Pulsar TypeScript/JavaScript SDK

100% on-chain messaging SDK for TypeScript and JavaScript.

Quick Links

• QuickStart Guide - Get started in 30 minutes
• Examples - Complete, runnable code examples
• API Reference - Full method documentation
• Troubleshooting - Common issues and solutions

Installation

npm install @pulsar/sdk
# or
yarn add @pulsar/sdk
# or
pnpm add @pulsar/sdk

Quick Start

import { PulsarClient, CHAIN_CONFIGS } from '@pulsar/sdk';

// Initialize client
const client = new PulsarClient(CHAIN_CONFIGS.baseSepolia());

// Create application
const { applicationId } = await client.application.createApplication({
  name: 'My App',
  description: 'My decentralized app'
});

// Create topic
const { topicId } = await client.topic.createTopic({
  applicationId,
  name: 'my-topic',
  isPrivate: false,
  schemaId: 0,
  retentionPeriod: 0n
});

// Send message
await client.messages.sendMessage({
  topicId,
  payload: { message: 'Hello, Pulsar!' }
});

For a complete walkthrough, see the QuickStart Guide.

Configuration

Create a .env file in your project root:

# Required
PRIVATE_KEY=0x...

# RPC URLs (choose one per network)
BASE_SEPOLIA_RPC_URL=https://base-sepolia.g.alchemy.com/v2/YOUR_KEY
BASE_RPC_URL=https://mainnet.base.org

Security Note: Never commit .env to version control!

Available Networks

The SDK supports multiple networks via pre-configured chain settings:

import { PulsarClient, CHAIN_CONFIGS } from '@pulsar/sdk';

// Base Sepolia (testnet - recommended for development)
const client = new PulsarClient(CHAIN_CONFIGS.baseSepolia());

// Base Mainnet
const client = new PulsarClient(CHAIN_CONFIGS.base());

// Localhost (for local Hardhat node)
const client = new PulsarClient(CHAIN_CONFIGS.localhost());

// Custom configuration
const client = new PulsarClient({
  chainId: ChainId.BASE_SEPOLIA,
  privateKey: process.env.PRIVATE_KEY!,
  rpcUrl: process.env.BASE_SEPOLIA_RPC_URL
});

Features

• ✅ Application Management - Create and manage applications
• ✅ Topic Creation - Public and private topics with encryption
• ✅ Message Production - Send messages with automatic gas estimation
• ✅ Message Consumption - Consumer groups with offset management
• ✅ Access Control - Grant/revoke permissions for private topics
• ✅ Schema Registry - Register and validate message schemas
• ✅ Event Indexing - Query blockchain events efficiently
• ✅ Multi-Chain Support - Base, Ethereum, Arbitrum, Optimism, Avalanche
• ✅ TypeScript-First - Full type safety with IntelliSense
• ✅ Retry Logic - Automatic retries for transient failures
• ✅ Gas Optimization - Smart gas estimation with configurable buffers

Examples

The examples/ directory contains complete, runnable examples:

Basic Usage

npx ts-node examples/basic-usage.ts

Complete workflow: create app, create topic, send messages, consume with consumer groups

Consumer Groups

npx ts-node examples/consumer-groups.ts

Advanced patterns: multiple consumer groups, auto-commit vs manual, batch processing

Comprehensive

npx ts-node examples/comprehensive.ts

All SDK features: public/private topics, access control, schemas, error handling

Advanced Features

npx ts-node examples/advanced-features.ts

Optimization techniques: batching, event querying, performance monitoring

See examples/README.md for detailed example documentation.

API Overview

Client Initialization

import { PulsarClient, CHAIN_CONFIGS } from '@pulsar/sdk';

const client = new PulsarClient(CHAIN_CONFIGS.baseSepolia());

Application Management

// Create application
const { applicationId } = await client.application.createApplication({
  name: 'My App',
  description: 'Description'
});

// Add team member
await client.application.addMember({
  applicationId,
  member: '0x...',
  nickname: 'Alice'
});

// Get application details
const app = await client.application.getApplication(applicationId);

Topic Management

// Create public topic
const { topicId } = await client.topic.createTopic({
  applicationId,
  name: 'general-chat',
  isPrivate: false,
  schemaId: 0,
  retentionPeriod: 0n
});

// Create private topic (with encryption)
const { topicId } = await client.topic.createTopic({
  applicationId,
  name: 'private-data',
  isPrivate: true,
  schemaId: 0,
  retentionPeriod: 0n
});

// Get topic details
const topic = await client.topic.getTopic(topicId);

Message Production

// Send single message
const { txHash } = await client.messages.sendMessage({
  topicId,
  payload: {
    type: 'notification',
    message: 'Hello!',
    timestamp: Date.now()
  }
});

// Payload can be any JSON-serializable object

Consumer Groups & Consumption

// Create consumer group
const { groupId } = await client.consumerGroup.createConsumerGroup({
  topicId,
  groupName: 'notification-processor'
});

// Consume messages (auto-commit)
const result = await client.consumer.consumeMessages({
  groupId,
  limit: 100,
  autoCommit: true
});

console.log(`Consumed ${result.messageCount} messages`);
result.messages.forEach(msg => {
  console.log('Received:', msg.payload);
});

// Manual offset management
const result = await client.consumer.consumeMessages({
  groupId,
  limit: 100,
  autoCommit: false
});

// Process messages...

// Commit offset manually
if (result.messages.length > 0) {
  const lastMsg = result.messages[result.messages.length - 1];
  await client.consumer.commitOffset({
    groupId,
    offset: lastMsg.blockNumber
  });
}

Access Control (Private Topics)

import { Permission } from '@pulsar/sdk';

// Grant permissions
await client.access.grantPermissions({
  topicId,
  member: '0x...',
  permissions: Permission.READ_WRITE
});

// Revoke permissions
await client.access.revokePermissions({
  topicId,
  member: '0x...'
});

// Check permissions
const hasPermission = await client.access.checkPermissions({
  topicId,
  member: '0x...',
  requiredPermission: Permission.READ
});

For complete API documentation, see API.md.

Error Handling

import {
  ValidationError,
  NetworkError,
  TransactionError,
  PulsarError
} from '@pulsar/sdk';

try {
  await client.messages.sendMessage({...});
} catch (error) {
  if (error instanceof ValidationError) {
    console.error('Invalid input:', error.message);
  } else if (error instanceof NetworkError) {
    console.error('Network issue:', error.message);
  } else if (error instanceof TransactionError) {
    console.error('Transaction failed:', error.txHash);
  } else if (error instanceof PulsarError) {
    console.error('Pulsar error:', error.message);
  }
}

TypeScript Support

The SDK is built with TypeScript and provides complete type definitions:

import type {
  PulsarClient,
  CreateApplicationParams,
  CreateTopicParams,
  SendMessageParams,
  ApplicationResult,
  TopicResult,
  ConsumeResult
} from '@pulsar/sdk';

// All parameters are fully typed with IntelliSense
const params: CreateApplicationParams = {
  name: 'My App',
  description: 'Description'
};

const result: ApplicationResult = await client.application.createApplication(params);

Testing

The SDK includes comprehensive test coverage:

# Run all tests
npm test

# Run with coverage
npm run test:coverage

# Run specific test file
npm test -- MessageProducer

Building from Source

# Clone repository
git clone https://github.com/pulsar/sdk.git
cd sdk/packages/sdk

# Install dependencies
npm install

# Build
npm run build

# Run tests
npm test

Get Test ETH

Need test ETH for Base Sepolia?

• Coinbase Faucet
• Alchemy Faucet

Troubleshooting

"Cannot find module '@pulsar/sdk'"

Build the package:

npm run build

"Insufficient funds for gas"

• Get test ETH from faucets above
• Check balance: await client.getBalance()

"Transaction reverted"

• Verify topic/application exists
• Check permissions for private topics
• Ensure valid payload (JSON-serializable)

RPC Connection Issues

• Verify RPC URL is correct
• Try alternative RPC provider
• Check network connectivity

For more solutions, see TROUBLESHOOTING.md.

Contributing

See CONTRIBUTING.md for contribution guidelines.

Changelog

See CHANGELOG.md for release history.

License

MIT

Support

• Documentation: Pulsar Docs
• GitHub Issues: Report bugs
• Discord: Join our community

Built with ❤️ by the Pulsar team