@fastify/websocket

WebSocket support for Fastify, built on the `ws` library and integrated with Fastify routing.

@fastify/websocket

Fastify

WebSocket support for Fastify, built on the `ws` library and integrated with Fastify routing.

npm GitHub Docs

Fit

Bundle (gzip)

15.2 kB

50.6 kB raw

Install size includes transitive dependencies. Bundle size is gzipped browser payload.

Freshness

The Problem

Adding real-time WebSocket endpoints to a Fastify server usually means running a separate ws server alongside it, which complicates routing, lifecycle, and access to Fastify's hooks and decorators.

What It Does

@fastify/websocket lets you declare WebSocket routes directly in Fastify with the familiar route API, sharing the same server, hooks, and plugins. Each connection is handled through a standard ws socket.

Installation

bash

npm install @fastify/websocket

Usage Example

import Fastify from "fastify";
import websocket from "@fastify/websocket";

const app = Fastify();
await app.register(websocket);

app.get("/chat", { websocket: true }, (socket) => {
  socket.on("message", (message) => {
    socket.send(`echo: ${message}`);
  });
});

app.listen({ port: 3000 });

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