TrackPaymentV2

TrackPaymentV2 returns an update stream for the payment identified by the payment hash.

Source: routerrpc/router.proto

gRPC

info

This is a server-streaming RPC

rpc TrackPaymentV2 (TrackPaymentRequest) returns (stream Payment);

REST

HTTP Method	Path
GET	/v2/router/track/{payment_hash}

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', 'routerrpc/router.proto'], loaderOptions);
const routerrpc = grpc.loadPackageDefinition(packageDefinition).routerrpc;
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 routerrpc.Router(GRPC_HOST, creds);
let request = {
  payment_hash: <bytes>,
  no_inflight_updates: <bool>,
};
let call = client.trackPaymentV2(request);
call.on('data', function(response) {
  // A response was received from the server.
  console.log(response);
});
call.on('status', function(status) {
  // The current status of the stream.
});
call.on('end', function() {
  // The server has closed the stream.
});
// Console output:
//  {
//    "payment_hash": <string>,
//    "value": <int64>,
//    "creation_date": <int64>,
//    "fee": <int64>,
//    "payment_preimage": <string>,
//    "value_sat": <int64>,
//    "value_msat": <int64>,
//    "payment_request": <string>,
//    "status": <PaymentStatus>,
//    "fee_sat": <int64>,
//    "fee_msat": <int64>,
//    "creation_time_ns": <int64>,
//    "htlcs": <HTLCAttempt>,
//    "payment_index": <uint64>,
//    "failure_reason": <PaymentFailureReason>,
//  }

Python

import codecs, grpc, os
# Generate the following 2 modules by compiling the routerrpc/router.proto with the grpcio-tools.
# See https://github.com/lightningnetwork/lnd/blob/master/docs/grpc/python.md for instructions.
import router_pb2 as routerrpc, router_pb2_grpc as routerstub

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 = routerstub.RouterStub(channel)
request = routerrpc.TrackPaymentRequest(
  payment_hash=<bytes>,
  no_inflight_updates=<bool>,
)
for response in stub.TrackPaymentV2(request):
  print(response)
# {
#    "payment_hash": <string>,
#    "value": <int64>,
#    "creation_date": <int64>,
#    "fee": <int64>,
#    "payment_preimage": <string>,
#    "value_sat": <int64>,
#    "value_msat": <int64>,
#    "payment_request": <string>,
#    "status": <PaymentStatus>,
#    "fee_sat": <int64>,
#    "fee_msat": <int64>,
#    "creation_time_ns": <int64>,
#    "htlcs": <HTLCAttempt>,
#    "payment_index": <uint64>,
#    "failure_reason": <PaymentFailureReason>,
# }

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 options = {
  url: `https://${REST_HOST}/v2/router/track/{payment_hash}`,
  // Work-around for self-signed certificates.
  rejectUnauthorized: false,
  json: true,
  headers: {
    'Grpc-Metadata-macaroon': fs.readFileSync(MACAROON_PATH).toString('hex'),
  },
}
request.get(options, function(error, response, body) {
  console.log(body);
});
// Console output:
//  {
//    "payment_hash": <string>, // <string> 
//    "value": <string>, // <int64> 
//    "creation_date": <string>, // <int64> 
//    "fee": <string>, // <int64> 
//    "payment_preimage": <string>, // <string> 
//    "value_sat": <string>, // <int64> 
//    "value_msat": <string>, // <int64> 
//    "payment_request": <string>, // <string> 
//    "status": <string>, // <PaymentStatus> 
//    "fee_sat": <string>, // <int64> 
//    "fee_msat": <string>, // <int64> 
//    "creation_time_ns": <string>, // <int64> 
//    "htlcs": <array>, // <HTLCAttempt> 
//    "payment_index": <string>, // <uint64> 
//    "failure_reason": <string>, // <PaymentFailureReason> 
//  }



// --------------------------
// Example with websockets:
// --------------------------
const WebSocket = require('ws');
const fs = require('fs');

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

let ws = new WebSocket(`wss://${REST_HOST}/v2/router/track/{payment_hash}?method=GET`, {
  // Work-around for self-signed certificates.
  rejectUnauthorized: false,
  headers: {
    'Grpc-Metadata-Macaroon': fs.readFileSync(MACAROON_PATH).toString('hex'),
  },
});
let requestBody = {
  payment_hash: <bytes>, // <bytes> 
  no_inflight_updates: <bool>, // <bool> 
};
ws.on('open', function() {
    ws.send(JSON.stringify(requestBody));
});
ws.on('error', function(err) {
    console.log('Error: ' + err);
});
ws.on('message', function(body) {
    console.log(body);
});
// Console output:
//  {
//    "payment_hash": <string>, // <string>
//    "value": <string>, // <int64>
//    "creation_date": <string>, // <int64>
//    "fee": <string>, // <int64>
//    "payment_preimage": <string>, // <string>
//    "value_sat": <string>, // <int64>
//    "value_msat": <string>, // <int64>
//    "payment_request": <string>, // <string>
//    "status": <string>, // <PaymentStatus>
//    "fee_sat": <string>, // <int64>
//    "fee_msat": <string>, // <int64>
//    "creation_time_ns": <string>, // <int64>
//    "htlcs": <array>, // <HTLCAttempt>
//    "payment_index": <string>, // <uint64>
//    "failure_reason": <string>, // <PaymentFailureReason>
//  }

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/router/track/{payment_hash}'
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
headers = {'Grpc-Metadata-macaroon': macaroon}
r = requests.get(url, headers=headers, stream=True, verify=TLS_PATH)
for raw_response in r.iter_lines():
  json_response = json.loads(raw_response)
  print(json_response)
# {
#    "payment_hash": <string>,
#    "value": <int64>,
#    "creation_date": <int64>,
#    "fee": <int64>,
#    "payment_preimage": <string>,
#    "value_sat": <int64>,
#    "value_msat": <int64>,
#    "payment_request": <string>,
#    "status": <PaymentStatus>,
#    "fee_sat": <int64>,
#    "fee_msat": <int64>,
#    "creation_time_ns": <int64>,
#    "htlcs": <HTLCAttempt>,
#    "payment_index": <uint64>,
#    "failure_reason": <PaymentFailureReason>,
# }

Shell

# There is no CLI command for this RPC

Messages

routerrpc.TrackPaymentRequest

Source: routerrpc/router.proto

Field	gRPC Type	REST Type	REST Placement
payment_hash The hash of the payment to look up.	bytes	string	path
no_inflight_updates If set, only the final payment update is streamed back. Intermediate updates that show which htlcs are still in flight are suppressed.	bool	boolean	query

lnrpc.Payment

Source: lightning.proto

Field	gRPC Type	REST Type
payment_hash The payment hash	string	string
value Deprecated, use value_sat or value_msat.	int64	string
creation_date Deprecated, use creation_time_ns	int64	string
fee Deprecated, use fee_sat or fee_msat.	int64	string
payment_preimage The payment preimage	string	string
value_sat The value of the payment in satoshis	int64	string
value_msat The value of the payment in milli-satoshis	int64	string
payment_request The optional payment request being fulfilled.	string	string
status The status of the payment.	PaymentStatus	string
fee_sat The fee paid for this payment in satoshis	int64	string
fee_msat The fee paid for this payment in milli-satoshis	int64	string
creation_time_ns The time in UNIX nanoseconds at which the payment was created.	int64	string
htlcs The HTLCs made in attempt to settle the payment.	HTLCAttempt[]	array
payment_index The creation index of this payment. Each payment can be uniquely identified by this index, which may not strictly increment by 1 for payments made in older versions of lnd.	uint64	string
failure_reason	PaymentFailureReason	string

Nested Messages

lnrpc.HTLCAttempt

Field	gRPC Type	REST Type
attempt_id The unique ID that is used for this attempt.	uint64	string
status The status of the HTLC.	HTLCStatus	string
route The route taken by this HTLC.	Route	object
attempt_time_ns The time in UNIX nanoseconds at which this HTLC was sent.	int64	string
resolve_time_ns The time in UNIX nanoseconds at which this HTLC was settled or failed. This value will not be set if the HTLC is still IN_FLIGHT.	int64	string
failure Detailed htlc failure info.	Failure	object
preimage The preimage that was used to settle the HTLC.	bytes	string

lnrpc.Route

Field	gRPC Type	REST Type
total_time_lock The cumulative (final) time lock across the entire route. This is the CLTV value that should be extended to the first hop in the route. All other hops will decrement the time-lock as advertised, leaving enough time for all hops to wait for or present the payment preimage to complete the payment.	uint32	integer
total_fees The sum of the fees paid at each hop within the final route. In the case of a one-hop payment, this value will be zero as we don't need to pay a fee to ourselves.	int64	string
total_amt The total amount of funds required to complete a payment over this route. This value includes the cumulative fees at each hop. As a result, the HTLC extended to the first-hop in the route will need to have at least this many satoshis, otherwise the route will fail at an intermediate node due to an insufficient amount of fees.	int64	string
hops Contains details concerning the specific forwarding details at each hop.	Hop[]	array
total_fees_msat The total fees in millisatoshis.	int64	string
total_amt_msat The total amount in millisatoshis.	int64	string

lnrpc.Hop

Field	gRPC Type	REST Type
chan_id The unique channel ID for the channel. The first 3 bytes are the block height, the next 3 the index within the block, and the last 2 bytes are the output index for the channel.	uint64	string
chan_capacity	int64	string
amt_to_forward	int64	string
fee	int64	string
expiry	uint32	integer
amt_to_forward_msat	int64	string
fee_msat	int64	string
pub_key An optional public key of the hop. If the public key is given, the payment can be executed without relying on a copy of the channel graph.	string	string
tlv_payload If set to true, then this hop will be encoded using the new variable length TLV format. Note that if any custom tlv_records below are specified, then this field MUST be set to true for them to be encoded properly.	bool	boolean
mpp_record An optional TLV record that signals the use of an MPP payment. If present, the receiver will enforce that the same mpp_record is included in the final hop payload of all non-zero payments in the HTLC set. If empty, a regular single-shot payment is or was attempted.	MPPRecord	object
amp_record An optional TLV record that signals the use of an AMP payment. If present, the receiver will treat all received payments including the same (payment_addr, set_id) pair as being part of one logical payment. The payment will be settled by XORing the root_share's together and deriving the child hashes and preimages according to BOLT XX. Must be used in conjunction with mpp_record.	AMPRecord	object
custom_records An optional set of key-value TLV records. This is useful within the context of the SendToRoute call as it allows callers to specify arbitrary K-V pairs to drop off at each hop within the onion.	CustomRecordsEntry[]	object
metadata The payment metadata to send along with the payment to the payee.	bytes	string

lnrpc.MPPRecord

Field	gRPC Type	REST Type
payment_addr A unique, random identifier used to authenticate the sender as the intended payer of a multi-path payment. The payment_addr must be the same for all subpayments, and match the payment_addr provided in the receiver's invoice. The same payment_addr must be used on all subpayments.	bytes	string
total_amt_msat The total amount in milli-satoshis being sent as part of a larger multi-path payment. The caller is responsible for ensuring subpayments to the same node and payment_hash sum exactly to total_amt_msat. The same total_amt_msat must be used on all subpayments.	int64	string

lnrpc.AMPRecord

Field	gRPC Type	REST Type
root_share	bytes	string
set_id	bytes	string
child_index	uint32	integer

lnrpc.Hop.CustomRecordsEntry

Field	gRPC Type	REST Type
key	uint64	unknown
value	bytes	unknown

lnrpc.Failure

Field	gRPC Type	REST Type
code Failure code as defined in the Lightning spec	FailureCode	string
channel_update An optional channel update message.	ChannelUpdate	object
htlc_msat A failure type-dependent htlc value.	uint64	string
onion_sha_256 The sha256 sum of the onion payload.	bytes	string
cltv_expiry A failure type-dependent cltv expiry value.	uint32	integer
flags A failure type-dependent flags value.	uint32	integer
failure_source_index The position in the path of the intermediate or final node that generated the failure message. Position zero is the sender node.	uint32	integer
height A failure type-dependent block height.	uint32	integer

lnrpc.ChannelUpdate

Field	gRPC Type	REST Type
signature The signature that validates the announced data and proves the ownership of node id.	bytes	string
chain_hash The target chain that this channel was opened within. This value should be the genesis hash of the target chain. Along with the short channel ID, this uniquely identifies the channel globally in a blockchain.	bytes	string
chan_id The unique description of the funding transaction.	uint64	string
timestamp A timestamp that allows ordering in the case of multiple announcements. We should ignore the message if timestamp is not greater than the last-received.	uint32	integer
message_flags The bitfield that describes whether optional fields are present in this update. Currently, the least-significant bit must be set to 1 if the optional field MaxHtlc is present.	uint32	integer
channel_flags The bitfield that describes additional meta-data concerning how the update is to be interpreted. Currently, the least-significant bit must be set to 0 if the creating node corresponds to the first node in the previously sent channel announcement and 1 otherwise. If the second bit is set, then the channel is set to be disabled.	uint32	integer
time_lock_delta The minimum number of blocks this node requires to be added to the expiry of HTLCs. This is a security parameter determined by the node operator. This value represents the required gap between the time locks of the incoming and outgoing HTLC's set to this node.	uint32	integer
htlc_minimum_msat The minimum HTLC value which will be accepted.	uint64	string
base_fee The base fee that must be used for incoming HTLC's to this particular channel. This value will be tacked onto the required for a payment independent of the size of the payment.	uint32	integer
fee_rate The fee rate that will be charged per millionth of a satoshi.	uint32	integer
htlc_maximum_msat The maximum HTLC value which will be accepted.	uint64	string
extra_opaque_data The set of data that was appended to this message, some of which we may not actually know how to iterate or parse. By holding onto this data, we ensure that we're able to properly validate the set of signatures that cover these new fields, and ensure we're able to make upgrades to the network in a forwards compatible manner.	bytes	string

Enums

lnrpc.Payment.PaymentStatus

Name	Number
UNKNOWN	0
IN_FLIGHT	1
SUCCEEDED	2
FAILED	3

lnrpc.HTLCAttempt.HTLCStatus

Name	Number
IN_FLIGHT	0
SUCCEEDED	1
FAILED	2

lnrpc.Failure.FailureCode

Name	Number
RESERVED The numbers assigned in this enumeration match the failure codes as defined in BOLT #4. Because protobuf 3 requires enums to start with 0, a RESERVED value is added.	0
INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS	1
INCORRECT_PAYMENT_AMOUNT	2
FINAL_INCORRECT_CLTV_EXPIRY	3
FINAL_INCORRECT_HTLC_AMOUNT	4
FINAL_EXPIRY_TOO_SOON	5
INVALID_REALM	6
EXPIRY_TOO_SOON	7
INVALID_ONION_VERSION	8
INVALID_ONION_HMAC	9
INVALID_ONION_KEY	10
AMOUNT_BELOW_MINIMUM	11
FEE_INSUFFICIENT	12
INCORRECT_CLTV_EXPIRY	13
CHANNEL_DISABLED	14
TEMPORARY_CHANNEL_FAILURE	15
REQUIRED_NODE_FEATURE_MISSING	16
REQUIRED_CHANNEL_FEATURE_MISSING	17
UNKNOWN_NEXT_PEER	18
TEMPORARY_NODE_FAILURE	19
PERMANENT_NODE_FAILURE	20
PERMANENT_CHANNEL_FAILURE	21
EXPIRY_TOO_FAR	22
MPP_TIMEOUT	23
INVALID_ONION_PAYLOAD	24
INTERNAL_FAILURE An internal error occurred.	997
UNKNOWN_FAILURE The error source is known, but the failure itself couldn't be decoded.	998
UNREADABLE_FAILURE An unreadable failure result is returned if the received failure message cannot be decrypted. In that case the error source is unknown.	999

lnrpc.PaymentFailureReason

Name	Number
FAILURE_REASON_NONE Payment isn't failed (yet).	0
FAILURE_REASON_TIMEOUT There are more routes to try, but the payment timeout was exceeded.	1
FAILURE_REASON_NO_ROUTE All possible routes were tried and failed permanently. Or were no routes to the destination at all.	2
FAILURE_REASON_ERROR A non-recoverable error has occured.	3
FAILURE_REASON_INCORRECT_PAYMENT_DETAILS Payment details incorrect (unknown hash, invalid amt or invalid final cltv delta)	4
FAILURE_REASON_INSUFFICIENT_BALANCE Insufficient local balance.	5