nostr-websocket-utils

A TypeScript library for building Nostr protocol WebSocket clients and servers.

Release note — v0.5.0 (staged, pending publish). Part of the coordinated 2026-07 correctness pass across the Nostr library family, verified against a shared known-answer vector set (NIP-44 v2 / NIP-49 / NIP-19 TLV / BIP-340). This release rebuilds the NIP-01 wire builders to spec and adds real crypto tests. The family dogfoods only its own libraries — no upstream nostr-tools dependency.

Features

• 🚀 Full Nostr protocol support with nostr-crypto-utils integration
• 🔒 Secure WebSocket connections
• ♥️ Heartbeat mechanism for connection health
• 🔄 Automatic reconnection handling
• 📝 Comprehensive logging with Pino v8
• 🎯 Type-safe message handling
• 📦 Easy to use API
• 🧪 Vitest-powered test suite

NIPs Support Status

🟢 Fully implemented 🟡 Partially implemented 🔴 Not implemented

NIP	Status	Description
01	🟢	Basic protocol flow & WebSocket connections
02	🟢	Contact List and Petnames
04	🟢	Encrypted Direct Messages
11	🟢	Relay Information Document
13	🟢	Proof of Work
15	🟢	End of Stored Events Notice
16	🟢	Event Treatment
19	🟢	bech32-encoded entities
20	🟢	Command Results
26	🟢	Delegated Event Signing
42	🟢	Authentication of clients to relays
44	🟢	Versioned Encrypted Payloads
46	🟢	Nostr Connect / Remote Signing transport

⚠️ 0.5.0 is a breaking release. It fixes the wire/crypto layer — message builders now emit spec-compliant NIP-01 positional arrays (earlier versions emitted an object shape that every compliant relay rejects) and the NIP-04 DM implementation had its key arguments swapped. Any consumer relying on the old (non-functional) output must update. See CHANGELOG.md.

Wire format (NIP-01)

All builders emit spec-shaped positional arrays exactly as they appear on the wire:

import { createReqMessage, createCloseMessage, createNoticeMessage } from 'nostr-websocket-utils';
import { createOkMessage } from 'nostr-websocket-utils';

createReqMessage('sub1', [{ kinds: [1] }]); // ["REQ","sub1",{"kinds":[1]}]
createCloseMessage('sub1');                 // ["CLOSE","sub1"]
createNoticeMessage('hello');               // ["NOTICE","hello"]
createOkMessage('<eventId>', true, 'ok');   // ["OK","<eventId>",true,"ok"]

Tag filters use NIP-01 #e / #p keys (e.g. { kinds: [4], '#p': [pubkey] }).

WebSocket Protocol Implementation Details

This package implements the Nostr WebSocket protocol with full support for the core NIPs that define WebSocket behavior. Here's how it works:

Key Features & Compliance

1. Protocol Implementation:

   • Full implementation of Nostr WebSocket protocol
   • Support for all standard message types (EVENT, REQ, CLOSE, etc.)
   • Robust error handling and status reporting

2. Connection Management:

   • Automatic reconnection with configurable backoff
   • Heartbeat mechanism for connection health
   • Connection pooling and load balancing

3. Message Handling:

   • Type-safe message processing
   • Support for subscription management
   • Efficient event filtering

4. Security & Best Practices:

   • Secure WebSocket connections (WSS)
   • Implementation of authentication protocols
   • Rate limiting and protection mechanisms

Interoperability

This implementation ensures compatibility with:

• All major Nostr relays
• Other Nostr clients and libraries
• Standard WebSocket tooling and infrastructure

Validation & Testing

The package includes:

• Comprehensive test suites for protocol compliance
• Connection reliability testing
• Performance benchmarks for message handling

Installation

npm install nostr-websocket-utils

Quick Start

Creating a Nostr WebSocket Client

import { NostrWSClient } from 'nostr-websocket-utils';

const client = new NostrWSClient('wss://relay.example.com', {
  logger: console,
  heartbeatInterval: 30000,
  handlers: {
    message: async (msg) => console.log('Received:', msg),
    error: (err) => console.error('Error:', err),
    close: () => console.log('Connection closed')
  }
});

await client.connect();

Creating a Nostr WebSocket Server

import { createNostrServer } from 'nostr-websocket-utils';

const server = await createNostrServer(8080, {
  logger: console,
  heartbeatInterval: 30000,
  handlers: {
    message: async (ws, msg) => {
      console.log('Received message:', msg);
      // Handle the message
    }
  }
});

Browser Usage

This library now supports direct browser usage! You can use it in your client-side applications in two ways:

Via NPM (Recommended)

import { NostrWSClient } from 'nostr-websocket-utils';

const client = new NostrWSClient({
  url: 'wss://relay.damus.io',
  options: {
    autoReconnect: true,
    maxRetries: 3
  }
});

client.onMessage((message) => {
  console.log('Received:', message);
});

client.connect();

Via CDN

<script src="https://unpkg.com/nostr-websocket-utils/dist/browser/nostr-websocket-utils.min.js"></script>
<script>
  const client = new NostrWebSocketUtils.NostrWSClient({
    url: 'wss://relay.damus.io',
    options: {
      autoReconnect: true,
      maxRetries: 3
    }
  });

  client.onMessage((message) => {
    console.log('Received:', message);
  });

  client.connect();
</script>

Features in Browser Environment

• Direct WebSocket connections to Nostr relays
• Automatic reconnection handling
• Message queueing
• Type-safe handlers
• Full compatibility with browser environments
• Source maps for better debugging

See the examples/browser.html file for a complete example of browser usage.

Dependencies

This package uses:

• nostr-crypto-utils (^0.7.0) for cryptographic operations
• @noble/curves + @noble/hashes (^2.0.1) for NIP-26 schnorr delegation tokens
• pino (^10.3.1) for logging
• ws (^8.19.0) for WebSocket functionality
• uuid (^13.0.0) for unique identifiers

Documentation

Comprehensive API documentation is available in our documentation site. Here's what you'll find:

Core Components

• NostrWSClient - WebSocket client implementation
• NostrWSServer - WebSocket server implementation
• NostrServer - High-level Nostr server

Types and Interfaces

• NostrWSMessage - Message structure
• NostrWSOptions - Configuration options
• NostrWSSubscription - Subscription interface
• ExtendedWebSocket - Enhanced WebSocket interface

Utility Functions

• createServer - Server creation helper
• getLogger - Logging utility

Type Definitions

• ConnectionState - Connection state enumeration
• Global Types - Global type definitions

Examples

Subscribe to a Channel

client.subscribe('my-channel', {
  filter: {
    authors: ['pubkey1', 'pubkey2'],
    kinds: [1]
  }
});

Broadcast a Message

server.broadcast({
  type: 'event',
  data: {
    content: 'Hello everyone!',
    kind: 1
  }
});

Security

Dependency Vulnerability Status

We actively monitor and address security vulnerabilities in this codebase. npm audit --omit=dev reports zero vulnerabilities for this package — there are no known security issues in production dependencies.

Any remaining npm audit findings are in development-only tooling (eslint, typescript-eslint, vitest, typedoc, etc.) and stem from transitive dependencies with no upstream fix available. These are devDependencies that are never included in the published package and pose no risk to consumers of this library. We monitor upstream fixes and update promptly when they become available.

Contributing

Contributions are welcome! Please read our Contributing Guide for details on our code of conduct and the process for submitting pull requests.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Related Projects

• nostr-protocol

Support

If you have any questions or need help, please:

1. Check the documentation
2. Open an issue