ai-assistant

AI Assistant plugin for CodeOnTheGo

An in-IDE AI chat assistant with tool calling. It provides the chat UI, settings, and the agent tool-loop (read/write files, list/search the project, add dependencies, run Gradle sync, etc.), and delegates all model inference to the sibling ai-core plugin.

This is the frontend plugin. It has no compile-time dependency on ai-core; the two communicate at runtime through the CodeOnTheGo plugin manager (SharedServices). Install ai-core first, then ai-assistant.

Architecture

┌──────────────────────────┐
│  ai-assistant  (this)    │  ← Chat UI, settings, agent tool-loop
└────────────┬─────────────┘
             │ SharedServices (runtime)
             ▼
┌──────────────────────────┐
│  ai-core                 │  ← LLM inference: local (llama.cpp) + Gemini
└──────────────────────────┘

Features

• Chat UI (RecyclerView + Markdown rendering via Markwon)
• Agent tool-loop with per-tool approval dialogs
• Session persistence
• Works with either backend exposed by ai-core (on-device GGUF or Gemini API)

Building

Prerequisites: Android SDK (API 33+), JDK 17. Create local.properties with sdk.dir=.... This plugin needs no NDK, submodule, or native toolchain.

cd ai-assistant
./gradlew assemblePlugin          # release  -> build/plugin/ai-assistant.cgp
./gradlew assemblePluginDebug     # debug variant

The build resolves plugin-api.jar from the repo-root ../libs/.

Installation

1. Build and install ai-core first (see ../ai-core/README.md).
2. Build this plugin, copy build/plugin/ai-assistant.cgp to the device.
3. Install via CodeOnTheGo's Plugin Manager, then restart the IDE.
4. Open AI Settings to pick a local model or configure a Gemini API key.

Key classes

• AiAssistantPlugin.kt — plugin entry point / lifecycle
• fragments/ChatFragment.kt, viewmodel/ChatViewModel.kt — chat UI + state
• fragments/AiSettingsFragment.kt, viewmodel/AiSettingsViewModel.kt — model/backend config
• tool/ — the agent tool-loop (executor, router, per-tool handlers, approval)

Security

• Gemini API key at rest. The key is encrypted with AES/GCM under a hardware-backed Android Keystore secret and only the ciphertext is written to this plugin's private SharedPreferences (AgentSettings), as enc:v1: + base64(iv‖ciphertext). A copied prefs file — root, adb backup, forensic dump — is useless without this device's Keystore. Remove the key any time from AI Settings (or clearGeminiApiKey()).
  • A key stored before this plugin encrypted them is still plaintext on disk; it is re-encrypted in place the first time it's read (SecureApiKeyStore.readAndMigrate), so no user action is needed.
  • The key is not bound to user authentication (setUserAuthenticationRequired is not set), so it stays usable for background inference and a lock-screen credential change does not invalidate it. If the Keystore entry is lost anyway — the app's data is cleared, or an OEM Keystore drops the alias — the stored key can no longer be decrypted and must be re-entered; Edit says so instead of presenting an empty field. Saving surfaces a failure message rather than silently storing nothing.
  • Encryption at rest defends against offline recovery of the prefs file. It does not defend against code already running as the host IDE's UID, which can simply call decrypt — that would need a host-provided secure-storage service with per-plugin isolation.
• Shared crypto across two plugins. ai-core performs the Gemini calls and therefore has to read the same key. Both plugins run in the host IDE's process (same UID) and so share one Android Keystore; each ships an identical copy of SecureApiKeyStore pinned to the alias cotg_ai_gemini_key_v1. The two copies must stay byte-identical apart from their package line — if ALIAS, TRANSFORM, IV_LEN or ENC_PREFIX drift, ai-core silently fails to decrypt and Gemini reports "backend not available". A host-provided secure-storage service would remove the duplication.
• Gemini API key in transit. The key is sent to Google as an x-goog-api-key request header (and via the SDK on the chat path), never in a URL query string.
• File tools are confined to the project root — see the in-IDE help page.
• The context-file picker is confined to the open project and fails closed: with no project open it refuses to open rather than falling back to a broader root.

License

GPL-3.0 — same as AndroidIDE / CodeOnTheGo.