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