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getting-startedBun

Last Updated: 3/11/2026

Bun

Bun  is a fast JavaScript runtime with built-in TypeScript support. Hono works seamlessly on Bun.

Install Bun

Follow the instructions at bun.com  to install the bun command.

Setup

Create a new Bun project:

bun create hono@latest my-app

Select bun when prompted, then install dependencies:

cd my-app
bun install

Existing Project

To add Hono to an existing Bun project:

bun add hono

Add the dev script to package.json:

{
  "scripts": {
    "dev": "bun run --hot src/index.ts"
  }
}

Hello World

Create src/index.ts:

import { Hono } from 'hono'
 
const app = new Hono()
app.get('/', (c) => c.text('Hello Bun!'))
 
export default app

Run Locally

Start the development server:

bun run dev

Access http://localhost:3000 in your browser.

Change Port

Export a port property:

import { Hono } from 'hono'
 
const app = new Hono()
app.get('/', (c) => c.text('Hello Bun!'))
 
export default {
  port: 8787,
  fetch: app.fetch,
}

Serve Static Files

Use serveStatic from hono/bun:

import { serveStatic } from 'hono/bun'
 
const app = new Hono()
 
app.use('/static/*', serveStatic({ root: './' }))
app.use('/favicon.ico', serveStatic({ path: './favicon.ico' }))
app.get('/', (c) => c.text('You can access: /static/hello.txt'))

Directory structure:

./
├── favicon.ico
├── src
└── static
    ├── hello.txt
    └── images
        └── logo.png

Options

rewriteRequestPath: Map URLs to different paths:

app.get(
  '/static/*',
  serveStatic({
    root: './',
    rewriteRequestPath: (path) => path.replace(/^\/static/, '/statics'),
  })
)

mimes: Add custom MIME types:

app.get(
  '/static/*',
  serveStatic({
    mimes: {
      m3u8: 'application/vnd.apple.mpegurl',
      ts: 'video/mp2t',
    },
  })
)

precompressed: Serve pre-compressed files:

app.get(
  '/static/*',
  serveStatic({
    precompressed: true,
  })
)

Testing

Use bun:test for testing:

import { describe, expect, it } from 'bun:test'
import app from '.'
 
describe('My first test', () => {
  it('Should return 200 Response', async () => {
    const req = new Request('http://localhost/')
    const res = await app.fetch(req)
    expect(res.status).toBe(200)
  })
})

Run tests:

bun test index.test.ts
NodejsMiddleware