Adding a Backend

The extension uses Java's ServiceLoader mechanism for backend discovery, making it straightforward to add new AI backends without modifying core code.

Steps

1. Implement the Backend Adapter

Create two classes:

• AiBackendFactory: Factory that creates backend instances. Provides metadata (ID, display name, type).

• AiBackend: The actual backend that implements send() to communicate with the AI.

• AgentConnection: Interface for send/receive operations.

For HTTP backends, you can also implement DiagnosableConnection to expose exit codes and output for debugging.

2. Register via ServiceLoader

Create a file at:

META-INF/services/com.six2dez.burp.aiagent.backends.AiBackendFactory

Add the fully qualified class name of your factory:

com.example.mybackend.MyBackendFactory

3. Add UI Configuration Fields (Optional)

If your backend needs custom settings (API URL, model name, etc.), add configuration keys to AgentSettings.kt and corresponding UI fields to SettingsPanel.kt.

4. Ensure Audit Logging

Use the backend ID consistently so audit logs can trace which backend was used for each interaction.

5. Package and Deploy

Option A: Built-in Add your backend to the main source tree and rebuild the extension JAR.

Option B: Drop-in JAR Package your backend as a standalone JAR and place it in ~/.burp-ai-agent/backends/. The BackendRegistry will discover it automatically via URLClassLoader on startup.

Backend Interface

interface AiBackendFactory {
    val id: String           // Unique identifier (e.g., "my-backend")
    val displayName: String  // UI display name
    fun create(config: BackendLaunchConfig): AiBackend
}

interface AiBackend {
    fun send(prompt: String): AgentConnection
}

interface AgentConnection {
    fun receive(): String    // Blocking read of response
    fun close()              // Clean up resources
}

Tips

• Follow existing backend implementations as examples (e.g., OllamaBackendFactory for HTTP, CodexCliBackendFactory for CLI).

• HTTP backends should handle connection errors and timeouts gracefully.

• CLI backends should manage process lifecycle (stdin/stdout communication, exit handling).