn nu63_protocol_versions_match_current_version() {
+        let _init_guard = zakura_test::init();
+
         assert_eq!(
-            Version::min_specified_for_upgrade(&Network::new_regtest(Default::default()), Nu6_3),
+            Version::min_specified_for_upgrade(&Mainnet, Nu6_3),
+            CURRENT_NETWORK_PROTOCOL_VERSION
+        );
+        assert_eq!(
+            Version::min_specified_for_upgrade(&Network::new_default_testnet(), Nu6_3),
             CURRENT_NETWORK_PROTOCOL_VERSION
         );
     }
diff --git a/crates/zakura-network/src/zakura/block_sync/tests.rs b/crates/zakura-network/src/zakura/block_sync/tests.rs
index 462da5ca72..9dab47c815 100644
--- a/crates/zakura-network/src/zakura/block_sync/tests.rs
+++ b/crates/zakura-network/src/zakura/block_sync/tests.rs
@@ -108,6 +108,8 @@ fn fake_block_at_height(template: &Arc<block::Block>, height: block::Height) ->
         | Transaction::V4 { inputs, .. }
         | Transaction::V5 { inputs, .. } => &mut inputs[0],
         Transaction::V6 { inputs, .. } => &mut inputs[0],
+        #[cfg(zcash_unstable = "nutachyon")]
+        Transaction::V7 { inputs, .. } => &mut inputs[0],
     };
     match input {
         transparent::Input::Coinbase {
diff --git a/crates/zakura-network/src/zakura/testkit/cluster.rs b/crates/zakura-network/src/zakura/testkit/cluster.rs
index 4c4a02b63b..a9c8440bc7 100644
--- a/crates/zakura-network/src/zakura/testkit/cluster.rs
+++ b/crates/zakura-network/src/zakura/testkit/cluster.rs
@@ -925,6 +925,8 @@ mod tests {
                 nu6_2: None,
                 nu6_3: None,
                 nu7: None,
+                #[cfg(zcash_unstable = "nutachyon")]
+                nu_tachyon: None,
                 #[cfg(zcash_unstable = "zfuture")]
                 zfuture: None,
             })
diff --git a/crates/zakura-network/src/zakura/testkit/mock_blocksync.rs b/crates/zakura-network/src/zakura/testkit/mock_blocksync.rs
index 1adc319c8f..bdfd2fef69 100644
--- a/crates/zakura-network/src/zakura/testkit/mock_blocksync.rs
+++ b/crates/zakura-network/src/zakura/testkit/mock_blocksync.rs
@@ -739,6 +739,8 @@ fn synthetic_block_at_height(
         | Transaction::V4 { inputs, .. }
         | Transaction::V5 { inputs, .. } => &mut inputs[0],
         Transaction::V6 { inputs, .. } => &mut inputs[0],
+        #[cfg(zcash_unstable = "nutachyon")]
+        Transaction::V7 { inputs, .. } => &mut inputs[0],
     };
     match input {
         transparent::Input::Coinbase {
diff --git a/crates/zakura-rpc/Cargo.toml b/crates/zakura-rpc/Cargo.toml
index a6a320a482..aa653cb510 100644
--- a/crates/zakura-rpc/Cargo.toml
+++ b/crates/zakura-rpc/Cargo.toml
@@ -123,7 +123,14 @@ tokio-rustls = { version = "0.26.4", default-features = false, features = ["logg
 # Only used to read the validity dates of the configured RPC TLS certificates.
 der = "0.7.10"
 
+[target.'cfg(zcash_unstable = "nutachyon")'.dependencies]
+zcash_tachyon = { workspace = true }
+
+[target.'cfg(zcash_unstable = "nutachyon")'.dev-dependencies]
+ragu = { workspace = true }
+
 [dev-dependencies]
+blake2b_simd = { workspace = true }
 bytes = { workspace = true }
 http-body = { workspace = true }
 insta = { workspace = true, features = ["redactions", "json", "ron"] }
diff --git a/crates/zakura-rpc/src/config/mining.rs b/crates/zakura-rpc/src/config/mining.rs
index 15583080d5..44ceca1134 100644
--- a/crates/zakura-rpc/src/config/mining.rs
+++ b/crates/zakura-rpc/src/config/mining.rs
@@ -57,12 +57,22 @@ pub struct Config {
 
     /// Mine blocks using Zakura's internal miner, without an external mining pool or equihash solver.
     ///
-    /// This experimental feature is only supported on regtest as it uses null solutions and skips checking
-    /// for a valid Proof of Work.
+    /// This experimental feature is only supported on proof-of-work-disabled test networks because
+    /// it uses null solutions.
     ///
     /// The internal miner is off by default.
     #[serde(default)]
     pub internal_miner: bool,
+
+    /// Generate a deterministic Tachyon transaction workload for every internally mined block.
+    ///
+    /// This test-only workload replaces externally submitted mempool transactions. It pays miner
+    /// rewards to anyone-can-spend outputs, then shields each output into an independently derived
+    /// Tachyon recipient as soon as the coinbase matures. It is only accepted together with
+    /// [`Self::internal_miner`] on a proof-of-work-disabled test network.
+    #[cfg(zcash_unstable = "nutachyon")]
+    #[serde(default)]
+    pub tachyon_workload: bool,
 }
 
 impl Config {
diff --git a/crates/zakura-rpc/src/methods.rs b/crates/zakura-rpc/src/methods.rs
index ff694fa262..1a1cbb042f 100644
--- a/crates/zakura-rpc/src/methods.rs
+++ b/crates/zakura-rpc/src/methods.rs
@@ -139,6 +139,14 @@ use types::{
     z_validate_address::ZValidateAddressResponse,
 };
 
+/// Value pool balances returned by the blockchain RPCs.
+#[cfg(not(zcash_unstable = "nutachyon"))]
+pub type BlockchainValuePoolBalances = [GetBlockchainInfoBalance; 6];
+
+/// Value pool balances returned by the blockchain RPCs.
+#[cfg(zcash_unstable = "nutachyon")]
+pub type BlockchainValuePoolBalances = [GetBlockchainInfoBalance; 7];
+
 /// Calls a Tower service and maps readiness or call errors to
 /// [`server::error::LegacyCode::Misc`].
 async fn call_service<S, Request>(service: S, request: Request) -> Result<S::Response>
@@ -2754,6 +2762,14 @@ where
                 precomputed_coinbase = wait_for_new_tip => {
                     let chain_info = fetch_chain_info(read_state.clone()).await?;
 
+                    // Each mature coinbase reward has one deterministic workload at its first
+                    // spendable height. Do not let the internal miner race that full template
+                    // with the usual empty, provisional tip-change template.
+                    #[cfg(zcash_unstable = "nutachyon")]
+                    if miner_params.tachyon_workload() {
+                        continue;
+                    }
+
                     let server_long_poll_id = LongPollInput::new(
                         chain_info.tip_height,
                         chain_info.tip_hash,
@@ -2821,7 +2837,33 @@ where
 
         let height = chain_info.tip_height.next().map_misc_error()?;
 
-        // Randomly select some mempool transactions.
+        // Randomly select some mempool transactions, or replace them with the internal miner's
+        // self-funded Tachyon workload.
+        #[cfg(zcash_unstable = "nutachyon")]
+        let mempool_txs = if miner_params.tachyon_workload() {
+            let generated = types::get_block_template::generate_tachyon_workload_transactions(
+                &self.network,
+                height,
+                chain_info.tip_hash,
+                read_state.clone(),
+            )
+            .await;
+
+            #[cfg(test)]
+            let generated = generated.into_iter().map(|tx| (0, tx)).collect();
+
+            generated
+        } else {
+            select_mempool_transactions(
+                &self.network,
+                height,
+                miner_params,
+                mempool_txs,
+                mempool_tx_deps,
+            )
+        };
+
+        #[cfg(not(zcash_unstable = "nutachyon"))]
         let mempool_txs = select_mempool_transactions(
             &self.network,
             height,
@@ -2830,6 +2872,26 @@ where
             mempool_tx_deps,
         );
 
+        #[cfg(all(test, zcash_unstable = "nutachyon"))]
+        let (dependency_depths, selected_txs): (Vec<_>, Vec<_>) = mempool_txs.into_iter().unzip();
+        #[cfg(all(not(test), zcash_unstable = "nutachyon"))]
+        let selected_txs = mempool_txs;
+
+        #[cfg(zcash_unstable = "nutachyon")]
+        let selected_txs = types::get_block_template::tachyon::aggregate_transactions(
+            self.network.clone(),
+            height,
+            chain_info.tip_hash,
+            read_state,
+            selected_txs,
+        )
+        .await;
+
+        #[cfg(all(test, zcash_unstable = "nutachyon"))]
+        let mempool_txs: Vec<_> = dependency_depths.into_iter().zip(selected_txs).collect();
+        #[cfg(all(not(test), zcash_unstable = "nutachyon"))]
+        let mempool_txs = selected_txs;
+
         tracing::debug!(
             selected_mempool_tx_hashes = ?mempool_txs
                 .iter()
@@ -3648,9 +3710,6 @@ pub struct EndOfService {
     estimated_time: i64,
 }
 
-/// Type alias for the array of `GetBlockchainInfoBalance` objects
-pub type BlockchainValuePoolBalances = [GetBlockchainInfoBalance; 6];
-
 fn deserialize_blockchain_value_pool_balances<'de, D>(
     deserializer: D,
 ) -> std::result::Result<BlockchainValuePoolBalances, D::Error>
@@ -3678,20 +3737,40 @@ fn blockchain_value_pool_balances_from_vec<E>(
 where
     E: serde::de::Error,
 {
+    let missing_pool_delta = value_pools
+        .iter()
+        .any(|pool| pool.value_delta().is_some() || pool.value_delta_zat().is_some())
+        .then(Amount::zero);
+
     match value_pools.len() {
         5 => {
-            let ironwood_delta = value_pools
-                .iter()
-                .any(|pool| pool.value_delta().is_some() || pool.value_delta_zat().is_some())
-                .then(Amount::zero);
-
             value_pools.push(GetBlockchainInfoBalance::ironwood(
                 Amount::zero(),
-                ironwood_delta,
+                missing_pool_delta,
+            ));
+            #[cfg(zcash_unstable = "nutachyon")]
+            value_pools.push(GetBlockchainInfoBalance::tachyon(
+                Amount::zero(),
+                missing_pool_delta,
             ));
         }
-        6 => {}
-        len => return Err(E::invalid_length(len, &"five or six value pool balances")),
+        6 => {
+            #[cfg(zcash_unstable = "nutachyon")]
+            value_pools.push(GetBlockchainInfoBalance::tachyon(
+                Amount::zero(),
+                missing_pool_delta,
+            ));
+        }
+        #[cfg(zcash_unstable = "nutachyon")]
+        7 => {}
+        len => {
+            #[cfg(not(zcash_unstable = "nutachyon"))]
+            let expected = &"five or six value pool balances";
+            #[cfg(zcash_unstable = "nutachyon")]
+            let expected = &"five, six, or seven value pool balances";
+
+            return Err(E::invalid_length(len, expected));
+        }
     }
 
     value_pools
diff --git a/crates/zakura-rpc/src/methods/tests/snapshot.rs b/crates/zakura-rpc/src/methods/tests/snapshot.rs
index 5d05edac44..ee2cbbe78b 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshot.rs
+++ b/crates/zakura-rpc/src/methods/tests/snapshot.rs
@@ -1020,6 +1020,8 @@ pub async fn test_mining_rpcs<State, ReadState>(
         miner_memo: None,
         // TODO: Use default field values when optional features are enabled in tests #8183
         internal_miner: true,
+        #[cfg(zcash_unstable = "nutachyon")]
+        tachyon_workload: false,
     };
 
     // nu5 block height
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_1@mainnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_1@mainnet_10.snap
index 49b5c9decc..0c39f9a326 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_1@mainnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_1@mainnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: block
 ---
 {
@@ -73,6 +73,14 @@ expression: block
       "monitored": false,
       "valueDelta": 0.0,
       "valueDeltaZat": 0
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false,
+      "valueDelta": 0.0,
+      "valueDeltaZat": 0
     }
   ],
   "trees": {},
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_1@testnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_1@testnet_10.snap
index cb0bcbb39f..4f100179e1 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_1@testnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_1@testnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: block
 ---
 {
@@ -73,6 +73,14 @@ expression: block
       "monitored": false,
       "valueDelta": 0.0,
       "valueDeltaZat": 0
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false,
+      "valueDelta": 0.0,
+      "valueDeltaZat": 0
     }
   ],
   "trees": {},
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_2@mainnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_2@mainnet_10.snap
index 82a48b36fa..31b291622e 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_2@mainnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_2@mainnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: block
 ---
 {
@@ -128,6 +128,14 @@ expression: block
       "monitored": false,
       "valueDelta": 0.0,
       "valueDeltaZat": 0
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false,
+      "valueDelta": 0.0,
+      "valueDeltaZat": 0
     }
   ],
   "trees": {},
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_2@testnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_2@testnet_10.snap
index 9652f62dc2..04e6350c28 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_2@testnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_2@testnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: block
 ---
 {
@@ -128,6 +128,14 @@ expression: block
       "monitored": false,
       "valueDelta": 0.0,
       "valueDeltaZat": 0
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false,
+      "valueDelta": 0.0,
+      "valueDeltaZat": 0
     }
   ],
   "trees": {},
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_default@mainnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_default@mainnet_10.snap
index 49b5c9decc..0c39f9a326 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_default@mainnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_default@mainnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: block
 ---
 {
@@ -73,6 +73,14 @@ expression: block
       "monitored": false,
       "valueDelta": 0.0,
       "valueDeltaZat": 0
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false,
+      "valueDelta": 0.0,
+      "valueDeltaZat": 0
     }
   ],
   "trees": {},
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_default@testnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_default@testnet_10.snap
index cb0bcbb39f..4f100179e1 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_default@testnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_hash_verbosity_default@testnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: block
 ---
 {
@@ -73,6 +73,14 @@ expression: block
       "monitored": false,
       "valueDelta": 0.0,
       "valueDeltaZat": 0
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false,
+      "valueDelta": 0.0,
+      "valueDeltaZat": 0
     }
   ],
   "trees": {},
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_1@mainnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_1@mainnet_10.snap
index 49b5c9decc..0c39f9a326 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_1@mainnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_1@mainnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: block
 ---
 {
@@ -73,6 +73,14 @@ expression: block
       "monitored": false,
       "valueDelta": 0.0,
       "valueDeltaZat": 0
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false,
+      "valueDelta": 0.0,
+      "valueDeltaZat": 0
     }
   ],
   "trees": {},
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_1@testnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_1@testnet_10.snap
index cb0bcbb39f..4f100179e1 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_1@testnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_1@testnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: block
 ---
 {
@@ -73,6 +73,14 @@ expression: block
       "monitored": false,
       "valueDelta": 0.0,
       "valueDeltaZat": 0
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false,
+      "valueDelta": 0.0,
+      "valueDeltaZat": 0
     }
   ],
   "trees": {},
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_2@mainnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_2@mainnet_10.snap
index 82a48b36fa..31b291622e 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_2@mainnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_2@mainnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: block
 ---
 {
@@ -128,6 +128,14 @@ expression: block
       "monitored": false,
       "valueDelta": 0.0,
       "valueDeltaZat": 0
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false,
+      "valueDelta": 0.0,
+      "valueDeltaZat": 0
     }
   ],
   "trees": {},
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_2@testnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_2@testnet_10.snap
index 9652f62dc2..04e6350c28 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_2@testnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_2@testnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: block
 ---
 {
@@ -128,6 +128,14 @@ expression: block
       "monitored": false,
       "valueDelta": 0.0,
       "valueDeltaZat": 0
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false,
+      "valueDelta": 0.0,
+      "valueDeltaZat": 0
     }
   ],
   "trees": {},
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_default@mainnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_default@mainnet_10.snap
index 49b5c9decc..0c39f9a326 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_default@mainnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_default@mainnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: block
 ---
 {
@@ -73,6 +73,14 @@ expression: block
       "monitored": false,
       "valueDelta": 0.0,
       "valueDeltaZat": 0
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false,
+      "valueDelta": 0.0,
+      "valueDeltaZat": 0
     }
   ],
   "trees": {},
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_default@testnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_default@testnet_10.snap
index cb0bcbb39f..4f100179e1 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_default@testnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_block_verbose_height_verbosity_default@testnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: block
 ---
 {
@@ -73,6 +73,14 @@ expression: block
       "monitored": false,
       "valueDelta": 0.0,
       "valueDeltaZat": 0
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false,
+      "valueDelta": 0.0,
+      "valueDeltaZat": 0
     }
   ],
   "trees": {},
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_blockchain_info@mainnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_blockchain_info@mainnet_10.snap
index 78eb8be8ea..9e875dfdaa 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_blockchain_info@mainnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_blockchain_info@mainnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: info
 ---
 {
@@ -55,6 +55,12 @@ expression: info
       "chainValue": 0.0,
       "chainValueZat": 0,
       "monitored": false
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false
     }
   ],
   "upgrades": {
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_blockchain_info@testnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_blockchain_info@testnet_10.snap
index 5e65a23dec..68e6dd9de6 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_blockchain_info@testnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_blockchain_info@testnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: info
 ---
 {
@@ -55,6 +55,12 @@ expression: info
       "chainValue": 0.0,
       "chainValueZat": 0,
       "monitored": false
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false
     }
   ],
   "upgrades": {
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_blockchain_info_future_nu6_height@nu6testnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_blockchain_info_future_nu6_height@nu6testnet_10.snap
index 897d41b14c..63cb87889f 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_blockchain_info_future_nu6_height@nu6testnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_blockchain_info_future_nu6_height@nu6testnet_10.snap
@@ -1,5 +1,5 @@
 ---
-source: zebra-rpc/src/methods/tests/snapshot.rs
+source: crates/zakura-rpc/src/methods/tests/snapshot.rs
 expression: info
 ---
 {
@@ -55,6 +55,12 @@ expression: info
       "chainValue": 0.0,
       "chainValueZat": 0,
       "monitored": false
+    },
+    {
+      "id": "tachyon",
+      "chainValue": 0.0,
+      "chainValueZat": 0,
+      "monitored": false
     }
   ],
   "upgrades": {
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_info@mainnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_info@mainnet_10.snap
index 6aa8f2e1aa..b06015ec0e 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_info@mainnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_info@mainnet_10.snap
@@ -6,7 +6,7 @@ expression: info
   "version": 100,
   "build": "v0.0.1",
   "subversion": "[SubVersion]",
-  "protocolversion": 170160,
+  "protocolversion": 170190,
   "blocks": 10,
   "connections": 0,
   "difficulty": 1.0,
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_info@testnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_info@testnet_10.snap
index 894224b8b3..fc9a0e52cd 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_info@testnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_info@testnet_10.snap
@@ -6,7 +6,7 @@ expression: info
   "version": 100,
   "build": "v0.0.1",
   "subversion": "[SubVersion]",
-  "protocolversion": 170160,
+  "protocolversion": 170190,
   "blocks": 10,
   "connections": 0,
   "difficulty": 1.0,
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_network_info@mainnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_network_info@mainnet_10.snap
index 7f7eb1ccdb..aa90ae69e6 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_network_info@mainnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_network_info@mainnet_10.snap
@@ -5,7 +5,7 @@ expression: get_network_info
 {
   "version": 100,
   "subversion": "RPC test",
-  "protocolversion": 170160,
+  "protocolversion": 170190,
   "localservices": "0000000000000001",
   "timeoffset": 0,
   "connections": 1,
diff --git a/crates/zakura-rpc/src/methods/tests/snapshots/get_network_info@testnet_10.snap b/crates/zakura-rpc/src/methods/tests/snapshots/get_network_info@testnet_10.snap
index 7f7eb1ccdb..aa90ae69e6 100644
--- a/crates/zakura-rpc/src/methods/tests/snapshots/get_network_info@testnet_10.snap
+++ b/crates/zakura-rpc/src/methods/tests/snapshots/get_network_info@testnet_10.snap
@@ -5,7 +5,7 @@ expression: get_network_info
 {
   "version": 100,
   "subversion": "RPC test",
-  "protocolversion": 170160,
+  "protocolversion": 170190,
   "localservices": "0000000000000001",
   "timeoffset": 0,
   "connections": 1,
diff --git a/crates/zakura-rpc/src/methods/tests/utils.rs b/crates/zakura-rpc/src/methods/tests/utils.rs
index 9d6dde1405..26ae2c7af4 100644
--- a/crates/zakura-rpc/src/methods/tests/utils.rs
+++ b/crates/zakura-rpc/src/methods/tests/utils.rs
@@ -22,6 +22,8 @@ pub fn fake_history_tree(network: &Network) -> Arc<HistoryTree> {
         &first_sapling_root,
         &Default::default(),
         &Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )
     .unwrap();
 
diff --git a/crates/zakura-rpc/src/methods/tests/vectors.rs b/crates/zakura-rpc/src/methods/tests/vectors.rs
index 9f0d30e3b4..773d19a69f 100644
--- a/crates/zakura-rpc/src/methods/tests/vectors.rs
+++ b/crates/zakura-rpc/src/methods/tests/vectors.rs
@@ -3094,6 +3094,8 @@ async fn gbt_with(net: Network, addr: ZcashAddress) {
         extra_coinbase_data: None,
         miner_memo: None,
         internal_miner: true,
+        #[cfg(zcash_unstable = "nutachyon")]
+        tachyon_workload: false,
     };
 
     // nu5 block height
@@ -3784,6 +3786,8 @@ async fn rpc_getdifficulty() {
         extra_coinbase_data: None,
         miner_memo: None,
         internal_miner: true,
+        #[cfg(zcash_unstable = "nutachyon")]
+        tachyon_workload: false,
     };
 
     // nu5 block height
diff --git a/crates/zakura-rpc/src/methods/types/get_block_template.rs b/crates/zakura-rpc/src/methods/types/get_block_template.rs
index df4702fb3b..da64eb0b31 100644
--- a/crates/zakura-rpc/src/methods/types/get_block_template.rs
+++ b/crates/zakura-rpc/src/methods/types/get_block_template.rs
@@ -3,6 +3,10 @@
 pub mod constants;
 pub mod parameters;
 pub mod proposal;
+#[cfg(zcash_unstable = "nutachyon")]
+pub mod tachyon;
+#[cfg(zcash_unstable = "nutachyon")]
+mod tachyon_workload;
 pub mod zip317;
 
 #[cfg(test)]
@@ -64,6 +68,11 @@ pub use parameters::{
     GetBlockTemplateCapability, GetBlockTemplateParameters, GetBlockTemplateRequestMode,
 };
 pub use proposal::{BlockProposalResponse, BlockTemplateTimeSource};
+#[cfg(zcash_unstable = "nutachyon")]
+pub(crate) use tachyon_workload::{
+    generate_transactions as generate_tachyon_workload_transactions, REDEEM_SCRIPT_HASH,
+    TRANSACTIONS_PER_BLOCK,
+};
 
 /// An alias to indicate that a usize value represents the depth of in-block dependencies of a
 /// transaction.
@@ -442,6 +451,10 @@ pub struct MinerParams {
     ///
     /// Applies only if [`Self::addr`] contains a shielded component.
     memo: Option<MemoBytes>,
+
+    /// Generate the internal miner's Tachyon test workload.
+    #[cfg(zcash_unstable = "nutachyon")]
+    tachyon_workload: bool,
 }
 
 /// Builds the coinbase input data for a block Zakura constructs.
@@ -463,6 +476,30 @@ impl MinerParams {
     // (`extra_coinbase_data` is length-validated), not a recoverable error.
     #[allow(clippy::unwrap_in_result)]
     pub fn new(net: &Network, conf: config::mining::Config) -> Result<Self, MinerParamsError> {
+        #[cfg(zcash_unstable = "nutachyon")]
+        if conf.tachyon_workload && !conf.internal_miner {
+            return Err(MinerParamsError::TachyonWorkloadNeedsInternalMiner);
+        }
+        #[cfg(zcash_unstable = "nutachyon")]
+        if conf.tachyon_workload && (!net.is_a_test_network() || !net.disable_pow()) {
+            return Err(MinerParamsError::UnsupportedTachyonWorkloadNetwork);
+        }
+
+        #[cfg(zcash_unstable = "nutachyon")]
+        let workload_enabled = conf.tachyon_workload;
+
+        #[cfg(zcash_unstable = "nutachyon")]
+        let addr = if workload_enabled {
+            Address::Transparent(zcash_transparent::address::TransparentAddress::ScriptHash(
+                REDEEM_SCRIPT_HASH,
+            ))
+        } else {
+            conf.miner_address
+                .map(|addr| Address::try_from_zcash_address(net, addr))
+                .ok_or(MinerParamsError::MissingAddr)??
+        };
+
+        #[cfg(not(zcash_unstable = "nutachyon"))]
         let addr = conf
             .miner_address
             .map(|addr| Address::try_from_zcash_address(net, addr))
@@ -483,7 +520,13 @@ impl MinerParams {
             .map(|memo| MemoBytes::from_bytes(memo.as_bytes()))
             .transpose()?;
 
-        Ok(Self { addr, data, memo })
+        Ok(Self {
+            addr,
+            data,
+            memo,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_workload: workload_enabled,
+        })
     }
 
     /// Returns the miner address.
@@ -501,6 +544,12 @@ impl MinerParams {
         self.memo.as_ref()
     }
 
+    /// Is the internal miner's Tachyon workload enabled?
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_workload(&self) -> bool {
+        self.tachyon_workload
+    }
+
     /// Randomizes the memo.
     pub fn randomize_memo(&mut self) {
         let mut random = [0u8; 512];
@@ -522,6 +571,8 @@ impl From<Address> for MinerParams {
             addr,
             data: None,
             memo: None,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_workload: false,
         }
     }
 }
@@ -535,6 +586,12 @@ pub enum MinerParamsError {
     InvalidAddr(zcash_address::ConversionError<&'static str>),
     #[error(transparent)]
     InvalidMemo(#[from] zcash_protocol::memo::Error),
+    #[cfg(zcash_unstable = "nutachyon")]
+    #[error("tachyon_workload requires internal_miner = true")]
+    TachyonWorkloadNeedsInternalMiner,
+    #[cfg(zcash_unstable = "nutachyon")]
+    #[error("tachyon_workload is only supported on proof-of-work-disabled test networks")]
+    UnsupportedTachyonWorkloadNetwork,
 }
 
 impl From<zcash_address::ConversionError<&'static str>> for MinerParamsError {
diff --git a/crates/zakura-rpc/src/methods/types/get_block_template/proposal.rs b/crates/zakura-rpc/src/methods/types/get_block_template/proposal.rs
index fef79555c2..59cc0e9edd 100644
--- a/crates/zakura-rpc/src/methods/types/get_block_template/proposal.rs
+++ b/crates/zakura-rpc/src/methods/types/get_block_template/proposal.rs
@@ -218,6 +218,8 @@ pub fn proposal_block_from_template(
         | NetworkUpgrade::Nu6_2
         | NetworkUpgrade::Nu6_3
         | NetworkUpgrade::Nu7 => block_commitments_hash.bytes_in_serialized_order(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        NetworkUpgrade::NuTachyon => block_commitments_hash.bytes_in_serialized_order(),
         _ => Err(SerializationError::Parse(
             "Zakura does not support generating pre-Canopy block templates",
         ))?,
diff --git a/crates/zakura-rpc/src/methods/types/get_block_template/tachyon.rs b/crates/zakura-rpc/src/methods/types/get_block_template/tachyon.rs
new file mode 100644
index 0000000000..332b1dd13f
--- /dev/null
+++ b/crates/zakura-rpc/src/methods/types/get_block_template/tachyon.rs
@@ -0,0 +1,740 @@
+//! Tachyon transaction aggregation for mined block templates.
+
+use std::{
+    collections::{BTreeMap, BTreeSet, HashSet},
+    sync::Arc,
+    time::Duration,
+};
+
+use rand_10::rngs::ThreadRng;
+use tokio::time::timeout;
+use tower::{BoxError, Service, ServiceExt};
+use zakura_chain::{
+    block::{self, Block},
+    parameters::Network,
+    tachyon,
+    transaction::{Transaction, UnminedTx, VerifiedUnminedTx, WtxId},
+};
+use zakura_state::{ReadRequest, ReadResponse, TachyonMiningData};
+use zcash_tachyon::{Bundle, EpochIndex, PointerStamp, ProofStamp, TachyonBundle};
+
+const STATE_QUERY_TIMEOUT: Duration = Duration::from_secs(5);
+const AGGREGATION_TIMEOUT: Duration = Duration::from_secs(30);
+
+/// Aggregate the selected autonome Tachyon transactions without changing their effecting data.
+///
+/// A Tachyon transaction is omitted unless its anchor and tachygrams are valid for the exact
+/// candidate tip. Proving failures leave the remaining safe transactions autonome, so block
+/// template generation remains available while aggregation is temporarily unavailable.
+pub async fn aggregate_transactions<S>(
+    network: Network,
+    candidate_height: block::Height,
+    tip_hash: block::Hash,
+    mut read_state: S,
+    transactions: Vec<VerifiedUnminedTx>,
+) -> Vec<VerifiedUnminedTx>
+where
+    S: Service<ReadRequest, Response = ReadResponse, Error = BoxError> + Send + Clone + 'static,
+    S::Future: Send + 'static,
+{
+    if !transactions
+        .iter()
+        .any(|tx| tx.transaction.transaction().has_tachyon_shielded_data())
+    {
+        return transactions;
+    }
+
+    let candidates = transactions
+        .iter()
+        .filter_map(|tx| autonome_bundle(tx.transaction.transaction()))
+        .collect::<Vec<_>>();
+
+    if candidates.is_empty() {
+        return without_tachyon_transactions(transactions);
+    }
+
+    let anchors = candidates
+        .iter()
+        .map(|bundle| tachyon::Anchor::from(bundle.stamp.anchor))
+        .collect::<HashSet<_>>();
+    let tachygrams = candidates
+        .into_iter()
+        .flat_map(|bundle| bundle.stamp.tachygrams.iter().copied())
+        .map(tachyon::Tachygram::from)
+        .collect::<HashSet<_>>();
+
+    let request = ReadRequest::TachyonMiningData {
+        anchors,
+        tachygrams,
+        tip_hash,
+        candidate_height,
+    };
+    let state_response = timeout(STATE_QUERY_TIMEOUT, async move {
+        read_state.ready().await?.call(request).await
+    })
+    .await;
+
+    let mining_data = match state_response {
+        Ok(Ok(ReadResponse::TachyonMiningData(Some(mining_data)))) => mining_data,
+        Ok(Ok(ReadResponse::TachyonMiningData(None))) => {
+            return without_tachyon_transactions(transactions);
+        }
+        Ok(Ok(_)) => unreachable!("TachyonMiningData requests have matching responses"),
+        Ok(Err(error)) => {
+            tracing::warn!(?error, "could not load Tachyon mining data");
+            return without_tachyon_transactions(transactions);
+        }
+        Err(_) => {
+            tracing::warn!("timed out loading Tachyon mining data");
+            return without_tachyon_transactions(transactions);
+        }
+    };
+
+    let transactions = valid_for_candidate(&network, candidate_height, transactions, &mining_data);
+    if transactions
+        .iter()
+        .filter_map(|tx| autonome_bundle(tx.transaction.transaction()))
+        .count()
+        < 2
+    {
+        return transactions;
+    }
+
+    let fallback_transactions = transactions.clone();
+    let aggregation = tokio::task::spawn_blocking(move || {
+        aggregate_with_data(&network, transactions, mining_data)
+    });
+
+    match timeout(AGGREGATION_TIMEOUT, aggregation).await {
+        Ok(Ok(Ok(transactions))) => transactions,
+        Ok(Ok(Err(error))) => {
+            tracing::warn!(%error, "could not aggregate Tachyon transactions");
+            fallback_transactions
+        }
+        Ok(Err(error)) => {
+            tracing::warn!(?error, "Tachyon aggregation task failed");
+            fallback_transactions
+        }
+        Err(_) => {
+            tracing::warn!("timed out aggregating Tachyon transactions");
+            fallback_transactions
+        }
+    }
+}
+
+fn valid_for_candidate(
+    network: &Network,
+    candidate_height: block::Height,
+    transactions: Vec<VerifiedUnminedTx>,
+    mining_data: &TachyonMiningData,
+) -> Vec<VerifiedUnminedTx> {
+    let mut seen_descriptors = BTreeSet::new();
+    let mut seen_tachygrams = BTreeSet::new();
+    let mut omitted_ids = HashSet::new();
+    let mut valid = Vec::with_capacity(transactions.len());
+
+    // ZIP-317 selection orders parents before descendants, so recording every omitted mined ID
+    // removes its dependent transactions transitively in this single pass.
+    for transaction in transactions {
+        let mined_id = transaction.transaction.id().mined_id();
+        if transaction
+            .transaction
+            .transaction()
+            .spent_outpoints()
+            .any(|outpoint| omitted_ids.contains(&outpoint.hash))
+        {
+            omitted_ids.insert(mined_id);
+            continue;
+        }
+
+        let Some(data) = transaction
+            .transaction
+            .transaction()
+            .tachyon_shielded_data()
+        else {
+            valid.push(transaction);
+            continue;
+        };
+        let TachyonBundle::Proven(bundle) = &data.0 else {
+            omitted_ids.insert(mined_id);
+            continue;
+        };
+
+        if !bundle.is_autonome() || bundle.verify_coverage(&[]).is_err() {
+            omitted_ids.insert(mined_id);
+            continue;
+        }
+
+        let anchor = tachyon::Anchor::from(bundle.stamp.anchor);
+        let Some(&anchor_height) = mining_data.anchor_heights.get(&anchor) else {
+            omitted_ids.insert(mined_id);
+            continue;
+        };
+        if !tachyon::within_scan_window(network, anchor_height, candidate_height) {
+            omitted_ids.insert(mined_id);
+            continue;
+        }
+
+        let descriptors = bundle
+            .actions
+            .iter()
+            .map(|action| action.descriptor())
+            .collect::<BTreeSet<_>>();
+        if descriptors
+            .iter()
+            .any(|item| seen_descriptors.contains(item))
+        {
+            omitted_ids.insert(mined_id);
+            continue;
+        }
+
+        let tachygrams = bundle
+            .stamp
+            .tachygrams
+            .iter()
+            .copied()
+            .collect::<BTreeSet<_>>();
+        if tachygrams.iter().any(|item| {
+            seen_tachygrams.contains(item)
+                || mining_data
+                    .revealed_tachygrams
+                    .contains(&tachyon::Tachygram::from(*item))
+        }) {
+            omitted_ids.insert(mined_id);
+            continue;
+        }
+
+        seen_descriptors.extend(descriptors);
+        seen_tachygrams.extend(tachygrams);
+        valid.push(transaction);
+    }
+
+    valid
+}
+
+fn without_tachyon_transactions(transactions: Vec<VerifiedUnminedTx>) -> Vec<VerifiedUnminedTx> {
+    let mut omitted_ids = HashSet::new();
+    let mut valid = Vec::with_capacity(transactions.len());
+
+    // Preserve dependency closure when a Tachyon parent is omitted.
+    for transaction in transactions {
+        let mined_id = transaction.transaction.id().mined_id();
+        let depends_on_omitted = transaction
+            .transaction
+            .transaction()
+            .spent_outpoints()
+            .any(|outpoint| omitted_ids.contains(&outpoint.hash));
+
+        if transaction
+            .transaction
+            .transaction()
+            .has_tachyon_shielded_data()
+            || depends_on_omitted
+        {
+            omitted_ids.insert(mined_id);
+        } else {
+            valid.push(transaction);
+        }
+    }
+
+    valid
+}
+
+fn aggregate_with_data(
+    network: &Network,
+    mut transactions: Vec<VerifiedUnminedTx>,
+    mining_data: TachyonMiningData,
+) -> Result<Vec<VerifiedUnminedTx>, String> {
+    let mut epoch_groups = BTreeMap::<u32, Vec<(usize, block::Height)>>::new();
+
+    for (index, transaction) in transactions.iter().enumerate() {
+        let Some(bundle) = autonome_bundle(transaction.transaction.transaction()) else {
+            continue;
+        };
+        let anchor = tachyon::Anchor::from(bundle.stamp.anchor);
+        let Some(&height) = mining_data.anchor_heights.get(&anchor) else {
+            continue;
+        };
+        let Some(epoch) = tachyon::epoch(network, height) else {
+            continue;
+        };
+
+        epoch_groups.entry(epoch).or_default().push((index, height));
+    }
+
+    let mut rng = rand_10::rng();
+    for (epoch, group) in epoch_groups {
+        if group.len() < 2 {
+            continue;
+        }
+
+        aggregate_epoch_group(
+            &mut rng,
+            &mut transactions,
+            &mining_data.blocks,
+            EpochIndex(epoch),
+            &group,
+        )?;
+    }
+
+    Ok(transactions)
+}
+
+fn aggregate_epoch_group(
+    rng: &mut ThreadRng,
+    transactions: &mut [VerifiedUnminedTx],
+    blocks: &BTreeMap<block::Height, Arc<Block>>,
+    epoch: EpochIndex,
+    group: &[(usize, block::Height)],
+) -> Result<(), String> {
+    let target_height = group
+        .iter()
+        .map(|(_index, height)| *height)
+        .max()
+        .expect("non-empty aggregation groups have a target height");
+    let target_anchor = group
+        .iter()
+        .find_map(|(index, height)| {
+            (*height == target_height)
+                .then(|| autonome_bundle(transactions[*index].transaction.transaction()))
+                .flatten()
+                .map(|bundle| bundle.stamp.anchor)
+        })
+        .expect("group transactions have autonome bundles");
+
+    let mut lifted_stamps = Vec::with_capacity(group.len());
+
+    for &(index, start_height) in group {
+        let bundle = autonome_bundle(transactions[index].transaction.transaction())
+            .expect("group transactions have autonome bundles");
+        let descriptors = bundle
+            .actions
+            .iter()
+            .map(|action| action.descriptor())
+            .collect::<BTreeSet<_>>();
+        let mut lifted_bundle = bundle.clone();
+
+        if lifted_bundle.stamp.anchor != target_anchor {
+            let mut next_bundles = Vec::new();
+            for height_value in (start_height.0 + 1)..=target_height.0 {
+                let height = block::Height(height_value);
+                let block = blocks
+                    .get(&height)
+                    .ok_or_else(|| format!("missing block at {height:?} for Tachyon lift"))?;
+                next_bundles.extend(
+                    block
+                        .transactions
+                        .iter()
+                        .filter_map(|transaction| proof_bundle(transaction)),
+                );
+            }
+
+            lifted_bundle = lifted_bundle
+                .lift(rng, &[], (epoch, &next_bundles))
+                .map_err(|error| format!("could not lift Tachyon proof stamp: {error}"))?;
+        }
+
+        lifted_stamps.push((lifted_bundle.stamp, descriptors));
+    }
+
+    let mut lifted_stamps = lifted_stamps.into_iter();
+    let (mut merged_stamp, mut merged_descriptors) = lifted_stamps
+        .next()
+        .expect("non-empty aggregation groups have a first stamp");
+    for (stamp, descriptors) in lifted_stamps {
+        let combined_descriptors = merged_descriptors
+            .union(&descriptors)
+            .copied()
+            .collect::<BTreeSet<_>>();
+        merged_stamp = ProofStamp::merge(
+            rng,
+            (merged_stamp, merged_descriptors),
+            (stamp, descriptors),
+        )
+        .map_err(|error| format!("could not merge Tachyon proof stamps: {error}"))?;
+        merged_descriptors = combined_descriptors;
+    }
+
+    let aggregate_index = group[0].0;
+    let mut aggregate_bundle =
+        autonome_bundle(transactions[aggregate_index].transaction.transaction())
+            .expect("group transactions have autonome bundles")
+            .clone();
+    aggregate_bundle.stamp = merged_stamp;
+    replace_bundle(
+        &mut transactions[aggregate_index],
+        TachyonBundle::Proven(aggregate_bundle),
+    );
+
+    let aggregate_wtxid = WtxId::from(
+        transactions[aggregate_index]
+            .transaction
+            .transaction()
+            .as_ref(),
+    )
+    .as_bytes();
+    let pointer = PointerStamp::try_from(aggregate_wtxid)
+        .map_err(|error| format!("invalid Tachyon aggregate wtxid: {error}"))?;
+
+    for &(index, _height) in &group[1..] {
+        let adjunct = autonome_bundle(transactions[index].transaction.transaction())
+            .expect("group transactions have autonome bundles")
+            .clone()
+            .strip(pointer);
+        replace_bundle(&mut transactions[index], TachyonBundle::Adjunct(adjunct));
+    }
+
+    Ok(())
+}
+
+fn autonome_bundle(transaction: &Transaction) -> Option<&Bundle<ProofStamp>> {
+    let bundle = proof_bundle(transaction)?;
+    bundle.is_autonome().then_some(bundle)
+}
+
+fn proof_bundle(transaction: &Transaction) -> Option<&Bundle<ProofStamp>> {
+    let data = transaction.tachyon_shielded_data()?;
+    let TachyonBundle::Proven(bundle) = &data.0 else {
+        return None;
+    };
+    Some(bundle)
+}
+
+fn replace_bundle(transaction: &mut VerifiedUnminedTx, bundle: TachyonBundle) {
+    let mut mined_transaction = transaction.transaction.transaction().as_ref().clone();
+    let Transaction::V7 {
+        tachyon_shielded_data,
+        ..
+    } = &mut mined_transaction
+    else {
+        unreachable!("Tachyon bundles only appear in V7 transactions");
+    };
+    *tachyon_shielded_data = Some(bundle.into());
+    transaction.transaction = UnminedTx::from(Arc::new(mined_transaction));
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::HashMap;
+
+    use zakura_chain::{
+        amount::Amount,
+        block::{Block, Height},
+        parameters::{testnet::ConfiguredActivationHeights, NetworkUpgrade},
+        serialization::ZcashDeserialize,
+        transaction::LockTime,
+        transparent,
+    };
+    use zcash_tachyon::{
+        entropy::ActionEntropy,
+        keys::private,
+        note::{CommitmentTrapdoor, Note},
+        nullifier,
+        stamp::StampState as _,
+        value, Anchor, TachygramSetPoly,
+    };
+
+    use super::*;
+
+    #[test]
+    fn same_anchor_autonome_transactions_are_aggregated() {
+        let network = nutachyon_network();
+        let anchor = Anchor::read(&[0u8; 32][..]).expect("zero anchor reads");
+        let original = vec![verified_transaction(anchor), verified_transaction(anchor)];
+        let original_ids = original
+            .iter()
+            .map(|tx| tx.transaction.id().mined_id())
+            .collect::<Vec<_>>();
+        let mining_data = TachyonMiningData {
+            tip_anchor: tachyon::Anchor::from(anchor),
+            anchor_heights: HashMap::from([(tachyon::Anchor::from(anchor), Height(10))]),
+            blocks: BTreeMap::new(),
+            revealed_tachygrams: HashSet::new(),
+        };
+
+        let original = valid_for_candidate(&network, Height(11), original, &mining_data);
+        let aggregated = aggregate_with_data(&network, original, mining_data)
+            .expect("same-anchor stamps can be merged");
+
+        assert_aggregated(&aggregated, &original_ids);
+    }
+
+    #[test]
+    fn older_autonome_stamp_is_lifted_before_aggregation() {
+        let network = nutachyon_network();
+        let start_anchor = Anchor::read(&[0u8; 32][..]).expect("zero anchor reads");
+        let intervening_transaction = verified_transaction(start_anchor)
+            .transaction
+            .transaction()
+            .clone();
+        let intervening_bundle = proof_bundle(&intervening_transaction)
+            .expect("intervening transaction has a proof-stamped bundle");
+        let target_anchor = start_anchor
+            .next_stamp(EpochIndex(0), &intervening_bundle.stamp.tachygram_set)
+            .expect("intervening stamp advances the anchor");
+        let original = vec![
+            verified_transaction(start_anchor),
+            verified_transaction(target_anchor),
+        ];
+        let original_ids = original
+            .iter()
+            .map(|tx| tx.transaction.id().mined_id())
+            .collect::<Vec<_>>();
+
+        let mut intervening_block =
+            Block::zcash_deserialize(&zakura_test::vectors::BLOCK_MAINNET_GENESIS_BYTES[..])
+                .expect("hardcoded genesis block deserializes");
+        intervening_block.transactions = vec![intervening_transaction];
+        let mining_data = TachyonMiningData {
+            tip_anchor: tachyon::Anchor::from(target_anchor),
+            anchor_heights: HashMap::from([
+                (tachyon::Anchor::from(start_anchor), Height(10)),
+                (tachyon::Anchor::from(target_anchor), Height(11)),
+            ]),
+            blocks: BTreeMap::from([(Height(11), Arc::new(intervening_block))]),
+            revealed_tachygrams: HashSet::new(),
+        };
+
+        let original = valid_for_candidate(&network, Height(12), original, &mining_data);
+        let aggregated = aggregate_with_data(&network, original, mining_data)
+            .expect("the older stamp can be lifted and merged");
+
+        assert_aggregated(&aggregated, &original_ids);
+        let TachyonBundle::Proven(aggregate) = &aggregated[0]
+            .transaction
+            .transaction()
+            .tachyon_shielded_data()
+            .expect("aggregate has Tachyon data")
+            .0
+        else {
+            panic!("the first transaction should carry the aggregate proof");
+        };
+        assert_eq!(aggregate.stamp.anchor, target_anchor);
+    }
+
+    #[test]
+    fn stale_anchor_transactions_are_omitted() {
+        let network = nutachyon_network();
+        let anchor = Anchor::read(&[0u8; 32][..]).expect("zero anchor reads");
+        let parent = verified_transaction(anchor);
+        let child = verified_dependent_transaction(parent.transaction.id().mined_id());
+        let transactions = vec![parent, child];
+        let mining_data = TachyonMiningData {
+            tip_anchor: tachyon::Anchor::from(anchor),
+            anchor_heights: HashMap::from([(tachyon::Anchor::from(anchor), Height(10))]),
+            blocks: BTreeMap::new(),
+            revealed_tachygrams: HashSet::new(),
+        };
+        let candidate_height = Height(10 + 2 * tachyon::EPOCH_LENGTH);
+
+        assert!(
+            valid_for_candidate(&network, candidate_height, transactions, &mining_data).is_empty(),
+            "stale-anchor transactions and their descendants must not enter a block template",
+        );
+    }
+
+    #[test]
+    fn already_revealed_tachygram_transactions_are_omitted() {
+        let network = nutachyon_network();
+        let anchor = Anchor::read(&[0u8; 32][..]).expect("zero anchor reads");
+        let transaction = verified_transaction(anchor);
+        let revealed = autonome_bundle(transaction.transaction.transaction())
+            .expect("test transaction is autonome")
+            .stamp
+            .tachygrams
+            .iter()
+            .next()
+            .copied()
+            .expect("test stamp has tachygrams");
+        let mining_data = TachyonMiningData {
+            tip_anchor: tachyon::Anchor::from(anchor),
+            anchor_heights: HashMap::from([(tachyon::Anchor::from(anchor), Height(10))]),
+            blocks: BTreeMap::new(),
+            revealed_tachygrams: HashSet::from([tachyon::Tachygram::from(revealed)]),
+        };
+
+        assert!(
+            valid_for_candidate(&network, Height(11), vec![transaction], &mining_data).is_empty(),
+            "a tachygram already revealed in the scan window must not enter a block template",
+        );
+    }
+
+    fn nutachyon_network() -> Network {
+        Network::new_regtest(
+            ConfiguredActivationHeights {
+                canopy: Some(1),
+                nu5: Some(2),
+                nu6: Some(3),
+                nu6_1: Some(4),
+                nu6_2: Some(5),
+                nu6_3: Some(6),
+                nu7: Some(8),
+                nu_tachyon: Some(10),
+                ..Default::default()
+            }
+            .into(),
+        )
+    }
+
+    fn assert_aggregated(
+        aggregated: &[VerifiedUnminedTx],
+        original_ids: &[zakura_chain::transaction::Hash],
+    ) {
+        assert_eq!(
+            aggregated
+                .iter()
+                .map(|tx| tx.transaction.id().mined_id())
+                .collect::<Vec<_>>(),
+            original_ids,
+            "aggregation must not change mined transaction IDs",
+        );
+
+        let TachyonBundle::Proven(aggregate) = &aggregated[0]
+            .transaction
+            .transaction()
+            .tachyon_shielded_data()
+            .expect("aggregate has Tachyon data")
+            .0
+        else {
+            panic!("the first transaction should carry the aggregate proof");
+        };
+        let TachyonBundle::Adjunct(adjunct) = &aggregated[1]
+            .transaction
+            .transaction()
+            .tachyon_shielded_data()
+            .expect("adjunct has Tachyon data")
+            .0
+        else {
+            panic!("the second transaction should point to the aggregate");
+        };
+
+        assert!(aggregate.is_aggregate());
+        let adjunct_dyn: &Bundle<dyn zcash_tachyon::stamp::StampState> = adjunct;
+        assert!(aggregate.is_covering(&[adjunct_dyn]));
+        assert_eq!(
+            adjunct.stamp.stamp_digest(),
+            WtxId::from(aggregated[0].transaction.transaction().as_ref()).as_bytes(),
+        );
+    }
+
+    fn verified_transaction(anchor: Anchor) -> VerifiedUnminedTx {
+        let bundle = autonome_bundle_at(anchor);
+        let transaction = Transaction::V7 {
+            network_upgrade: NetworkUpgrade::NuTachyon,
+            lock_time: LockTime::min_lock_time_timestamp(),
+            expiry_height: Height(0),
+            inputs: Vec::new(),
+            outputs: Vec::new(),
+            sapling_shielded_data: None,
+            orchard_shielded_data: None,
+            ironwood_shielded_data: None,
+            tachyon_shielded_data: Some(TachyonBundle::Proven(bundle).into()),
+        };
+
+        VerifiedUnminedTx::new(
+            UnminedTx::from(transaction),
+            Amount::try_from(100_000u64).expect("fee is in range"),
+            0,
+            0,
+            Arc::new(Vec::new()),
+        )
+        .expect("test transaction pays the conventional fee")
+    }
+
+    fn verified_dependent_transaction(
+        parent: zakura_chain::transaction::Hash,
+    ) -> VerifiedUnminedTx {
+        let transaction = Transaction::V7 {
+            network_upgrade: NetworkUpgrade::NuTachyon,
+            lock_time: LockTime::min_lock_time_timestamp(),
+            expiry_height: Height(0),
+            inputs: vec![transparent::Input::PrevOut {
+                outpoint: transparent::OutPoint {
+                    hash: parent,
+                    index: 0,
+                },
+                unlock_script: transparent::Script::new(&[]),
+                sequence: 0,
+            }],
+            outputs: vec![transparent::Output::new(
+                Amount::zero(),
+                transparent::Script::new(&[]),
+            )],
+            sapling_shielded_data: None,
+            orchard_shielded_data: None,
+            ironwood_shielded_data: None,
+            tachyon_shielded_data: None,
+        };
+
+        VerifiedUnminedTx::new(
+            UnminedTx::from(transaction),
+            Amount::try_from(100_000u64).expect("fee is in range"),
+            0,
+            0,
+            Arc::new(Vec::new()),
+        )
+        .expect("test transaction pays the conventional fee")
+    }
+
+    fn autonome_bundle_at(anchor: Anchor) -> Bundle<ProofStamp> {
+        let mut rng = rand_10::rng();
+        let spending_key = private::SpendingKey::random(&mut rng);
+        let note = Note {
+            pk: spending_key.derive_payment_key(),
+            value: value::Positive::try_from(100u64).expect("positive value"),
+            psi: nullifier::Trapdoor::random(&mut rng),
+            rcm: CommitmentTrapdoor::random(&mut rng),
+        };
+        let padding_note = Note {
+            pk: spending_key.derive_payment_key(),
+            value: value::Positive::try_from(1u64).expect("positive value"),
+            psi: nullifier::Trapdoor::random(&mut rng),
+            rcm: CommitmentTrapdoor::random(&mut rng),
+        };
+        let tachygrams =
+            BTreeSet::from([note.commitment().into(), padding_note.commitment().into()]);
+        let ask = spending_key.derive_auth_private();
+        let theta = ActionEntropy::random(&mut rng);
+        let rcv = value::Trapdoor::random(&mut rng);
+        let spend = zcash_tachyon::action::Plan::spend(note, theta, rcv, |alpha| {
+            ask.derive_action_private(&alpha).derive_action_public()
+        });
+        let plan = zcash_tachyon::bundle::Plan::new(vec![spend], vec![]);
+        let bundle = plan
+            .sign(&mut rng, &[0u8; 32], &ask)
+            .expect("test bundle signs");
+        let coverage = action_descriptor_digest(&bundle.actions);
+        let tachygram_set = tachygrams
+            .iter()
+            .copied()
+            .collect::<TachygramSetPoly>()
+            .commit();
+
+        bundle.stamp(ProofStamp {
+            coverage,
+            anchor,
+            tachygram_set,
+            tachygrams,
+            proof: Box::new(ragu::Proof::trivial()),
+        })
+    }
+
+    fn action_descriptor_digest(actions: &[zcash_tachyon::Action]) -> [u8; 32] {
+        let mut descriptors: Vec<[u8; 64]> =
+            actions.iter().map(|action| action.descriptor()).collect();
+        descriptors.sort_unstable();
+
+        let mut state = blake2b_simd::Params::new()
+            .hash_length(32)
+            .personal(b"Tachyon-Actions")
+            .to_state();
+        for descriptor in descriptors {
+            state.update(&descriptor);
+        }
+        state
+            .finalize()
+            .as_bytes()
+            .try_into()
+            .expect("hash length is 32")
+    }
+}
diff --git a/crates/zakura-rpc/src/methods/types/get_block_template/tachyon_workload.rs b/crates/zakura-rpc/src/methods/types/get_block_template/tachyon_workload.rs
new file mode 100644
index 0000000000..932aac90a7
--- /dev/null
+++ b/crates/zakura-rpc/src/methods/types/get_block_template/tachyon_workload.rs
@@ -0,0 +1,431 @@
+//! Internally generated Tachyon transactions for proof-of-work-disabled test networks.
+
+use std::{collections::HashSet, sync::Arc, time::Duration};
+
+use rand_10::{rngs::StdRng, SeedableRng};
+use tokio::time::timeout;
+use tower::{BoxError, Service, ServiceExt};
+use zcash_tachyon::{
+    action, bundle,
+    entropy::ActionEntropy,
+    keys::private,
+    note::{CommitmentTrapdoor, Note},
+    nullifier, value, TachyonBundle,
+};
+
+use zakura_chain::{
+    amount::Amount,
+    block::{self, Height},
+    parameters::{Network, NetworkUpgrade},
+    transaction::{HashType, LockTime, Transaction, UnminedTx, VerifiedUnminedTx},
+    transparent::{self, MIN_TRANSPARENT_COINBASE_MATURITY},
+};
+use zakura_state::{ReadRequest, ReadResponse};
+
+/// The number of independently proof-stamped transactions generated in each eligible block.
+pub const TRANSACTIONS_PER_BLOCK: usize = 3;
+
+/// HASH160 of the one-byte `OP_TRUE` redeem script used by the workload's coinbase outputs.
+pub const REDEEM_SCRIPT_HASH: [u8; 20] = [
+    0xda, 0x17, 0x45, 0xe9, 0xb5, 0x49, 0xbd, 0x0b, 0xfa, 0x1a, 0x56, 0x99, 0x71, 0xc7, 0x7e, 0xba,
+    0x30, 0xcd, 0x5a, 0x4b,
+];
+
+const OP_TRUE: u8 = 0x51;
+const WORKLOAD_FEE: u64 = 50_000;
+const STATE_QUERY_TIMEOUT: Duration = Duration::from_secs(5);
+
+/// Generate transactions that shield the first newly mature internal-miner reward into Tachyon.
+///
+/// The miner reward at each height is split into [`TRANSACTIONS_PER_BLOCK`] outputs. Exactly when
+/// that reward matures, this function spends every matching output into a separately generated
+/// Tachyon recipient. Recipient randomness and mock-Ragu proof randomness are seeded by the source
+/// outpoint, so repeated templates at the same height contain identical transactions.
+pub async fn generate_transactions<S>(
+    network: &Network,
+    candidate_height: Height,
+    tip_hash: block::Hash,
+    read_state: S,
+) -> Vec<VerifiedUnminedTx>
+where
+    S: Service<ReadRequest, Response = ReadResponse, Error = BoxError> + Send + Clone + 'static,
+    S::Future: Send + 'static,
+{
+    if NetworkUpgrade::current(network, candidate_height) != NetworkUpgrade::NuTachyon {
+        return Vec::new();
+    }
+
+    let Some(source_height) = candidate_height
+        .0
+        .checked_sub(MIN_TRANSPARENT_COINBASE_MATURITY)
+        .map(Height)
+        .filter(|height| *height > Height::MIN)
+    else {
+        return Vec::new();
+    };
+
+    let block_request = read_state
+        .clone()
+        .oneshot(ReadRequest::Block(source_height.into()));
+    let mining_request = read_state.oneshot(ReadRequest::TachyonMiningData {
+        anchors: HashSet::new(),
+        tachygrams: HashSet::new(),
+        tip_hash,
+        candidate_height,
+    });
+
+    let responses = timeout(STATE_QUERY_TIMEOUT, async {
+        tokio::try_join!(block_request, mining_request)
+    })
+    .await;
+
+    let (source_block, tip_anchor) = match responses {
+        Ok(Ok((
+            ReadResponse::Block(Some(source_block)),
+            ReadResponse::TachyonMiningData(Some(mining_data)),
+        ))) => (source_block, mining_data.tip_anchor),
+        Ok(Ok((_block, _mining_data))) => {
+            tracing::warn!(?source_height, "could not load Tachyon workload state");
+            return Vec::new();
+        }
+        Ok(Err(error)) => {
+            tracing::warn!(?error, "could not query Tachyon workload state");
+            return Vec::new();
+        }
+        Err(_) => {
+            tracing::warn!("timed out querying Tachyon workload state");
+            return Vec::new();
+        }
+    };
+
+    let Some(coinbase) = source_block.transactions.first() else {
+        tracing::warn!(
+            ?source_height,
+            "Tachyon workload source block has no coinbase"
+        );
+        return Vec::new();
+    };
+
+    let source_hash = coinbase.hash();
+    let workload_script = workload_address(network).script();
+    let mut transactions = Vec::with_capacity(TRANSACTIONS_PER_BLOCK);
+
+    for (index, output) in coinbase.outputs().iter().enumerate() {
+        if output.lock_script != workload_script {
+            continue;
+        }
+
+        let outpoint = transparent::OutPoint::from_usize(source_hash, index);
+        match build_transaction(candidate_height, outpoint, output.clone(), tip_anchor) {
+            Ok(transaction) => transactions.push(transaction),
+            Err(error) => {
+                tracing::warn!(
+                    ?source_height,
+                    index,
+                    %error,
+                    "could not build Tachyon workload transaction"
+                );
+                return Vec::new();
+            }
+        }
+    }
+
+    if transactions.len() != TRANSACTIONS_PER_BLOCK {
+        tracing::warn!(
+            ?source_height,
+            expected = TRANSACTIONS_PER_BLOCK,
+            actual = transactions.len(),
+            "mature coinbase does not have the expected Tachyon workload outputs",
+        );
+        return Vec::new();
+    }
+
+    transactions
+}
+
+fn workload_address(network: &Network) -> transparent::Address {
+    transparent::Address::from_script_hash(network.t_addr_kind(), REDEEM_SCRIPT_HASH)
+}
+
+fn build_transaction(
+    candidate_height: Height,
+    outpoint: transparent::OutPoint,
+    source_output: transparent::Output,
+    anchor: zakura_chain::tachyon::Anchor,
+) -> Result<VerifiedUnminedTx, String> {
+    let input_value = u64::try_from(source_output.value.zatoshis())
+        .map_err(|error| format!("invalid source value: {error}"))?;
+    let output_value = input_value
+        .checked_sub(WORKLOAD_FEE)
+        .ok_or_else(|| "miner reward part is smaller than the workload fee".to_string())?;
+
+    let mut seed: [u8; 32] = outpoint.hash.into();
+    for (seed_byte, index_byte) in seed
+        .iter_mut()
+        .zip(outpoint.index.to_le_bytes().iter().cycle())
+    {
+        *seed_byte ^= index_byte;
+    }
+    let mut rng = StdRng::from_seed(seed);
+
+    let spending_key = private::SpendingKey::random(&mut rng);
+    let note = Note {
+        pk: spending_key.derive_payment_key(),
+        value: value::Positive::try_from(output_value)
+            .map_err(|error| format!("invalid Tachyon note value: {error}"))?,
+        psi: nullifier::Trapdoor::random(&mut rng),
+        rcm: CommitmentTrapdoor::random(&mut rng),
+    };
+    let output_plan = action::Plan::output(
+        note,
+        ActionEntropy::random(&mut rng),
+        value::Trapdoor::random(&mut rng),
+    );
+    let plan = bundle::Plan::new(Vec::new(), vec![output_plan]);
+    let proof_key = spending_key.derive_proof_private();
+    let auth_key = spending_key.derive_auth_private();
+    let anchor_bytes: [u8; 32] = anchor.into();
+    let anchor = zcash_tachyon::Anchor::read(&anchor_bytes[..])
+        .map_err(|error| format!("invalid stored Tachyon anchor: {error}"))?;
+    let stamp = plan
+        .clone()
+        .stamp_plan(anchor)
+        .prove(&mut rng, &proof_key, Vec::new())
+        .map_err(|error| format!("could not create mock Ragu proof: {error}"))?;
+
+    let placeholder_bundle = plan
+        .sign(&mut rng, &[0; 32], &auth_key)
+        .map_err(|error| format!("could not create placeholder signatures: {error}"))?
+        .stamp(stamp.clone());
+    let placeholder = transaction(
+        candidate_height,
+        outpoint,
+        TachyonBundle::Proven(placeholder_bundle),
+    );
+    let spent_outputs = Arc::new(vec![source_output]);
+    let sighash = placeholder
+        .sighash(
+            NetworkUpgrade::NuTachyon,
+            HashType::ALL,
+            spent_outputs.clone(),
+            None,
+        )
+        .map_err(|error| format!("could not compute V7 sighash: {error}"))?;
+
+    let bundle = plan
+        .sign(&mut rng, sighash.as_ref(), &auth_key)
+        .map_err(|error| format!("could not sign Tachyon bundle: {error}"))?
+        .stamp(stamp);
+    let transaction = transaction(candidate_height, outpoint, TachyonBundle::Proven(bundle));
+    let fee = Amount::try_from(WORKLOAD_FEE)
+        .map_err(|error| format!("invalid Tachyon workload fee: {error}"))?;
+
+    VerifiedUnminedTx::new(UnminedTx::from(transaction), fee, 0, 0, spent_outputs)
+        .map_err(|error| format!("invalid generated transaction: {error}"))
+}
+
+fn transaction(
+    candidate_height: Height,
+    outpoint: transparent::OutPoint,
+    bundle: TachyonBundle,
+) -> Transaction {
+    Transaction::V7 {
+        network_upgrade: NetworkUpgrade::NuTachyon,
+        lock_time: LockTime::min_lock_time_timestamp(),
+        expiry_height: candidate_height,
+        inputs: vec![transparent::Input::PrevOut {
+            outpoint,
+            // Push the one-byte OP_TRUE redeem script onto the P2SH script stack.
+            unlock_script: transparent::Script::new(&[1, OP_TRUE]),
+            sequence: u32::MAX,
+        }],
+        outputs: Vec::new(),
+        sapling_shielded_data: None,
+        orchard_shielded_data: None,
+        ironwood_shielded_data: None,
+        tachyon_shielded_data: Some(bundle.into()),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::HashMap;
+
+    use zakura_chain::{
+        amount::NonNegative,
+        parameters::testnet::ConfiguredActivationHeights,
+        serialization::{ZcashDeserialize, ZcashDeserializeInto},
+        transaction::Hash,
+    };
+    use zakura_node_services::BoxError;
+    use zakura_state::TachyonMiningData;
+    use zakura_test::mock_service::MockService;
+
+    use super::*;
+
+    #[test]
+    fn generated_transaction_has_a_valid_tachyon_bundle() {
+        let network = Network::new_regtest(Default::default());
+        let source_output = transparent::Output::new(
+            Amount::<NonNegative>::try_from(100_000_000u64).expect("test value is valid"),
+            workload_address(&network).script(),
+        );
+        let outpoint = transparent::OutPoint {
+            hash: Hash([7; 32]),
+            index: 2,
+        };
+
+        let generated = build_transaction(
+            Height(200),
+            outpoint,
+            source_output,
+            zakura_chain::tachyon::Anchor::default(),
+        )
+        .expect("output-only mock proof can be generated");
+        let transaction = generated.transaction.transaction();
+        let TachyonBundle::Proven(bundle) = &transaction
+            .tachyon_shielded_data()
+            .expect("generated transaction has Tachyon data")
+            .0
+        else {
+            panic!("generated transaction must carry its own proof");
+        };
+
+        assert!(bundle.is_autonome());
+        assert_eq!(transaction.outputs().len(), 0);
+        assert_eq!(transaction.inputs().len(), 1);
+        assert_eq!(
+            generated.miner_fee,
+            Amount::<NonNegative>::try_from(WORKLOAD_FEE).unwrap()
+        );
+        bundle
+            .verify_coverage(&[])
+            .expect("proof stamp covers the generated action");
+    }
+
+    #[tokio::test]
+    async fn mature_reward_generates_and_aggregates_three_transactions() {
+        let network = Network::new_regtest(
+            ConfiguredActivationHeights {
+                canopy: Some(1),
+                nu5: Some(2),
+                nu6: Some(3),
+                nu6_1: Some(4),
+                nu6_2: Some(5),
+                nu6_3: Some(6),
+                nu7: Some(8),
+                nu_tachyon: Some(10),
+                ..Default::default()
+            }
+            .into(),
+        );
+        let candidate_height = Height(200);
+        let source_height = Height(candidate_height.0 - MIN_TRANSPARENT_COINBASE_MATURITY);
+        let miner_params = super::super::MinerParams::new(
+            &network,
+            crate::config::mining::Config {
+                internal_miner: true,
+                tachyon_workload: true,
+                ..Default::default()
+            },
+        )
+        .expect("test network supports the workload");
+        let coinbase = crate::methods::types::transaction::TransactionTemplate::new_coinbase(
+            &network,
+            source_height,
+            &miner_params,
+            Amount::zero(),
+        )
+        .expect("workload coinbase can be built");
+        let coinbase = coinbase
+            .data
+            .as_ref()
+            .zcash_deserialize_into()
+            .expect("workload coinbase deserializes");
+        let mut source_block =
+            block::Block::zcash_deserialize(&zakura_test::vectors::BLOCK_MAINNET_GENESIS_BYTES[..])
+                .expect("hardcoded genesis block deserializes");
+        source_block.transactions = vec![Arc::new(coinbase)];
+        let tip_hash = source_block.hash();
+        let tip_anchor = zakura_chain::tachyon::Anchor::default();
+
+        let mut read_state: MockService<_, _, _, BoxError> = MockService::build().for_unit_tests();
+        let generation =
+            generate_transactions(&network, candidate_height, tip_hash, read_state.clone());
+        let responses = async {
+            read_state
+                .expect_request(ReadRequest::Block(source_height.into()))
+                .await
+                .respond(ReadResponse::Block(Some(Arc::new(source_block))));
+            read_state
+                .expect_request(ReadRequest::TachyonMiningData {
+                    anchors: HashSet::new(),
+                    tachygrams: HashSet::new(),
+                    tip_hash,
+                    candidate_height,
+                })
+                .await
+                .respond(ReadResponse::TachyonMiningData(Some(TachyonMiningData {
+                    tip_anchor,
+                    anchor_heights: HashMap::new(),
+                    blocks: Default::default(),
+                    revealed_tachygrams: HashSet::new(),
+                })));
+        };
+        let (generated, ()) = tokio::join!(generation, responses);
+
+        assert_eq!(generated.len(), TRANSACTIONS_PER_BLOCK);
+        assert!(generated.iter().all(|transaction| matches!(
+            &transaction
+                .transaction
+                .transaction()
+                .tachyon_shielded_data()
+                .expect("generated transaction has Tachyon data")
+                .0,
+            TachyonBundle::Proven(bundle) if bundle.is_autonome()
+        )));
+
+        let anchor_heights = HashMap::from([(tip_anchor, Height(candidate_height.0 - 1))]);
+        let aggregation = super::super::tachyon::aggregate_transactions(
+            network,
+            candidate_height,
+            tip_hash,
+            read_state.clone(),
+            generated,
+        );
+        let aggregation_response = async {
+            read_state
+                .expect_request_that(|request| {
+                    matches!(request, ReadRequest::TachyonMiningData { .. })
+                })
+                .await
+                .respond(ReadResponse::TachyonMiningData(Some(TachyonMiningData {
+                    tip_anchor,
+                    anchor_heights,
+                    blocks: Default::default(),
+                    revealed_tachygrams: HashSet::new(),
+                })));
+        };
+        let (aggregated, ()) = tokio::join!(aggregation, aggregation_response);
+
+        assert_eq!(aggregated.len(), TRANSACTIONS_PER_BLOCK);
+        assert!(matches!(
+            &aggregated[0]
+                .transaction
+                .transaction()
+                .tachyon_shielded_data()
+                .expect("aggregate has Tachyon data")
+                .0,
+            TachyonBundle::Proven(bundle) if bundle.is_aggregate()
+        ));
+        assert!(aggregated[1..].iter().all(|transaction| matches!(
+            transaction
+                .transaction
+                .transaction()
+                .tachyon_shielded_data()
+                .expect("adjunct has Tachyon data")
+                .0,
+            TachyonBundle::Adjunct(_)
+        )));
+    }
+}
diff --git a/crates/zakura-rpc/src/methods/types/get_block_template/tests.rs b/crates/zakura-rpc/src/methods/types/get_block_template/tests.rs
index 307455e43f..081d1e23ef 100644
--- a/crates/zakura-rpc/src/methods/types/get_block_template/tests.rs
+++ b/crates/zakura-rpc/src/methods/types/get_block_template/tests.rs
@@ -126,6 +126,130 @@ fn local_genesis_activation_coinbase_includes_lockbox_marker() -> anyhow::Result
     Ok(())
 }
 
+/// The Tachyon workload is limited to internal mining on proof-of-work-disabled test networks and
+/// splits the miner reward into independently spendable outputs.
+#[cfg(zcash_unstable = "nutachyon")]
+#[test]
+fn tachyon_workload_coinbase_outputs() {
+    use crate::{
+        config::mining::Config,
+        methods::types::get_block_template::{REDEEM_SCRIPT_HASH, TRANSACTIONS_PER_BLOCK},
+    };
+
+    let network = Network::new_regtest(Default::default());
+    let config = Config {
+        internal_miner: true,
+        tachyon_workload: true,
+        ..Default::default()
+    };
+    let miner_params = MinerParams::new(&network, config.clone())
+        .expect("proof-of-work-disabled test networks support the Tachyon workload");
+    let height = Height(20);
+    let template =
+        TransactionTemplate::new_coinbase(&network, height, &miner_params, Amount::zero())
+            .expect("workload coinbase can be built");
+    let coinbase: Transaction = template
+        .data()
+        .as_ref()
+        .zcash_deserialize_into()
+        .expect("workload coinbase deserializes");
+    let workload_script =
+        transparent::Address::from_script_hash(network.t_addr_kind(), REDEEM_SCRIPT_HASH).script();
+
+    assert_eq!(
+        coinbase
+            .outputs()
+            .iter()
+            .filter(|output| output.lock_script == workload_script)
+            .count(),
+        TRANSACTIONS_PER_BLOCK,
+    );
+
+    let mut missing_internal_miner = config;
+    missing_internal_miner.internal_miner = false;
+    assert!(MinerParams::new(&network, missing_internal_miner).is_err());
+    assert!(MinerParams::new(
+        &Network::Mainnet,
+        Config {
+            internal_miner: true,
+            tachyon_workload: true,
+            ..Default::default()
+        }
+    )
+    .is_err());
+}
+
+/// A NuTachyon template must convert into a mineable proposal block.
+#[cfg(zcash_unstable = "nutachyon")]
+#[test]
+fn nu_tachyon_template_converts_to_proposal_block() -> anyhow::Result<()> {
+    use crate::methods::types::{
+        get_block_template::proposal::proposal_block_from_template, long_poll::LongPollInput,
+    };
+    use zakura_chain::{
+        block::ChainHistoryMmrRootHash,
+        serialization::{BytesInDisplayOrder, DateTime32},
+        work::difficulty::{CompactDifficulty, ExpandedDifficulty, U256},
+    };
+
+    let net = testnet::Parameters::build()
+        .with_activation_heights(ConfiguredActivationHeights {
+            canopy: Some(1),
+            nu5: Some(2),
+            nu6: Some(3),
+            nu6_1: Some(4),
+            nu6_2: Some(5),
+            nu6_3: Some(6),
+            nu_tachyon: Some(7),
+            ..Default::default()
+        })?
+        .clear_funding_streams()
+        .to_network()?;
+    let height = NetworkUpgrade::NuTachyon
+        .activation_height(&net)
+        .ok_or(anyhow!("NuTachyon activation height must be configured"))?;
+    let tip_height = height.previous()?;
+    let miner_params = MinerParams::from(
+        Address::decode(
+            &net,
+            default_miner_address(net.kind(), &MinerAddressType::Transparent),
+        )
+        .ok_or(anyhow!("hard-coded transparent address must be valid"))?,
+    );
+    let now = DateTime32::now();
+    let chain_info = zakura_state::GetBlockTemplateChainInfo {
+        tip_hash: net.genesis_hash(),
+        tip_height,
+        chain_history_root: Some(ChainHistoryMmrRootHash::default()),
+        expected_difficulty: CompactDifficulty::from(ExpandedDifficulty::from(U256::one())),
+        cur_time: now,
+        min_time: now,
+        max_time: now,
+    };
+    let long_poll_id = LongPollInput::new(tip_height, chain_info.tip_hash, now, []).generate_id();
+    let template = super::BlockTemplateResponse::new_internal(
+        &net,
+        None,
+        &miner_params,
+        &chain_info,
+        long_poll_id,
+        vec![],
+        None,
+    );
+
+    let block = proposal_block_from_template(&template, None, &net)?;
+
+    assert_eq!(
+        block.header.commitment_bytes.0,
+        template
+            .default_roots
+            .block_commitments_hash
+            .bytes_in_serialized_order(),
+    );
+
+    Ok(())
+}
+
 /// The Zakura marker is always prepended, and `extra_coinbase_data` can't exceed
 /// the limit.
 #[test]
diff --git a/crates/zakura-rpc/src/methods/types/get_blockchain_info.rs b/crates/zakura-rpc/src/methods/types/get_blockchain_info.rs
index 227e76b47d..9c351aafc7 100644
--- a/crates/zakura-rpc/src/methods/types/get_blockchain_info.rs
+++ b/crates/zakura-rpc/src/methods/types/get_blockchain_info.rs
@@ -9,6 +9,8 @@ use zakura_chain::{
 
 use zec::Zec;
 
+use crate::methods::BlockchainValuePoolBalances;
+
 use super::*;
 
 /// A value pool's balance in Zec and Zatoshis
@@ -37,9 +39,8 @@ pub struct GetBlockchainInfoBalance {
 }
 
 impl GetBlockchainInfoBalance {
-    /// Returns zero-value transparent, Sprout, Sapling, Orchard, Lockbox, and
-    /// Ironwood value pools.
-    pub fn zero_pools() -> [Self; 6] {
+    /// Returns zero-value entries for every tracked value pool.
+    pub fn zero_pools() -> BlockchainValuePoolBalances {
         Self::value_pools(Default::default(), None)
     }
 
@@ -88,18 +89,22 @@ impl GetBlockchainInfoBalance {
         Self::new_internal("ironwood", amount, delta)
     }
 
+    /// Creates a [`GetBlockchainInfoBalance`] for the Tachyon pool.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon(amount: Amount<NonNegative>, delta: Option<Amount<NegativeAllowed>>) -> Self {
+        Self::new_internal("tachyon", amount, delta)
+    }
+
     /// Creates a [`GetBlockchainInfoBalance`] for the Lockbox pool.
     pub fn deferred(amount: Amount<NonNegative>, delta: Option<Amount<NegativeAllowed>>) -> Self {
         Self::new_internal("lockbox", amount, delta)
     }
 
-    /// Converts a [`ValueBalance`] to transparent, Sprout, Sapling, Orchard,
-    /// Lockbox, and Ironwood value pool entries, keeping the pre-Ironwood pool
-    /// indexes stable.
+    /// Converts a [`ValueBalance`] to RPC value pool entries in activation order.
     pub fn value_pools(
         value_balance: ValueBalance<NonNegative>,
         delta_balance: Option<ValueBalance<NegativeAllowed>>,
-    ) -> [Self; 6] {
+    ) -> BlockchainValuePoolBalances {
         [
             Self::transparent(
                 value_balance.transparent_amount(),
@@ -125,6 +130,11 @@ impl GetBlockchainInfoBalance {
                 value_balance.ironwood_amount(),
                 delta_balance.map(|b| b.ironwood_amount()),
             ),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Self::tachyon(
+                value_balance.tachyon_amount(),
+                delta_balance.map(|b| b.tachyon_amount()),
+            ),
         ]
     }
 
@@ -143,3 +153,40 @@ impl GetBlockchainInfoBalance {
             .expect("at least one pool")
     }
 }
+
+#[cfg(all(test, zcash_unstable = "nutachyon"))]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn tachyon_pool_is_included_in_rpc_balances_and_chain_supply() {
+        let tachyon_amount = Amount::try_from(123_456_u64).expect("test amount is valid");
+        let value_balance = ValueBalance::from_tachyon_amount(tachyon_amount);
+
+        let pools = GetBlockchainInfoBalance::value_pools(value_balance, None);
+
+        assert_eq!(pools.len(), 7);
+        assert_eq!(pools[6].id().as_str(), "tachyon");
+        assert_eq!(pools[6].chain_value_zat(), tachyon_amount);
+        assert_eq!(
+            GetBlockchainInfoBalance::chain_supply(value_balance).chain_value_zat(),
+            tachyon_amount,
+        );
+    }
+
+    #[test]
+    fn legacy_rpc_balances_decode_with_an_empty_tachyon_pool() {
+        let legacy_pools = GetBlockchainInfoBalance::value_pools(ValueBalance::zero(), None)
+            .into_iter()
+            .take(6)
+            .collect();
+
+        let pools = crate::methods::blockchain_value_pool_balances_from_vec::<
+            serde::de::value::Error,
+        >(legacy_pools)
+        .expect("six-pool RPC balances remain compatible");
+
+        assert_eq!(pools[6].id().as_str(), "tachyon");
+        assert_eq!(pools[6].chain_value_zat(), Amount::<NonNegative>::zero());
+    }
+}
diff --git a/crates/zakura-rpc/src/methods/types/transaction.rs b/crates/zakura-rpc/src/methods/types/transaction.rs
index 7fc8dd9bc4..a2209b0ac8 100644
--- a/crates/zakura-rpc/src/methods/types/transaction.rs
+++ b/crates/zakura-rpc/src/methods/types/transaction.rs
@@ -220,6 +220,28 @@ impl TransactionTemplate<NegativeOrZero> {
         };
 
         let add_transparent_reward = |builder: &mut Builder<_, _>, addr| {
+            #[cfg(zcash_unstable = "nutachyon")]
+            if miner_params.tachyon_workload() {
+                let output_count = super::get_block_template::TRANSACTIONS_PER_BLOCK;
+                let output_count_u64 =
+                    u64::try_from(output_count).expect("the fixed workload count fits in u64");
+                let total = miner_reward.into_u64();
+                let quotient = total / output_count_u64;
+                let remainder = total % output_count_u64;
+
+                return (0..output_count)
+                    .try_for_each(|index| {
+                        let value = quotient + u64::from(index == 0) * remainder;
+                        builder.add_transparent_output(
+                            addr,
+                            Zatoshis::from_u64(value)
+                                .expect("parts of a valid miner reward remain valid"),
+                        )
+                    })
+                    .map_err(|err| tracing::error!("Failed to add transparent output: {err}"))
+                    .ok();
+            }
+
             trace_err!(
                 builder.add_transparent_output(addr, miner_reward),
                 "transparent"
diff --git a/crates/zakura-rpc/tests/serialization_tests.rs b/crates/zakura-rpc/tests/serialization_tests.rs
index 2d9b89bee0..0e32b44b52 100644
--- a/crates/zakura-rpc/tests/serialization_tests.rs
+++ b/crates/zakura-rpc/tests/serialization_tests.rs
@@ -236,12 +236,22 @@ fn test_get_blockchain_info_accepts_legacy_value_pools() -> Result<(), Box<dyn s
     let obj: GetBlockchainInfoResponse = serde_json::from_value(json)?;
     let value_pools = obj.value_pools();
 
+    #[cfg(not(zcash_unstable = "nutachyon"))]
     assert_eq!(value_pools.len(), 6);
+    #[cfg(zcash_unstable = "nutachyon")]
+    assert_eq!(value_pools.len(), 7);
     assert_eq!(value_pools[4].id().as_str(), "deferred");
     assert_eq!(value_pools[5].id().as_str(), "ironwood");
     assert_eq!(value_pools[5].chain_value_zat().zatoshis(), 0);
     assert!(value_pools[5].value_delta().is_none());
     assert!(value_pools[5].value_delta_zat().is_none());
+    #[cfg(zcash_unstable = "nutachyon")]
+    {
+        assert_eq!(value_pools[6].id().as_str(), "tachyon");
+        assert_eq!(value_pools[6].chain_value_zat().zatoshis(), 0);
+        assert!(value_pools[6].value_delta().is_none());
+        assert!(value_pools[6].value_delta_zat().is_none());
+    }
 
     Ok(())
 }
@@ -474,7 +484,10 @@ fn test_get_block_accepts_legacy_value_pools() -> Result<(), Box<dyn std::error:
         .as_ref()
         .expect("verbose block has valuePools");
 
+    #[cfg(not(zcash_unstable = "nutachyon"))]
     assert_eq!(value_pools.len(), 6);
+    #[cfg(zcash_unstable = "nutachyon")]
+    assert_eq!(value_pools.len(), 7);
     assert_eq!(value_pools[4].id().as_str(), "lockbox");
     assert_eq!(value_pools[5].id().as_str(), "ironwood");
     assert_eq!(value_pools[5].chain_value_zat().zatoshis(), 0);
@@ -485,6 +498,18 @@ fn test_get_block_accepts_legacy_value_pools() -> Result<(), Box<dyn std::error:
             .map(|amount| amount.zatoshis()),
         Some(0)
     );
+    #[cfg(zcash_unstable = "nutachyon")]
+    {
+        assert_eq!(value_pools[6].id().as_str(), "tachyon");
+        assert_eq!(value_pools[6].chain_value_zat().zatoshis(), 0);
+        assert!(value_pools[6].value_delta().is_some());
+        assert_eq!(
+            value_pools[6]
+                .value_delta_zat()
+                .map(|amount| amount.zatoshis()),
+            Some(0)
+        );
+    }
 
     Ok(())
 }
diff --git a/crates/zakura-state/Cargo.toml b/crates/zakura-state/Cargo.toml
index e57caa75bc..c1065f4b51 100644
--- a/crates/zakura-state/Cargo.toml
+++ b/crates/zakura-state/Cargo.toml
@@ -87,6 +87,9 @@ proptest-derive = { workspace = true, optional = true }
 derive-getters.workspace = true
 derive-new.workspace = true
 
+[target.'cfg(zcash_unstable = "nutachyon")'.dependencies]
+zcash_tachyon = { workspace = true }
+
 [dev-dependencies]
 zakura-header-chain = { path = "../zakura-header-chain", version = "2.0.0", features = ["test-support"] }
 color-eyre = { workspace = true }
diff --git a/crates/zakura-state/src/constants.rs b/crates/zakura-state/src/constants.rs
index ab5b73eae2..b65aa3607b 100644
--- a/crates/zakura-state/src/constants.rs
+++ b/crates/zakura-state/src/constants.rs
@@ -95,7 +95,10 @@ pub const MAX_PRUNE_HEIGHTS_PER_COMMIT: u32 = 100;
 ///
 /// Instead of using this constant directly, use [`constants::state_database_format_version_in_code()`]
 /// or [`config::database_format_version_on_disk()`] to get the full semantic format version.
+#[cfg(not(zcash_unstable = "nutachyon"))]
 const DATABASE_FORMAT_VERSION: u64 = 28;
+#[cfg(zcash_unstable = "nutachyon")]
+const DATABASE_FORMAT_VERSION: u64 = 29;
 
 /// The database format minor version, incremented each time the on-disk database format has a
 /// significant data format change.
@@ -104,11 +107,23 @@ const DATABASE_FORMAT_VERSION: u64 = 28;
 /// - adding new column families,
 /// - changing the format of a column family in a compatible way, or
 /// - breaking changes with compatibility code in all supported Zebra versions.
+///
+/// Version history:
+/// - 29.0.0: adds the Tachyon anchor and Tachygram column families, widens the chain value
+///   balance from 48 to 56 bytes, and widens history entries for the V4 history-node fields.
+///   Existing value-balance and history rows remain readable, so version 29 can reuse a version
+///   28 database without a row migration.
+#[cfg(not(zcash_unstable = "nutachyon"))]
 const DATABASE_FORMAT_MINOR_VERSION: u64 = 1;
+#[cfg(zcash_unstable = "nutachyon")]
+const DATABASE_FORMAT_MINOR_VERSION: u64 = 0;
 
 /// The database format patch version, incremented each time the on-disk database format has a
 /// significant format compatibility fix.
+#[cfg(not(zcash_unstable = "nutachyon"))]
 const DATABASE_FORMAT_PATCH_VERSION: u64 = 5;
+#[cfg(zcash_unstable = "nutachyon")]
+const DATABASE_FORMAT_PATCH_VERSION: u64 = 0;
 
 /// Returns the full semantic version of the currently running state database format code.
 ///
diff --git a/crates/zakura-state/src/error.rs b/crates/zakura-state/src/error.rs
index d598a82229..48e1d09e48 100644
--- a/crates/zakura-state/src/error.rs
+++ b/crates/zakura-state/src/error.rs
@@ -767,6 +767,10 @@ pub enum ValidateContextError {
     #[error("error updating a note commitment tree: {0}")]
     NoteCommitmentTreeError(#[from] zakura_chain::parallel::tree::NoteCommitmentTreeError),
 
+    #[error("error advancing the Tachyon anchor: {0}")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonAnchorError(#[source] Arc<zcash_tachyon::AnchorError>),
+
     #[error("error building the history tree: {0}")]
     HistoryTreeError(#[from] Arc<HistoryTreeError>),
 
@@ -820,6 +824,31 @@ pub enum ValidateContextError {
         tx_index_in_block: Option<usize>,
         transaction_hash: transaction::Hash,
     },
+
+    #[error("unknown Tachyon anchor {anchor:?}")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    #[non_exhaustive]
+    UnknownTachyonAnchor {
+        anchor: zakura_chain::tachyon::Anchor,
+        height: Option<block::Height>,
+        tx_index_in_block: Option<usize>,
+        transaction_hash: transaction::Hash,
+    },
+
+    #[error("duplicate Tachyon Tachygram {tachygram:?}, in finalized state: {in_finalized_state}")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    #[non_exhaustive]
+    DuplicateTachyonTachygram {
+        tachygram: zakura_chain::tachyon::Tachygram,
+        in_finalized_state: bool,
+    },
+}
+
+#[cfg(zcash_unstable = "nutachyon")]
+impl From<zcash_tachyon::AnchorError> for ValidateContextError {
+    fn from(error: zcash_tachyon::AnchorError) -> Self {
+        Self::TachyonAnchorError(Arc::new(error))
+    }
 }
 
 impl ValidateContextError {
@@ -853,6 +882,10 @@ impl ValidateContextError {
             | Self::HistoryTreeError(_) => {
                 BodyVerificationClass::Retryable(TransientBodyFailureKind::Storage)
             }
+            #[cfg(zcash_unstable = "nutachyon")]
+            Self::TachyonAnchorError(_) => {
+                BodyVerificationClass::Retryable(TransientBodyFailureKind::Storage)
+            }
             Self::InvalidBlockCommitment(error) => {
                 let kind = match error {
                     CommitmentError::InvalidAuthDataRoot { .. } => BodyCommitmentKind::AuthDataRoot,
@@ -942,6 +975,12 @@ impl ValidateContextError {
             Self::UnknownSaplingAnchor { .. } => consensus("context.unknown_sapling_anchor"),
             Self::UnknownOrchardAnchor { .. } => consensus("context.unknown_orchard_anchor"),
             Self::UnknownIronwoodAnchor { .. } => consensus("context.unknown_ironwood_anchor"),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Self::UnknownTachyonAnchor { .. } => consensus("context.unknown_tachyon_anchor"),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Self::DuplicateTachyonTachygram { .. } => {
+                consensus("context.duplicate_tachyon_tachygram")
+            }
         }
     }
 
@@ -971,6 +1010,10 @@ impl ValidateContextError {
             | ValidateContextError::UnknownSaplingAnchor { .. }
             | ValidateContextError::UnknownOrchardAnchor { .. }
             | ValidateContextError::UnknownIronwoodAnchor { .. } => 100,
+            #[cfg(zcash_unstable = "nutachyon")]
+            ValidateContextError::DuplicateTachyonTachygram { .. } => 100,
+            #[cfg(zcash_unstable = "nutachyon")]
+            ValidateContextError::UnknownTachyonAnchor { .. } => 100,
 
             // Residual arithmetic failures in our own value summation, not
             // consensus violations. `remaining_transaction_value()` and
@@ -1001,6 +1044,8 @@ impl ValidateContextError {
             | ValidateContextError::OrphanedBlock { .. }
             | ValidateContextError::NoteCommitmentTreeError(_)
             | ValidateContextError::HistoryTreeError(_) => 0,
+            #[cfg(zcash_unstable = "nutachyon")]
+            ValidateContextError::TachyonAnchorError(_) => 0,
         }
     }
 
diff --git a/crates/zakura-state/src/lib.rs b/crates/zakura-state/src/lib.rs
index 3210385ce8..d30177183f 100644
--- a/crates/zakura-state/src/lib.rs
+++ b/crates/zakura-state/src/lib.rs
@@ -64,6 +64,8 @@ pub use request::{
 #[cfg(feature = "indexer")]
 pub use request::Spend;
 
+#[cfg(zcash_unstable = "nutachyon")]
+pub use response::TachyonMiningData;
 pub use response::{
     AnyTx, BlockSyncBodyMetadata, GetBlockTemplateChainInfo, KnownBlock, MinedTx,
     NonFinalizedBlocksListener, ReadResponse, Response,
diff --git a/crates/zakura-state/src/request.rs b/crates/zakura-state/src/request.rs
index 9f699e4a65..2728582331 100644
--- a/crates/zakura-state/src/request.rs
+++ b/crates/zakura-state/src/request.rs
@@ -11,6 +11,8 @@ use std::{
 };
 
 use tower::{BoxError, Service, ServiceExt};
+#[cfg(zcash_unstable = "nutachyon")]
+use zakura_chain::tachyon;
 use zakura_chain::{
     amount::{DeferredPoolBalanceChange, NegativeAllowed},
     block::{
@@ -370,6 +372,10 @@ impl Treestate {
         sapling_subtree: Option<NoteCommitmentSubtree<sapling_crypto::Node>>,
         orchard_subtree: Option<NoteCommitmentSubtree<orchard::tree::Node>>,
         ironwood_subtree: Option<NoteCommitmentSubtree<ironwood::tree::Node>>,
+        #[cfg(zcash_unstable = "nutachyon")] tachyon_anchor: zakura_chain::tachyon::Anchor,
+        #[cfg(zcash_unstable = "nutachyon")] tachyon_epoch_anchor: Option<
+            zakura_chain::tachyon::Anchor,
+        >,
         history_tree: Arc<HistoryTree>,
     ) -> Self {
         Self {
@@ -381,6 +387,10 @@ impl Treestate {
                 orchard_subtree,
                 ironwood,
                 ironwood_subtree,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_anchor,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_epoch_anchor,
             },
             history_tree,
         }
@@ -1463,6 +1473,25 @@ pub enum ReadRequest {
     /// with the pool values of the current best chain tip.
     TipPoolValues,
 
+    /// Returns the chain data needed to aggregate transactions rooted at Tachyon anchors.
+    ///
+    /// Returns [`ReadResponse::TachyonMiningData`] if `tip_hash` is still the current best-chain
+    /// tip. Unknown anchors are omitted. For every epoch represented by a known anchor, the
+    /// response also contains the current tip anchor, the blocks between the earliest and latest
+    /// requested anchors, and any requested tachygrams already revealed within the candidate's
+    /// two-epoch window.
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonMiningData {
+        /// Anchors referenced by the selected autonome transactions.
+        anchors: HashSet<tachyon::Anchor>,
+        /// Tachygrams revealed by the selected autonome transactions.
+        tachygrams: HashSet<tachyon::Tachygram>,
+        /// The chain tip on which the block template is being built.
+        tip_hash: block::Hash,
+        /// The height of the candidate block being built on `tip_hash`.
+        candidate_height: block::Height,
+    },
+
     /// Looks up the block info after a block by hash or height in the current best chain.
     ///
     /// * [`ReadResponse::BlockInfo(Some(pool_values))`](ReadResponse::BlockInfo) if the block is in the best chain;
@@ -1939,6 +1968,8 @@ impl ReadRequest {
             ReadRequest::Tip => "tip",
             ReadRequest::FinalizedTip => "finalized_tip",
             ReadRequest::TipPoolValues => "tip_pool_values",
+            #[cfg(zcash_unstable = "nutachyon")]
+            ReadRequest::TachyonMiningData { .. } => "tachyon_mining_data",
             ReadRequest::BlockInfo(_) => "block_info",
             ReadRequest::Depth(_) => "depth",
             ReadRequest::Block(_) => "block",
diff --git a/crates/zakura-state/src/response.rs b/crates/zakura-state/src/response.rs
index 4293db3d48..2578f6d1e1 100644
--- a/crates/zakura-state/src/response.rs
+++ b/crates/zakura-state/src/response.rs
@@ -7,6 +7,10 @@ use std::{
 
 use chrono::{DateTime, Utc};
 
+#[cfg(zcash_unstable = "nutachyon")]
+use std::collections::HashMap;
+#[cfg(zcash_unstable = "nutachyon")]
+use zakura_chain::tachyon;
 use zakura_chain::{
     amount::{Amount, NonNegative},
     block::{self, Block, ChainHistoryMmrRootHash},
@@ -35,6 +39,23 @@ use crate::{
 #[cfg(test)]
 mod tests;
 
+/// Best-chain data used to aggregate selected autonome Tachyon transactions.
+#[derive(Clone, Debug, PartialEq, Eq)]
+#[cfg(zcash_unstable = "nutachyon")]
+pub struct TachyonMiningData {
+    /// The Tachyon anchor at the current best-chain tip.
+    pub tip_anchor: tachyon::Anchor,
+
+    /// Heights that created the requested anchors. Unknown anchors are omitted.
+    pub anchor_heights: HashMap<tachyon::Anchor, block::Height>,
+
+    /// Blocks needed to advance from each epoch's earliest requested anchor to its latest one.
+    pub blocks: BTreeMap<block::Height, Arc<Block>>,
+
+    /// Requested tachygrams already revealed in the candidate block's two-epoch window.
+    pub revealed_tachygrams: HashSet<tachyon::Tachygram>,
+}
+
 #[derive(Clone, Debug, PartialEq, Eq)]
 /// A response to a [`StateService`](crate::service::StateService) [`Request`].
 pub enum Response {
@@ -427,6 +448,11 @@ pub enum ReadResponse {
         value_balance: ValueBalance<NonNegative>,
     },
 
+    /// Response to [`ReadRequest::TachyonMiningData`], or `None` when the requested chain tip is
+    /// no longer current.
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonMiningData(Option<TachyonMiningData>),
+
     /// Response to [`ReadRequest::BlockInfo`] with
     /// the block info after the specified block.
     BlockInfo(Option<BlockInfo>),
@@ -729,6 +755,11 @@ impl TryFrom<ReadResponse> for Response {
                 Err("there is no corresponding Response for this ReadResponse")
             }
 
+            #[cfg(zcash_unstable = "nutachyon")]
+            ReadResponse::TachyonMiningData(_) => {
+                Err("there is no corresponding Response for this ReadResponse")
+            }
+
             #[cfg(feature = "indexer")]
             ReadResponse::TransactionId(_) | ReadResponse::RawBlocks(_) => {
                 Err("there is no corresponding Response for this ReadResponse")
diff --git a/crates/zakura-state/src/service.rs b/crates/zakura-state/src/service.rs
index 862677446e..6cbaf4c6ef 100644
--- a/crates/zakura-state/src/service.rs
+++ b/crates/zakura-state/src/service.rs
@@ -2499,6 +2499,103 @@ impl Service<ReadRequest> for ReadStateService {
                 })
             }
 
+            #[cfg(zcash_unstable = "nutachyon")]
+            ReadRequest::TachyonMiningData {
+                anchors,
+                tachygrams,
+                tip_hash,
+                candidate_height,
+            } => {
+                let best_chain = state.latest_best_chain();
+                if read::tip(best_chain.clone(), &state.db).is_none_or(
+                    |(current_tip_height, current_tip_hash)| {
+                        current_tip_hash != tip_hash
+                            || current_tip_height.0.checked_add(1) != Some(candidate_height.0)
+                    },
+                ) {
+                    return Ok(ReadResponse::TachyonMiningData(None));
+                }
+
+                let anchor_heights: HashMap<_, _> = anchors
+                    .into_iter()
+                    .filter_map(|anchor| {
+                        best_chain
+                            .as_ref()
+                            .and_then(|chain| chain.tachyon_anchors.get(&anchor))
+                            .and_then(|heights| heights.last().copied())
+                            .or_else(|| state.db.tachyon_anchor_height(&anchor))
+                            .map(|height| (anchor, height))
+                    })
+                    .collect();
+
+                let tip_anchor = best_chain.as_ref().map_or_else(
+                    || state.db.tachyon_anchor_for_tip(),
+                    |chain| chain.tachyon_anchor_for_tip(),
+                );
+
+                let mut epoch_ranges = HashMap::new();
+                for &height in anchor_heights.values() {
+                    let Some(epoch) = zakura_chain::tachyon::epoch(&state.network, height) else {
+                        continue;
+                    };
+
+                    epoch_ranges
+                        .entry(epoch)
+                        .and_modify(|(start, end): &mut (block::Height, block::Height)| {
+                            *start = (*start).min(height);
+                            *end = (*end).max(height);
+                        })
+                        .or_insert((height, height));
+                }
+
+                let mut blocks = BTreeMap::new();
+                for (start, end) in epoch_ranges.into_values() {
+                    if start == end {
+                        continue;
+                    }
+
+                    for height_value in (start.0 + 1)..=end.0 {
+                        let height = block::Height(height_value);
+                        if let Some(block) =
+                            read::block(best_chain.clone(), &state.db, height.into())
+                        {
+                            blocks.insert(height, block);
+                        }
+                    }
+                }
+
+                let revealed_tachygrams = tachygrams
+                    .into_iter()
+                    .filter(|tachygram| {
+                        let in_window = |revealed_height| {
+                            zakura_chain::tachyon::within_scan_window(
+                                &state.network,
+                                revealed_height,
+                                candidate_height,
+                            )
+                        };
+
+                        best_chain
+                            .as_ref()
+                            .and_then(|chain| chain.tachyon_tachygrams.get(tachygram))
+                            .is_some_and(|heights| heights.iter().copied().any(in_window))
+                            || state
+                                .db
+                                .tachyon_tachygram_revealed_height(tachygram)
+                                .is_some_and(in_window)
+                    })
+                    .collect();
+
+                Ok(ReadResponse::TachyonMiningData(Some(
+                    crate::response::TachyonMiningData {
+                        tip_anchor,
+                        anchor_heights,
+                        blocks,
+                        revealed_tachygrams,
+                    },
+                )))
+            }
+
             // Used by getblock
             ReadRequest::BlockInfo(hash_or_height) => Ok(ReadResponse::BlockInfo(
                 read::block_info(state.latest_best_chain(), &state.db, hash_or_height),
diff --git a/crates/zakura-state/src/service/arbitrary.rs b/crates/zakura-state/src/service/arbitrary.rs
index cae90342fe..721ac8a4e1 100644
--- a/crates/zakura-state/src/service/arbitrary.rs
+++ b/crates/zakura-state/src/service/arbitrary.rs
@@ -175,6 +175,8 @@ impl Strategy for PreparedChain {
                 &Default::default(),
                 &Default::default(),
                 &Default::default(),
+                #[cfg(zcash_unstable = "nutachyon")]
+                &Default::default(),
             )
             .expect("history tree should be created");
             *chain = Some((
diff --git a/crates/zakura-state/src/service/check/anchors.rs b/crates/zakura-state/src/service/check/anchors.rs
index 3e39fd8eb0..7954bc0522 100644
--- a/crates/zakura-state/src/service/check/anchors.rs
+++ b/crates/zakura-state/src/service/check/anchors.rs
@@ -154,6 +154,39 @@ fn sapling_orchard_ironwood_anchors_refer_to_final_treestates(
         );
     }
 
+    #[cfg(zcash_unstable = "nutachyon")]
+    if let Some(tachyon_shielded_data) = transaction.tachyon_shielded_data() {
+        if let zcash_tachyon::TachyonBundle::Proven(bundle) = &tachyon_shielded_data.0 {
+            let anchor = zakura_chain::tachyon::Anchor::from(bundle.stamp.anchor);
+            let network = finalized_state.network();
+            let anchor_in_window = |anchor_height: Height| match height {
+                Some(height) => {
+                    zakura_chain::tachyon::within_scan_window(&network, anchor_height, height)
+                }
+                None => true,
+            };
+            let in_parent_chain = parent_chain.is_some_and(|chain| {
+                chain
+                    .tachyon_anchors
+                    .get(&anchor)
+                    .is_some_and(|heights| heights.iter().copied().any(anchor_in_window))
+            });
+
+            if !in_parent_chain
+                && !finalized_state
+                    .tachyon_anchor_height(&anchor)
+                    .is_some_and(anchor_in_window)
+            {
+                return Err(ValidateContextError::UnknownTachyonAnchor {
+                    anchor,
+                    height,
+                    tx_index_in_block,
+                    transaction_hash,
+                });
+            }
+        }
+    }
+
     Ok(())
 }
 
diff --git a/crates/zakura-state/src/service/check/nullifier.rs b/crates/zakura-state/src/service/check/nullifier.rs
index c8914cb3ac..0fe34f5729 100644
--- a/crates/zakura-state/src/service/check/nullifier.rs
+++ b/crates/zakura-state/src/service/check/nullifier.rs
@@ -62,6 +62,29 @@ pub(crate) fn no_duplicates_in_finalized_chain(
         }
     }
 
+    #[cfg(zcash_unstable = "nutachyon")]
+    let network = finalized_state.network();
+    #[cfg(zcash_unstable = "nutachyon")]
+    for transaction in &semantically_verified.block.transactions {
+        for tachygram in transaction.tachyon_tachygrams() {
+            if finalized_state
+                .tachyon_tachygram_revealed_height(&tachygram)
+                .is_some_and(|revealed_height| {
+                    zakura_chain::tachyon::within_scan_window(
+                        &network,
+                        revealed_height,
+                        semantically_verified.height,
+                    )
+                })
+            {
+                return Err(ValidateContextError::DuplicateTachyonTachygram {
+                    tachygram,
+                    in_finalized_state: true,
+                });
+            }
+        }
+    }
+
     Ok(())
 }
 
diff --git a/crates/zakura-state/src/service/check/tests/vectors.rs b/crates/zakura-state/src/service/check/tests/vectors.rs
index 59b871ddd7..9293d1d266 100644
--- a/crates/zakura-state/src/service/check/tests/vectors.rs
+++ b/crates/zakura-state/src/service/check/tests/vectors.rs
@@ -89,6 +89,8 @@ fn block_commitment_uses_the_precomputed_auth_data_root() {
         &sapling_root,
         &Default::default(),
         &Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )
     .expect("NU5 parent builds a history tree");
 
diff --git a/crates/zakura-state/src/service/finalized_state.rs b/crates/zakura-state/src/service/finalized_state.rs
index 6fafed123d..00822e4d26 100644
--- a/crates/zakura-state/src/service/finalized_state.rs
+++ b/crates/zakura-state/src/service/finalized_state.rs
@@ -214,6 +214,14 @@ pub const STATE_COLUMN_FAMILIES_IN_CODE: &[&str] = &[
     "ironwood_anchors",
     "ironwood_note_commitment_tree",
     "ironwood_note_commitment_subtree",
+    #[cfg(zcash_unstable = "nutachyon")]
+    "tachyon_anchors",
+    #[cfg(zcash_unstable = "nutachyon")]
+    "tachyon_anchor_by_height",
+    #[cfg(zcash_unstable = "nutachyon")]
+    "tachyon_epoch_anchor_by_epoch",
+    #[cfg(zcash_unstable = "nutachyon")]
+    "tachyon_tachygrams",
     // Chain
     "history_tree",
     "tip_chain_value_pool",
@@ -897,6 +905,13 @@ impl FinalizedState {
                         }),
                     };
 
+                    // The roots-only VCT payload does not carry Tachyon anchors or transaction
+                    // counts, so NuTachyon blocks must use the body-derived commitment path.
+                    #[cfg(zcash_unstable = "nutachyon")]
+                    let vct_roots = vct_roots.filter(|_| {
+                        NetworkUpgrade::current(&network, height) < NetworkUpgrade::NuTachyon
+                    });
+
                     let mut vct_write = VctWriteData::default();
 
                     if let Some((sapling_root, orchard_root, ironwood_root)) = vct_roots {
@@ -1028,6 +1043,8 @@ impl FinalizedState {
                                 commitment_aux_verify::verify_commitment_roots(
                                     &network,
                                     (*history_tree).clone(),
+                                    #[cfg(zcash_unstable = "nutachyon")]
+                                    prev_note_commitment_trees.tachyon_anchor,
                                     verification_items,
                                 )
                             })
@@ -1171,6 +1188,10 @@ impl FinalizedState {
                                 orchard_subtree: None,
                                 ironwood: ironwood_frontier,
                                 ironwood_subtree: None,
+                                #[cfg(zcash_unstable = "nutachyon")]
+                                tachyon_anchor: note_commitment_trees.tachyon_anchor,
+                                #[cfg(zcash_unstable = "nutachyon")]
+                                tachyon_epoch_anchor: None,
                             };
 
                             // The handoff writes the real final frontier as the tip
@@ -1256,10 +1277,24 @@ impl FinalizedState {
                         commitment_result.expect("scope has already finished")?;
 
                         // Update the history tree (depends on both operations above).
+                        #[cfg(zcash_unstable = "nutachyon")]
+                        if let Some(pool_height) =
+                            zakura_chain::tachyon::pool_height(&network, checkpoint_verified.height)
+                        {
+                            let advance = note_commitment_trees
+                                .tachyon_anchor
+                                .advance_with_block(pool_height, &block)
+                                .map_err(ValidateContextError::from)?;
+                            note_commitment_trees.tachyon_anchor = advance.post_block;
+                            note_commitment_trees.tachyon_epoch_anchor = advance.epoch_boundary;
+                        }
+
                         let history_tree_mut = Arc::make_mut(&mut history_tree);
                         let sapling_root = note_commitment_trees.sapling.root();
                         let orchard_root = note_commitment_trees.orchard.root();
                         let ironwood_root = note_commitment_trees.ironwood.root();
+                        #[cfg(zcash_unstable = "nutachyon")]
+                        let tachyon_anchor = note_commitment_trees.tachyon_anchor;
                         history_tree_mut
                             .push(
                                 &network,
@@ -1267,6 +1302,8 @@ impl FinalizedState {
                                 &sapling_root,
                                 &orchard_root,
                                 &ironwood_root,
+                                #[cfg(zcash_unstable = "nutachyon")]
+                                &tachyon_anchor,
                             )
                             .map_err(Arc::new)
                             .map_err(ValidateContextError::from)?;
diff --git a/crates/zakura-state/src/service/finalized_state/commitment_aux_verify.rs b/crates/zakura-state/src/service/finalized_state/commitment_aux_verify.rs
index 0a75849788..354163c331 100644
--- a/crates/zakura-state/src/service/finalized_state/commitment_aux_verify.rs
+++ b/crates/zakura-state/src/service/finalized_state/commitment_aux_verify.rs
@@ -246,6 +246,7 @@ pub(crate) fn verify_supplied_ironwood_root_below_nu6_3(
 pub(crate) fn verify_commitment_roots<I>(
     network: &Network,
     mut history_tree: HistoryTree,
+    #[cfg(zcash_unstable = "nutachyon")] mut tachyon_anchor: zakura_chain::tachyon::Anchor,
     blocks_to_verify: I,
 ) -> Result<HistoryTree, CommitmentRootVerificationError>
 where
@@ -295,6 +296,14 @@ where
                     auth_data_root,
                 )
                 .map_err(|error| match error {
+                    #[cfg(zcash_unstable = "nutachyon")]
+                    SuppliedRootsError::TachyonDataUnavailable => {
+                        ValidateContextError::HistoryTreeError(Arc::new(
+                            zakura_chain::history_tree::HistoryTreeError::InvalidCachedTree {
+                                reason: "Tachyon history commitments require block bodies",
+                            },
+                        ))
+                    }
                     SuppliedRootsError::InvalidHeaderCommitment(error) => {
                         ValidateContextError::InvalidBlockCommitment(error)
                     }
@@ -328,10 +337,27 @@ where
         verify_supplied_ironwood_root_below_nu6_3(network, height, &ironwood_root)
             .map_err(|error| CommitmentRootVerificationError::CurrentRoots { height, error })?;
 
+        #[cfg(zcash_unstable = "nutachyon")]
+        if let Some(pool_height) = zakura_chain::tachyon::pool_height(network, height) {
+            tachyon_anchor = tachyon_anchor
+                .advance_with_block(pool_height, &block)
+                .map_err(ValidateContextError::from)
+                .map_err(|error| CommitmentRootVerificationError::CurrentRoots { height, error })?
+                .post_block;
+        }
+
         // Fold this block's supplied roots into the running MMR (builds the leaf
         // from the block body tx-counts + the roots).
         history_tree
-            .push(network, block, &sapling_root, &orchard_root, &ironwood_root)
+            .push(
+                network,
+                block,
+                &sapling_root,
+                &orchard_root,
+                &ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                &tachyon_anchor,
+            )
             .map_err(Arc::new)
             .map_err(ValidateContextError::from)
             .map_err(|error| CommitmentRootVerificationError::CurrentRoots { height, error })?;
@@ -367,6 +393,8 @@ mod tests {
             &Default::default(),
             &Default::default(),
             &Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            &Default::default(),
         )
         .expect("empty history tree for a pre-Heartwood block")
     }
@@ -702,8 +730,14 @@ mod tests {
                 Some(next_block.auth_data_root()),
             ),
         ];
-        verify_commitment_roots(&Mainnet, empty_history_tree(), ok_items)
-            .expect("real roots verify against the headers");
+        verify_commitment_roots(
+            &Mainnet,
+            empty_history_tree(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Default::default(),
+            ok_items,
+        )
+        .expect("real roots verify against the headers");
 
         // Negative + lag: a wrong root at the activation height (here, the next
         // block's root, which is a valid but different root) is only caught when the
@@ -717,8 +751,14 @@ mod tests {
                 Some(next_block.auth_data_root()),
             ),
         ];
-        let failure = verify_commitment_roots(&Mainnet, empty_history_tree(), bad_items)
-            .expect_err("a wrong root must be rejected");
+        let failure = verify_commitment_roots(
+            &Mainnet,
+            empty_history_tree(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Default::default(),
+            bad_items,
+        )
+        .expect_err("a wrong root must be rejected");
         assert_eq!(
             failure.height().0,
             activation + 1,
@@ -824,8 +864,14 @@ mod tests {
         let items: Vec<_> = (start..=end + 1).map(item_at).collect();
 
         // Positive: every supplied root in the range is confirmed by the V2 headers.
-        verify_commitment_roots(&Mainnet, seed.clone(), items.clone())
-            .expect("real NU5 roots verify against the headers");
+        verify_commitment_roots(
+            &Mainnet,
+            seed.clone(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Default::default(),
+            items.clone(),
+        )
+        .expect("real NU5 roots verify against the headers");
         eprintln!("VCT NU5 positive: {} blocks verified", items.len());
 
         // Negative + lag: corrupt one root mid-range with a distinct valid root (the
@@ -848,8 +894,14 @@ mod tests {
             .as_mut()
             .expect("test verification item has roots")
             .0 = wrong_root;
-        let failure = verify_commitment_roots(&Mainnet, seed, bad_items)
-            .expect_err("a wrong NU5 root must be rejected");
+        let failure = verify_commitment_roots(
+            &Mainnet,
+            seed,
+            #[cfg(zcash_unstable = "nutachyon")]
+            Default::default(),
+            bad_items,
+        )
+        .expect_err("a wrong NU5 root must be rejected");
         assert_eq!(
             failure.height().0,
             bad_height + 1,
@@ -1060,15 +1112,20 @@ mod tests {
             .0;
         for &(start, end) in ranges.iter().filter(|(start, _)| *start < heartwood) {
             let items = (start..=end).map(|height| verification_item_at(Height(height)));
-            verify_commitment_roots(&Mainnet, empty_history_tree(), items).unwrap_or_else(
-                |failure| {
-                    panic!(
-                        "pre-Heartwood roots failed at {:?}: {}",
-                        failure.height(),
-                        failure.error()
-                    )
-                },
-            );
+            verify_commitment_roots(
+                &Mainnet,
+                empty_history_tree(),
+                #[cfg(zcash_unstable = "nutachyon")]
+                Default::default(),
+                items,
+            )
+            .unwrap_or_else(|failure| {
+                panic!(
+                    "pre-Heartwood roots failed at {:?}: {}",
+                    failure.height(),
+                    failure.error()
+                )
+            });
             eprintln!("validated direct pre-Heartwood commitments for {start}..={end}");
         }
 
@@ -1104,6 +1161,8 @@ mod tests {
                 &sapling_root,
                 &orchard_root,
                 &ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                &Default::default(),
             )
             .expect("network-upgrade activation starts a history-tree epoch");
             let confirm_end = end
@@ -1112,7 +1171,14 @@ mod tests {
             let items =
                 (activation + 1..=confirm_end).map(|height| verification_item_at(Height(height)));
 
-            verify_commitment_roots(&Mainnet, history_tree, items).unwrap_or_else(|failure| {
+            verify_commitment_roots(
+                &Mainnet,
+                history_tree,
+                #[cfg(zcash_unstable = "nutachyon")]
+                Default::default(),
+                items,
+            )
+            .unwrap_or_else(|failure| {
                 panic!(
                     "{upgrade:?} MMR linkage failed at {:?} while validating through \
                      {confirm_end}: {}",
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/chain.rs b/crates/zakura-state/src/service/finalized_state/disk_format/chain.rs
index 9c527c2314..00ee22145c 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/chain.rs
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/chain.rs
@@ -26,14 +26,17 @@ use crate::service::finalized_state::disk_format::{FromDisk, IntoDisk};
 /// An error decoding a persisted history-tree snapshot.
 #[derive(Debug, Error)]
 pub enum HistoryTreeDecodeError {
-    /// The snapshot does not use either supported serialization format.
+    /// The snapshot does not use any supported serialization format.
     #[error(
-        "history tree snapshot is neither the current nor legacy format: \
-         current format error: {current}; legacy format error: {legacy}"
+        "history tree snapshot is neither the current, Ironwood, nor legacy format: \
+         current format error: {current}; Ironwood format error: {ironwood}; \
+         legacy format error: {legacy}"
     )]
     InvalidEncoding {
         /// The current-width decoding error.
         current: bincode::Error,
+        /// The Ironwood-width decoding error.
+        ironwood: bincode::Error,
         /// The legacy-width decoding error.
         legacy: bincode::Error,
     },
@@ -55,7 +58,10 @@ pub enum HistoryTreeDecodeError {
 }
 
 impl IntoDisk for ValueBalance<NonNegative> {
+    #[cfg(not(zcash_unstable = "nutachyon"))]
     type Bytes = [u8; 48];
+    #[cfg(zcash_unstable = "nutachyon")]
+    type Bytes = [u8; 56];
 
     fn as_bytes(&self) -> Self::Bytes {
         self.to_bytes()
@@ -89,19 +95,26 @@ impl HistoryTreeParts {
         let bytes = bytes.as_ref();
         let options = bincode::DefaultOptions::new();
 
-        // Try the current entry width first. Databases written before NU6.3 widened
-        // `zcash_history::Entry` store narrower entries that fail to parse at the current width,
-        // so fall back to the legacy width and zero-pad each entry up to the current width.
+        // Try the current entry width first. Earlier databases store narrower entries, so fall
+        // back through the Ironwood and pre-Ironwood widths and zero-pad each entry to the current
+        // width.
         //
         // Legacy-width rows can fail the current-width decoder with errors other than
         // `UnexpectedEof`, because the wider entry can read into the next legacy entry and
         // interpret arbitrary entry bytes as bincode control bytes.
         match options.deserialize::<HistoryTreeParts>(bytes) {
             Ok(parts) => Ok(parts),
-            Err(current) => options
-                .deserialize::<LegacyHistoryTreeParts>(bytes)
-                .map(HistoryTreeParts::from)
-                .map_err(|legacy| HistoryTreeDecodeError::InvalidEncoding { current, legacy }),
+            Err(current) => match options.deserialize::<IronwoodHistoryTreeParts>(bytes) {
+                Ok(parts) => Ok(parts.into()),
+                Err(ironwood) => options
+                    .deserialize::<LegacyHistoryTreeParts>(bytes)
+                    .map(HistoryTreeParts::from)
+                    .map_err(|legacy| HistoryTreeDecodeError::InvalidEncoding {
+                        current,
+                        ironwood,
+                        legacy,
+                    }),
+            },
         }
     }
 
@@ -152,6 +165,46 @@ impl IntoDisk for HistoryTreeParts {
 /// before NU6.3 widened `zcash_history::NodeData`.
 const LEGACY_MAX_ENTRY_SIZE: usize = 253;
 
+/// The width of a history-tree [`zcash_history::Entry`] from NU6.3 until NuTachyon support
+/// reserved space for V4 node data.
+const IRONWOOD_MAX_ENTRY_SIZE: usize = 326;
+
+/// A mirror of [`HistoryTreeParts`] using the NU6.3 [`zcash_history::Entry`] width.
+#[derive(serde::Serialize, serde::Deserialize)]
+struct IronwoodHistoryTreeParts {
+    network_kind: NetworkKind,
+    size: u32,
+    peaks: BTreeMap<u32, IronwoodEntry>,
+    current_height: Height,
+}
+
+/// A history-tree entry serialized at the NU6.3 [`IRONWOOD_MAX_ENTRY_SIZE`] width.
+#[derive(serde::Serialize, serde::Deserialize)]
+struct IronwoodEntry {
+    #[serde(with = "BigArray")]
+    inner: [u8; IRONWOOD_MAX_ENTRY_SIZE],
+}
+
+impl From<IronwoodHistoryTreeParts> for HistoryTreeParts {
+    fn from(ironwood: IronwoodHistoryTreeParts) -> Self {
+        HistoryTreeParts {
+            network_kind: ironwood.network_kind,
+            size: ironwood.size,
+            peaks: ironwood
+                .peaks
+                .into_iter()
+                .map(|(index, entry)| {
+                    (
+                        index,
+                        zcash_history::Entry::from_raw_bytes_padded(&entry.inner),
+                    )
+                })
+                .collect(),
+            current_height: ironwood.current_height,
+        }
+    }
+}
+
 /// A mirror of [`HistoryTreeParts`] using the pre-NU6.3 [`zcash_history::Entry`] width.
 #[derive(serde::Serialize, serde::Deserialize)]
 struct LegacyHistoryTreeParts {
@@ -210,18 +263,34 @@ impl IntoDisk for BlockInfo {
 
 impl FromDisk for BlockInfo {
     fn from_bytes(bytes: impl AsRef<[u8]>) -> Self {
-        // We have two different DB formats, one from NU6_1 (Lockbox) one for Ironwood and onwards.
+        // We have different DB formats for NU6.1, Ironwood, and NuTachyon onward.
         const NU6_1_VALUE_BALANCE_LEN: usize = 40;
         const IRONWOOD_VALUE_BALANCE_LEN: usize = 48;
+        #[cfg(zcash_unstable = "nutachyon")]
+        const TACHYON_VALUE_BALANCE_LEN: usize = 56;
         const BLOCK_SIZE_LEN: usize = 4;
         const NU6_1_BLOCK_INFO_LEN: usize = NU6_1_VALUE_BALANCE_LEN + BLOCK_SIZE_LEN;
         const IRONWOOD_BLOCK_INFO_LEN: usize = IRONWOOD_VALUE_BALANCE_LEN + BLOCK_SIZE_LEN;
+        #[cfg(zcash_unstable = "nutachyon")]
+        const TACHYON_BLOCK_INFO_LEN: usize = TACHYON_VALUE_BALANCE_LEN + BLOCK_SIZE_LEN;
 
         let bytes = bytes.as_ref();
 
         // We want to be forward-compatible, so this must work even if the
         // size of the buffer is larger than expected.
         match bytes.len() {
+            #[cfg(zcash_unstable = "nutachyon")]
+            TACHYON_BLOCK_INFO_LEN.. => {
+                let value_pools =
+                    ValueBalance::<NonNegative>::from_bytes(&bytes[..TACHYON_VALUE_BALANCE_LEN])
+                        .expect("must work for 56 bytes");
+                let size = u32::from_le_bytes(
+                    bytes[TACHYON_VALUE_BALANCE_LEN..TACHYON_VALUE_BALANCE_LEN + BLOCK_SIZE_LEN]
+                        .try_into()
+                        .expect("must be 4 bytes"),
+                );
+                BlockInfo::new(value_pools, size)
+            }
             IRONWOOD_BLOCK_INFO_LEN.. => {
                 let value_pools =
                     ValueBalance::<NonNegative>::from_bytes(&bytes[..IRONWOOD_VALUE_BALANCE_LEN])
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/chain/tests.rs b/crates/zakura-state/src/service/finalized_state/disk_format/chain/tests.rs
index b7403a40f8..103ba19953 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/chain/tests.rs
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/chain/tests.rs
@@ -40,9 +40,13 @@ fn valid_history_tree() -> NonEmptyHistoryTree {
                 sapling_root: &sapling_root,
                 orchard_root: &orchard_root,
                 ironwood_root: &ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_anchor: &Default::default(),
                 sapling_tx: 0,
                 orchard_tx: 0,
                 ironwood_tx: 0,
+                #[cfg(zcash_unstable = "nutachyon")]
+                tachyon_tx: 0,
             },
         )
         .expect("test history tree must be valid")
@@ -73,6 +77,26 @@ fn legacy_parts_from(tree: &NonEmptyHistoryTree) -> LegacyHistoryTreeParts {
     }
 }
 
+fn ironwood_parts_from(tree: &NonEmptyHistoryTree) -> IronwoodHistoryTreeParts {
+    IronwoodHistoryTreeParts {
+        network_kind: tree.network().kind(),
+        size: tree.size(),
+        peaks: tree
+            .peaks()
+            .iter()
+            .map(|(index, entry)| {
+                let serialized = bincode::DefaultOptions::new()
+                    .serialize(entry)
+                    .expect("history tree entry serialization succeeds");
+                let mut inner = [0; IRONWOOD_MAX_ENTRY_SIZE];
+                inner.copy_from_slice(&serialized[..IRONWOOD_MAX_ENTRY_SIZE]);
+                (*index, IronwoodEntry { inner })
+            })
+            .collect(),
+        current_height: tree.current_height(),
+    }
+}
+
 fn ephemeral_db(network: &Network) -> ZakuraDb {
     ZakuraDb::new(
         &Config::ephemeral(),
@@ -135,6 +159,30 @@ fn history_tree_parts_reads_legacy_entry_width() {
     assert!(parts.as_bytes().len() > legacy_bytes.len());
 }
 
+/// A history tree written with the NU6.3 entry width must be read in place and zero-padded to the
+/// current width.
+#[test]
+fn history_tree_parts_reads_ironwood_entry_width() {
+    let tree = valid_history_tree();
+    let ironwood = ironwood_parts_from(&tree);
+    let ironwood_bytes = bincode::DefaultOptions::new()
+        .serialize(&ironwood)
+        .expect("Ironwood serialization succeeds");
+
+    let parts =
+        HistoryTreeParts::try_from_bytes(&ironwood_bytes).expect("Ironwood snapshot must decode");
+
+    assert_eq!(parts.network_kind, tree.network().kind());
+    assert_eq!(parts.size, tree.size());
+    assert_eq!(parts.current_height, tree.current_height());
+    assert_eq!(parts.peaks.len(), tree.peaks().len());
+    assert_eq!(
+        parts.as_bytes(),
+        HistoryTreeParts::from(ironwood).as_bytes()
+    );
+    assert!(parts.as_bytes().len() > ironwood_bytes.len());
+}
+
 /// A legacy-width row can fail current-width decoding with a non-EOF error if the wider entry
 /// consumes into the next legacy map entry and interprets entry bytes as bincode control bytes.
 #[test]
@@ -154,7 +202,7 @@ fn history_tree_parts_reads_legacy_entry_width_after_non_eof_current_error() {
                 LegacyEntry {
                     inner: {
                         let mut inner = [0xCD; LEGACY_MAX_ENTRY_SIZE];
-                        inner[72] = 0xFE;
+                        inner[zcash_history::MAX_ENTRY_SIZE - LEGACY_MAX_ENTRY_SIZE - 1] = 0xFE;
                         inner
                     },
                 },
@@ -216,7 +264,7 @@ fn history_tree_parts_round_trips_current_width() {
 }
 
 #[test]
-fn malformed_history_tree_parts_return_both_decode_errors() {
+fn malformed_history_tree_parts_return_all_decode_errors() {
     let error = match HistoryTreeParts::try_from_bytes([0xFF]) {
         Ok(_) => panic!("malformed bytes must fail"),
         Err(error) => error,
@@ -226,6 +274,7 @@ fn malformed_history_tree_parts_return_both_decode_errors() {
         error,
         HistoryTreeDecodeError::InvalidEncoding {
             current: _,
+            ironwood: _,
             legacy: _
         }
     ));
@@ -337,6 +386,7 @@ fn try_history_tree_propagates_malformed_snapshot() {
         error,
         HistoryTreeDecodeError::InvalidEncoding {
             current: _,
+            ironwood: _,
             legacy: _
         }
     ));
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/header_chain.rs b/crates/zakura-state/src/service/finalized_state/disk_format/header_chain.rs
index ebfd66084a..edc2274e78 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/header_chain.rs
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/header_chain.rs
@@ -528,7 +528,10 @@ mod tests {
                 "missing opened column family {expected}"
             );
         }
-        assert_eq!(db.format_version_in_code().minor, 1);
+        assert_eq!(
+            db.format_version_in_code(),
+            state_database_format_version_in_code()
+        );
 
         drop(db);
         let reopened = ZakuraDb::new(
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/shielded.rs b/crates/zakura-state/src/service/finalized_state/disk_format/shielded.rs
index c34ce15806..38dfa64eff 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/shielded.rs
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/shielded.rs
@@ -7,6 +7,8 @@
 
 use bincode::Options;
 
+#[cfg(zcash_unstable = "nutachyon")]
+use zakura_chain::tachyon;
 use zakura_chain::{
     block::{merkle::AuthDataRoot, Height},
     ironwood, orchard, sapling, sprout,
@@ -87,6 +89,71 @@ impl FromDisk for orchard::tree::Root {
     }
 }
 
+#[cfg(zcash_unstable = "nutachyon")]
+impl IntoDisk for tachyon::Anchor {
+    type Bytes = [u8; 32];
+
+    fn as_bytes(&self) -> Self::Bytes {
+        self.into()
+    }
+}
+
+#[cfg(zcash_unstable = "nutachyon")]
+impl FromDisk for tachyon::Anchor {
+    fn from_bytes(bytes: impl AsRef<[u8]>) -> Self {
+        let bytes: [u8; 32] = bytes
+            .as_ref()
+            .try_into()
+            .expect("Tachyon anchors have a fixed 32-byte disk encoding");
+        bytes.into()
+    }
+}
+
+#[cfg(zcash_unstable = "nutachyon")]
+impl IntoDisk for tachyon::Tachygram {
+    type Bytes = [u8; 32];
+
+    fn as_bytes(&self) -> Self::Bytes {
+        self.into()
+    }
+}
+
+#[cfg(zcash_unstable = "nutachyon")]
+impl FromDisk for tachyon::Tachygram {
+    fn from_bytes(bytes: impl AsRef<[u8]>) -> Self {
+        let bytes: [u8; 32] = bytes
+            .as_ref()
+            .try_into()
+            .expect("Tachygrams have a fixed 32-byte disk encoding");
+        bytes.into()
+    }
+}
+
+/// An on-disk Tachyon epoch index, encoded big-endian for sort order.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[cfg(zcash_unstable = "nutachyon")]
+pub struct TachyonEpoch(pub u32);
+
+#[cfg(zcash_unstable = "nutachyon")]
+impl IntoDisk for TachyonEpoch {
+    type Bytes = [u8; 4];
+
+    fn as_bytes(&self) -> Self::Bytes {
+        self.0.to_be_bytes()
+    }
+}
+
+#[cfg(zcash_unstable = "nutachyon")]
+impl FromDisk for TachyonEpoch {
+    fn from_bytes(bytes: impl AsRef<[u8]>) -> Self {
+        let bytes: [u8; 4] = bytes
+            .as_ref()
+            .try_into()
+            .expect("Tachyon epochs have a fixed 4-byte disk encoding");
+        Self(u32::from_be_bytes(bytes))
+    }
+}
+
 /// The per-height Sapling and Orchard note-commitment roots, as stored in the
 /// `commitment_roots_by_height` index (keyed by [`Height`]).
 ///
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/prop.rs b/crates/zakura-state/src/service/finalized_state/disk_format/tests/prop.rs
index c40206c7a5..ad3c933b94 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/prop.rs
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/prop.rs
@@ -576,16 +576,43 @@ fn roundtrip_value_balance() {
 }
 
 #[test]
-fn roundtrip_block_info_with_ironwood_value_pool() {
+#[cfg(zcash_unstable = "nutachyon")]
+fn roundtrip_block_info_with_tachyon_value_pool() {
     let _init_guard = zakura_test::init();
 
     let ironwood_amount = Amount::<NonNegative>::try_from(7).expect("7 zatoshi is a valid amount");
-    let block_info = BlockInfo::new(ValueBalance::from_ironwood_amount(ironwood_amount), 123);
+    let tachyon_amount = Amount::<NonNegative>::try_from(13).expect("13 zatoshi is a valid amount");
+    let block_info = BlockInfo::new(
+        (ValueBalance::from_ironwood_amount(ironwood_amount)
+            + ValueBalance::from_tachyon_amount(tachyon_amount))
+        .expect("small non-negative pool balances have a valid sum"),
+        123,
+    );
 
-    assert_eq!(block_info.as_bytes().len(), 52);
+    assert_eq!(block_info.as_bytes().len(), 60);
     assert_value_properties(block_info);
 }
 
+#[test]
+fn block_info_decodes_ironwood_value_pools() {
+    let _init_guard = zakura_test::init();
+
+    let ironwood_amount = Amount::<NonNegative>::try_from(7).expect("7 zatoshi is a valid amount");
+    let ironwood_value_pools = ValueBalance::from_ironwood_amount(ironwood_amount);
+    let mut ironwood_bytes = ironwood_value_pools.as_bytes()[..48].to_vec();
+    ironwood_bytes.extend_from_slice(&123_u32.to_le_bytes());
+
+    let block_info = BlockInfo::from_bytes(ironwood_bytes);
+
+    assert_eq!(block_info.value_pools().ironwood_amount(), ironwood_amount);
+    #[cfg(zcash_unstable = "nutachyon")]
+    assert_eq!(
+        block_info.value_pools().tachyon_amount(),
+        Amount::<NonNegative>::zero()
+    );
+    assert_eq!(block_info.size(), 123);
+}
+
 #[test]
 fn block_info_decodes_legacy_value_pools() {
     let _init_guard = zakura_test::init();
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@mainnet_0.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@mainnet_0.snap
index 8841b8565e..07978821dc 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@mainnet_0.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@mainnet_0.snap
@@ -5,6 +5,6 @@ expression: cf_data
 [
   KV(
     k: "000000",
-    v: "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009c060000",
+    v: "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009c060000",
   ),
 ]
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@mainnet_1.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@mainnet_1.snap
index d67bac0b1e..346db9eff3 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@mainnet_1.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@mainnet_1.snap
@@ -5,10 +5,10 @@ expression: cf_data
 [
   KV(
     k: "000000",
-    v: "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009c060000",
+    v: "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009c060000",
   ),
   KV(
     k: "000001",
-    v: "24f40000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000051060000",
+    v: "24f400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000051060000",
   ),
 ]
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@mainnet_2.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@mainnet_2.snap
index 7adf04d44a..ebda32d2fd 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@mainnet_2.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@mainnet_2.snap
@@ -5,14 +5,14 @@ expression: cf_data
 [
   KV(
     k: "000000",
-    v: "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009c060000",
+    v: "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009c060000",
   ),
   KV(
     k: "000001",
-    v: "24f40000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000051060000",
+    v: "24f400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000051060000",
   ),
   KV(
     k: "000002",
-    v: "6cdc0200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000051060000",
+    v: "6cdc02000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000051060000",
   ),
 ]
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@testnet_0.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@testnet_0.snap
index 8841b8565e..07978821dc 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@testnet_0.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@testnet_0.snap
@@ -5,6 +5,6 @@ expression: cf_data
 [
   KV(
     k: "000000",
-    v: "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009c060000",
+    v: "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009c060000",
   ),
 ]
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@testnet_1.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@testnet_1.snap
index 853b7bec64..0eb5739915 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@testnet_1.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@testnet_1.snap
@@ -5,10 +5,10 @@ expression: cf_data
 [
   KV(
     k: "000000",
-    v: "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009c060000",
+    v: "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009c060000",
   ),
   KV(
     k: "000001",
-    v: "24f40000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000052060000",
+    v: "24f400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000052060000",
   ),
 ]
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@testnet_2.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@testnet_2.snap
index 29cda9499f..7508da84e0 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@testnet_2.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/block_info_raw_data@testnet_2.snap
@@ -5,14 +5,14 @@ expression: cf_data
 [
   KV(
     k: "000000",
-    v: "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009c060000",
+    v: "00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000009c060000",
   ),
   KV(
     k: "000001",
-    v: "24f40000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000052060000",
+    v: "24f400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000052060000",
   ),
   KV(
     k: "000002",
-    v: "6cdc0200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000052060000",
+    v: "6cdc02000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000052060000",
   ),
 ]
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/column_family_names.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/column_family_names.snap
index 5f9bbd55e3..6a72fd5fcb 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/column_family_names.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/column_family_names.snap
@@ -41,6 +41,10 @@ expression: cf_names
   "sprout_anchors",
   "sprout_note_commitment_tree",
   "sprout_nullifiers",
+  "tachyon_anchor_by_height",
+  "tachyon_anchors",
+  "tachyon_epoch_anchor_by_epoch",
+  "tachyon_tachygrams",
   "tip_chain_value_pool",
   "tx_by_loc",
   "tx_loc_by_hash",
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@mainnet_0.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@mainnet_0.snap
index db60cc5ab7..b7c4315eab 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@mainnet_0.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@mainnet_0.snap
@@ -26,6 +26,10 @@ expression: empty_column_families
   "sapling_note_commitment_subtree: no entries",
   "sapling_nullifiers: no entries",
   "sprout_nullifiers: no entries",
+  "tachyon_anchor_by_height: no entries",
+  "tachyon_anchors: no entries",
+  "tachyon_epoch_anchor_by_epoch: no entries",
+  "tachyon_tachygrams: no entries",
   "tx_loc_by_spent_out_loc: no entries",
   "tx_loc_by_transparent_addr_loc: no entries",
   "utxo_by_out_loc: no entries",
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@mainnet_1.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@mainnet_1.snap
index 6f6e13334c..79765ebce3 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@mainnet_1.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@mainnet_1.snap
@@ -25,6 +25,10 @@ expression: empty_column_families
   "sapling_note_commitment_subtree: no entries",
   "sapling_nullifiers: no entries",
   "sprout_nullifiers: no entries",
+  "tachyon_anchor_by_height: no entries",
+  "tachyon_anchors: no entries",
+  "tachyon_epoch_anchor_by_epoch: no entries",
+  "tachyon_tachygrams: no entries",
   "tx_loc_by_spent_out_loc: no entries",
   "vct_sync_metadata: no entries",
   "zakura_header_body_size_by_height: no entries",
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@mainnet_2.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@mainnet_2.snap
index 6f6e13334c..79765ebce3 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@mainnet_2.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@mainnet_2.snap
@@ -25,6 +25,10 @@ expression: empty_column_families
   "sapling_note_commitment_subtree: no entries",
   "sapling_nullifiers: no entries",
   "sprout_nullifiers: no entries",
+  "tachyon_anchor_by_height: no entries",
+  "tachyon_anchors: no entries",
+  "tachyon_epoch_anchor_by_epoch: no entries",
+  "tachyon_tachygrams: no entries",
   "tx_loc_by_spent_out_loc: no entries",
   "vct_sync_metadata: no entries",
   "zakura_header_body_size_by_height: no entries",
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@no_blocks.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@no_blocks.snap
index 6d1314558c..3d5c8c9ef3 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@no_blocks.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@no_blocks.snap
@@ -40,6 +40,10 @@ expression: empty_column_families
   "sprout_anchors: no entries",
   "sprout_note_commitment_tree: no entries",
   "sprout_nullifiers: no entries",
+  "tachyon_anchor_by_height: no entries",
+  "tachyon_anchors: no entries",
+  "tachyon_epoch_anchor_by_epoch: no entries",
+  "tachyon_tachygrams: no entries",
   "tip_chain_value_pool: no entries",
   "tx_by_loc: no entries",
   "tx_loc_by_hash: no entries",
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@testnet_0.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@testnet_0.snap
index db60cc5ab7..b7c4315eab 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@testnet_0.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@testnet_0.snap
@@ -26,6 +26,10 @@ expression: empty_column_families
   "sapling_note_commitment_subtree: no entries",
   "sapling_nullifiers: no entries",
   "sprout_nullifiers: no entries",
+  "tachyon_anchor_by_height: no entries",
+  "tachyon_anchors: no entries",
+  "tachyon_epoch_anchor_by_epoch: no entries",
+  "tachyon_tachygrams: no entries",
   "tx_loc_by_spent_out_loc: no entries",
   "tx_loc_by_transparent_addr_loc: no entries",
   "utxo_by_out_loc: no entries",
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@testnet_1.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@testnet_1.snap
index 6f6e13334c..79765ebce3 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@testnet_1.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@testnet_1.snap
@@ -25,6 +25,10 @@ expression: empty_column_families
   "sapling_note_commitment_subtree: no entries",
   "sapling_nullifiers: no entries",
   "sprout_nullifiers: no entries",
+  "tachyon_anchor_by_height: no entries",
+  "tachyon_anchors: no entries",
+  "tachyon_epoch_anchor_by_epoch: no entries",
+  "tachyon_tachygrams: no entries",
   "tx_loc_by_spent_out_loc: no entries",
   "vct_sync_metadata: no entries",
   "zakura_header_body_size_by_height: no entries",
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@testnet_2.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@testnet_2.snap
index 6f6e13334c..79765ebce3 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@testnet_2.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/empty_column_families@testnet_2.snap
@@ -25,6 +25,10 @@ expression: empty_column_families
   "sapling_note_commitment_subtree: no entries",
   "sapling_nullifiers: no entries",
   "sprout_nullifiers: no entries",
+  "tachyon_anchor_by_height: no entries",
+  "tachyon_anchors: no entries",
+  "tachyon_epoch_anchor_by_epoch: no entries",
+  "tachyon_tachygrams: no entries",
   "tx_loc_by_spent_out_loc: no entries",
   "vct_sync_metadata: no entries",
   "zakura_header_body_size_by_height: no entries",
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@mainnet_0.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@mainnet_0.snap
index 265231f491..1387f97a82 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@mainnet_0.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@mainnet_0.snap
@@ -5,6 +5,6 @@ expression: cf_data
 [
   KV(
     k: "",
-    v: "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+    v: "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
   ),
 ]
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@mainnet_1.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@mainnet_1.snap
index d0457c51a5..48ed2dbd87 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@mainnet_1.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@mainnet_1.snap
@@ -5,6 +5,6 @@ expression: cf_data
 [
   KV(
     k: "",
-    v: "24f400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+    v: "24f4000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
   ),
 ]
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@mainnet_2.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@mainnet_2.snap
index aca4654f3f..c37a66fc80 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@mainnet_2.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@mainnet_2.snap
@@ -5,6 +5,6 @@ expression: cf_data
 [
   KV(
     k: "",
-    v: "6cdc02000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+    v: "6cdc020000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
   ),
 ]
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@testnet_0.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@testnet_0.snap
index 265231f491..1387f97a82 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@testnet_0.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@testnet_0.snap
@@ -5,6 +5,6 @@ expression: cf_data
 [
   KV(
     k: "",
-    v: "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+    v: "0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
   ),
 ]
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@testnet_1.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@testnet_1.snap
index d0457c51a5..48ed2dbd87 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@testnet_1.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@testnet_1.snap
@@ -5,6 +5,6 @@ expression: cf_data
 [
   KV(
     k: "",
-    v: "24f400000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+    v: "24f4000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
   ),
 ]
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@testnet_2.snap b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@testnet_2.snap
index aca4654f3f..c37a66fc80 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@testnet_2.snap
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/tests/snapshots/tip_chain_value_pool_raw_data@testnet_2.snap
@@ -5,6 +5,6 @@ expression: cf_data
 [
   KV(
     k: "",
-    v: "6cdc02000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
+    v: "6cdc020000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
   ),
 ]
diff --git a/crates/zakura-state/src/service/finalized_state/disk_format/upgrade.rs b/crates/zakura-state/src/service/finalized_state/disk_format/upgrade.rs
index e0b1f58f27..34b92a560f 100644
--- a/crates/zakura-state/src/service/finalized_state/disk_format/upgrade.rs
+++ b/crates/zakura-state/src/service/finalized_state/disk_format/upgrade.rs
@@ -111,8 +111,8 @@ fn format_upgrades(
     let min_version = move || min_version.clone().unwrap_or(Version::new(0, 0, 0));
 
     // Note: Disk format upgrades must be run in order of database version.
-    ([
-        Box::new(block_info_and_address_received::Upgrade),
+    vec![
+        Box::new(block_info_and_address_received::Upgrade) as Box<dyn DiskFormatUpgrade>,
         Box::new(no_migration::NoMigration::new(
             "add pruning metadata column family",
             Version::new(27, 1, 0),
@@ -144,9 +144,19 @@ fn format_upgrades(
         )),
         Box::new(drop_header_root_auth_frontier::Upgrade),
         Box::new(unauthenticated_commitment_roots::Upgrade),
-    ] as [Box<dyn DiskFormatUpgrade>; 10])
-        .into_iter()
-        .filter(move |upgrade| upgrade.version() > min_version())
+        #[cfg(zcash_unstable = "nutachyon")]
+        Box::new(no_migration::NoMigration::new(
+            "widen history tree entries for NuTachyon",
+            Version::new(28, 2, 5),
+        )),
+        #[cfg(zcash_unstable = "nutachyon")]
+        Box::new(no_migration::NoMigration::new(
+            "add Tachyon state and widen chain value balance and history entries",
+            Version::new(29, 0, 0),
+        )),
+    ]
+    .into_iter()
+    .filter(move |upgrade| upgrade.version() > min_version())
 }
 
 /// Returns a list of all the major db format versions that can restored from the
@@ -1109,13 +1119,15 @@ fn vct_format_changes_include_root_auth_metadata_updates() {
 
     let upgrades: Vec<_> = format_upgrades(Some(Version::new(27, 3, 0))).collect();
 
-    assert_eq!(upgrades.len(), 6);
+    assert_eq!(upgrades.len(), 8);
     assert_eq!(upgrades[0].version(), Version::new(28, 0, 0));
     assert_eq!(upgrades[1].version(), Version::new(28, 0, 1));
     assert_eq!(upgrades[2].version(), Version::new(28, 0, 2));
     assert_eq!(upgrades[3].version(), Version::new(28, 1, 3));
     assert_eq!(upgrades[4].version(), Version::new(28, 1, 4));
     assert_eq!(upgrades[5].version(), Version::new(28, 1, 5));
+    assert_eq!(upgrades[6].version(), Version::new(28, 2, 5));
+    assert_eq!(upgrades[7].version(), Version::new(29, 0, 0));
     assert!(
         !upgrades[3].needs_migration(),
         "the header-chain column families are created on open without rebasing authenticated roots"
diff --git a/crates/zakura-state/src/service/finalized_state/tests/prop.rs b/crates/zakura-state/src/service/finalized_state/tests/prop.rs
index 672212b220..6bf942e27d 100644
--- a/crates/zakura-state/src/service/finalized_state/tests/prop.rs
+++ b/crates/zakura-state/src/service/finalized_state/tests/prop.rs
@@ -315,6 +315,8 @@ fn vct_generated_final_frontier_bytes_are_node_loader_compatible() -> Result<()>
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -430,6 +432,8 @@ fn all_upgrades_and_wrong_commitments_with_fake_activation_heights() -> Result<(
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -551,6 +555,8 @@ fn vct_fast_path_matches_legacy_and_rejects_wrong_roots() -> Result<()> {
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -773,6 +779,8 @@ fn vct_frozen_frontier_hole_refuses_instead_of_recomputing() -> Result<()> {
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -878,6 +886,8 @@ fn vct_retryable_root_miss_keeps_checkpoint_response_pending() -> Result<()> {
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -979,6 +989,8 @@ fn vct_untrusted_source_defers_unverifiable_tip_root_until_successor() -> Result
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -1224,6 +1236,8 @@ fn vct_untrusted_source_bad_root_replacement_commits_same_height() -> Result<()>
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -1377,6 +1391,8 @@ fn vct_frozen_frontier_survives_reopen() -> Result<()> {
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -1554,6 +1570,8 @@ fn vct_fast_sync_handoff_marks_database_and_resumes() -> Result<()> {
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -2089,6 +2107,8 @@ fn vct_mode_switches_continue_from_safe_boundaries() -> Result<()> {
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -2294,6 +2314,8 @@ fn vct_dedup_skips_redundant_check_and_guards_stale_cache() -> Result<()> {
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -2566,6 +2588,8 @@ fn vct_clear_prevalidation_cache_disarms_skip_then_dedup_resumes() -> Result<()>
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -2674,6 +2698,8 @@ fn vct_db_produced_payload_round_trips_to_byte_identical_state() -> Result<()> {
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -3071,6 +3097,8 @@ fn vct_untrusted_fixture_drives_byte_identical_state() -> Result<()> {
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
@@ -3245,6 +3273,8 @@ fn vct_read_service_serves_or_refuses_absent_band_treestates() -> Result<()> {
             nu6_2: Some(47),
             nu6_3: Some(48),
             nu7: Some(50),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("failed to set activation heights")
         .extend_funding_streams()
diff --git a/crates/zakura-state/src/service/finalized_state/tests/rollback.rs b/crates/zakura-state/src/service/finalized_state/tests/rollback.rs
index 61e39ae285..a004ba84e8 100644
--- a/crates/zakura-state/src/service/finalized_state/tests/rollback.rs
+++ b/crates/zakura-state/src/service/finalized_state/tests/rollback.rs
@@ -870,6 +870,8 @@ fn modern_rollback_network() -> Network {
             nu6_2: Some(10),
             nu6_3: Some(11),
             nu7: Some(12),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("configured activation heights are valid")
         .extend_funding_streams()
diff --git a/crates/zakura-state/src/service/finalized_state/vct_fast_sync_fixture.rs b/crates/zakura-state/src/service/finalized_state/vct_fast_sync_fixture.rs
index d038c853c9..bc6eb5a0c0 100644
--- a/crates/zakura-state/src/service/finalized_state/vct_fast_sync_fixture.rs
+++ b/crates/zakura-state/src/service/finalized_state/vct_fast_sync_fixture.rs
@@ -125,6 +125,8 @@ impl VctFastSyncedChain {
                 nu6_2: Some(47),
                 nu6_3: Some(48),
                 nu7: Some(50),
+                #[cfg(zcash_unstable = "nutachyon")]
+                nu_tachyon: None,
             })
             .expect("the fixture activation heights are ordered")
             .extend_funding_streams()
diff --git a/crates/zakura-state/src/service/finalized_state/zakura_db/rollback.rs b/crates/zakura-state/src/service/finalized_state/zakura_db/rollback.rs
index c41b27b94b..355a6b899d 100644
--- a/crates/zakura-state/src/service/finalized_state/zakura_db/rollback.rs
+++ b/crates/zakura-state/src/service/finalized_state/zakura_db/rollback.rs
@@ -238,6 +238,11 @@ pub enum RollbackFinalizedStateError {
     #[error("failed to rebuild history tree")]
     HistoryTree(#[from] HistoryTreeError),
 
+    /// Rebuilding the Tachyon anchor failed.
+    #[error("failed to rebuild the Tachyon anchor")]
+    #[cfg(zcash_unstable = "nutachyon")]
+    TachyonAnchor(#[from] zcash_tachyon::AnchorError),
+
     /// Computing a block subsidy failed.
     #[error("failed to compute block subsidy")]
     Subsidy(#[from] SubsidyError),
@@ -606,14 +611,44 @@ fn rebuild_history_tree_from_upgrade_activation(
 
     let (block, sapling_root, orchard_root, ironwood_root) =
         history_rebuild_inputs_at_height(db, start_height)?;
-    let mut history_tree =
-        HistoryTree::from_block(network, block, &sapling_root, &orchard_root, &ironwood_root)?;
+    #[cfg(zcash_unstable = "nutachyon")]
+    let mut tachyon_anchor = zakura_chain::tachyon::Anchor::default();
+    #[cfg(zcash_unstable = "nutachyon")]
+    if let Some(pool_height) = zakura_chain::tachyon::pool_height(network, start_height) {
+        tachyon_anchor = tachyon_anchor
+            .advance_with_block(pool_height, &block)?
+            .post_block;
+    }
+    let mut history_tree = HistoryTree::from_block(
+        network,
+        block,
+        &sapling_root,
+        &orchard_root,
+        &ironwood_root,
+        #[cfg(zcash_unstable = "nutachyon")]
+        &tachyon_anchor,
+    )?;
 
     for height in ((start_height.0 + 1)..=target_height.0).map(Height) {
         let (block, sapling_root, orchard_root, ironwood_root) =
             history_rebuild_inputs_at_height(db, height)?;
 
-        history_tree.push(network, block, &sapling_root, &orchard_root, &ironwood_root)?;
+        #[cfg(zcash_unstable = "nutachyon")]
+        if let Some(pool_height) = zakura_chain::tachyon::pool_height(network, height) {
+            tachyon_anchor = tachyon_anchor
+                .advance_with_block(pool_height, &block)?
+                .post_block;
+        }
+
+        history_tree.push(
+            network,
+            block,
+            &sapling_root,
+            &orchard_root,
+            &ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            &tachyon_anchor,
+        )?;
     }
 
     Ok(history_tree)
@@ -679,12 +714,28 @@ fn rebuild_treestate_to_height(
             .ok_or(RollbackFinalizedStateError::MissingBlock { height })?;
 
         note_commitment_trees.update_trees_parallel(&block)?;
+        #[cfg(zcash_unstable = "nutachyon")]
+        if let Some(pool_height) = zakura_chain::tachyon::pool_height(network, height) {
+            let advance = note_commitment_trees
+                .tachyon_anchor
+                .advance_with_block(pool_height, &block)?;
+            note_commitment_trees.tachyon_anchor = advance.post_block;
+            note_commitment_trees.tachyon_epoch_anchor = advance.epoch_boundary;
+        }
         retained_sprout_roots.insert(note_commitment_trees.sprout.root());
 
         let sapling_root = note_commitment_trees.sapling.root();
         let orchard_root = note_commitment_trees.orchard.root();
         let ironwood_root = note_commitment_trees.ironwood.root();
-        history_tree.push(network, block, &sapling_root, &orchard_root, &ironwood_root)?;
+        history_tree.push(
+            network,
+            block,
+            &sapling_root,
+            &orchard_root,
+            &ironwood_root,
+            #[cfg(zcash_unstable = "nutachyon")]
+            &note_commitment_trees.tachyon_anchor,
+        )?;
     }
 
     Ok(RebuiltTreestate {
diff --git a/crates/zakura-state/src/service/finalized_state/zakura_db/shielded.rs b/crates/zakura-state/src/service/finalized_state/zakura_db/shielded.rs
index a10688fbd5..841de476ea 100644
--- a/crates/zakura-state/src/service/finalized_state/zakura_db/shielded.rs
+++ b/crates/zakura-state/src/service/finalized_state/zakura_db/shielded.rs
@@ -17,6 +17,8 @@ use std::{
     sync::Arc,
 };
 
+#[cfg(zcash_unstable = "nutachyon")]
+use zakura_chain::tachyon;
 use zakura_chain::{
     block::Height,
     ironwood, orchard,
@@ -26,6 +28,8 @@ use zakura_chain::{
     transaction::Transaction,
 };
 
+#[cfg(zcash_unstable = "nutachyon")]
+use crate::service::finalized_state::disk_format::shielded::TachyonEpoch;
 use crate::{
     request::{FinalizedBlock, Treestate},
     service::finalized_state::{
@@ -182,6 +186,53 @@ impl ZakuraDb {
         self.db.zs_contains(&ironwood_anchors, &ironwood_anchor)
     }
 
+    /// Returns the finalized height that created `tachyon_anchor` while it remains retained.
+    #[allow(clippy::unwrap_in_result)]
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_anchor_height(&self, tachyon_anchor: &tachyon::Anchor) -> Option<Height> {
+        let tachyon_anchors = self.db.cf_handle("tachyon_anchors").unwrap();
+        self.db.zs_get(&tachyon_anchors, tachyon_anchor)
+    }
+
+    /// Returns the Tachyon pool anchor after the finalized tip.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_anchor_for_tip(&self) -> tachyon::Anchor {
+        let anchors_by_height = self.db.cf_handle("tachyon_anchor_by_height").unwrap();
+        self.db
+            .zs_last_key_value(&anchors_by_height)
+            .map(|(_height, anchor): (Height, tachyon::Anchor)| anchor)
+            .unwrap_or_default()
+    }
+
+    /// Returns the finalized height that revealed `tachygram` while it remains retained.
+    #[allow(clippy::unwrap_in_result)]
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_tachygram_revealed_height(
+        &self,
+        tachygram: &tachyon::Tachygram,
+    ) -> Option<Height> {
+        let tachygrams = self.db.cf_handle("tachyon_tachygrams").unwrap();
+        self.db.zs_get(&tachygrams, tachygram)
+    }
+
+    /// Returns the boundary anchor for a finalized Tachyon epoch.
+    #[allow(clippy::unwrap_in_result)]
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_epoch_anchor(&self, epoch: u32) -> Option<tachyon::Anchor> {
+        let anchors = self.db.cf_handle("tachyon_epoch_anchor_by_epoch").unwrap();
+        self.db.zs_get(&anchors, &TachyonEpoch(epoch))
+    }
+
+    /// Returns the latest finalized Tachyon epoch.
+    #[allow(clippy::unwrap_in_result)]
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_current_epoch(&self) -> Option<u32> {
+        let anchors = self.db.cf_handle("tachyon_epoch_anchor_by_epoch").unwrap();
+        self.db
+            .zs_last_key_value(&anchors)
+            .map(|(epoch, _anchor): (TachyonEpoch, tachyon::Anchor)| epoch.0)
+    }
+
     // # Sprout trees
 
     /// Returns the Sprout note commitment tree of the finalized tip,
@@ -716,6 +767,10 @@ impl ZakuraDb {
             orchard_subtree: self.orchard_subtree_for_tip(),
             ironwood: self.ironwood_tree_for_tip(),
             ironwood_subtree: self.ironwood_subtree_for_tip(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_anchor: self.tachyon_anchor_for_tip(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_epoch_anchor: None,
         })
     }
 }
@@ -745,6 +800,60 @@ impl DiskWriteBatch {
         for transaction in &finalized.block.transactions {
             self.prepare_nullifier_batch(zakura_db, transaction);
         }
+
+        #[cfg(zcash_unstable = "nutachyon")]
+        self.prepare_tachyon_tachygram_batch(zakura_db, finalized);
+    }
+
+    /// Stores this block's Tachygrams and prunes data outside the two-epoch scan window.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn prepare_tachyon_tachygram_batch(
+        &mut self,
+        zakura_db: &ZakuraDb,
+        finalized: &FinalizedBlock,
+    ) {
+        let height = finalized.height;
+        let block_tachygrams: Vec<_> = finalized
+            .block
+            .transactions
+            .iter()
+            .flat_map(|transaction| transaction.tachyon_tachygrams())
+            .collect();
+        let starts_epoch =
+            tachyon::pool_height(&zakura_db.network(), height).is_some_and(tachyon::is_epoch_first);
+
+        if !starts_epoch && block_tachygrams.is_empty() {
+            return;
+        }
+
+        let tachyon_tachygrams = zakura_db.db.cf_handle("tachyon_tachygrams").unwrap();
+        if starts_epoch {
+            let cutoff = Height(height.0.saturating_sub(tachyon::EPOCH_LENGTH));
+            let expired_tachygrams: Vec<tachyon::Tachygram> = zakura_db
+                .db
+                .zs_forward_range_iter(&tachyon_tachygrams, ..)
+                .filter(|&(_, revealed): &(tachyon::Tachygram, Height)| revealed < cutoff)
+                .map(|(tachygram, _)| tachygram)
+                .collect();
+            for tachygram in expired_tachygrams {
+                self.zs_delete(&tachyon_tachygrams, tachygram);
+            }
+
+            let tachyon_anchors = zakura_db.db.cf_handle("tachyon_anchors").unwrap();
+            let expired_anchors: Vec<tachyon::Anchor> = zakura_db
+                .db
+                .zs_forward_range_iter(&tachyon_anchors, ..)
+                .filter(|&(_, anchor_height): &(tachyon::Anchor, Height)| anchor_height < cutoff)
+                .map(|(anchor, _)| anchor)
+                .collect();
+            for anchor in expired_anchors {
+                self.zs_delete(&tachyon_anchors, anchor);
+            }
+        }
+
+        for tachygram in block_tachygrams {
+            self.zs_insert(&tachyon_tachygrams, tachygram, height);
+        }
     }
 
     /// Prepare a database batch containing `finalized.block`'s nullifiers,
@@ -825,6 +934,26 @@ impl DiskWriteBatch {
         let orchard_tx = finalized.block.orchard_transactions_count();
         let ironwood_tx = finalized.block.ironwood_transactions_count();
 
+        #[cfg(zcash_unstable = "nutachyon")]
+        let previous_tachyon_anchor = prev_note_commitment_trees.as_ref().map_or_else(
+            || zakura_db.tachyon_anchor_for_tip(),
+            |trees| trees.tachyon_anchor,
+        );
+        #[cfg(zcash_unstable = "nutachyon")]
+        if previous_tachyon_anchor != note_commitment_trees.tachyon_anchor {
+            self.create_tachyon_anchor(zakura_db, height, &note_commitment_trees.tachyon_anchor);
+        }
+        #[cfg(zcash_unstable = "nutachyon")]
+        if let Some(epoch_anchor) = note_commitment_trees.tachyon_epoch_anchor {
+            let epoch = tachyon::epoch(&zakura_db.network(), *height)
+                .expect("a block carrying a Tachyon epoch anchor is NuTachyon-onward");
+            let epoch_anchors = zakura_db
+                .db
+                .cf_handle("tachyon_epoch_anchor_by_epoch")
+                .unwrap();
+            self.zs_insert(&epoch_anchors, TachyonEpoch(epoch), epoch_anchor);
+        }
+
         // Record the upgrade height `U` once, on the first block this binary commits: the lowest
         // height in the serving index, and the boundary below which roots are served from the
         // pre-upgrade per-height trees instead. Written on both commit paths so it is set even for
@@ -1097,6 +1226,20 @@ impl DiskWriteBatch {
         self.zs_insert(&sapling_subtree_cf, subtree.index, subtree.into_data());
     }
 
+    /// Stores an end-of-block Tachyon anchor by value and height.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn create_tachyon_anchor(
+        &mut self,
+        zakura_db: &ZakuraDb,
+        height: &Height,
+        anchor: &tachyon::Anchor,
+    ) {
+        let anchors = zakura_db.db.cf_handle("tachyon_anchors").unwrap();
+        let anchors_by_height = zakura_db.db.cf_handle("tachyon_anchor_by_height").unwrap();
+        self.zs_insert(&anchors, anchor, height);
+        self.zs_insert(&anchors_by_height, height, anchor);
+    }
+
     /// Deletes the Sapling note commitment tree at the given [`Height`].
     pub fn delete_sapling_tree(&mut self, zakura_db: &ZakuraDb, height: &Height) {
         let sapling_tree_cf = zakura_db
diff --git a/crates/zakura-state/src/service/non_finalized_state.rs b/crates/zakura-state/src/service/non_finalized_state.rs
index eb58c2e5a9..7a24d31695 100644
--- a/crates/zakura-state/src/service/non_finalized_state.rs
+++ b/crates/zakura-state/src/service/non_finalized_state.rs
@@ -473,6 +473,8 @@ impl NonFinalizedState {
                 finalized_state.sapling_tree_for_tip(),
                 finalized_state.orchard_tree_for_tip(),
                 finalized_state.ironwood_tree_for_tip(),
+                #[cfg(zcash_unstable = "nutachyon")]
+                finalized_state.tachyon_anchor_for_tip(),
                 finalized_state.history_tree(),
                 finalized_state.finalized_value_pool(),
             );
@@ -538,6 +540,8 @@ impl NonFinalizedState {
             finalized_state.sapling_tree_for_tip(),
             finalized_state.orchard_tree_for_tip(),
             finalized_state.ironwood_tree_for_tip(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            finalized_state.tachyon_anchor_for_tip(),
             finalized_state.history_tree(),
             finalized_state.finalized_value_pool(),
         );
diff --git a/crates/zakura-state/src/service/non_finalized_state/chain.rs b/crates/zakura-state/src/service/non_finalized_state/chain.rs
index 71c2722b1c..2af19409bf 100644
--- a/crates/zakura-state/src/service/non_finalized_state/chain.rs
+++ b/crates/zakura-state/src/service/non_finalized_state/chain.rs
@@ -11,6 +11,8 @@ use std::{
 use chrono::{DateTime, Utc};
 use tracing::instrument;
 
+#[cfg(zcash_unstable = "nutachyon")]
+use zakura_chain::tachyon;
 use zakura_chain::{
     amount::{Amount, NegativeAllowed, NonNegative},
     block::{self, Height},
@@ -217,6 +219,22 @@ pub struct ChainInner {
     /// This extra root is removed when the first non-finalized block is committed.
     pub(crate) ironwood_anchors_by_height: BTreeMap<block::Height, ironwood::tree::Root>,
 
+    /// Tachyon end-of-block anchors and the heights that created them.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub(crate) tachyon_anchors: HashMap<tachyon::Anchor, Vec<block::Height>>,
+    /// Tachyon end-of-block anchors indexed by height.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub(crate) tachyon_anchors_by_height: BTreeMap<block::Height, tachyon::Anchor>,
+    /// Tachyon epoch-boundary anchors indexed by epoch.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub(crate) tachyon_epoch_anchors_by_epoch: BTreeMap<u32, tachyon::Anchor>,
+    /// Tachygrams and every non-finalized height that revealed them.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub(crate) tachyon_tachygrams: HashMap<tachyon::Tachygram, Vec<block::Height>>,
+    /// Tachygrams revealed by each non-finalized block.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub(crate) tachyon_tachygrams_by_height: BTreeMap<block::Height, Vec<tachyon::Tachygram>>,
+
     // Nullifiers
     //
     /// The Sprout nullifiers revealed by `blocks` and, if the `indexer` feature is selected,
@@ -269,6 +287,7 @@ impl Chain {
         sapling_note_commitment_tree: Arc<sapling::tree::NoteCommitmentTree>,
         orchard_note_commitment_tree: Arc<orchard::tree::NoteCommitmentTree>,
         ironwood_note_commitment_tree: Arc<ironwood::tree::NoteCommitmentTree>,
+        #[cfg(zcash_unstable = "nutachyon")] finalized_tip_tachyon_anchor: tachyon::Anchor,
         history_tree: Arc<HistoryTree>,
         finalized_tip_chain_value_pools: ValueBalance<NonNegative>,
     ) -> Self {
@@ -294,6 +313,16 @@ impl Chain {
             ironwood_anchors_by_height: Default::default(),
             ironwood_trees_by_height: Default::default(),
             ironwood_subtrees: Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_anchors: Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_anchors_by_height: Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_epoch_anchors_by_epoch: Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_tachygrams: Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_tachygrams_by_height: Default::default(),
             sprout_nullifiers: Default::default(),
             sapling_nullifiers: Default::default(),
             orchard_nullifiers: Default::default(),
@@ -317,6 +346,13 @@ impl Chain {
         chain.add_ironwood_tree_and_anchor(finalized_tip_height, ironwood_note_commitment_tree);
         chain.add_history_tree(finalized_tip_height, history_tree);
 
+        // Only seed a real Tachyon anchor: the default anchor means the pool has not
+        // started (pre-NuTachyon finalized tip), and only NuTachyon-onward anchors are tracked.
+        #[cfg(zcash_unstable = "nutachyon")]
+        if finalized_tip_tachyon_anchor != tachyon::Anchor::default() {
+            chain.add_tachyon_anchor(finalized_tip_height, finalized_tip_tachyon_anchor);
+        }
+
         chain
     }
 
@@ -1316,6 +1352,179 @@ impl Chain {
         }
     }
 
+    /// Returns the Tachyon anchor after `hash_or_height`.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_anchor(&self, hash_or_height: HashOrHeight) -> Option<tachyon::Anchor> {
+        let height =
+            hash_or_height.height_or_else(|hash| self.height_by_hash.get(&hash).copied())?;
+        Some(
+            self.tachyon_anchors_by_height
+                .range(..=height)
+                .next_back()
+                .map(|(_, anchor)| *anchor)
+                .unwrap_or_default(),
+        )
+    }
+
+    /// Returns the Tachyon anchor after this chain's tip.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_anchor_for_tip(&self) -> tachyon::Anchor {
+        self.tachyon_anchors_by_height
+            .last_key_value()
+            .map(|(_, anchor)| *anchor)
+            .unwrap_or_default()
+    }
+
+    #[cfg(zcash_unstable = "nutachyon")]
+    fn add_tachyon_anchor(&mut self, height: Height, anchor: tachyon::Anchor) {
+        assert_eq!(
+            self.tachyon_anchors_by_height.insert(height, anchor),
+            None,
+            "Tachyon anchors must be reverted before replacement",
+        );
+        self.tachyon_anchors.entry(anchor).or_default().push(height);
+    }
+
+    #[cfg(zcash_unstable = "nutachyon")]
+    fn remove_tachyon_anchor(&mut self, position: RevertPosition, height: Height) {
+        let removed: Vec<_> = if position == RevertPosition::Root {
+            let removed = self
+                .tachyon_anchors_by_height
+                .range(..=height)
+                .map(|(height, anchor)| (*height, *anchor))
+                .collect::<Vec<_>>();
+            for (height, _) in &removed {
+                self.tachyon_anchors_by_height.remove(height);
+            }
+            removed
+        } else {
+            self.tachyon_anchors_by_height
+                .remove(&height)
+                .map(|anchor| (height, anchor))
+                .into_iter()
+                .collect()
+        };
+
+        for (anchor_height, anchor) in removed {
+            let heights = self
+                .tachyon_anchors
+                .get_mut(&anchor)
+                .expect("the Tachyon anchor value index mirrors its height index");
+            let index = heights
+                .iter()
+                .position(|&height| height == anchor_height)
+                .expect("the Tachyon anchor height exists in both indexes");
+            heights.swap_remove(index);
+            if heights.is_empty() {
+                self.tachyon_anchors.remove(&anchor);
+            }
+        }
+    }
+
+    /// Returns the boundary anchor for `epoch`.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_epoch_anchor(&self, epoch: u32) -> Option<tachyon::Anchor> {
+        self.tachyon_epoch_anchors_by_epoch.get(&epoch).copied()
+    }
+
+    /// Returns the Tachyon epoch containing this chain's tip.
+    #[cfg(zcash_unstable = "nutachyon")]
+    pub fn tachyon_current_epoch(&self) -> Option<u32> {
+        let tip_height = (!self.is_empty()).then(|| self.non_finalized_tip_height())?;
+        tachyon::epoch(&self.network, tip_height)
+    }
+
+    #[cfg(zcash_unstable = "nutachyon")]
+    fn add_tachyon_epoch_anchor(&mut self, epoch: u32, anchor: tachyon::Anchor) {
+        assert_eq!(
+            self.tachyon_epoch_anchors_by_epoch.insert(epoch, anchor),
+            None,
+            "a Tachyon epoch starts at most once per chain",
+        );
+    }
+
+    #[cfg(zcash_unstable = "nutachyon")]
+    fn remove_tachyon_epoch_anchor(&mut self, position: RevertPosition, height: Height) {
+        let Some(pool_height) = tachyon::pool_height(&self.network, height) else {
+            return;
+        };
+        if position == RevertPosition::Root {
+            let root_epoch = tachyon::epoch_of_pool_height(pool_height);
+            let epochs = self
+                .tachyon_epoch_anchors_by_epoch
+                .range(..=root_epoch)
+                .map(|(&epoch, _)| epoch)
+                .collect::<Vec<_>>();
+            for epoch in epochs {
+                self.tachyon_epoch_anchors_by_epoch.remove(&epoch);
+            }
+        } else if tachyon::is_epoch_first(pool_height) {
+            self.tachyon_epoch_anchors_by_epoch
+                .remove(&tachyon::epoch_of_pool_height(pool_height));
+        }
+    }
+
+    #[cfg(zcash_unstable = "nutachyon")]
+    fn add_tachyon_tachygrams(
+        &mut self,
+        height: Height,
+        tachygrams: Vec<tachyon::Tachygram>,
+    ) -> Result<(), ValidateContextError> {
+        if tachygrams.is_empty() {
+            return Ok(());
+        }
+
+        let network = self.network.clone();
+        for &tachygram in &tachygrams {
+            let revealed_heights = self.tachyon_tachygrams.entry(tachygram).or_default();
+            if revealed_heights
+                .iter()
+                .any(|&revealed| tachyon::within_scan_window(&network, revealed, height))
+            {
+                return Err(ValidateContextError::DuplicateTachyonTachygram {
+                    tachygram,
+                    in_finalized_state: false,
+                });
+            }
+            revealed_heights.push(height);
+        }
+        self.tachyon_tachygrams_by_height.insert(height, tachygrams);
+        Ok(())
+    }
+
+    #[cfg(zcash_unstable = "nutachyon")]
+    fn remove_tachyon_tachygrams(&mut self, position: RevertPosition, height: Height) {
+        let removed_heights: Vec<_> = if position == RevertPosition::Root {
+            self.tachyon_tachygrams_by_height
+                .range(..=height)
+                .map(|(height, _)| *height)
+                .collect()
+        } else {
+            self.tachyon_tachygrams_by_height
+                .contains_key(&height)
+                .then_some(height)
+                .into_iter()
+                .collect()
+        };
+
+        for height in removed_heights {
+            let tachygrams = self
+                .tachyon_tachygrams_by_height
+                .remove(&height)
+                .expect("the Tachygram height was selected from this index");
+            for tachygram in tachygrams {
+                let revealed_heights = self
+                    .tachyon_tachygrams
+                    .get_mut(&tachygram)
+                    .expect("the Tachygram value index mirrors its height index");
+                revealed_heights.retain(|&revealed| revealed != height);
+                if revealed_heights.is_empty() {
+                    self.tachyon_tachygrams.remove(&tachygram);
+                }
+            }
+        }
+    }
+
     /// Returns the History tree of the tip of this [`Chain`],
     /// including all finalized blocks, and the non-finalized blocks below the chain tip.
     ///
@@ -1391,6 +1600,17 @@ impl Chain {
         let sapling_subtree = self.sapling_subtree(hash_or_height);
         let orchard_subtree = self.orchard_subtree(hash_or_height);
         let ironwood_subtree = self.ironwood_subtree(hash_or_height);
+        #[cfg(zcash_unstable = "nutachyon")]
+        let tachyon_anchor = self.tachyon_anchor(hash_or_height)?;
+        #[cfg(zcash_unstable = "nutachyon")]
+        let height =
+            hash_or_height.height_or_else(|hash| self.height_by_hash.get(&hash).copied())?;
+        #[cfg(zcash_unstable = "nutachyon")]
+        let tachyon_epoch_anchor = tachyon::pool_height(&self.network, height)
+            .filter(|&pool_height| tachyon::is_epoch_first(pool_height))
+            .and_then(|pool_height| {
+                self.tachyon_epoch_anchor(tachyon::epoch_of_pool_height(pool_height))
+            });
 
         Some(Treestate::new(
             sprout_tree,
@@ -1400,6 +1620,10 @@ impl Chain {
             sapling_subtree,
             orchard_subtree,
             ironwood_subtree,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_anchor,
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_epoch_anchor,
             history_tree,
         ))
     }
@@ -1687,6 +1911,10 @@ impl Chain {
             orchard_subtree: self.orchard_subtree_for_tip(),
             ironwood: self.ironwood_note_commitment_tree_for_tip(),
             ironwood_subtree: self.ironwood_subtree_for_tip(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_anchor: self.tachyon_anchor_for_tip(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            tachyon_epoch_anchor: None,
         };
 
         let mut tree_result = None;
@@ -1731,6 +1959,40 @@ impl Chain {
         let orchard_root = self.orchard_note_commitment_tree_for_tip().root();
         let ironwood_root = self.ironwood_note_commitment_tree_for_tip().root();
 
+        // Advance the Tachyon pool anchor with this block, if the pool has started.
+        // `nct.tachyon_anchor` still holds the parent block's anchor here.
+        //
+        // In builds without tachyon support V7 transactions cannot be parsed, so a NuTachyon
+        // chain cannot be synced and the anchor legitimately stays at its default.
+        #[cfg(zcash_unstable = "nutachyon")]
+        {
+            if let Some(pool_height) = zakura_chain::tachyon::pool_height(&self.network, height) {
+                let advance = nct
+                    .tachyon_anchor
+                    .advance_with_block(pool_height, &contextually_valid.block)?;
+                nct.tachyon_anchor = advance.post_block;
+                nct.tachyon_epoch_anchor = advance.epoch_boundary;
+                self.add_tachyon_anchor(height, advance.post_block);
+                if let Some(boundary_anchor) = advance.epoch_boundary {
+                    self.add_tachyon_epoch_anchor(
+                        zakura_chain::tachyon::epoch_of_pool_height(pool_height),
+                        boundary_anchor,
+                    );
+                }
+            }
+            // Add this block's tachygrams to the epoch working set, rejecting same-epoch
+            // duplicates within this chain.
+            let block_tachygrams: Vec<_> = contextually_valid
+                .block
+                .transactions
+                .iter()
+                .flat_map(|transaction| transaction.tachyon_tachygrams())
+                .collect();
+            self.add_tachyon_tachygrams(height, block_tachygrams)?;
+        }
+        #[cfg(zcash_unstable = "nutachyon")]
+        let tachyon_anchor = nct.tachyon_anchor;
+
         // TODO: update the history trees in a rayon thread, if they show up in CPU profiles
         let mut history_tree = self.history_block_commitment_tree();
         let history_tree_mut = Arc::make_mut(&mut history_tree);
@@ -1741,6 +2003,8 @@ impl Chain {
                 &sapling_root,
                 &orchard_root,
                 &ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                &tachyon_anchor,
             )
             .map_err(Arc::new)?;
 
@@ -1863,6 +2127,23 @@ impl Chain {
                     orchard_shielded_data,
                     ironwood_shielded_data,
                 ),
+                #[cfg(zcash_unstable = "nutachyon")]
+                V7 {
+                    inputs,
+                    outputs,
+                    sapling_shielded_data,
+                    orchard_shielded_data,
+                    ironwood_shielded_data,
+                    ..
+                } => (
+                    inputs,
+                    outputs,
+                    &None,
+                    &None,
+                    sapling_shielded_data,
+                    orchard_shielded_data,
+                    ironwood_shielded_data,
+                ),
 
                 V1 { .. } | V2 { .. } | V3 { .. } => unreachable!(
                     "older transaction versions only exist in finalized blocks, because of the mandatory canopy checkpoint",
@@ -2072,6 +2353,23 @@ impl UpdateWith<ContextuallyVerifiedBlock> for Chain {
                     orchard_shielded_data,
                     ironwood_shielded_data,
                 ),
+                #[cfg(zcash_unstable = "nutachyon")]
+                V7 {
+                    inputs,
+                    outputs,
+                    sapling_shielded_data,
+                    orchard_shielded_data,
+                    ironwood_shielded_data,
+                    ..
+                } => (
+                    inputs,
+                    outputs,
+                    &None,
+                    &None,
+                    sapling_shielded_data,
+                    orchard_shielded_data,
+                    ironwood_shielded_data,
+                ),
 
                 V1 { .. } | V2 { .. } | V3 { .. } => unreachable!(
                     "older transaction versions only exist in finalized blocks, because of the mandatory canopy checkpoint",
@@ -2116,6 +2414,12 @@ impl UpdateWith<ContextuallyVerifiedBlock> for Chain {
         self.remove_sapling_tree_and_anchor(position, height);
         self.remove_orchard_tree_and_anchor(position, height);
         self.remove_ironwood_tree_and_anchor(position, height);
+        #[cfg(zcash_unstable = "nutachyon")]
+        {
+            self.remove_tachyon_anchor(position, height);
+            self.remove_tachyon_epoch_anchor(position, height);
+            self.remove_tachyon_tachygrams(position, height);
+        }
 
         // TODO: move this to the history tree UpdateWith.revert...()?
         self.remove_history_tree(position, height);
@@ -2726,3 +3030,153 @@ impl Chain {
             .insert(subtree.index, subtree.into_data());
     }
 }
+
+#[cfg(all(test, zcash_unstable = "nutachyon"))]
+mod tachyon_tests {
+    use zakura_chain::parameters::testnet::ConfiguredActivationHeights;
+
+    use super::*;
+
+    /// A chain on a regtest network with NuTachyon (tachyon) activated at height 10, forked
+    /// from a finalized tip at height 9 (so pool height 0 is chain height 10).
+    fn nutachyon_chain() -> Chain {
+        let network = Network::new_regtest(
+            ConfiguredActivationHeights {
+                canopy: Some(1),
+                nu5: Some(2),
+                nu6: Some(3),
+                nu6_1: Some(4),
+                nu6_2: Some(5),
+                nu6_3: Some(6),
+                nu7: Some(8),
+                nu_tachyon: Some(10),
+                ..Default::default()
+            }
+            .into(),
+        );
+
+        Chain::new(
+            &network,
+            Height(9),
+            Default::default(),
+            Default::default(),
+            Default::default(),
+            Default::default(),
+            Default::default(),
+            Default::default(),
+            ValueBalance::zero(),
+        )
+    }
+
+    fn tachygram(byte: u8) -> tachyon::Tachygram {
+        tachyon::Tachygram([byte; 32])
+    }
+
+    /// The height of the first block of `epoch` on the [`nutachyon_chain`] network
+    /// (NuTachyon activates at chain height 10).
+    fn epoch_first_height(epoch: u32) -> Height {
+        Height(10 + epoch * tachyon::EPOCH_LENGTH)
+    }
+
+    #[test]
+    fn same_epoch_duplicate_tachygram_is_rejected() {
+        let mut chain = nutachyon_chain();
+
+        chain
+            .add_tachyon_tachygrams(Height(20), vec![tachygram(1), tachygram(2)])
+            .expect("distinct tachygrams are accepted");
+
+        let result = chain.add_tachyon_tachygrams(Height(30), vec![tachygram(2)]);
+        assert!(
+            matches!(
+                result,
+                Err(ValidateContextError::DuplicateTachyonTachygram {
+                    in_finalized_state: false,
+                    ..
+                })
+            ),
+            "expected DuplicateTachyonTachygram, got: {result:?}",
+        );
+    }
+
+    #[test]
+    fn duplicate_tachygram_scan_window_spans_two_epochs() {
+        let mut chain = nutachyon_chain();
+
+        // Epoch 0 (chain heights 10..10+EPOCH_LENGTH).
+        chain
+            .add_tachyon_tachygrams(Height(20), vec![tachygram(1)])
+            .expect("first reveal is accepted");
+
+        // The same tachygram in the immediately following epoch is still within the
+        // two-epoch scan window: a repeat there is exactly what a double spend's
+        // next-epoch nullifier would look like.
+        let result = chain.add_tachyon_tachygrams(epoch_first_height(1), vec![tachygram(1)]);
+        assert!(
+            result.is_err(),
+            "adjacent-epoch duplicate must be rejected: {result:?}",
+        );
+
+        // Two epochs later the tachygram has left the scan window. (An honest repeat
+        // out here would imply a nullifier-derivation collision, but consensus no
+        // longer tracks it.)
+        chain
+            .add_tachyon_tachygrams(epoch_first_height(2), vec![tachygram(1)])
+            .expect("a tachygram outside the two-epoch window is accepted again");
+
+        // And the fresh reveal re-arms the window.
+        let result =
+            chain.add_tachyon_tachygrams(Height(epoch_first_height(2).0 + 1), vec![tachygram(1)]);
+        assert!(result.is_err(), "same-epoch duplicate must be rejected");
+    }
+
+    #[test]
+    fn reverting_a_block_restores_its_tachygrams() {
+        let mut chain = nutachyon_chain();
+
+        chain
+            .add_tachyon_tachygrams(Height(20), vec![tachygram(1)])
+            .expect("first reveal is accepted");
+        chain
+            .add_tachyon_tachygrams(Height(30), vec![tachygram(2)])
+            .expect("distinct tachygram is accepted");
+
+        // Fork off the tip block: its tachygram becomes revealable again.
+        chain.remove_tachyon_tachygrams(RevertPosition::Tip, Height(30));
+        chain
+            .add_tachyon_tachygrams(Height(30), vec![tachygram(2)])
+            .expect("a reverted tachygram is revealable again");
+
+        // A root revert (finalization) drops everything at or below the height.
+        chain.remove_tachyon_tachygrams(RevertPosition::Root, Height(30));
+        assert!(chain.tachyon_tachygrams.is_empty());
+        assert!(chain.tachyon_tachygrams_by_height.is_empty());
+    }
+
+    #[test]
+    fn epoch_anchors_are_tracked_and_reverted() {
+        let mut chain = nutachyon_chain();
+        let anchor_0 = tachyon::Anchor([10; 32]);
+        let anchor_1 = tachyon::Anchor([11; 32]);
+
+        chain.add_tachyon_epoch_anchor(0, anchor_0);
+        chain.add_tachyon_epoch_anchor(1, anchor_1);
+        assert_eq!(chain.tachyon_epoch_anchor(0), Some(anchor_0));
+        assert_eq!(chain.tachyon_epoch_anchor(1), Some(anchor_1));
+
+        // Reverting epoch 1's first block from the tip removes its epoch anchor.
+        chain.remove_tachyon_epoch_anchor(RevertPosition::Tip, epoch_first_height(1));
+        assert_eq!(chain.tachyon_epoch_anchor(1), None);
+        assert_eq!(chain.tachyon_epoch_anchor(0), Some(anchor_0));
+
+        // Reverting a mid-epoch block from the tip removes nothing.
+        chain.remove_tachyon_epoch_anchor(RevertPosition::Tip, Height(20));
+        assert_eq!(chain.tachyon_epoch_anchor(0), Some(anchor_0));
+
+        // A root revert at an epoch's first block drops that epoch and everything before it.
+        chain.add_tachyon_epoch_anchor(1, anchor_1);
+        chain.remove_tachyon_epoch_anchor(RevertPosition::Root, epoch_first_height(0));
+        assert_eq!(chain.tachyon_epoch_anchor(0), None);
+        assert_eq!(chain.tachyon_epoch_anchor(1), Some(anchor_1));
+    }
+}
diff --git a/crates/zakura-state/src/service/non_finalized_state/tests/prop.rs b/crates/zakura-state/src/service/non_finalized_state/tests/prop.rs
index 28a9e06807..8aaa60254d 100644
--- a/crates/zakura-state/src/service/non_finalized_state/tests/prop.rs
+++ b/crates/zakura-state/src/service/non_finalized_state/tests/prop.rs
@@ -71,7 +71,7 @@ fn push_genesis_chain() -> Result<()> {
     |((chain, count, network, empty_tree) in PreparedChain::default())| {
         prop_assert!(empty_tree.is_none());
 
-        let mut only_chain = Chain::new(&network, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), empty_tree, ValueBalance::zero());
+        let mut only_chain = Chain::new(&network, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), #[cfg(zcash_unstable = "nutachyon")] Default::default(), empty_tree, ValueBalance::zero());
         // contains the block value pool changes and chain value pool balances for each height
         let mut chain_values = BTreeMap::new();
 
@@ -124,7 +124,7 @@ fn push_history_tree_chain() -> Result<()> {
         let count = std::cmp::min(count, chain.len() - 1);
         let chain = &chain[1..];
 
-        let mut only_chain = Chain::new(&network, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), finalized_tree, ValueBalance::zero());
+        let mut only_chain = Chain::new(&network, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), #[cfg(zcash_unstable = "nutachyon")] Default::default(), finalized_tree, ValueBalance::zero());
 
         for block in chain
             .iter()
@@ -173,6 +173,8 @@ fn forked_equals_pushed_genesis() -> Result<()> {
             Default::default(),
             Default::default(),
             Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Default::default(),
             empty_tree.clone(),
             ValueBalance::zero(),
         );
@@ -195,6 +197,8 @@ fn forked_equals_pushed_genesis() -> Result<()> {
             Default::default(),
             Default::default(),
             Default::default(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Default::default(),
             empty_tree,
             ValueBalance::zero(),
         );
@@ -293,8 +297,8 @@ fn forked_equals_pushed_history_tree() -> Result<()> {
         // use `fork_at_count` as the fork tip
         let fork_tip_hash = chain[fork_at_count - 1].hash;
 
-        let mut full_chain = Chain::new(&network, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), finalized_tree.clone(), ValueBalance::zero());
-        let mut partial_chain = Chain::new(&network, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), finalized_tree, ValueBalance::zero());
+        let mut full_chain = Chain::new(&network, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), #[cfg(zcash_unstable = "nutachyon")] Default::default(), finalized_tree.clone(), ValueBalance::zero());
+        let mut partial_chain = Chain::new(&network, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), #[cfg(zcash_unstable = "nutachyon")] Default::default(), finalized_tree, ValueBalance::zero());
 
         for block in chain
             .iter()
@@ -361,7 +365,7 @@ fn finalized_equals_pushed_genesis() -> Result<()> {
 
         let fake_value_pool = ValueBalance::<NonNegative>::fake_populated_pool();
 
-        let mut full_chain = Chain::new(&network, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), empty_tree, fake_value_pool);
+        let mut full_chain = Chain::new(&network, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), #[cfg(zcash_unstable = "nutachyon")] Default::default(), empty_tree, fake_value_pool);
         for block in chain
             .clone()
             .take(finalized_count) {
@@ -375,6 +379,8 @@ fn finalized_equals_pushed_genesis() -> Result<()> {
             full_chain.sapling_note_commitment_tree_for_tip(),
             full_chain.orchard_note_commitment_tree_for_tip(),
             full_chain.ironwood_note_commitment_tree_for_tip(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Default::default(),
             full_chain.history_block_commitment_tree(),
             full_chain.chain_value_pools,
         );
@@ -439,7 +445,7 @@ fn finalized_equals_pushed_history_tree() -> Result<()> {
 
         let fake_value_pool = ValueBalance::<NonNegative>::fake_populated_pool();
 
-        let mut full_chain = Chain::new(&network, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), finalized_tree, fake_value_pool);
+        let mut full_chain = Chain::new(&network, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), #[cfg(zcash_unstable = "nutachyon")] Default::default(), finalized_tree, fake_value_pool);
         for block in chain
             .iter()
             .take(finalized_count)
@@ -454,6 +460,8 @@ fn finalized_equals_pushed_history_tree() -> Result<()> {
             full_chain.sapling_note_commitment_tree_for_tip(),
             full_chain.orchard_note_commitment_tree_for_tip(),
             full_chain.ironwood_note_commitment_tree_for_tip(),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Default::default(),
             full_chain.history_block_commitment_tree(),
             full_chain.chain_value_pools,
         );
@@ -629,6 +637,8 @@ fn different_blocks_different_chains() -> Result<()> {
                     &Default::default(),
                     &Default::default(),
                     &Default::default(),
+                    #[cfg(zcash_unstable = "nutachyon")]
+                    &Default::default(),
                 ).unwrap().into()
             )
         } else {
@@ -642,14 +652,16 @@ fn different_blocks_different_chains() -> Result<()> {
                     &Default::default(),
                     &Default::default(),
                     &Default::default(),
+                    #[cfg(zcash_unstable = "nutachyon")]
+                    &Default::default(),
                 ).unwrap().into()
             )
         } else {
             Default::default()
         };
 
-        let chain1 = Chain::new(&Network::Mainnet, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), finalized_tree1, ValueBalance::fake_populated_pool());
-        let chain2 = Chain::new(&Network::Mainnet, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), finalized_tree2, ValueBalance::fake_populated_pool());
+        let chain1 = Chain::new(&Network::Mainnet, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), #[cfg(zcash_unstable = "nutachyon")] Default::default(), finalized_tree1, ValueBalance::fake_populated_pool());
+        let chain2 = Chain::new(&Network::Mainnet, Height(0), Default::default(), Default::default(), Default::default(), Default::default(), #[cfg(zcash_unstable = "nutachyon")] Default::default(), finalized_tree2, ValueBalance::fake_populated_pool());
 
         let block1 = vec1[1].clone().prepare().test_with_zero_spent_utxos();
         let block2 = vec2[1].clone().prepare().test_with_zero_spent_utxos();
diff --git a/crates/zakura-state/src/service/non_finalized_state/tests/vectors.rs b/crates/zakura-state/src/service/non_finalized_state/tests/vectors.rs
index 6395ea9550..fcbd2d00bc 100644
--- a/crates/zakura-state/src/service/non_finalized_state/tests/vectors.rs
+++ b/crates/zakura-state/src/service/non_finalized_state/tests/vectors.rs
@@ -35,6 +35,8 @@ fn construct_empty() {
         Default::default(),
         Default::default(),
         Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        Default::default(),
         Default::default(),
         ValueBalance::zero(),
     );
@@ -53,6 +55,8 @@ fn construct_single() -> Result<()> {
         Default::default(),
         Default::default(),
         Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        Default::default(),
         Default::default(),
         ValueBalance::fake_populated_pool(),
     );
@@ -88,6 +92,8 @@ fn construct_many() -> Result<()> {
         Default::default(),
         Default::default(),
         Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        Default::default(),
         Default::default(),
         ValueBalance::fake_populated_pool(),
     );
@@ -116,6 +122,8 @@ fn ord_matches_work() -> Result<()> {
         Default::default(),
         Default::default(),
         Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        Default::default(),
         Default::default(),
         ValueBalance::fake_populated_pool(),
     );
@@ -128,6 +136,8 @@ fn ord_matches_work() -> Result<()> {
         Default::default(),
         Default::default(),
         Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        Default::default(),
         Default::default(),
         ValueBalance::zero(),
     );
@@ -239,6 +249,8 @@ fn finalize_drops_empty_side_chain_for_network(network: Network) -> Result<()> {
         Default::default(),
         Default::default(),
         Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        Default::default(),
         Default::default(),
         ValueBalance::fake_populated_pool(),
     )
@@ -986,6 +998,8 @@ fn history_tree_is_updated_for_network_upgrade(
         &chain.sapling_note_commitment_tree_for_tip().root(),
         &chain.orchard_note_commitment_tree_for_tip().root(),
         &chain.ironwood_note_commitment_tree_for_tip().root(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )
     .unwrap();
 
@@ -1066,6 +1080,8 @@ fn commitment_is_validated_for_network_upgrade(network: Network, network_upgrade
         &chain.sapling_note_commitment_tree_for_tip().root(),
         &chain.orchard_note_commitment_tree_for_tip().root(),
         &chain.ironwood_note_commitment_tree_for_tip().root(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )
     .unwrap();
 
@@ -1172,6 +1188,8 @@ fn fork_drops_subtrees_above_fork_point() -> Result<()> {
         Default::default(),
         Default::default(),
         Default::default(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        Default::default(),
         Default::default(),
         ValueBalance::fake_populated_pool(),
     );
diff --git a/crates/zakura-state/src/service/write/tests/full_state_coherence.rs b/crates/zakura-state/src/service/write/tests/full_state_coherence.rs
index f6775a0759..3f0f69948c 100644
--- a/crates/zakura-state/src/service/write/tests/full_state_coherence.rs
+++ b/crates/zakura-state/src/service/write/tests/full_state_coherence.rs
@@ -176,6 +176,8 @@ fn generated_nu5_graph_matches_full_state_before_finalization() {
                 nu6_2: Some(120),
                 nu6_3: Some(130),
                 nu7: Some(140),
+                #[cfg(zcash_unstable = "nutachyon")]
+                nu_tachyon: None,
             })
             .expect("the compressed activation schedule is ordered")
             .with_disable_pow(true)
@@ -315,6 +317,8 @@ fn generated_nu5_graph_matches_full_state_before_finalization() {
                     &sapling_root,
                     &orchard_root,
                     &ironwood_root,
+                    #[cfg(zcash_unstable = "nutachyon")]
+                    &Default::default(),
                 )
                 .expect("the deterministic history tree advances");
             blocks.push(block);
diff --git a/crates/zakura-state/src/service/write/vct_authentication_sweep/tests.rs b/crates/zakura-state/src/service/write/vct_authentication_sweep/tests.rs
index cc02a59c38..8863eb768d 100644
--- a/crates/zakura-state/src/service/write/vct_authentication_sweep/tests.rs
+++ b/crates/zakura-state/src/service/write/vct_authentication_sweep/tests.rs
@@ -108,6 +108,8 @@ fn parameters(checkpoint_blocks: Option<&[Arc<Block>]>) -> Network {
             nu6_2: Some(NU6_2),
             nu6_3: Some(NU6_3),
             nu7: Some(NU7),
+            #[cfg(zcash_unstable = "nutachyon")]
+            nu_tachyon: None,
         })
         .expect("the compressed activation schedule is ordered")
         .with_disable_pow(true)
@@ -201,6 +203,16 @@ fn generate_chain(network: &Network) -> Vec<Arc<Block>> {
                 sapling_shielded_data: None,
                 orchard_shielded_data: None,
             },
+            #[cfg(zcash_unstable = "nutachyon")]
+            NetworkUpgrade::NuTachyon => Transaction::V5 {
+                network_upgrade: upgrade,
+                lock_time: LockTime::unlocked(),
+                expiry_height: height,
+                inputs: vec![input],
+                outputs: Vec::new(),
+                sapling_shielded_data: None,
+                orchard_shielded_data: None,
+            },
         };
         let transactions = vec![Arc::new(transaction)];
         let merkle_root = transactions.iter().cloned().collect();
@@ -251,6 +263,8 @@ fn generate_chain(network: &Network) -> Vec<Arc<Block>> {
                 &sapling_root,
                 &orchard_root,
                 &ironwood_root,
+                #[cfg(zcash_unstable = "nutachyon")]
+                &Default::default(),
             )
             .expect("the deterministic history tree advances");
         blocks.push(block);
@@ -641,6 +655,8 @@ impl Fixture {
                 &empty_sapling_root(),
                 &empty_orchard_root(),
                 &empty_ironwood_root(),
+                #[cfg(zcash_unstable = "nutachyon")]
+                &Default::default(),
             )
             .expect("the generated history tree advances");
         }
@@ -666,6 +682,8 @@ impl Fixture {
         verify_commitment_roots(
             &self.network,
             self.history_tree_through(parent),
+            #[cfg(zcash_unstable = "nutachyon")]
+            Default::default(),
             vec![
                 CommitmentRootVerification::with_roots(
                     block.clone(),
@@ -1084,6 +1102,8 @@ fn fold_placement_is_checked_before_every_history_tree_push() {
         &empty_sapling_root(),
         &empty_orchard_root(),
         &empty_ironwood_root(),
+        #[cfg(zcash_unstable = "nutachyon")]
+        &Default::default(),
     )
     .expect("the activation block creates the tree");
 
diff --git a/crates/zakura-state/src/tests.rs b/crates/zakura-state/src/tests.rs
index 4be00ad1f2..2ecbfe0eeb 100644
--- a/crates/zakura-state/src/tests.rs
+++ b/crates/zakura-state/src/tests.rs
@@ -37,6 +37,8 @@ impl FakeChainHelper for Arc<Block> {
             Transaction::V4 { inputs, .. } => &mut inputs[0],
             Transaction::V5 { inputs, .. } => &mut inputs[0],
             Transaction::V6 { inputs, .. } => &mut inputs[0],
+            #[cfg(zcash_unstable = "nutachyon")]
+            Transaction::V7 { inputs, .. } => &mut inputs[0],
         };
 
         match input {
diff --git a/crates/zakura-utils/coverage b/crates/zakura-utils/coverage
index 942681d4b2..d3509ca8b5 100755
--- a/crates/zakura-utils/coverage
+++ b/crates/zakura-utils/coverage
@@ -5,7 +5,7 @@ set -o xtrace
 export CARGO_TARGET_DIR="coverage-target"
 export SKIP_NETWORK_TESTS=1
 export LLVM_PROFILE_FILE="${PWD}/$CARGO_TARGET_DIR/coverage/test.%m.profraw"
-export RUSTFLAGS="-Zinstrument-coverage -C link-dead-code -C debuginfo=2"
+export RUSTFLAGS='--cfg zcash_unstable="nutachyon" -Zinstrument-coverage -C link-dead-code -C debuginfo=2'
 
 rm -rf ./"$CARGO_TARGET_DIR"/coverage
 mkdir -p ./$CARGO_TARGET_DIR/coverage
diff --git a/crates/zakurad/src/components/mempool/storage/tests/prop.rs b/crates/zakurad/src/components/mempool/storage/tests/prop.rs
index d1423b1762..ac03f3fcdb 100644
--- a/crates/zakurad/src/components/mempool/storage/tests/prop.rs
+++ b/crates/zakurad/src/components/mempool/storage/tests/prop.rs
@@ -661,6 +661,8 @@ impl SpendConflictTestInput {
                 // No JoinSplits
                 Transaction::V1 { .. } | Transaction::V5 { .. } => {}
                 Transaction::V6 { .. } => {}
+                #[cfg(zcash_unstable = "nutachyon")]
+                Transaction::V7 { .. } => {}
             }
         }
     }
@@ -737,6 +739,13 @@ impl SpendConflictTestInput {
                 } => {
                     Self::remove_sapling_transfers_with_conflicts(sapling_shielded_data, &conflicts)
                 }
+                #[cfg(zcash_unstable = "nutachyon")]
+                Transaction::V7 {
+                    sapling_shielded_data,
+                    ..
+                } => {
+                    Self::remove_sapling_transfers_with_conflicts(sapling_shielded_data, &conflicts)
+                }
 
                 // No Spends
                 Transaction::V1 { .. } | Transaction::V2 { .. } | Transaction::V3 { .. } => {}
@@ -813,6 +822,11 @@ impl SpendConflictTestInput {
                     orchard_shielded_data,
                     ..
                 } => Self::remove_orchard_actions_with_conflicts(orchard_shielded_data, &conflicts),
+                #[cfg(zcash_unstable = "nutachyon")]
+                Transaction::V7 {
+                    orchard_shielded_data,
+                    ..
+                } => Self::remove_orchard_actions_with_conflicts(orchard_shielded_data, &conflicts),
 
                 // No Spends
                 Transaction::V1 { .. }
diff --git a/docs/changelog/unreleased/795.md b/docs/changelog/unreleased/795.md
new file mode 100644
index 0000000000..cc2a8827ad
--- /dev/null
+++ b/docs/changelog/unreleased/795.md
@@ -0,0 +1,5 @@
+## Added
+
+- Added NuTachyon network-upgrade and V7 transaction support, including Tachyon bundle
+  serialization, consensus validation, chain state, and block-template aggregation
+  ([#795](https://github.com/zakura-core/zakura/pull/795)).