NextScriptKey

NextScriptKey derives the next script key (and its corresponding internal key) and stores them both in the database to make sure they are identified as local keys later on when importing proofs.

Source: assetwalletrpc/assetwallet.proto

gRPC

rpc NextScriptKey (NextScriptKeyRequest) returns (NextScriptKeyResponse);

REST

HTTP Method	Path
POST	/v1/taproot-assets/wallet/script-key/next

Code Samples

gRPC

Javascript

const fs = require('fs');
const grpc = require('@grpc/grpc-js');
const protoLoader = require('@grpc/proto-loader');

const GRPC_HOST = 'localhost:10029'
const MACAROON_PATH = 'TAPROOT-ASSETS_DIR/regtest/taproot-assets.macaroon'
const TLS_PATH = 'TAPROOT-ASSETS_DIR/tls.cert'

const loaderOptions = {
  keepCase: true,
  longs: String,
  enums: String,
  defaults: true,
  oneofs: true,
};
const packageDefinition = protoLoader.loadSync('assetwalletrpc/assetwallet.proto', loaderOptions);
const assetwalletrpc = grpc.loadPackageDefinition(packageDefinition).assetwalletrpc;
process.env.GRPC_SSL_CIPHER_SUITES = 'HIGH+ECDSA';
const tlsCert = fs.readFileSync(TLS_PATH);
const sslCreds = grpc.credentials.createSsl(tlsCert);
const macaroon = fs.readFileSync(MACAROON_PATH).toString('hex');
const macaroonCreds = grpc.credentials.createFromMetadataGenerator(function(args, callback) {
  let metadata = new grpc.Metadata();
  metadata.add('macaroon', macaroon);
  callback(null, metadata);
});
let creds = grpc.credentials.combineChannelCredentials(sslCreds, macaroonCreds);
let client = new assetwalletrpc.AssetWallet(GRPC_HOST, creds);
let request = {
  key_family: <uint32>,
};
client.nextScriptKey(request, function(err, response) {
  console.log(response);
});
// Console output:
//  {
//    "script_key": <ScriptKey>,
//  }

Python

import codecs, grpc, os
# Generate the following 2 modules by compiling the assetwalletrpc/assetwallet.proto with the grpcio-tools.
# See https://github.com/lightningnetwork/lnd/blob/master/docs/grpc/python.md for instructions.
import assetwallet_pb2 as assetwalletrpc, assetwallet_pb2_grpc as assetwalletstub

GRPC_HOST = 'localhost:10029'
MACAROON_PATH = 'TAPROOT-ASSETS_DIR/regtest/taproot-assets.macaroon'
TLS_PATH = 'TAPROOT-ASSETS_DIR/tls.cert'

# create macaroon credentials
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
def metadata_callback(context, callback):
  callback([('macaroon', macaroon)], None)
auth_creds = grpc.metadata_call_credentials(metadata_callback)
# create SSL credentials
os.environ['GRPC_SSL_CIPHER_SUITES'] = 'HIGH+ECDSA'
cert = open(TLS_PATH, 'rb').read()
ssl_creds = grpc.ssl_channel_credentials(cert)
# combine macaroon and SSL credentials
combined_creds = grpc.composite_channel_credentials(ssl_creds, auth_creds)
# make the request
channel = grpc.secure_channel(GRPC_HOST, combined_creds)
stub = assetwalletstub.AssetWalletStub(channel)
request = assetwalletrpc.NextScriptKeyRequest(
  key_family=<uint32>,
)
response = stub.NextScriptKey(request)
print(response)
# {
#    "script_key": <ScriptKey>,
# }

REST

Javascript

const fs = require('fs');
const request = require('request');

const REST_HOST = 'localhost:8089'
const MACAROON_PATH = 'TAPROOT-ASSETS_DIR/regtest/taproot-assets.macaroon'

let requestBody = {
  key_family: <integer>, // <uint32> 
};
let options = {
  url: `https://${REST_HOST}/v1/taproot-assets/wallet/script-key/next`,
  // Work-around for self-signed certificates.
  rejectUnauthorized: false,
  json: true,
  headers: {
    'Grpc-Metadata-macaroon': fs.readFileSync(MACAROON_PATH).toString('hex'),
  },
  form: JSON.stringify(requestBody),
}
request.post(options, function(error, response, body) {
  console.log(body);
});
// Console output:
//  {
//    "script_key": <object>, // <ScriptKey> 
//  }

Python

import base64, codecs, json, requests

REST_HOST = 'localhost:8089'
MACAROON_PATH = 'TAPROOT-ASSETS_DIR/regtest/taproot-assets.macaroon'
TLS_PATH = 'TAPROOT-ASSETS_DIR/tls.cert'

url = f'https://{REST_HOST}/v1/taproot-assets/wallet/script-key/next'
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
headers = {'Grpc-Metadata-macaroon': macaroon}
data = {
  'key_family': <uint32>,
}
r = requests.post(url, headers=headers, data=json.dumps(data), verify=TLS_PATH)
print(r.json())
# {
#    "script_key": <ScriptKey>,
# }

Shell

# There is no CLI command for this RPC

Messages

assetwalletrpc.NextScriptKeyRequest

Source: assetwalletrpc/assetwallet.proto

Field	gRPC Type	REST Type	REST Placement
key_family	uint32	integer	body

assetwalletrpc.NextScriptKeyResponse

Source: assetwalletrpc/assetwallet.proto

Field	gRPC Type	REST Type
script_key	ScriptKey	object

Nested Messages

taprpc.KeyDescriptor

Field	gRPC Type	REST Type
raw_key_bytes The raw bytes of the key being identified.	bytes	string
key_loc The key locator that identifies which key to use for signing.	KeyLocator	object

taprpc.KeyLocator

Field	gRPC Type	REST Type
key_family The family of key being identified.	int32	integer
key_index The precise index of the key being identified.	int32	integer

taprpc.ScriptKey

Field	gRPC Type	REST Type
pub_key The full Taproot output key the asset is locked to. This is either a BIP-86 key if the tap_tweak below is empty, or a key with the tap tweak applied to it.	bytes	string
key_desc The key descriptor describing the internal key of the above Taproot key.	KeyDescriptor	object
tap_tweak The optional Taproot tweak to apply to the above internal key. If this is empty then a BIP-86 style tweak is applied to the internal key.	bytes	string