Cloudflare Pages

Cloudflare Pages is an edge platform for full-stack web applications. It serves static files and dynamic content provided by Cloudflare Workers.

Hono fully supports Cloudflare Pages. It introduces a delightful developer experience. Vite's dev server is fast, and deploying with Wrangler is super quick.

1. Setup

A starter for Cloudflare Pages is available. Start your project with "create-hono" command. Select cloudflare-pages template for this example.

npm

npm create hono@latest my-app

yarn

yarn create hono my-app

pnpm

pnpm create hono my-app

bun

bunx create-hono my-app

deno

deno run -A npm:create-hono my-app

Move into my-app and install the dependencies.

npm

cd my-app
npm i

yarn

cd my-app
yarn

pnpm

cd my-app
pnpm i

bun

cd my-app
bun i

Below is a basic directory structure.

./
├── package.json
├── public
│   └── static // Put your static files.
│       └── style.css // You can refer to it as `/static/style.css`.
├── src
│   ├── index.tsx // The entry point for server-side.
│   └── renderer.tsx
├── tsconfig.json
└── vite.config.ts

2. Hello World

Edit src/index.tsx like the following:

import { Hono } from 'hono'
import { renderer } from './renderer'

const app = new Hono()

app.get('*', renderer)

app.get('/', (c) => {
  return c.render(<h1>Hello, Cloudflare Pages!</h1>)
})

export default app

3. Run

Run the development server locally. Then, access http://localhost:5173 in your Web browser.

npm

npm run dev

yarn

yarn dev

pnpm

pnpm dev

bun

bun run dev

4. Deploy

If you have a Cloudflare account, you can deploy to Cloudflare. In package.json, $npm_execpath needs to be changed to your package manager of choice.

npm

npm run deploy

yarn

yarn deploy

pnpm

pnpm run deploy

bun

bun run deploy

Deploy via the Cloudflare dashboard with GitHub

1. Log in to the Cloudflare dashboard and select your account.
2. In Account Home, select Workers & Pages > Create application > Pages > Connect to Git.
3. Authorize your GitHub account, and select the repository. In Set up builds and deployments, provide the following information:

Configuration option	Value
Production branch	main
Build command	npm run build
Build directory	dist

Bindings

You can use Cloudflare Bindings like Variables, KV, D1, and others. In this section, let's use Variables and KV.

Create wrangler.toml

First, create wrangler.toml for local Bindings:

touch wrangler.toml

Edit wrangler.toml. Specify Variable with the name MY_NAME.

[vars]
MY_NAME = "Hono"

Create KV

Next, make the KV. Run the following wrangler command:

wrangler kv namespace create MY_KV --preview

Note down the preview_id as the following output:

{ binding = "MY_KV", preview_id = "abcdef" }

Specify preview_id with the name of Bindings, MY_KV:

[[kv_namespaces]]
binding = "MY_KV"
id = "abcdef"

Edit vite.config.ts

Edit the vite.config.ts:

import devServer from '@hono/vite-dev-server'
import adapter from '@hono/vite-dev-server/cloudflare'
import build from '@hono/vite-cloudflare-pages'
import { defineConfig } from 'vite'

export default defineConfig({
  plugins: [
    devServer({
      entry: 'src/index.tsx',
      adapter, // Cloudflare Adapter
    }),
    build(),
  ],
})

Use Bindings in your application

Use Variable and KV in your application. Set the types.

type Bindings = {
  MY_NAME: string
  MY_KV: KVNamespace
}

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

Use them:

app.get('/', async (c) => {
  await c.env.MY_KV.put('name', c.env.MY_NAME)
  const name = await c.env.MY_KV.get('name')
  return c.render(<h1>Hello! {name}</h1>)
})

In production

For Cloudflare Pages, you will use wrangler.toml for local development, but for production, you will set up Bindings in the dashboard.

Client-side

You can write client-side scripts and import them into your application using Vite's features. If /src/client.ts is the entry point for the client, simply write it in the script tag. Additionally, import.meta.env.PROD is useful for detecting whether it's running on a dev server or in the build phase.

app.get('/', (c) => {
  return c.html(
    <html>
      <head>
        {import.meta.env.PROD ? (
          <script type='module' src='/static/client.js'></script>
        ) : (
          <script type='module' src='/src/client.ts'></script>
        )}
      </head>
      <body>
        <h1>Hello</h1>
      </body>
    </html>
  )
})

In order to build the script properly, you can use the example config file vite.config.ts as shown below.

import pages from '@hono/vite-cloudflare-pages'
import devServer from '@hono/vite-dev-server'
import { defineConfig } from 'vite'

export default defineConfig(({ mode }) => {
  if (mode === 'client') {
    return {
      build: {
        rollupOptions: {
          input: './src/client.ts',
          output: {
            entryFileNames: 'static/client.js',
          },
        },
      },
    }
  } else {
    return {
      plugins: [
        pages(),
        devServer({
          entry: 'src/index.tsx',
        }),
      ],
    }
  }
})

You can run the following command to build the server and client script.

vite build --mode client && vite build

Cloudflare Pages Middleware

Cloudflare Pages uses its own middleware system that is different from Hono's middleware. You can enable it by exporting onRequest in a file named _middleware.ts like this:

// functions/_middleware.ts
export async function onRequest(pagesContext) {
  console.log(`You are accessing ${pagesContext.request.url}`)
  return await pagesContext.next()
}

Using handleMiddleware, you can use Hono's middleware as Cloudflare Pages middleware.

// functions/_middleware.ts
import { handleMiddleware } from 'hono/cloudflare-pages'

export const onRequest = handleMiddleware(async (c, next) => {
  console.log(`You are accessing ${c.req.url}`)
  await next()
})

You can also use built-in and 3rd party middleware for Hono. For example, to add Basic Authentication, you can use Hono's Basic Authentication Middleware.

// functions/_middleware.ts
import { handleMiddleware } from 'hono/cloudflare-pages'
import { basicAuth } from 'hono/basic-auth'

export const onRequest = handleMiddleware(
  basicAuth({
    username: 'hono',
    password: 'acoolproject',
  })
)

If you want to apply multiple middleware, you can write it like this:

import { handleMiddleware } from 'hono/cloudflare-pages'

// ...

export const onRequest = [
  handleMiddleware(middleware1),
  handleMiddleware(middleware2),
  handleMiddleware(middleware3),
]

Accessing EventContext

You can access EventContext object via c.env in handleMiddleware.

// functions/_middleware.ts
import { handleMiddleware } from 'hono/cloudflare-pages'

export const onRequest = [
  handleMiddleware(async (c, next) => {
    c.env.eventContext.data.user = 'Joe'
    await next()
  }),
]

Then, you can access the data value in via c.env.eventContext in the handler:

// functions/api/[[route]].ts
import type { EventContext } from 'hono/cloudflare-pages'
import { handle } from 'hono/cloudflare-pages'

// ...

type Env = {
  Bindings: {
    eventContext: EventContext
  }
}

const app = new Hono<Env>()

app.get('/hello', (c) => {
  return c.json({
    message: `Hello, ${c.env.eventContext.data.user}!`, // 'Joe'
  })
})

export const onRequest = handle(app)