NUT-01: return keyset metadata

01.md

@@ -10,7 +10,7 @@ This document outlines the exchange of the public keys of the mint `Bob` with th
 
 Wallet user `Alice` receives public keys from mint `Bob` via `GET /v1/keys`. The set of all public keys for a set of amounts is called a _keyset_.
 
-The mint responds only with its `active` keysets. Keyset are `active` if the mint will sign outputs with it. The mint will accept tokens from inactive keysets as inputs but will not sign with them for new outputs. The `active` keysets can change over time, for example due to key rotation. A list of all keysets, active and inactive, can be requested separately (see [NUT-02][02]).
+The mint responds only with its `active` keysets. Keysets are `active` if the mint will sign outputs with it. The mint will accept tokens from inactive keysets as inputs but will not sign with them for new outputs. The `active` keysets can change over time, for example due to key rotation. A list of all keysets, active and inactive, can be requested separately (see [NUT-02][02]).
 
 Note that a mint can support multiple keysets at the same time but will only respond with the active keysets on the endpoint `GET /v1/keys`. A wallet can ask for the keys of a specific (active or inactive) keyset via the endpoint `GET /v1/keys/{keyset_id}` (see [NUT-02][02]).
 
@@ -63,6 +63,8 @@ Response `GetKeysResponse` of `Bob`:
     {
       "id": <keyset_id_hex_str>,
       "unit": <currency_unit_str>,
+      "active": <bool>,
+      "input_fee_ppk": <int|null>,
       "final_expiry": <unix_timestamp_int|null>
       "keys": {
         <amount_int>: <public_key_str>,
@@ -73,6 +75,8 @@ Response `GetKeysResponse` of `Bob`:
 }
 ```
 
+Here, `active` indicates whether the mint will sign new outputs with this keyset, and `input_fee_ppk` is the fee in parts per thousand (ppk) per input spent from this keyset (see [NUT-02][02]).
+
 ## Example response
 
 ```json
@@ -81,6 +85,8 @@ Response `GetKeysResponse` of `Bob`:
     {
       "id": "009a1f293253e41e",
       "unit": "sat",
+      "active": true,
+      "input_fee_ppk": 100,
       "final_expiry": 1896187313,
       "keys": {
           "1": "02194603ffa36356f4a56b7df9371fc3192472351453ec7398b8da8117e7c3e104",
@@ -102,6 +108,8 @@ Note that for a keyset in an ISO 4217 currency, the key amounts represent values
     {
       "id": "00a2f293253e41f9",
       "unit": "usd",
+      "active": true,
+      "input_fee_ppk": 100,
       "final_expiry": 1896187313,
       "keys": {
           "1": "0229...e101", // 1 cent (0.01 USD)

02.md

@@ -203,17 +203,19 @@ Response of `Bob` (same as [NUT-01][01]):
 
 ```json
 {
-  "keysets": [
-    {
-      "id": "015ba18a8adcd02e715a58358eb618da4a4b3791151a4bee5e968bb88406ccf76a",
-      "unit": "sat",
-      "keys": {
-        "1": "03a40f20667ed53513075dc51e715ff2046cad64eb68960632269ba7f0210e38bc",
-        "2": "03fd4ce5a16b65576145949e6f99f445f8249fee17c606b688b504a849cdc452de",
-        "4": "02648eccfa4c026960966276fa5a4cae46ce0fd432211a4f449bf84f13aa5f8303",
-        "8": "02fdfd6796bfeac490cbee12f778f867f0a2c68f6508d17c649759ea0dc3547528"
-      }
-    }
+  "keysets": [{
+    "id": "009a1f293253e41e",
+    "unit": "sat",
+    "active": true,
+    "input_fee_ppk": 100,
+    "keys": {
+        "1": "02194603ffa36356f4a56b7df9371fc3192472351453ec7398b8da8117e7c3e104",
+        "2": "03b0f36d6d47ce14df8a7be9137712c42bcdd960b19dd02f1d4a9703b1f31d7513",
+        "4": "0366be6e026e42852498efb82014ca91e89da2e7a5bd3761bdad699fa2aec9fe09",
+        "8": "0253de5237f189606f29d8a690ea719f74d65f617bb1cb6fbea34f2bc4f930016d",
+        ...
+    },
+  }, ...
   ]
 }
 ```