fastify-uws

A performant HTTP and WebSocket server for Fastify with uWebSockets.

Installation

Install fastify-uws with your favorite package manager:

$ npm i fastify-uws
# or
$ yarn add fastify-uws
# or
$ pnpm i fastify-uws
# or
$ bun add fastify-uws

Supported

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

Usage

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

// app.ts
import fastify from 'fastify';
import { serverFactory } from 'fastify-uws'; // Import here

import router from '~/plugins/router';

export default () => {
  const app = fastify({
    logger: {
      transport: {
        target: '@fastify/one-line-logger',
      },
    },
    serverFactory, // And use here
  });

  app.register(router);

  return app;
};

// server.ts
import app from './app';

const server = app();

const start = async () => {
  try {
    await server.listen({
      host: '127.0.0.1',
      port: 3000,
    });
  } catch (err) {
    server.log.error(err);
    process.exit(1);
  }
};

start();

Use Fetch

// src/routes/hello-http/+handler.ts
import type { FastifyPluginAsyncTypebox } from '@fastify/type-provider-typebox';
import { Type } from '@sinclair/typebox';

export default (async (app) => {
  app.get(
    '',
    {
      schema: {
        response: {
          200: Type.Object({
            message: Type.String(),
          }),
        },
      },
    },
    async (req, reply) => {
      return reply.send({
        message: 'Hello, World!',
      });
    },
  );
}) as FastifyPluginAsyncTypebox;

With FormData

// app.ts
import multipart from '@fastify/multipart';

app.register(multipart);

// src/routes/hello-fd/+handler.ts
import type { FastifyPluginAsyncTypebox } from '@fastify/type-provider-typebox';
import fs from 'node:fs';
import { pipeline } from 'node:stream/promises';

export default (async (app) => {
  app.post('', async (req, reply) => {
    const data = await req.file();

    data.file; // stream
    data.fields; // other parsed parts
    data.fieldname;
    data.filename;
    data.encoding;
    data.mimetype;

    await pipeline(data.file, fs.createWriteStream(data.filename));
    // or
    // await data.toBuffer(); // Buffer

    return reply.send({ message: 'ok' });
  });
}) as FastifyPluginAsyncTypebox;

Use WebSocket

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

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

// app.ts
import { websocket } from 'fastify-uws';

app.register(websocket);

// src/routes/hello-ws/+handler.ts
import type { FastifyPluginAsyncTypebox } from '@fastify/type-provider-typebox';

export default (async (app) => {
  app.get('', { websocket: true }, (socket, request) => {
    app.log.info('Client connected');

    socket.on('message', (message: MessageEvent) => {
      console.log(`Client message: ${message}`);
      socket.send('Hello from Fastify!');
    });

    socket.on('close', () => {
      app.log.info('Client disconnected');
    });
  });
}) as FastifyPluginAsyncTypebox;

Use EventSource

// app.ts
import { eventsource } from 'fastify-uws';

app.register(eventsource);

// src/routes/hello-sse/+handler.ts
import type { FastifyPluginAsyncTypebox } from '@fastify/type-provider-typebox';

export default (async (app) => {
  app.get('', (req, reply) => {
    let index = 0;

    reply.sse({ id: String(index), data: `Some message ${index}` });

    const interval = setInterval(() => {
      index += 1;

      reply.sse({ id: String(index), data: `Some message ${index}` });

      if (index === 10) {
        clearInterval(interval);
      }
    }, 1000);

    req.raw.on('close', () => {
      clearInterval(interval);
      app.log.info('Client disconnected');
      reply.sse({ event: 'close' });
    });
  });
}) as FastifyPluginAsyncTypebox;

Benchmarks

oha v1.4.5

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

	Version	Language	Router	Requests/sec
hyper	1.4.0	Rust	✗	54,852.5710
viz	0.8.8	Rust	✓	54,767.9522
salvo	0.68.4	Rust	✓	54,550.5513
warp	0.3.7	Rust	✓	54,412.2379
graphul	1.0.1	Rust	✓	53,995.5395
axum	0.7.5	Rust	✓	53,730.4898
poem	3.0.1	Rust	✓	53,011.8436
uws	20.44.0	JavaScript/Node	✗	52,569.3922
bun	1.1.18	TypeScript/Bun	✗	51,434.7305
rocket	0.5.1	Rust	✓	50,213.6357
actix-web	4.8.0	Rust	✓	48,072.2446
nhttp	2.0.2	TypeScript/Deno	✓	47,501.5437
elysia	1.0.27	TypeScript/Bun	✓	45,774.7223
hyper-express	6.16.4	JavaScript/Node	✓	44,410.8668
hono	4.4.12	TypeScript/Bun	✓	44,272.6046
hono	4.4.12	TypeScript/Deno	✓	42,049.4956
deno	1.44.4	TypeScript/Deno	✗	40,959.3045
				~
h3	1.12.0	TypeScript/Bun	✓	33,830.7969
fastify-uws	0.8.1	JavaScript/Node	✓	32,644.0851
oak	16.1.0	TypeScript/Deno	✓	31,757.4717
h3	1.12.0	JavaScript/Node	✓	30,557.6711
polka	1.0.0-next.25	JavaScript/Node	✓	30,074.4079
node	20.15.0	JavaScript/Node	✗	28,620.6313
oak	16.1.0	TypeScript/Bun	✓	26,580.4056
fastify	4.28.1	JavaScript/Node	✓	25,896.2251
hono	4.4.12	JavaScript/Node	✓	23,898.3443
				~
express	4.19.2	JavaScript/Node	✓	10,599.2688