EncodeCustomRecords

EncodeCustomRecords allows RPC users to encode Taproot Asset channel related data into the TLV format that is used in the custom records of the lnd payment or other channel related RPCs. This RPC is completely stateless and does not perform any checks on the data provided, other than pure format validation.

Source: tapchannelrpc/tapchannel.proto

gRPC

rpc EncodeCustomRecords (EncodeCustomRecordsRequest) returns (EncodeCustomRecordsResponse);

REST

HTTP Method	Path
POST	/v1/taproot-assets/channels/encode-custom-data

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('tapchannelrpc/tapchannel.proto', loaderOptions);
const tapchannelrpc = grpc.loadPackageDefinition(packageDefinition).tapchannelrpc;
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 tapchannelrpc.TaprootAssetChannels(GRPC_HOST, creds);
let request = {
  router_send_payment: <RouterSendPaymentData>,
};
client.encodeCustomRecords(request, function(err, response) {
  console.log(response);
});
// Console output:
//  {
//    "custom_records": <CustomRecordsEntry>,
//  }

Python

import codecs, grpc, os
# Generate the following 2 modules by compiling the tapchannelrpc/tapchannel.proto with the grpcio-tools.
# See https://github.com/lightningnetwork/lnd/blob/master/docs/grpc/python.md for instructions.
import tapchannel_pb2 as tapchannelrpc, tapchannel_pb2_grpc as tapchannelstub

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 = tapchannelstub.TaprootAssetChannelsStub(channel)
request = tapchannelrpc.EncodeCustomRecordsRequest(
  router_send_payment=<RouterSendPaymentData>,
)
response = stub.EncodeCustomRecords(request)
print(response)
# {
#    "custom_records": <CustomRecordsEntry>,
# }

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 = {
  router_send_payment: <object>, // <RouterSendPaymentData> 
};
let options = {
  url: `https://${REST_HOST}/v1/taproot-assets/channels/encode-custom-data`,
  // 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:
//  {
//    "custom_records": <object>, // <CustomRecordsEntry> 
//  }

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/channels/encode-custom-data'
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
headers = {'Grpc-Metadata-macaroon': macaroon}
data = {
  'router_send_payment': <RouterSendPaymentData>,
}
r = requests.post(url, headers=headers, data=json.dumps(data), verify=TLS_PATH)
print(r.json())
# {
#    "custom_records": <CustomRecordsEntry>,
# }

Shell

# There is no CLI command for this RPC

Messages

tapchannelrpc.EncodeCustomRecordsRequest

Source: tapchannelrpc/tapchannel.proto

Field	gRPC Type	REST Type	REST Placement
router_send_payment	RouterSendPaymentData	object	body

tapchannelrpc.EncodeCustomRecordsResponse

Source: tapchannelrpc/tapchannel.proto

Field	gRPC Type	REST Type
custom_records The encoded custom records in TLV format.	CustomRecordsEntry[]	object

Nested Messages

tapchannelrpc.EncodeCustomRecordsResponse.CustomRecordsEntry

Field	gRPC Type	REST Type
key	uint64	unknown
value	bytes	unknown

tapchannelrpc.RouterSendPaymentData

Field	gRPC Type	REST Type
asset_amounts The string encoded asset ID to amount mapping. Instructs the router to use these assets in the given amounts for the payment. Can be empty for a payment of an invoice, if the RFQ ID is set instead.	AssetAmountsEntry[]	object
rfq_id The RFQ ID to use for the payment. Can be empty for a direct keysend payment that doesn't involve any conversion (and thus no RFQ).	bytes	string

tapchannelrpc.RouterSendPaymentData.AssetAmountsEntry

Field	gRPC Type	REST Type
key	string	unknown
value	uint64	unknown