Last Updated: 3/7/2026

Bun

Bun is another JavaScript runtime. Bun includes a trans compiler, we can write the code with TypeScript. Hono also works on Bun.

1. Install Bun

To install bun command, follow the instruction in the official web site .

2. Setup

A starter for Bun is available. Start your project with “bun create” command.


bun create hono@latest my-app

Move into my-app and install the dependencies.


cd my-app
bun install

3. Hello World

“Hello World” script is below. Almost the same as writing on other platforms.


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

4. Run

Run the command.


bun run dev

Then, access http://localhost:3000 in your browser.

Change port number

You can specify the port number with exporting the port.


import { Hono } from 'hono'
 
const app = new Hono()
app.get('/', (c) => c.text('Hello Bun!'))
 
export default app
 
export default {
  port: 3000,
  fetch: app.fetch,
}

Serve static files

To serve static files, use serveStatic imported 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'))
app.get('*', serveStatic({ path: './static/fallback.txt' }))

Testing

You can use bun:test for testing on Bun.


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)
  })
})

Then, run the command.


bun test index.test.ts