ExpressJs

🦍 ExpressJs — Basic Example

A minimal real-time chat app demonstrating api-ape core concepts.

Quick Start

npm install
npm start

Open http://localhost:3000 in multiple browser windows.

Project Structure

ExpressJs/
├── backend.js        # Express server with api-ape + onConnect hook
├── api/
│   └── message.js    # Broadcast to other clients
├── index.html        # Chat UI
└── styles.css        # Styling

How It Works

Server (backend.js)

npm i api-ape

const express = require('express')
const { ape } = require('api-ape')  // Server initializer (named export)

const app = express()
const server = app.listen(3000)

ape(server, {
  where: 'api',
  onConnect: (socket, req, send) => {
    // Push history + user count on connect
    const { _messages } = require('./api/message')
    send('init', { history: _messages, users: ape.clients.size })
    ape.publish.users({ count: ape.clients.size })

    return {
      onDisconnect: () => ape.publish.users({ count: ape.clients.size })
    }
  }
})

Controller (api/message.js)

module.exports = function (data) {
    // Send to all other clients
    this.clients.forEach((client) => {
        if (client.clientId !== this.clientId) {
            client.send('message', data)
        }
    })
    return data  // Reply to sender
}

Client (index.html)

<script src="/api/ape.js"></script>
<script>
  // Receive init on connect (pushed by server)
  api.on('init', ({ data }) => {
    console.log('History:', data.history)
    console.log('Users online:', data.users)
  })
  
  // Listen for user count updates
  api.on('users', ({ data }) => console.log('Online:', data.count))
  
  // Listen for messages
  api.on('message', ({ data }) => console.log(data))
  
  // Send message
  api.message({ text: 'Hello!' })
</script>

Key Concepts Demonstrated

Concept	Example
Auto-wiring	ape(app, { where: 'api' }) loads api/*.js
onConnect hook	onConnect: (socket, req, send) => { ... }
Push on connect	send('init', { history, users })
Publish to channel	ape.publish.users({ count })
Send to specific clients	this.clients.forEach(c => c.send(...))
Listen	api.on('init', handler)

Zero dependencies: api-ape uses Node.js 24+ native WebSocket when available, otherwise a built-in RFC 6455 polyfill.