NUT-XX: Get quotes by pubkeys

README.md

@@ -44,6 +44,7 @@ Wallets and mints `MUST` implement all mandatory specs and `CAN` implement optio
 | [26][26] | Payment Request Bech32m Encoding  | [cdk]                                                                          | -                                                |
 | [27][27] | Nostr Mint Backup                 | [Cashu.me][cashume], [cdk]                                                     | -                                                |
 | [28][28] | Pay to Blinded Key (P2BK)         | -                                                                              | -                                                |
+| [XX][XX] | Get Locked Mint Quotes By Pubkey  | -                                                                              | -                                                |
 
 #### Wallets:
 
@@ -104,3 +105,4 @@ Wallets and mints `MUST` implement all mandatory specs and `CAN` implement optio
 [26]: 26.md
 [27]: 27.md
 [28]: 28.md
+[XX]: xx.md

xx.md

@@ -0,0 +1,60 @@
+# NUT-28: 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 on `pubkeys` in the same order (64 bytes each)
+
+The wallet **MUST** provide a valid signature in `pubkey_signatures` for each public key in `pubkeys` with the corresponding private key in the same order as the `pubkeys` array. The message to sign is the byte representation of the public key.
+
+## 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
+{
+  "28": {
+    "supported": <bool>
+  }
+}
+```
+
+[04]: 04.md
+[06]: 06.md
+[20]: 20.md
+[errors]: error_codes.md