Create a Simple API Proxy to Bypass CORS Issues (Node.js/Express)

// 1. Install Express and node-fetch: npm install express node-fetch
// 2. Create server.js:

const express = require('express');
const fetch = require('node-fetch');
const cors = require('cors'); // Optional: for allowing specific origins to access this proxy

const app = express();
const PORT = process.env.PORT || 3001;

// Use CORS middleware if your frontend is on a different origin than this proxy
// app.use(cors({ origin: 'http://localhost:3000' })); 
app.use(cors()); // Allow all origins for simplicity in example

// Define the target API base URL (e.g., a third-party API)
const TARGET_API_BASE_URL = 'https://api.example.com'; // Replace with your actual target API
const API_KEY = process.env.API_KEY || 'YOUR_SECURE_API_KEY'; // Load from .env in production

app.get('/api-proxy/:endpoint*', async (req, res) => {
  const endpoint = req.params.endpoint + req.params[0]; // Capture the full endpoint path
  const targetUrl = `${TARGET_API_BASE_URL}/${endpoint}${req.url.includes('?') ? '&' : '?'}_=${API_KEY}`; // Append API key

  console.log(`Proxying request to: ${targetUrl}`);

  try {
    const apiResponse = await fetch(targetUrl, {
      method: req.method,
      headers: { 'Content-Type': 'application/json' }
      // Add other headers as needed, e.g., Authorization: `Bearer ${API_KEY}` if target API uses it in header
    });
    
    // Forward headers from target API to client, e.g., Content-Type
    res.set(apiResponse.headers.raw());
    res.status(apiResponse.status).send(await apiResponse.text());
  } catch (error) {
    console.error('Proxy error:', error);
    res.status(500).json({ error: 'Failed to proxy request' });
  }
});

app.listen(PORT, () => {
  console.log(`Proxy server listening on port ${PORT}`);
});

// Frontend JavaScript to use the proxy:
// fetch('/api-proxy/data?param=value')
//   .then(response => response.json())
//   .then(data => console.log(data))
//   .catch(error => console.error('Error fetching via proxy:', error));