Node.js Adapter for Hono

This adapter @hono/node-server allows you to run your Hono application on Node.js. Initially, Hono wasn't designed for Node.js, but with this adapter, you can now use Hono on Node.js. It utilizes web standard APIs implemented in Node.js version 18 or higher.

Benchmarks

Hono is 3.5 times faster than Express.

Express:

$ bombardier -d 10s --fasthttp http://localhost:3000/

Statistics        Avg      Stdev        Max
  Reqs/sec     16438.94    1603.39   19155.47
  Latency        7.60ms     7.51ms   559.89ms
  HTTP codes:
    1xx - 0, 2xx - 164494, 3xx - 0, 4xx - 0, 5xx - 0
    others - 0
  Throughput:     4.55MB/s

Hono + @hono/node-server:

$ bombardier -d 10s --fasthttp http://localhost:3000/

Statistics        Avg      Stdev        Max
  Reqs/sec     58296.56    5512.74   74403.56
  Latency        2.14ms     1.46ms   190.92ms
  HTTP codes:
    1xx - 0, 2xx - 583059, 3xx - 0, 4xx - 0, 5xx - 0
    others - 0
  Throughput:    12.56MB/s

Requirements

It works on Node.js versions greater than 18.x. The specific required Node.js versions are as follows:

• 18.x => 18.14.1+
• 19.x => 19.7.0+
• 20.x => 20.0.0+

Essentially, you can simply use the latest version of each major release.

Installation

You can install it from the npm registry with npm command:

npm install @hono/node-server

Or use yarn:

yarn add @hono/node-server

Usage

Just import @hono/node-server at the top and write the code as usual. The same code that runs on Cloudflare Workers, Deno, and Bun will work.

import { serve } from '@hono/node-server'
import { Hono } from 'hono'

const app = new Hono()
app.get('/', (c) => c.text('Hono meets Node.js'))

serve(app, (info) => {
  console.log(`Listening on http://localhost:${info.port}`) // Listening on http://localhost:3000
})

For example, run it using ts-node. Then an HTTP server will be launched. The default port is 3000.

ts-node ./index.ts

Open http://localhost:3000 with your browser.

Options

port

serve({
  fetch: app.fetch,
  port: 8787, // Port number, default is 3000
})

createServer

import { createServer } from 'node:https'
import fs from 'node:fs'

//...

serve({
  fetch: app.fetch,
  createServer: createServer,
  serverOptions: {
    key: fs.readFileSync('test/fixtures/keys/agent1-key.pem'),
    cert: fs.readFileSync('test/fixtures/keys/agent1-cert.pem'),
  },
})

overrideGlobalObjects

The default value is true. The Node.js Adapter rewrites the global Request/Response and uses a lightweight Request/Response to improve performance. If you don't want to do that, set false.

serve({
  fetch: app.fetch,
  overrideGlobalObjects: false,
})

Middleware

Most built-in middleware also works with Node.js. Read the documentation and use the Middleware of your liking.

import { serve } from '@hono/node-server'
import { Hono } from 'hono'
import { prettyJSON } from 'hono/pretty-json'

const app = new Hono()

app.get('*', prettyJSON())
app.get('/', (c) => c.json({ 'Hono meets': 'Node.js' }))

serve(app)

Serve Static Middleware

Use Serve Static Middleware that has been created for Node.js.

import { serveStatic } from '@hono/node-server/serve-static'

//...

app.use('/static/*', serveStatic({ root: './' }))

Note that root must be relative to the current working directory from which the app was started. Absolute paths are not supported.

This can cause confusion when running your application locally.

Imagine your project structure is:

my-hono-project/
  src/
    index.ts
  static/
    index.html

Typically, you would run your app from the project's root directory (my-hono-project), so you would need the following code to serve the static folder:

app.use('/static/*', serveStatic({ root: './static' }))

Notice that root here is not relative to src/index.ts, rather to my-hono-project.

Options

rewriteRequestPath

If you want to serve files in ./.foojs with the request path /__foo/*, you can write like the following.

app.use(
  '/__foo/*',
  serveStatic({
    root: './.foojs/',
    rewriteRequestPath: (path: string) => path.replace(/^\/__foo/, ''),
  })
)

onNotFound

The onNotFound is useful for debugging. You can write a handle for when a file is not found.

app.use(
  '/static/*',
  serveStatic({
    root: './non-existent-dir',
    onNotFound: (path, c) => {
      console.log(`${path} is not found, request to ${c.req.path}`)
    },
  })
)

ConnInfo Helper

You can use the ConnInfo Helper by importing getConnInfo from @hono/node-server/conninfo.

import { getConnInfo } from '@hono/node-server/conninfo'

app.get('/', (c) => {
  const info = getConnInfo(c) // info is `ConnInfo`
  return c.text(`Your remote address is ${info.remote.address}`)
})

Accessing Node.js API

You can access the Node.js API from c.env in Node.js. For example, if you want to specify a type, you can write the following.

import { serve } from '@hono/node-server'
import type { HttpBindings } from '@hono/node-server'
import { Hono } from 'hono'

const app = new Hono<{ Bindings: HttpBindings }>()

app.get('/', (c) => {
  return c.json({
    remoteAddress: c.env.incoming.socket.remoteAddress,
  })
})

serve(app)

The APIs that you can get from c.env are as follows.

type HttpBindings = {
  incoming: IncomingMessage
  outgoing: ServerResponse
}

type Http2Bindings = {
  incoming: Http2ServerRequest
  outgoing: Http2ServerResponse
}

Direct response from Node.js API

You can directly respond to the client from the Node.js API. In that case, the response from Hono should be ignored, so return RESPONSE_ALREADY_SENT.

Note

This feature can be used when migrating existing Node.js applications to Hono, but we recommend using Hono's API for new applications.

import { serve } from '@hono/node-server'
import type { HttpBindings } from '@hono/node-server'
import { RESPONSE_ALREADY_SENT } from '@hono/node-server/utils/response'
import { Hono } from 'hono'

const app = new Hono<{ Bindings: HttpBindings }>()

app.get('/', (c) => {
  const { outgoing } = c.env
  outgoing.writeHead(200, { 'Content-Type': 'text/plain' })
  outgoing.end('Hello World\n')

  return RESPONSE_ALREADY_SENT
})

serve(app)

Related projects

• Hono - https://hono.dev
• Hono GitHub repository - https://github.com/honojs/hono

Author

Yusuke Wada https://github.com/yusukebe

License

MIT