Node gRPC API

For services that need to process a large volume of blocks or transactions, the node’s gRPC API is faster to consume than the REST API: it returns Protobuf-serialized binary messages instead of JSON, and supports server-streaming for large result sets. See Node Extensions for enabling it on your own node.

Note

Verified against @decentralchain/node-api-grpc v2.0.0 (monorepo main).

Warning

@decentralchain/node-api-grpc is not published to npm yet (checked 2026-09-28: npm install returns 404). This page reflects the package’s source, showing the API you’ll get once it’s released. Check npmjs.com/package/@decentralchain/node-api-grpc before relying on it.

Installing (once published)

npm install @decentralchain/node-api-grpc

Requires Node.js >= 24 and an ESM environment ("type": "module").

Connecting

import { mkDefaultChannel, mkTransactionsApi } from '@decentralchain/node-api-grpc';

const channel = mkDefaultChannel('mainnet-node.decentralchain.io'); // defaults to port 6870
const txApi = mkTransactionsApi(channel);

for await (const tx of txApi.getTransactions({ sender: '3D...' })) {
  console.log(tx);
}

mkDefaultChannel(host, options?) accepts a bare hostname (defaults to port 6870), a host:port pair, or a full http(s):// or grpc(s):// URL. Pass Connect transport options (TLS, interceptors, timeouts) as the second argument.

APIs

Client factory	Service	Methods
mkAccountsApi(channel)	AccountsApi	getBalances, getScript, getActiveLeases, getDataEntries, resolveAlias
mkAssetsApi(channel)	AssetsApi	getInfo, getNFTList
mkBlockchainApi(channel)	BlockchainApi	getActivationStatus, getBaseTarget, getCumulativeScore
mkBlocksApi(channel)	BlocksApi	getBlock, getBlockRange
mkTransactionsApi(channel)	TransactionsApi	getTransactions, getTransactionSnapshots, getStateChanges, getStatuses, getUnconfirmed, sign, broadcast

Request and response types are re-exported from the protobuf schema package (published today as @decentralchain/protobuf-serialization; the monorepo is renaming it to protobuf-schemas), so importing @decentralchain/node-api-grpc alone is enough — no separate import is needed.

Blockchain Updates

The BlockchainUpdates API streams block-level events (appends, rollbacks, microblocks) in real time — useful for indexers and services that need to react to chain state as it happens, without polling. It runs on a separate port, 6881, from the rest of the gRPC API.

import { mkDefaultBlockchainUpdatesChannel, mkBlockchainUpdatesApi } from '@decentralchain/node-api-grpc';

const channel = mkDefaultBlockchainUpdatesChannel('mainnet-node.decentralchain.io'); // defaults to port 6881
const updatesApi = mkBlockchainUpdatesApi(channel);

for await (const event of updatesApi.subscribe({ fromHeight: 1 })) {
  console.log(event);
}

Method	Purpose
getBlockUpdate	Fetch the update for a single height
getBlockUpdatesRange	Fetch updates for a height range
subscribe	Server-streaming subscription to new updates as they happen

See Node Extensions for enabling the gRPC server (and hence BlockchainUpdates) on a node you operate; a public node must expose both ports for this package to reach it.