Add NUT-XX for batched minting

README.md

@@ -40,6 +40,7 @@ Wallets and mints `MUST` implement all mandatory specs and `CAN` implement optio
 | [22][22] | Blind authentication              | [Nutshell][py], [cdk-cli]                                                          | [Nutshell][py], [cdk-mintd], [nutmix]            |
 | [23][23] | Payment Method: BOLT11            | [Nutshell][py], [cdk-cli]                                                          | [Nutshell][py], [cdk-mintd], [nutmix]            |
 | [24][24] | HTTP 402 Payment Required         | -                                                                                  | -                                                |
+| [XX][xx] | Batched Mint                      | -                                                                                  | -                                                |
 
 #### Wallets:
 
@@ -97,3 +98,4 @@ Wallets and mints `MUST` implement all mandatory specs and `CAN` implement optio
 [22]: 22.md
 [23]: 23.md
 [24]: 24.md
+[XX]: xx.md

error_codes.md

@@ -20,7 +20,7 @@
 | 20002 | Tokens have already been issued for quote       | [NUT-04][04]                             |
 | 20003 | Minting is disabled                             | [NUT-04][04]                             |
 | 20004 | Lightning payment failed                        | [NUT-05][05]                             |
-| 20005 | Quote is pending                                | [NUT-04][04], [NUT-05][05]               |
+| 20005 | Quote is pending                                | [NUT-04][04], [NUT-05][05], [NUT-XX][xx] |
 | 20006 | Invoice already paid                            | [NUT-05][05]                             |
 | 20007 | Quote is expired                                | [NUT-04][04], [NUT-05][05]               |
 | 20008 | Signature for mint request invalid              | [NUT-20][20]                             |
@@ -48,3 +48,4 @@
 [20]: 20.md
 [21]: 21.md
 [22]: 22.md
+[XX]: xx.md

xx.md

@@ -0,0 +1,104 @@
+# NUT-XX: Batched Mint
+
+`optional`
+
+`depends on: NUT-04`
+
+This spec describes how a wallet can mint multiple quotes in one batch operation.
+
+---
+
+## 1. Checking Quote Status
+
+Before minting, the wallet must verify that each mint quote has been paid.
+It does this by sending:
+
+```http
+POST https://mint.host:3338/v1/mint/{method}/check
+Content-Type: application/json
+
+{
+  "quotes": [ "quote_id_1", "quote_id_2", … ]
+}
+```
+
+- **quote**: an array of **unique** quote IDs previously obtained via the [NUT-04 creation process][04-creation].
+
+The mint returns a JSON array of quote objects, each containing:
+
+```json
+[
+  {
+    "quote": "quote_id_1",
+    "request": "payment_request_1",
+    "unit": "UNIT_NAME"
+    // …plus any additional fields specific to {method}
+  },
+  {
+    "quote": "quote_id_2",
+    "request": "payment_request_2",
+    "unit": "UNIT_NAME"
+    // …
+  }
+]
+```
+
+- **quote**: the original quote ID
+- **request**: the payment request string for that quote
+- **unit**: the unit type, matching what was requested
+
+NOTE: If a `quote_id` is not known by the mint it SHOULD omit it from the response.
+
+---
+
+## 2. Executing the Batched Mint
+
+Once all quoted payments are confirmed, the wallet mints the tokens by calling:
+
+```http
+POST https://mint.host:3338/v1/mint/{method}
+Content-Type: application/json
+
+{
+  "quotes":   [ "quote_id_1", "quote_id_2", … ],
+  "outputs": [ BlindedMessage_1, BlindedMessage_2, … ],
+  "signature": [signature_1, signature_2, ... ]
+}
+```
+
+- **quote**: an array of **unique** quote IDs previously obtained via the [NUT-04 creation process][04-creation].
+- **outputs**: an array of blinded messages (see [NUT-00][00]).
+  - The total value represented by these blinded messages must equal the sum of the quote amounts.
+- **signature**: The signature for a NUT-20 locked quote. See [NUT-20 Support][nut-20-support]
+  The mint responds with:
+
+```json
+{
+  "signatures": [ BlindSignature_1, BlindSignature_2, … ]
+}
+```
+
+- **signatures**: blind signatures corresponding to each provided blinded message.
+
+## NUT-20 support
+
+The `signature` field of the request can be used to add matching NUT-20 signatures to a batch mint. Signatures can be mapped to their quotes using both indexes in the request body. As long as there is a single NUT-20 quote in the request this field is mandatory, otherwise it can be fully omitted.
+
+- Signatures for NUT-20 quotes can be added to the `signature` key of the request.
+- Signatures need to be in the same index as the matching quote_id in the `quote` key.
+- If a request contains both signed and unsigned quotes, all unsigned quotes need to map to `null` in the `signature` array.
+- As soon as there is a single signed quote in the request: `quote.length === signature.length`
+
+Example:
+
+```json
+{
+  "quotes":   [ "locked_quote_id_1", "quote_id_2", "locked_quote_id_3" ],
+  "outputs": [ BlindedMessage_1, BlindedMessage_2, ... ],
+  "signature": [signature_1, null, signature_3 ]
+}
+```
+
+[00]: 00.md
+[04-creation]: 04.md#requesting-a-mint-quote
+[nut-20-support]: #nut-20-support