SignVirtualPsbt

SignVirtualPsbt signs the inputs of a virtual transaction and prepares the commitments of the inputs and outputs.

Source: assetwalletrpc/assetwallet.proto

gRPC

rpc SignVirtualPsbt (SignVirtualPsbtRequest) returns (SignVirtualPsbtResponse);

REST

HTTP Method	Path
POST	/v1/taproot-assets/wallet/virtual-psbt/sign

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 = {
  funded_psbt: <bytes>,
};
client.signVirtualPsbt(request, function(err, response) {
  console.log(response);
});
// Console output:
//  {
//    "signed_psbt": <bytes>,
//    "signed_inputs": <uint32>,
//  }

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.SignVirtualPsbtRequest(
  funded_psbt=<bytes>,
)
response = stub.SignVirtualPsbt(request)
print(response)
# {
#    "signed_psbt": <bytes>,
#    "signed_inputs": <uint32>,
# }

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 = {
  funded_psbt: <string>, // <bytes> (base64 encoded)
};
let options = {
  url: `https://${REST_HOST}/v1/taproot-assets/wallet/virtual-psbt/sign`,
  // 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:
//  {
//    "signed_psbt": <string>, // <bytes> 
//    "signed_inputs": <array>, // <uint32> 
//  }

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/virtual-psbt/sign'
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
headers = {'Grpc-Metadata-macaroon': macaroon}
data = {
  'funded_psbt': base64.b64encode(<bytes>),
}
r = requests.post(url, headers=headers, data=json.dumps(data), verify=TLS_PATH)
print(r.json())
# {
#    "signed_psbt": <bytes>,
#    "signed_inputs": <uint32>,
# }

Shell

# There is no CLI command for this RPC

Messages

assetwalletrpc.SignVirtualPsbtRequest

Source: assetwalletrpc/assetwallet.proto

Field	gRPC Type	REST Type	REST Placement
funded_psbt The PSBT of the virtual transaction that should be signed. The PSBT must contain all required inputs, outputs, UTXO data and custom fields required to identify the signing key.	bytes	string	body

assetwalletrpc.SignVirtualPsbtResponse

Source: assetwalletrpc/assetwallet.proto

Field	gRPC Type	REST Type
signed_psbt The signed virtual transaction in PSBT format.	bytes	string
signed_inputs The indices of signed inputs.	uint32[]	array