🚀 React Native Dev Proxy

Automatically detect React Native platform and rewrite API URLs for local development

🎯 The Problem This Solves

When developing React Native apps, you often face this frustrating issue:

// ❌ This works in iOS Simulator but fails on Android device
const response = await fetch('http://localhost:8000/api/users');
// Error: Network request failed

Why does this happen?

• iOS Simulator can access localhost directly
• Android Emulator needs 10.0.2.2 instead of localhost
• Physical devices need your computer's actual IP address
• Different platforms require different URL configurations

✨ The Solution

react-native-dev-proxy automatically handles URL rewriting for you:

// ✅ This works everywhere - iOS, Android, simulators, and devices
import { withDevProxy } from 'react-native-dev-proxy';
import axios from 'axios';

const api = withDevProxy(axios.create({
  baseURL: 'http://localhost:8000',
}), { strategy: 'auto' });

const users = await api.get('/api/users'); // Works everywhere!

🚀 Quick Start

1. Install the Package

npm install react-native-dev-proxy
# or
yarn add react-native-dev-proxy

2. Apply the Patch

npx rn-dev-proxy patch

Running the patch command to configure your React Native project

3. Wrap Your API Client

import { withDevProxy } from 'react-native-dev-proxy';
import axios from 'axios';

const api = withDevProxy(
  axios.create({
    baseURL: 'http://localhost:8000',
    timeout: 10000,
  }),
  {
    strategy: 'auto', // Automatically choose the best method
    log: true,        // Show URL rewriting logs
  }
);

// Now your API calls work everywhere!
const users = await api.get('/api/users');

See how easy it is to integrate with your existing code

📱 Platform Support

Platform	Original URL	Rewritten URL	Status
iOS Simulator	localhost:8000	localhost:8000	✅ Works
Android Emulator	localhost:8000	10.0.2.2:8000	✅ Works
Physical iOS Device	localhost:8000	192.168.1.100:8000	✅ Works
Physical Android Device	localhost:8000	192.168.1.100:8000	✅ Works

See how the proxy automatically adapts to different platforms

Platform Screenshots

iOS Simulator working with localhost

Android Emulator working with 10.0.2.2

Physical device working with IP address

🛠️ API Reference

withDevProxy(apiClient, options)

Wraps your API client with automatic URL rewriting.

Parameters:

• `apiClient: Your API client (axios, fetch, etc.)
• options: Configuration object

Options:

{
  strategy: 'auto' | 'lan' | 'tunnel', // URL rewriting strategy
  log: boolean,                         // Enable logging
  baseURL: string,                      // Base URL to rewrite
}

makeFetch(options)

Creates a fetch wrapper with automatic URL rewriting.

Parameters:

• options: Configuration object (same as above)

🎯 Usage Examples

Axios Integration

import { withDevProxy } from 'react-native-dev-proxy';
import axios from 'axios';

const api = withDevProxy(
  axios.create({
    baseURL: 'http://localhost:8000',
    timeout: 10000,
  }),
  { strategy: 'auto', log: true }
);

// All these work automatically on any platform
const users = await api.get('/api/users');
const user = await api.post('/api/users', { name: 'John' });
const updated = await api.put('/api/users/1', { name: 'Jane' });
const deleted = await api.delete('/api/users/1');

Fetch Integration

import { makeFetch } from 'react-native-dev-proxy';

const fetchApi = makeFetch({
  baseURL: 'http://localhost:8000',
  strategy: 'auto',
  log: true,
});

// Works everywhere
const response = await fetchApi('/api/users');
const data = await response.json();

React Hook Example

import { useState, useEffect } from 'react';
import { withDevProxy } from 'react-native-dev-proxy';
import axios from 'axios';

const api = withDevProxy(
  axios.create({ baseURL: 'http://localhost:8000' }),
  { strategy: 'auto', log: true }
);

const useUsers = () => {
  const [users, setUsers] = useState([]);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    const fetchUsers = async () => {
      try {
        const response = await api.get('/api/users');
        setUsers(response.data);
      } catch (error) {
        console.error('Failed to fetch users:', error);
      } finally {
        setLoading(false);
      }
    };

    fetchUsers();
  }, []);

  return { users, loading };
};

🔧 Configuration Options

Strategy Options:

• auto (recommended): Automatically detects the best method
• lan: Always uses your computer's IP address
• tunnel: Uses tunneling service (ngrok, etc.)

Logging:

// Enable detailed logging
const api = withDevProxy(axios, { 
  strategy: 'auto', 
  log: true 
});

// Console output:
// 🔧 [DevProxy] Detected platform: android
// 🔧 [DevProxy] Using strategy: lan
// 🔧 [DevProxy] Rewriting URL: http://localhost:8000/api/users
// 🔧 [DevProxy] To: http://192.168.1.100:8000/api/users
// 📡 [DevProxy] Request successful: 200 OK

🧪 Testing Your Setup

Create a simple test component:

import React, { useState } from 'react';
import { View, Text, TouchableOpacity, StyleSheet } from 'react-native';
import { withDevProxy } from 'react-native-dev-proxy';
import axios from 'axios';

const api = withDevProxy(
  axios.create({ baseURL: 'http://localhost:8000' }),
  { strategy: 'auto', log: true }
);

const TestComponent = () => {
  const [result, setResult] = useState('');

  const testAPI = async () => {
    try {
      const response = await api.get('/api/ping');
      setResult(`✅ Success: ${JSON.stringify(response.data)}`);
    } catch (error) {
      setResult(`❌ Error: ${error.message}`);
    }
  };

  return (
    <View style={styles.container}>
      <TouchableOpacity style={styles.button} onPress={testAPI}>
        <Text style={styles.buttonText}>Test API</Text>
      </TouchableOpacity>
      <Text style={styles.result}>{result}</Text>
    </View>
  );
};

const styles = StyleSheet.create({
  container: { flex: 1, justifyContent: 'center', alignItems: 'center' },
  button: { backgroundColor: '#007AFF', padding: 15, borderRadius: 8 },
  buttonText: { color: 'white', fontWeight: 'bold' },
  result: { marginTop: 20, textAlign: 'center' },
});

export default TestComponent;

Watch the test component in action across different platforms

🔧 Advanced Configuration

Custom Base URL

const api = withDevProxy(axios, {
  baseURL: 'http://localhost:3000', // Your custom server
  strategy: 'auto',
  log: true,
});

Environment-Specific Configuration

const isDevelopment = __DEV__;
const baseURL = isDevelopment 
  ? 'http://localhost:8000' 
  : 'https://api.yourapp.com';

const api = withDevProxy(axios.create({ baseURL }), {
  strategy: isDevelopment ? 'auto' : 'lan',
  log: isDevelopment,
});

🐛 Troubleshooting

Common Issues:

1. "Network request failed" error:

• Ensure your server is running on the correct port
• Check that adb reverse is set up for Android
• Verify your computer and device are on the same network

2. URLs not being rewritten:

• Make sure you're using the wrapped API client
• Check that the patch was applied correctly
• Verify the baseURL matches your server

3. iOS Simulator issues:

• Try using 127.0.0.1 instead of localhost
• Check your server's CORS settings

Debug Steps:

1. Enable logging:

const api = withDevProxy(axios, { log: true });

2. Check console output:

🔧 [DevProxy] Detected platform: android
🔧 [DevProxy] Using strategy: lan
🔧 [DevProxy] Rewriting URL: http://localhost:8000/api/users

3. Test with curl:

curl http://localhost:8000/api/users

See how to debug and fix common issues

Console Logging

Detailed console logging showing URL rewriting

Patch Command Output

Patch command successfully configuring your project

Code Editor Integration

Easy integration in your code editor

Network Architecture

Visual representation of how the proxy works

Error Handling

Comprehensive error handling and debugging

📚 Examples Repository

Check out our examples repository for:

• Complete React Native app examples
• Different API client integrations
• Testing setups
• Production configurations

🤝 Contributing

We welcome contributions! Please see our Contributing Guide for details.

📄 License

MIT License - see LICENSE file for details.

🙏 Acknowledgments

• React Native community for the amazing platform
• Contributors who helped make this package better
• All the developers who faced this problem before us

📞 Support

• 📖 Documentation
• 🐛 Issues
• 💬 Discussions
• 📧 Email Support

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Made with ❤️ for the React Native community