Hono RPC is a built-in feature of the Hono web framework that enables end‑to‑end type safety between your backend API and frontend client by automatically sharing and synchronising API specifications—without any code generation.

Let's see how we can create a monorepo with Hono API and a React app.

Monorepo

First, we need to create a folder for our new monorepo.

mkdir hono-rpc-and-react-monorepo
cd hono-rpc-and-react-monorepo

Check that we have the latest pnpm installed.

npm i -g pnpm@latest

Init new project.

pnpm init

Add the pnpm-workspace.yaml workspace configuration file.

packages:
  - 'api'
  - 'web'

Hono

Now we can create an empty Hono project.

pnpm create hono@latest api

We need to update the api/package.json.

{
  "name": "@repo/api",
  "type": "module",
  "main": "src/index.ts",
  "scripts": {
    "dev": "tsx watch src/index.ts",
    "build": "tsc --build",
    "start": "node dist/index.js"
  },
  "dependencies": {
    "@hono/node-server": "^1.19.14",
    "hono": "^4.12.18"
  },
  "devDependencies": {
    "@types/node": "^20.11.17",
    "tsx": "^4.7.1",
    "typescript": "^5.8.3"
  }
}

The name and build props were changed, and the main prop was added.

Let's export the hono application type from api/src/index.ts. We will need it to create a hono client inside our React app.

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

const app = new Hono()
  .get('/api', (c) => {
    return c.text('Hello Hono!')
  })

export type AppType = typeof app

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

Notice we are adding route handlers to the new Hono() object itself, so TypeScript could figure out the correct types for the hono client. Also, we changed the route from / to /api.

React

Let's create a Vite React project.

pnpm create vite

Now we need to install hono.

pnpm i hono

And add @repo/api as a development dependency to the web/package.json.

...
  "devDependencies": {
    "@repo/api": "workspace:*",
    ...

Install added dependency.

pnpm i

Let's update the web/vite.config.ts, so it would proxy all requests to our api in the development mode (add the server prop).

import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'

// https://vite.dev/config/
export default defineConfig({
  plugins: [react()],
  server: {
    proxy: {
      '/api': {
        target: 'http://localhost:3000',
        changeOrigin: true
      }
    }
  }
})

Now we can add a hono client to the web/src/App.tsx.

...
import { hc } from 'hono/client'
import type { AppType } from '@repo/api'

const client = hc<AppType>('/')

function App() {
  const [count, setCount] = useState('')

  useEffect(() => {
    const fetchData = async () => {
      const res = await client.index.$get()
      if (res.ok) {
        const data = await res.text()
        setCount(data)
      }
    }

    fetchData()
  }, [])
  ...

Test Time

Let's add one command to the root package.json to run both the api and web in development.

...
  "scripts": {
    "dev": "pnpm run --parallel dev"
  ...

Now we can start our backend and frontend apps with one command.

pnpm dev

Open your favorite web browser and navigate to http://localhost:5173. You will see the default Vite React page with Count is Hello Hono! text. The Hello Hono! was successfully fetched from our api. 🎉

Please check the repo and happy hacking! 💻

Credits

Photo by Janis Ringli on Unsplash