LeaseOutput

LeaseOutput locks an output to the given ID, preventing it from being available for any future coin selection attempts. The absolute time of the lock's expiration is returned. The expiration of the lock can be extended by successive invocations of this RPC. Outputs can be unlocked before their expiration through ReleaseOutput.

A non-zero release_after_spend_confs selects a confirmation-controlled lifetime. Such a lease ignores its wall-clock expiration and releases at the requested spend depth or through ReleaseOutput. The RPC fails if the wallet cannot apply this option. Renewing the same lease with the same ID and a zero depth preserves an existing non-zero depth.

Source: walletrpc/walletkit.proto

gRPC

rpc LeaseOutput (LeaseOutputRequest) returns (LeaseOutputResponse);

REST

HTTP Method	Path
POST	/v2/wallet/utxos/lease

Code Samples

gRPC

Javascript

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

const GRPC_HOST = 'localhost:10009'
const MACAROON_PATH = 'LND_DIR/data/chain/bitcoin/regtest/admin.macaroon'
const TLS_PATH = 'LND_DIR/tls.cert'

const loaderOptions = {
  keepCase: true,
  longs: String,
  enums: String,
  defaults: true,
  oneofs: true,
};
const packageDefinition = protoLoader.loadSync(['lightning.proto', 'walletrpc/walletkit.proto'], loaderOptions);
const walletrpc = grpc.loadPackageDefinition(packageDefinition).walletrpc;
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 walletrpc.WalletKit(GRPC_HOST, creds);
let request = {
  id: <bytes>,
  outpoint: <OutPoint>,
  expiration_seconds: <uint64>,
  release_after_spend_confs: <uint32>,
};
client.leaseOutput(request, function(err, response) {
  console.log(response);
});
// Console output:
//  {
//    "expiration": <uint64>,
//    "release_after_spend_confs": <uint32>,
//  }

Python

import codecs, grpc, os
# Generate the following 2 modules by compiling the walletrpc/walletkit.proto with the grpcio-tools.
# See https://github.com/lightningnetwork/lnd/blob/master/docs/grpc/python.md for instructions.
import walletkit_pb2 as walletrpc, walletkit_pb2_grpc as walletkitstub

GRPC_HOST = 'localhost:10009'
MACAROON_PATH = 'LND_DIR/data/chain/bitcoin/regtest/admin.macaroon'
TLS_PATH = 'LND_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 = walletkitstub.WalletKitStub(channel)
request = walletrpc.LeaseOutputRequest(
  id=<bytes>,
  outpoint=<OutPoint>,
  expiration_seconds=<uint64>,
  release_after_spend_confs=<uint32>,
)
response = stub.LeaseOutput(request)
print(response)
# {
#    "expiration": <uint64>,
#    "release_after_spend_confs": <uint32>,
# }

grpcurl

# grpcurl docs: https://github.com/fullstorydev/grpcurl
# Proto source: https://github.com/lightningnetwork/lnd
GRPC_HOST=localhost:10009
LND_DIR=~/.lnd
LND_SOURCE=path/to/lnd
NETWORK=mainnet
MACAROON_PATH="$LND_DIR/data/chain/bitcoin/$NETWORK/admin.macaroon"
TLS_PATH="$LND_DIR/tls.cert"

grpcurl \
    -import-path $LND_SOURCE/lnrpc/ \
    -proto walletrpc/walletkit.proto \
    -cacert $TLS_PATH \
    -H "macaroon: $(xxd -ps -u -c 1000 $MACAROON_PATH)" \
    -d '{ "id": BASE64_ENCODED_VALUE, "outpoint": <OutPoint>, "expiration_seconds": <uint64>, "release_after_spend_confs": <uint32> }' \
    $GRPC_HOST \
    walletrpc.WalletKit/LeaseOutput

REST

Javascript

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

const REST_HOST = 'localhost:8080'
const MACAROON_PATH = 'LND_DIR/data/chain/bitcoin/regtest/admin.macaroon'

let requestBody = {
  id: <string>, // <bytes> (base64 encoded)
  outpoint: <object>, // <OutPoint> 
  expiration_seconds: <string>, // <uint64> 
  release_after_spend_confs: <integer>, // <uint32> 
};
let options = {
  url: `https://${REST_HOST}/v2/wallet/utxos/lease`,
  // 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:
//  {
//    "expiration": <string>, // <uint64> 
//    "release_after_spend_confs": <integer>, // <uint32> 
//  }

Python

import base64, codecs, json, requests

REST_HOST = 'localhost:8080'
MACAROON_PATH = 'LND_DIR/data/chain/bitcoin/regtest/admin.macaroon'
TLS_PATH = 'LND_DIR/tls.cert'

url = f'https://{REST_HOST}/v2/wallet/utxos/lease'
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
headers = {'Grpc-Metadata-macaroon': macaroon}
data = {
  'id': base64.b64encode(<bytes>),
  'outpoint': <OutPoint>,
  'expiration_seconds': <uint64>,
  'release_after_spend_confs': <uint32>,
}
r = requests.post(url, headers=headers, data=json.dumps(data), verify=TLS_PATH)
print(r.json())
# {
#    "expiration": <uint64>,
#    "release_after_spend_confs": <uint32>,
# }

curl

REST_HOST=localhost:8080
LND_DIR=~/.lnd
NETWORK=mainnet
MACAROON_PATH="$LND_DIR/data/chain/bitcoin/$NETWORK/admin.macaroon"
TLS_PATH="$LND_DIR/tls.cert"

curl -X POST \
    --cacert $TLS_PATH \
    -H "Grpc-Metadata-macaroon: $(xxd -ps -u -c 1000 $MACAROON_PATH)" \
    -d '{ "id": BASE64_ENCODED_VALUE, "outpoint": <OutPoint>, "expiration_seconds": <uint64>, "release_after_spend_confs": <uint32> }' \
    https://$REST_HOST/v2/wallet/utxos/lease

lncli

$ lncli wallet leaseoutput --help

NAME:
   lncli wallet leaseoutput - Lease an output.

USAGE:
   lncli wallet leaseoutput [command options] [arguments...]

DESCRIPTION:
   
  The leaseoutput command locks an output, making it unavailable
  for coin selection.

  An app lock ID and expiration duration must be specified when locking
  the output.
  

OPTIONS:
   --outpoint value  the output to lock
   --lockid value    the hex-encoded app lock ID
   --expiry value    expiration duration in seconds (default: 0)
   

Messages

walletrpc.LeaseOutputRequest

Source: walletrpc/walletkit.proto

Field	gRPC Type	REST Type	REST Placement
id An ID of 32 random bytes that must be unique for each distinct application using this RPC which will be used to bound the output lease to.	bytes	string	body
outpoint The identifying outpoint of the output being leased.	OutPoint	object	body
expiration_seconds The time in seconds before a time-controlled lock expires. If set to zero, the default lock duration is used. A non-zero release_after_spend_confs makes this deadline informational only.	uint64	string	body
release_after_spend_confs Keep the lease until the transaction spending the output reaches this confirmation count or the owner explicitly releases it. A reorganization that disconnects the spending block resets maturity progress. A non-zero value ignores expiration_seconds; zero preserves the time-controlled lease behavior.	uint32	integer	body

walletrpc.LeaseOutputResponse

Source: walletrpc/walletkit.proto

Field	gRPC Type	REST Type
expiration The absolute expiration of a time-controlled output lease represented as a unix timestamp. Confirmation-controlled leases return the stored value for compatibility but do not apply it.	uint64	string
release_after_spend_confs The effective persisted spend maturity depth. A zero-depth renewal returns the retained non-zero depth of an existing confirmation-controlled lease. If that informational lookup fails after the lease succeeds, this field is zero and ListLeases can refresh it.	uint32	integer

Nested Messages

lnrpc.OutPoint

Field	gRPC Type	REST Type
txid_bytes Raw bytes representing the transaction id.	bytes	string
txid_str Reversed, hex-encoded string representing the transaction id.	string	string
output_index The index of the output on the transaction.	uint32	integer