FixLag - Gaming VPN Client

FixLag is a desktop application designed to reduce latency and jitter in online games like Valorant by routing traffic through optimized WireGuard servers. It features a modern, dark-themed UI built with Compose Multiplatform and communicates with a background Windows Service for secure tunnel management.

Features

• Optimized Routing: Connects to dedicated gaming servers (e.g., Mumbai, Singapore) using the WireGuard protocol.
• Real-time Metrics: Displays live Ping and Jitter stats to monitor connection quality.
• Session Stats: Tracks historical data for your connections including duration, average ping, and max jitter.
• Modern UI: A sleek, dark-themed interface with animated transitions and a custom window frame.
• Secure:
  • Uses a background Windows Service for privileged network operations.
  • Communicates via secure Named Pipes (IPC).
  • Encrypts sensitive configuration (keys, endpoints) on disk using AES-GCM.
  • Protects the encryption key using Windows ACLs.
• Live Logs & Debug Tools: View real-time service and UI logs, and access advanced tools via the Dev Mode flag.

Architecture

The project follows a clean architecture using Kotlin Multiplatform (KMP) targeting Desktop (JVM).

• UI Layer: Built with Compose Multiplatform.
  • HomeWindow: Main dashboard with server selection, metrics, and power button.
  • SplashWindow: Handles initialization and key generation.
  • ViewModels: Manage state and business logic (HomeViewModel, SplashViewModel).
• Domain/Data Layer:
  • Persistence: AppPreferences stores encrypted configuration using DataStore. EncryptionManager handles AES-GCM encryption.
  • IPC: IpcUseCase and FixLagIpcClient handle communication with the Windows Service via Named Pipes.
  • Command Execution: CommandUseCase executes system commands (e.g., ping, wg.exe).
• Dependency Injection: Uses Koin for modularity and testability.

Prerequisites

• OS: Windows 10/11 (64-bit).
• WireGuard: The app requires wg.exe to be present in the files/ directory or system path for key generation.
• FixLag Service: The companion Windows Service must be installed and running to handle the actual VPN connection.
  • Get the Service: FixLagAgent-Windows on GitHub

Build and Run

Development

1. Ensure wg.exe is placed in the files/ directory in the project root.

2. Provide a CLIENT_PRIVATE_KEY in your local.properties file for build config generation.

3. Run the app using Gradle:

   .\gradlew.bat :composeApp:run

   Tip: To enable the Debug tab, run with -DIS_DEV=true VM option.

Production Build

To create a distributable executable (MSI/EXE):

.\gradlew.bat :composeApp:packageDistributionForCurrentOS

The output will be located in composeApp/build/compose/binaries/main/. For a full installation setup, use the provided Inno Setup script (installer.iss).

Configuration

On first launch, the app generates a WireGuard key pair (wg genkey / wg pubkey) and initializes a default configuration. This data is stored securely in: C:\Users\<User>\AppData\Local\fixlag_app\fixlag.preferences_pb

The encryption key is securely stored in: C:\ProgramData\FixLag\secret.key

Logs

• App Logs: Displayed in the "Logs" tab within the application.
• Service Logs: Read from C:\ProgramData\FixLag\logs\agent.log.
• UI Logs: Read from C:\Users\<User>\AppData\Roaming\FixLag\ui.log (in Dev mode).

Tech Stack

• Language: Kotlin
• UI Framework: Compose Multiplatform
• DI: Koin
• Async: Kotlin Coroutines & Flow
• Storage: DataStore Preferences
• Serialization: Kotlinx Serialization

Server Setup

If you want to host your own routing servers, please refer to the Server Setup Guide.

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Built with ❤️ for Gamers.