Server Function Bridge

Run Node.js server functions directly from client-side JavaScript using WebSockets - without building an API or setting up endpoints.

Features

• ✅ Call server-side Node.js functions directly from client code
• ✅ No API endpoints to maintain
• ✅ No build process modifications required
• ✅ Lazy-loading WebSocket connection
• ✅ Works in both development and production environments
• ✅ Secure SSL/TLS communication
• ✅ Detailed logging and error handling

Installation

npm install server-function-bridge

Quick Start

Server-Side Setup

// server.js
const express = require('express');
const { setupServerFunctionBridge } = require('server-function-bridge/server');
const path = require('path');

// Create your Express app
const app = express();

// Setup the Server Function Bridge
setupServerFunctionBridge(app, {
  port: 8080, // WebSocket port (default: 8080)
  scriptsDir: path.join(__dirname, 'server-functions'), // Where your functions are stored
  ssl: {
    key: fs.readFileSync('path/to/key.pem'),
    cert: fs.readFileSync('path/to/cert.pem')
  }
});

// Your existing app setup
app.use(express.static('public'));

// Start your server
app.listen(3000, () => {
  console.log('Server running on port 3000');
});

Create Server Functions

Create server-side functions in your server-functions directory:

// server-functions/helloWorld.js
module.exports = async function helloWorld(name) {
  return {
    message: `Hello, ${name || 'World'}!`,
    timestamp: new Date().toISOString()
  };
};

Client-Side Usage

// In your React component or JavaScript file
import { serverCall } from 'server-function-bridge/client';

// Create a server function reference
const helloWorld = serverCall('helloWorld');

// Call it like a normal function
const result = await helloWorld('John');
console.log(result.message); // "Hello, John!"

Detailed Documentation

Server Configuration Options

The setupServerFunctionBridge function accepts the following options:

Option	Type	Default	Description
port	Number	8080	WebSocket server port
scriptsDir	String	path.join(process.cwd(), 'src', 'scripts')	Directory containing server functions
ssl	Object	undefined	SSL configuration with key and cert properties
logging	Boolean/Object	{ enabled: true, detailed: false }	Logging configuration
path	String	/ws	WebSocket server path
authFunction	Function	undefined	Optional function for connection authentication

Client Configuration Options

The serverCall function accepts the following options:

// With custom options
const helloWorld = serverCall('helloWorld', {
  timeout: 5000, // 5 second timeout (default: 10000)
  reconnect: true, // Auto-reconnect on disconnection
  debug: true // Verbose logging
});

Advanced Usage

Connection Management

import { getConnection, closeConnection } from 'server-function-bridge/client';

// Get the WebSocket connection
const connection = getConnection();

// Manually close the connection when done
closeConnection();

Custom WebSocket URL

import { configure, serverCall } from 'server-function-bridge/client';

// Configure custom WebSocket URL
configure({
  url: 'wss://api.example.com/websocket',
  debug: true
});

// Now use serverCall as normal
const helloWorld = serverCall('helloWorld');

Security Considerations

• The WebSocket server accepts connections from any origin by default
• Consider implementing the authFunction option for authentication
• Use HTTPS and WSS protocols in production
• Be careful about which server functions you expose

License

MIT