Android Source Explorer MCP Server

MCP server for exploring AOSP internals and Jetpack libraries.

Purpose

When building Android applications, AI tools often rely on outdated training data or incomplete summaries of the Android Framework. This MCP server provides on-demand, precise access to the actual source code (AOSP and AndroidX), enabling the AI to understand complex framework internals like the Activity lifecycle, ViewModel restoration, or Compose internals directly from the truth.

Installation & Setup

Prerequisites

uv (Recommended) or Python 3.11+
Git

Recommended Installation (via uv)

The easiest way to install and keep android-source-explorer up to date is using uv. It handles dependencies (including native ones like Tree-sitter and Cryptography) reliably across platforms.

uv tool install git+https://github.com/mrmike/android-source-explorer-mcp

This will make the android-source-explorer command available globally in your PATH.

Initial Sync

After installation, you need to perform an initial sync to fetch the Android source code:

# Sync API 36 (Android 16) and common AndroidX packages
android-source-explorer sync --api-level 36 --androidx "compose,lifecycle,activity"

# (Optional) Download LSP servers for cross-file features
android-source-explorer sync --lsp

Check sync status:

android-source-explorer status

Keeping Sources Up-to-Date

To check for and download the latest available Android Framework revisions (AOSP tags) and newer stable versions of your synced AndroidX packages, run:

# Update all synced framework APIs and AndroidX packages, then rebuild the index
android-source-explorer update

# (Optional) Clean up older versions of updated AndroidX packages
android-source-explorer update --clean

# Update only a specific API level or AndroidX package
android-source-explorer update --api-level 36
android-source-explorer update --androidx activity-compose

Configuration

Add the MCP server to your configuration file (e.g., Claude Desktop, Cursor, Gemini CLI).

Global Usage (Recommended)

If installed via uv tool install, the tool is available globally.

Basic Setup:

{
  "mcpServers": {
    "android-sources": {
      "command": "android-source-explorer",
      "args": ["serve"]
    }
  }
}

With LSP Features Enabled:

{
  "mcpServers": {
    "android-sources": {
      "command": "android-source-explorer",
      "args": ["serve"],
      "env": {
        "ANDROID_SOURCE_LSP": "true"
      }
    }
  }
}

Development Usage

If you cloned the repository and want to run it from the source:

{
  "mcpServers": {
    "android-sources": {
      "command": "uv",
      "args": ["run", "--directory", "/absolute/path/to/android-source-explorer", "android-source-explorer", "serve"]
    }
  }
}

How It Works

1. Hybrid Architecture (Tree-sitter + LSP)

The server uses a dual-engine approach to balance speed and intelligence:

Tree-sitter (Surgical Engine): Provides near-instant (sub-10ms) AST parsing of single files. It precisely extracts method bodies (including Javadoc and annotations), class members, and inheritance hierarchies without the overhead of a full compiler.
LSP (Global Engine): Optionally leverages the Eclipse JDT LS (Java) and Kotlin Language Server for cross-file navigation. This enables finding references across millions of lines of code and resolving types that span multiple libraries.

2. Local Sync Strategy

To ensure all lookups are instant and offline-ready, the server uses a sync or update command to manage sources in a local cache (~/.android-sources/):

AOSP: Fetches framework sources directly from android.googlesource.com using git sparse-checkouts.
AndroidX: Downloads -sources.jar files from the Google Maven repository (dl.google.com/dl/android/maven2/).
Hybrid Indexing: Prioritizes your local $ANDROID_HOME sources if available, supplemented by the downloaded cache.
Automatic Updates: The update command queries remote endpoints (AOSP Git tags & Google Maven indexes) for updates, downloads newer revisions/versions, and rebuilds the class index.

Available Tools

Tool	Engine	Description
`search_classes`	Index	Search for classes by glob pattern or substring.
`lookup_class`	FS	Retrieve the full source code for a specific class.
`lookup_method`	Tree-sitter	Extract a precise method body + its Javadoc/annotations.
`list_class_members`	Tree-sitter	List all method and field signatures in a class.
`get_class_hierarchy`	Tree-sitter	Get the inheritance chain (superclass + interfaces).
`search_in_source`	FS/Regex	Search for text/regex across the entire source tree.
`goto_definition`*	LSP	Resolve the cross-file definition of a symbol.
`find_references`*	LSP	Find all usages of a class/method across the whole tree.
`get_type_info`*	LSP	Get documentation and type info via hover data.

*Requires ANDROID_SOURCE_LSP=true

License

Apache License 2.0