SubscribeChannelGraph

SubscribeChannelGraph launches a streaming RPC that allows the caller to receive notifications upon any changes to the channel graph topology from the point of view of the responding node. Events notified include: new nodes coming online, nodes updating their authenticated attributes, new channels being advertised, updates in the routing policy for a directional channel edge, and when channels are closed on-chain.

Source: lightning.proto

gRPC

info

This is a server-streaming RPC

rpc SubscribeChannelGraph (GraphTopologySubscription) returns (stream GraphTopologyUpdate);

REST

HTTP Method	Path
GET	/v1/graph/subscribe

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', loaderOptions);
const lnrpc = grpc.loadPackageDefinition(packageDefinition).lnrpc;
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 lnrpc.Lightning(GRPC_HOST, creds);
let request = {};
let call = client.subscribeChannelGraph(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:
//  {
//    "node_updates": <NodeUpdate>,
//    "channel_updates": <ChannelEdgeUpdate>,
//    "closed_chans": <ClosedChannelUpdate>,
//  }

Python

import codecs, grpc, os
# Generate the following 2 modules by compiling the lightning.proto with the grpcio-tools.
# See https://github.com/lightningnetwork/lnd/blob/master/docs/grpc/python.md for instructions.
import lightning_pb2 as lnrpc, lightning_pb2_grpc as lightningstub

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 = lightningstub.LightningStub(channel)
request = lnrpc.GraphTopologySubscription()
for response in stub.SubscribeChannelGraph(request):
  print(response)
# {
#    "node_updates": <NodeUpdate>,
#    "channel_updates": <ChannelEdgeUpdate>,
#    "closed_chans": <ClosedChannelUpdate>,
# }

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}/v1/graph/subscribe`,
  // 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:
//  {
//    "node_updates": <array>, // <NodeUpdate> 
//    "channel_updates": <array>, // <ChannelEdgeUpdate> 
//    "closed_chans": <array>, // <ClosedChannelUpdate> 
//  }



// --------------------------
// 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}/v1/graph/subscribe?method=GET`, {
  // Work-around for self-signed certificates.
  rejectUnauthorized: false,
  headers: {
    'Grpc-Metadata-Macaroon': fs.readFileSync(MACAROON_PATH).toString('hex'),
  },
});
let requestBody = {
};
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:
//  {
//    "node_updates": <array>, // <NodeUpdate>
//    "channel_updates": <array>, // <ChannelEdgeUpdate>
//    "closed_chans": <array>, // <ClosedChannelUpdate>
//  }

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}/v1/graph/subscribe'
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)
# {
#    "node_updates": <NodeUpdate>,
#    "channel_updates": <ChannelEdgeUpdate>,
#    "closed_chans": <ClosedChannelUpdate>,
# }

Shell

# There is no CLI command for this RPC

Messages

lnrpc.GraphTopologySubscription

Source: lightning.proto

note

This request has no parameters.

lnrpc.GraphTopologyUpdate

Source: lightning.proto

Field	gRPC Type	REST Type
node_updates	NodeUpdate[]	array
channel_updates	ChannelEdgeUpdate[]	array
closed_chans	ClosedChannelUpdate[]	array

Nested Messages

lnrpc.ChannelEdgeUpdate

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_point	ChannelPoint	object
capacity	int64	string
routing_policy	RoutingPolicy	object
advertising_node	string	string
connecting_node	string	string

lnrpc.ChannelPoint

Field	gRPC Type	REST Type
funding_txid_bytes Txid of the funding transaction. When using REST, this field must be encoded as base64.	bytes	string
funding_txid_str Hex-encoded string representing the byte-reversed hash of the funding transaction.	string	string
output_index The index of the output of the funding transaction	uint32	integer

lnrpc.ClosedChannelUpdate

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
capacity	int64	string
closed_height	uint32	integer
chan_point	ChannelPoint	object

lnrpc.Feature

Field	gRPC Type	REST Type
name	string	string
is_required	bool	boolean
is_known	bool	boolean

lnrpc.NodeAddress

Field	gRPC Type	REST Type
network	string	string
addr	string	string

lnrpc.NodeUpdate

Field	gRPC Type	REST Type
addressesdeprecated Deprecated, use node_addresses.	string[]	array
identity_key	string	string
global_featuresdeprecated Deprecated, use features.	bytes	string
alias	string	string
color	string	string
node_addresses	NodeAddress[]	array
features Features that the node has advertised in the init message, node announcements and invoices.	FeaturesEntry[]	object

lnrpc.NodeUpdate.FeaturesEntry

Field	gRPC Type	REST Type
key	uint32	unknown
value	Feature	unknown

lnrpc.RoutingPolicy

Field	gRPC Type	REST Type
time_lock_delta	uint32	integer
min_htlc	int64	string
fee_base_msat	int64	string
fee_rate_milli_msat	int64	string
disabled	bool	boolean
max_htlc_msat	uint64	string
last_update	uint32	integer
custom_records Custom channel update tlv records.	CustomRecordsEntry[]	object
inbound_fee_base_msat	int32	integer
inbound_fee_rate_milli_msat	int32	integer

lnrpc.RoutingPolicy.CustomRecordsEntry

Field	gRPC Type	REST Type
key	uint64	unknown
value	bytes	unknown