🕵️‍♂️ fiddler network override #

A Flutter plugin to intercept and route all HTTP traffic through a custom proxy like Fiddler Everywhere, Charles Proxy, or Burp Suite for easy debugging and QA testing.

✨ Features #

• Globally override Dart HttpClient to route HTTP(S) traffic through a proxy.
• Load proxy configuration from:
  • External JSON config file (optional)
  • SharedPreferences with a built-in UI for manual input
• Simple bottom sheet UI to configure proxy:
  • Host & Port inputs with validation
  • Enable/disable toggle
  • Save & soft restart app to apply changes
• Cross-platform support (Android, iOS, macOS, Windows, Linux)
• No recompilation needed to change proxy after initial setup

🚀 Why Use fiddler? #

• Debug API calls by routing traffic through intercepting proxies
• Quickly enable/disable proxy on devices without rebuilds
• Useful for QA teams to test apps with various proxies
• Inspect, modify, and replay network requests easily

📦 Installation #

Add to your pubspec.yaml:

dependencies:
  fiddler_network_override: ^0.0.1

🎯 Usage #

To show the proxy configuration UI anywhere in your app:

showProxyInputSheet(context);

This sheet lets testers input the proxy host and port, toggle enable/disable, and save.

🗂 Proxy Configuration Sources #

1️⃣ External JSON File (Optional) #

Path: /storage/emulated/0/root/fiddler/config.json

Example JSON format:

{
  "proxy": "192.168.1.9:8866"
}

⚠️ Requires external storage read permission on Android.

2️⃣ SharedPreferences (Recommended) #

Proxy details stored under keys:

• fiddler_proxy = host:port
• fiddler_enabled = true or false

Managed via the Proxy Input Sheet UI.

🔧 How It Works #

• On app start, enableFiddlerIfConfigured() checks if proxy is enabled.
• If yes, fetches proxy from shared prefs or external file.
• Sets HttpOverrides.global to custom FiddlerNetworkOverride.
• All Dart HTTP clients route through the proxy.

📱 Proxy Input Sheet Features #

• Validates host (IP or domain) and port inputs
• Enable/disable proxy toggle switch
• Save & Restart button to apply new settings
• Works on Android and iOS with consistent design

🔒 Permissions #

• External JSON config file:

  • Requires READ_EXTERNAL_STORAGE permission on Android.
  • Not recommended for production apps.

• SharedPreferences config:

  • No extra permissions required.

🖥 Platform Support #

⚠️ Limitations & Notes #

• Only affects Dart HttpClient-based HTTP requests.
• Popular libraries like dio or http must be configured to use Dart HttpClient internally.
• Does not affect Web platform due to Flutter Web limitations.
• Proxy must be a valid and reachable address, or requests may fail.
• App restart required to fully apply new proxy settings.

🛡 License #

This project is licensed under the MIT License — see the LICENSE file for details.

💡 Future Enhancements #

• Soft restart without app exit
• Support for proxy authentication
• Certificate pinning and trust management
• UI improvements and dark mode support

🤝 Contributing #

Contributions are welcome! Feel free to open issues or pull requests.

To run example app:

cd example
flutter run

👤 Author #

Chandan Kumar Singh – GitHub | Email

Thank you for using fiddler_network_override! If you find this plugin useful, please ⭐️ star the repo and share with your peers.