GetBlockHeader

GetBlockHeader returns a block header with a particular block hash.

Source: neutrinorpc/neutrino.proto

gRPC

rpc GetBlockHeader (GetBlockHeaderRequest) returns (GetBlockHeaderResponse);

REST

HTTP Method	Path
GET	/v2/neutrino/blockheader/{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', 'neutrinorpc/neutrino.proto'], loaderOptions);
const neutrinorpc = grpc.loadPackageDefinition(packageDefinition).neutrinorpc;
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 neutrinorpc.NeutrinoKit(GRPC_HOST, creds);
let request = {
  hash: <string>,
};
client.getBlockHeader(request, function(err, response) {
  console.log(response);
});
// Console output:
//  {
//    "hash": <string>,
//    "confirmations": <int64>,
//    "stripped_size": <int64>,
//    "size": <int64>,
//    "weight": <int64>,
//    "height": <int32>,
//    "version": <int32>,
//    "version_hex": <string>,
//    "merkleroot": <string>,
//    "time": <int64>,
//    "nonce": <uint32>,
//    "bits": <string>,
//    "ntx": <int32>,
//    "previous_block_hash": <string>,
//    "raw_hex": <bytes>,
//  }

Python

import codecs, grpc, os
# Generate the following 2 modules by compiling the neutrinorpc/neutrino.proto with the grpcio-tools.
# See https://github.com/lightningnetwork/lnd/blob/master/docs/grpc/python.md for instructions.
import neutrino_pb2 as neutrinorpc, neutrino_pb2_grpc as neutrinostub

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 = neutrinostub.NeutrinoKitStub(channel)
request = neutrinorpc.GetBlockHeaderRequest(
  hash=<string>,
)
response = stub.GetBlockHeader(request)
print(response)
# {
#    "hash": <string>,
#    "confirmations": <int64>,
#    "stripped_size": <int64>,
#    "size": <int64>,
#    "weight": <int64>,
#    "height": <int32>,
#    "version": <int32>,
#    "version_hex": <string>,
#    "merkleroot": <string>,
#    "time": <int64>,
#    "nonce": <uint32>,
#    "bits": <string>,
#    "ntx": <int32>,
#    "previous_block_hash": <string>,
#    "raw_hex": <bytes>,
# }

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/neutrino/blockheader/{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:
//  {
//    "hash": <string>, // <string> 
//    "confirmations": <string>, // <int64> 
//    "stripped_size": <string>, // <int64> 
//    "size": <string>, // <int64> 
//    "weight": <string>, // <int64> 
//    "height": <integer>, // <int32> 
//    "version": <integer>, // <int32> 
//    "version_hex": <string>, // <string> 
//    "merkleroot": <string>, // <string> 
//    "time": <string>, // <int64> 
//    "nonce": <integer>, // <uint32> 
//    "bits": <string>, // <string> 
//    "ntx": <integer>, // <int32> 
//    "previous_block_hash": <string>, // <string> 
//    "raw_hex": <string>, // <bytes> 
//  }

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/neutrino/blockheader/{hash}'
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
headers = {'Grpc-Metadata-macaroon': macaroon}
r = requests.get(url, headers=headers, verify=TLS_PATH)
print(r.json())
# {
#    "hash": <string>,
#    "confirmations": <int64>,
#    "stripped_size": <int64>,
#    "size": <int64>,
#    "weight": <int64>,
#    "height": <int32>,
#    "version": <int32>,
#    "version_hex": <string>,
#    "merkleroot": <string>,
#    "time": <int64>,
#    "nonce": <uint32>,
#    "bits": <string>,
#    "ntx": <int32>,
#    "previous_block_hash": <string>,
#    "raw_hex": <bytes>,
# }

Shell

$ lncli neutrino getblockheader --help

NAME:
   lncli neutrino getblockheader - Get a block header.

USAGE:
   lncli neutrino getblockheader hash

CATEGORY:
   Neutrino

DESCRIPTION:
   Returns a block header with a particular block hash.

Messages

neutrinorpc.GetBlockHeaderRequest

Source: neutrinorpc/neutrino.proto

Field	gRPC Type	REST Type	REST Placement
hash Block hash in hex notation.	string	string	path

neutrinorpc.GetBlockHeaderResponse

Source: neutrinorpc/neutrino.proto

Field	gRPC Type	REST Type
hash The block hash (same as provided).	string	string
confirmations The number of confirmations.	int64	string
stripped_size The block size excluding witness data.	int64	string
size The block size (bytes).	int64	string
weight The block weight as defined in BIP 141.	int64	string
height The block height or index.	int32	integer
version The block version.	int32	integer
version_hex The block version.	string	string
merkleroot The merkle root.	string	string
time The block time in seconds since epoch (Jan 1 1970 GMT).	int64	string
nonce The nonce.	uint32	integer
bits The bits in hex notation.	string	string
ntx The number of transactions in the block.	int32	integer
previous_block_hash The hash of the previous block.	string	string
raw_hex The raw hex of the block.	bytes	string