CommitVirtualPsbts

CommitVirtualPsbts creates the output commitments and proofs for the given virtual transactions by committing them to the BTC level anchor transaction. In addition, the BTC level anchor transaction is funded and prepared up to the point where it is ready to be signed.

Source: assetwalletrpc/assetwallet.proto

gRPC

rpc CommitVirtualPsbts (CommitVirtualPsbtsRequest) returns (CommitVirtualPsbtsResponse);

REST

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

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 = {
  virtual_psbts: <bytes>,
  passive_asset_psbts: <bytes>,
  anchor_psbt: <bytes>,
  existing_output_index: <int32>,
  add: <bool>,
  target_conf: <uint32>,
  sat_per_vbyte: <uint64>,
};
client.commitVirtualPsbts(request, function(err, response) {
  console.log(response);
});
// Console output:
//  {
//    "anchor_psbt": <bytes>,
//    "virtual_psbts": <bytes>,
//    "passive_asset_psbts": <bytes>,
//    "change_output_index": <int32>,
//    "lnd_locked_utxos": <OutPoint>,
//  }

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.CommitVirtualPsbtsRequest(
  virtual_psbts=<bytes>,
  passive_asset_psbts=<bytes>,
  anchor_psbt=<bytes>,
  existing_output_index=<int32>,
  add=<bool>,
  target_conf=<uint32>,
  sat_per_vbyte=<uint64>,
)
response = stub.CommitVirtualPsbts(request)
print(response)
# {
#    "anchor_psbt": <bytes>,
#    "virtual_psbts": <bytes>,
#    "passive_asset_psbts": <bytes>,
#    "change_output_index": <int32>,
#    "lnd_locked_utxos": <OutPoint>,
# }

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 = {
  virtual_psbts: <array>, // <bytes> (base64 encoded)
  passive_asset_psbts: <array>, // <bytes> (base64 encoded)
  anchor_psbt: <string>, // <bytes> (base64 encoded)
  existing_output_index: <integer>, // <int32> 
  add: <boolean>, // <bool> 
  target_conf: <integer>, // <uint32> 
  sat_per_vbyte: <string>, // <uint64> 
};
let options = {
  url: `https://${REST_HOST}/v1/taproot-assets/wallet/virtual-psbt/commit`,
  // 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:
//  {
//    "anchor_psbt": <string>, // <bytes> 
//    "virtual_psbts": <array>, // <bytes> 
//    "passive_asset_psbts": <array>, // <bytes> 
//    "change_output_index": <integer>, // <int32> 
//    "lnd_locked_utxos": <array>, // <OutPoint> 
//  }

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/commit'
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
headers = {'Grpc-Metadata-macaroon': macaroon}
data = {
  'virtual_psbts': base64.b64encode(<bytes>),
  'passive_asset_psbts': base64.b64encode(<bytes>),
  'anchor_psbt': base64.b64encode(<bytes>),
  'existing_output_index': <int32>,
  'add': <bool>,
  'target_conf': <uint32>,
  'sat_per_vbyte': <uint64>,
}
r = requests.post(url, headers=headers, data=json.dumps(data), verify=TLS_PATH)
print(r.json())
# {
#    "anchor_psbt": <bytes>,
#    "virtual_psbts": <bytes>,
#    "passive_asset_psbts": <bytes>,
#    "change_output_index": <int32>,
#    "lnd_locked_utxos": <OutPoint>,
# }

Shell

# There is no CLI command for this RPC

Messages

assetwalletrpc.CommitVirtualPsbtsRequest

Source: assetwalletrpc/assetwallet.proto

Field	gRPC Type	REST Type	REST Placement
virtual_psbts The list of virtual transactions that should be mapped to the given BTC level anchor transaction template. The virtual transactions are expected to be signed (or use ASSET_VERSION_V1 with segregated witness to allow for signing after committing) and ready to be committed to the anchor transaction.	bytes[]	array	body
passive_asset_psbts The list of passive virtual transactions that are anchored in the same BTC level anchor transaction inputs as the "active" assets above. These can be obtained by calling FundVirtualPsbt and using the passive assets returned. The virtual transactions are expected to be signed (or use ASSET_VERSION_V1 with segregated witness to allow for signing after committing) and ready to be committed to the anchor transaction. The main difference to the "active" assets above is that the passive assets will not get their own entry in the transfer table of the database, since they are just carried along and not directly affected by the direct user action.	bytes[]	array	body
anchor_psbt The template of the BTC level anchor transaction that the virtual transactions should be mapped to. The template is expected to already contain all asset related inputs and outputs corresponding to the virtual transactions given above. This can be achieved by using tapfreighter.PrepareAnchoringTemplate for example.	bytes	string	body
existing_output_index Use the existing output within the anchor PSBT with the specified index as the change output. Any leftover change will be added to the already specified amount of that output. To add a new change output to the PSBT, set the "add" field below instead.	int32	integer	body
add Add a new P2TR change output to the PSBT if required.	bool	boolean	body
target_conf The target number of blocks that the transaction should be confirmed in.	uint32	integer	body
sat_per_vbyte The fee rate, expressed in sat/vbyte, that should be used to fund the BTC level anchor transaction.	uint64	string	body

assetwalletrpc.CommitVirtualPsbtsResponse

Source: assetwalletrpc/assetwallet.proto

Field	gRPC Type	REST Type
anchor_psbt The funded BTC level anchor transaction with all outputs updated to commit to the virtual transactions given. The transaction is ready to be signed, unless some of the asset inputs don't belong to this daemon, in which case the anchor input derivation info must be added to those inputs first.	bytes	string
virtual_psbts The updated virtual transactions that now contain the state transition proofs for being committed to the BTC level anchor transaction above. If the assets in the virtual transaction outputs are ASSET_VERSION_V1 and not yet signed, then the proofs need to be updated to include the witness before they become fully valid.	bytes[]	array
passive_asset_psbts The updated passive virtual transactions that were committed to the same BTC level anchor transaction as the "active" virtual transactions given. If the assets in the virtual transaction outputs are ASSET_VERSION_V1 and not yet signed, then the proofs need to be updated to include the witness before they become fully valid.	bytes[]	array
change_output_index The index of the (added) change output or -1 if no change was left over.	int32	integer
lnd_locked_utxos The list of UTXO lock leases that were acquired for the inputs in the funded PSBT packet from lnd. Only inputs added to the PSBT by this RPC are locked, inputs that were already present in the PSBT are not locked.	OutPoint[]	array

Nested Messages

taprpc.OutPoint

Field	gRPC Type	REST Type
txid Raw bytes representing the transaction id.	bytes	string
output_index The index of the output on the transaction.	uint32	integer