fastify-uws

A performant HTTP and WebSocket server for Fastify with uWebSockets.

Installation

Install fastify-uws with your favorite package manager:

1$ npm i fastify-uws
2# or
3$ yarn add fastify-uws
4# or
5$ pnpm i fastify-uws
6# or
7$ bun add fastify-uws

Supported

• fastify v5.x
• @fastify/websocket v11.x

Usage

Just two lines are needed to speed up your Fastify application.

1// app.ts
2import fastify from 'fastify';
3import { serverFactory } from 'fastify-uws'; // Import here
4
5import router from '~/plugins/router';
6
7export default () => {
8  const app = fastify({
9    logger: {
10      transport: {
11        target: '@fastify/one-line-logger',
12      },
13    },
14    serverFactory, // And use here
15  });
16
17  app.register(router);
18
19  return app;
20};

1// server.ts
2import app from './app';
3
4const server = app();
5
6const start = async () => {
7  try {
8    await server.listen({
9      host: '127.0.0.1',
10      port: 3000,
11    });
12  } catch (err) {
13    server.log.error(err);
14    process.exit(1);
15  }
16};
17
18start();

Use Fetch

1// src/routes/hello-http/+handler.ts
2import type { FastifyPluginAsyncTypebox } from '@fastify/type-provider-typebox';
3import { Type } from '@sinclair/typebox';
4
5export default (async (app) => {
6  app.get(
7    '',
8    {
9      schema: {
10        response: {
11          200: Type.Object({
12            message: Type.String(),
13          }),
14        },
15      },
16    },
17    async (req, reply) => {
18      return reply.send({
19        message: 'Hello, World!',
20      });
21    },
22  );
23}) as FastifyPluginAsyncTypebox;

With FormData

1// app.ts
2import multipart from '@fastify/multipart';
3
4app.register(multipart);

1// src/routes/hello-fd/+handler.ts
2import type { FastifyPluginAsyncTypebox } from '@fastify/type-provider-typebox';
3import fs from 'node:fs';
4import { pipeline } from 'node:stream/promises';
5
6export default (async (app) => {
7  app.post('', async (req, reply) => {
8    const data = await req.file();
9
10    data.file; // stream
11    data.fields; // other parsed parts
12    data.fieldname;
13    data.filename;
14    data.encoding;
15    data.mimetype;
16
17    await pipeline(data.file, fs.createWriteStream(data.filename));
18    // or
19    // await data.toBuffer(); // Buffer
20
21    return reply.send({ message: 'ok' });
22  });
23}) as FastifyPluginAsyncTypebox;

Use WebSocket

Just a single line of change can speed up your WebSocket application in Fastify.

1- import websocket from '@fastify/websocket';
2+ import { websocket } from 'fastify-uws';

1// app.ts
2import { websocket } from 'fastify-uws';
3
4app.register(websocket);

1// src/routes/hello-ws/+handler.ts
2import type { FastifyPluginAsyncTypebox } from '@fastify/type-provider-typebox';
3
4export default (async (app) => {
5  app.get('', { websocket: true }, (socket, request) => {
6    app.log.info('Client connected');
7
8    socket.on('message', (message: MessageEvent) => {
9      console.log(`Client message: ${message}`);
10      socket.send('Hello from Fastify!');
11    });
12
13    socket.on('close', () => {
14      app.log.info('Client disconnected');
15    });
16  });
17}) as FastifyPluginAsyncTypebox;

Use EventSource

1// app.ts
2import { eventsource } from 'fastify-uws';
3
4app.register(eventsource);

1// src/routes/hello-sse/+handler.ts
2import type { FastifyPluginAsyncTypebox } from '@fastify/type-provider-typebox';
3
4export default (async (app) => {
5  app.get('', (req, reply) => {
6    let index = 0;
7
8    reply.sse({ id: String(index), data: `Some message ${index}` });
9
10    const interval = setInterval(() => {
11      index += 1;
12
13      reply.sse({ id: String(index), data: `Some message ${index}` });
14
15      if (index === 10) {
16        clearInterval(interval);
17      }
18    }, 1000);
19
20    req.raw.on('close', () => {
21      clearInterval(interval);
22      app.log.info('Client disconnected');
23      reply.sse({ event: 'close' });
24    });
25  });
26}) as FastifyPluginAsyncTypebox;

Benchmarks

oha v1.4.5

1$ oha -c 500 -z 10s --no-tui http://0.0.0.0:3000/api/hello-world

	Version	Language	Router	Requests/sec
hyper	1.4.1	Rust	✗	56,175.6102
warp	0.3.7	Rust	✓	55,868.5861
axum	0.7.7	Rust	✓	54,588.2828
bun	1.1.30	TypeScript/Bun	✗	54,098.4841
graphul	1.0.1	Rust	✓	53,949.4400
poem	3.1.0	Rust	✓	53,849.0781
uws	20.48.0	JavaScript/Node	✗	52,802.8029
elysia	1.1.17	TypeScript/Bun	✓	52,257.3305
				~ 5.5k ~
hyper-express	6.17.2	JavaScript/Node	✓	46,745.4887
hono	4.6.3	TypeScript/Bun	✓	46,685.6014
nhttp	2.0.2	TypeScript/Deno	✓	44,874.2535
deno	2.0.0	TypeScript/Deno	✗	44,753.8552
hono	4.6.3	TypeScript/Deno	✓	43,280.7544
				~ 9.2k ~
h3	1.12.0	TypeScript/Bun	✓	34,043.4693
fastify-uws	1.0.0	JavaScript/Node	✓	31,295.8715
polka	1.0.0-next.28	JavaScript/Node	✓	31,086.5543
oak	17.0.0	TypeScript/Deno	✓	30,730.7971
node	20.18.0	JavaScript/Node	✗	29,230.1719
oak	17.0.0	TypeScript/Bun	✓	27,449.3417
fastify	5.0.0	JavaScript/Node	✓	27,408.6679
hono	4.6.3	JavaScript/Node	✓	25,138.5659
				~ 4.9k ~
h3	1.12.0	JavaScript/Node	✓	20,193.2311
				~ 9.2k ~
express	4.21.0	JavaScript/Node	✓	10,949.1532