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When building Android applications, AI tools often rely on outdated training data or incomplete summaries of the Android Framework.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

Python 3.11+
uv (recommended) or pip
Git

Initial Setup

Clone the repository:

git clone <repo-url> android-source-explorer
cd android-source-explorer

Install dependencies and perform an initial sync:

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

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

Check sync status:
```
uv run android-source-explorer status
```

Startup

The project provides a unified CLI. To start the MCP server for an AI client, use the serve command:

uv run android-source-explorer serve

Configuration

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

Basic Configuration

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

With LSP Features Enabled

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

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 command to pre-fetch sources into 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.

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

MCP Servers