river.ts is a powerful library for handling server-sent events (SSE) in TypeScript. It allows you to build a common interface for events, then use it consistently on both server and client sides. Compatible with express-like backends and modern frontend frameworks.
- 💡 Easy-to-use API for defining, emitting, and handling events
- 🔄 Automatic reconnection with configurable options
- 🔌 Works with various HTTP methods and supports custom headers, body, etc.
- 🛠️ Type-safe event handlers and payload definitions
- 🚀 Streamlined setup for both server and client sides
npm install river.ts
# or
yarn add river.ts
# or
pnpm add river.ts
# or
bun add river.tsUse the RiverEvents class to define your event structure:
import { RiverEvents } from 'river.ts';
const events = new RiverEvents()
.defineEvent('ping', {
message: 'pong'
})
.defineEvent('payload', {
data: [
{ id: 1, name: 'Alice' },
{ id: 2, name: 'Bob' }
],
stream: true
})
.build();Use RiverEmitter to set up the server-side event emitter:
import { RiverEmitter } from 'river.ts/server';
import { events } from './events';
const emitter = RiverEmitter.init(events);
function handleSSE(req: Request, res: Response) {
const stream = emitter.stream({
callback: async (emit) => {
await emit('ping', { message: 'pong' });
await emit('payload', {
data: [
{ id: 1, name: 'Alice' },
{ id: 2, name: 'Bob' }
]
});
},
clientId: '...', // optional param to set a custom client ID
ondisconnect: (clientId) => {
// optional param to handle disconnections
}
});
return new Response(stream, {
headers: emitter.headers()
});
}Use RiverClient to set up the client-side event listener:
import { RiverClient } from 'river.ts/client';
import { events } from './events';
const client = RiverClient.init(events);
client
.prepare('https://localhost:3000/events', {
method: 'GET',
headers: {
// Add any custom headers here
}
})
.on('ping', (data) => {
console.log('Ping received:', data.message);
})
.on('payload', (data) => {
console.log('Payload received:', data);
})
.stream();Leverage TypeScript's type system for type-safe event handling:
import { InferEventType } from 'river.ts';
type Events = typeof events;
type PingEvent = InferEventType<Events, 'ping'>;
// {
// message: string;
// type: "ping";
// }
const pingEvents: PingEvent[] = [];
pingEvents.push({
message: 'pong',
type: 'ping'
});Contributions are welcome! If you find any issues or have suggestions for improvements, please open an issue or submit a pull request.
This project is licensed under the MIT License.