@helius-laserstream

JavaScript/TypeScript client for Laserstream. Features automatic reconnection with slot tracking - if connection is lost, the client automatically reconnects and continues streaming from the last processed slot, ensuring no data is missed.

Installation

npm install helius-laserstream

Usage Example

import { subscribe, CommitmentLevel, LaserstreamConfig, SubscribeRequest } from 'helius-laserstream';

async function main() {
  const config: LaserstreamConfig = {
    apiKey: 'your-api-key',
    endpoint: 'your-endpoint',
  };

  const request: SubscribeRequest = {
    transactions: {
      client: {
        accountInclude: ['TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA'],
        accountExclude: [],
        accountRequired: [],
        vote: false,
        failed: false
      }
    },
    commitment: CommitmentLevel.CONFIRMED,
    // Empty objects for unused subscription types
    accounts: {},
    slots: {},
    transactionsStatus: {},
    blocks: {},
    blocksMeta: {},
    entry: {},
    accountsDataSlice: [],
  };

  // Client handles disconnections automatically:
  // - Reconnects on network issues
  // - Resumes from last processed slot
  // - Maintains subscription state
  await subscribe(
    config,
    request,
    async (data) => {
      console.log('Received update:', data);
    },
    async (error) => {
      console.error('Error:', error);
    }
  );
}

main().catch(console.error);

Runtime Support

Node.js

node your-app.js

Bun

bun your-app.js

The library uses Node-API (NAPI) bindings which are supported natively by both runtimes.

API Reference

Core Functions

• subscribe(config, request, onData, onError) - Main streaming function
• shutdownAllStreams() - Gracefully shutdown all active streams
• getActiveStreamCount() - Get number of active streams

Types

• LaserstreamConfig - Configuration interface
• SubscribeRequest - Stream subscription request
• CommitmentLevel - Solana commitment levels (PROCESSED, CONFIRMED, FINALIZED)

Performance

This library is built with Rust NAPI bindings, providing significant performance improvements:

4.6x faster throughput compared to the standard Yellowstone gRPC client.

Key Performance Features

• Zero-copy message passing
• Minimal JavaScript overhead
• Native async/await support
• Optimized memory usage
• High-performance Rust implementation

License

MIT