diff --git a/README.md b/README.md
index 1a5d266f9..d4d0ade00 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,7 @@ Wallets and mints `MUST` implement all mandatory specs and `CAN` implement optio
 | [28][28] | Pay to Blinded Key (P2BK)         | [cdk], [cashu-ts][ts]                                                                                 | -                                     |
 | [29][29] | Batched Mint                      | [cdk], [cashu-ts][ts]                                                                                 | [Nutshell][py], [cdk-mintd]           |
 | [30][30] | Payment Method: Onchain           | [cdk], [cashu-ts][ts], [Cashu.me][cashume]                                                            | [cdk-mintd]                           |
+| [XX][XX] | Get Locked Mint Quotes By Pubkey  | -                                                                                                     | -                                     |
 
 #### Wallets
 
@@ -103,3 +104,4 @@ Wallets and mints `MUST` implement all mandatory specs and `CAN` implement optio
 [28]: 28.md
 [29]: 29.md
 [30]: 30.md
+[XX]: xx.md
diff --git a/xx.md b/xx.md
new file mode 100644
index 000000000..a211b2a73
--- /dev/null
+++ b/xx.md
@@ -0,0 +1,68 @@
+# NUT-XX: Mint Quote Lookup by Public Key
+
+`optional`
+
+`depends on: NUT-04, NUT-20`
+
+---
+
+This NUT adds an endpoint for wallets to get all NUT-20 locked mint quotes associated with a set of public keys. Queries require a valid signature from the owner of the corresponding private keys.
+
+## Request
+
+To query quotes assigned to a public key, the wallet makes a `POST /v1/mint/quote/{method}/pubkey` request.
+
+```http
+POST https://mint.host:3338/v1/mint/quote/bolt11/pubkey
+```
+
+The wallet includes the following `PostMintQuotesByPubkeyRequest` data:
+
+```json
+{
+  "pubkeys": <Array[str]>,
+  "pubkey_signatures": <Array[str]>
+}
+```
+
+- `pubkeys` is an array of hex-encoded compressed secp256k1 NUT-20 public keys (33 bytes each)
+- `pubkey_signatures` is an array of hex-encoded Schnorr signatures in the same order as `pubkeys` (64 bytes each)
+
+For each `pubkey`, the corresponding `pubkey_signatures` entry signs the SHA-256 hash of:
+
+```
+"Cashu_MintQuoteLookup_v1" || mint_pubkey || pubkey
+```
+
+`mint_pubkey` is the mint's `pubkey` from its [NUT-06][06] info response, which a mint supporting this NUT **MUST** provide. Fields are concatenated as their UTF-8 string representations.
+
+The mint **MUST** reject the request unless every signature is valid.
+
+## Response
+
+The mint responds with a `PostMintQuotesByPubkeyResponse`:
+
+```json
+{
+  "quotes": <Array[MintQuoteResponse]>
+}
+```
+
+Where `MintQuoteResponse` is the quote response type defined in [NUT-04][04].
+
+## Settings
+
+The settings for this NUT are part of the mint info response ([NUT-06][06]):
+
+```json
+{
+  "XX": {
+    "supported": <bool>
+  }
+}
+```
+
+[04]: 04.md
+[06]: 06.md
+[20]: 20.md
+[errors]: error_codes.md