Message Gate

A lightweight library for seamless communication between threads, workers, and isolated contexts in JavaScript and TypeScript.

Features

• 🔄 Bidirectional communication between any contexts
• 📨 Synchronous and asynchronous messaging
• 🏷 Type-safe with full TypeScript support
• 🚀 Zero dependencies and minimal footprint
• 🔧 Transferable objects support
• ⚡ Easy setup with simple API

Installation

npm install message-gate

Browser Support

• ✅ Modern browsers (Chrome, Firefox, Safari, Edge)
• ✅ Web Workers
• ✅ Service Workers
• ✅ iframe communication
• ✅ Node.js with worker_threads

Performance

• ⚡ Lightweight: ~2KB gzipped
• 🚀 Zero dependencies
• 🔄 Efficient message routing
• 📦 Tree-shakable API

How to use

Create a channel in one scope

import MessageGate from "message-gate";

const [ gateA, gateB ] = MessageGate.createChannels();

Create a channel between two scopes (e.g., main and worker)

main.ts

import MessageGate from "message-gate";

const worker = new Worker("WORKER_URL", { type: "module" });
const { gate, port } = MessageGate.createChannelAndPort();
worker.postMessage(port, port);

worker.ts

import MessageGate from "message-gate";

self.onmessage = (port) => {
    self.gate = MessageGate.createFromPort(port);
    self.onmessage = undefined;
}

API Reference

Static Methods

MessageGate.createChannels(handlersA?, handlersB?)

Creates two interconnected channels.

const [gateA, gateB] = MessageGate.createChannels(
    { 'event-a': handlerA },
    { 'event-b': handlerB }
);

MessageGate.createChannelAndPort(handlers?)

Creates a gate and returns both the gate and its port.

const { gate, port } = MessageGate.createChannelAndPort(handlers);

MessageGate.createFromPort(port, handlers?)

Creates a gate from an existing MessagePort.

const gate = MessageGate.createFromPort(messagePort, {
    'custom-event': (data) => { /* handler */ }
});

MessageGate.createPorts()

Creates a pair of connected MessagePorts.

const [port1, port2] = MessageGate.createPorts();

Instance Methods

Register a message handler.

on(action: string, handler: Function)

gate.on('data-received', (data) => {
    console.log('Data:', data);
});

Remove a message handler.

off(action: string)

gate.off('data-received');

Send a synchronous message.

send(action: string, data: any)

gate.send('update-data', { value: 42 });

Send an asynchronous message and await response.

post(action: string, data: any): Promise<any>

const result = await gate.post('fetch-data', { query: 'test' });

Send a synchronous message with transferable objects.

sendTransfer(action: string, data: any, transfer: Transferable[])

const buffer = new ArrayBuffer(1024);
gate.sendTransfer('transfer-data', { buffer }, [buffer]);

Async message with transferable objects.

postTransfer(action: string, data: any, transfer: Transferable[]): Promise<any>

const result = await gate.postTransfer('process-buffer', { buffer }, [buffer]);

Close the communication channel.

close()

gate.close();

Properties

sidePort: MessagePort | undefined

Get the opposite port of the channel if gate was created with new MessageGate().

const oppositePort = gate.sidePort;

Advanced Usage

Transferable Objects

// Send large data efficiently
const largeBuffer = new ArrayBuffer(1024 * 1024);
gate.sendTransfer('large-data', { buffer: largeBuffer }, [largeBuffer]);

// Receive and process transferables
gate.on('large-data', (data) => {
    // data.buffer is now transferred, not copied
    processBuffer(data.buffer);
});

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT License - feel free to use in commercial projects.

Support

For bugs and feature requests, please create an issue on GitHub.