replicant-mcp

replicant-mcp

Let AI build, test, and debug your Android apps.

     

replicant-mcp is a Model Context Protocol server that gives AI assistants like Claude the ability to interact with your Android development environment. Build APKs, launch emulators, install apps, navigate UIs, and debug crashes—all through natural conversation.

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Demo

!replicant-mcp demo

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Why replicant-mcp?

| Without replicant-mcp | With replicant-mcp | |-----------------------|-------------------| | "Run ./gradlew assembleDebug, then adb install, then adb shell am start..." | "Build and run the app" | | Copy-paste logcat output, lose context | AI reads filtered logs directly | | Screenshot → describe UI → guess coordinates | AI sees accessibility tree, taps elements by text | | 5,000 tokens of raw Gradle output | 50-token summary + details on demand |

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Features

| Category | Capabilities | |----------|-------------| | Build & Test | Build APKs/bundles, run unit and instrumented tests, list modules/variants/tasks, test regression detection with baseline comparison | | Emulator | Create, start, stop, wipe emulators; save/load/delete snapshots | | Device Control | List connected devices, select active device, query device properties | | App Management | Install, uninstall, launch, stop apps; clear app data | | Log Analysis | Filter logcat by package, tag, level, time | | UI Automation | Accessibility-first element finding, spatial proximity search, tap, text input, screenshots | | Diagnostics | Environment health checks via replicant doctor; structured logging with configurable level and format |

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Coming Soon

• Custom build commands (project-specific overrides, auto-detect gradlew)
• Video capture (start/stop recording, duration-based capture)

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Quick Start

Prerequisites

• Node.js 18+
• Android SDK with adb and emulator in your PATH
• An Android project with gradlew (for build tools)

node --version      # Should be 18+
adb --version       # Should show Android Debug Bridge version
emulator -version   # Should show Android emulator version

<details> <summary><b>Installing prerequisites (macOS via Homebrew)</b></summary>

If you don't already have these tools, install them with Homebrew:

Node.js 18+

brew install node

Physical-device only — just adb, sufficient if you never run an emulator:

brew install --cask android-platform-tools

adb lands directly on your PATH; no further config needed.

Full Android SDK — needed for emulator workflows or building APKs via the gradle-* tools. Run the steps in order:

# 1. JDK — required by sdkmanager itself, and by the gradle-* tools
brew install --cask temurin@17

# 2. cmdline-tools (provides sdkmanager)
brew install --cask android-commandlinetools

# 3. Set ANDROID_HOME and create the directory BEFORE running sdkmanager,
#    otherwise sdkmanager has no install target.
export ANDROID_HOME="$HOME/Library/Android/sdk"
mkdir -p "$ANDROID_HOME"

# 4. Accept all SDK licenses first, then install packages.
#    `sdkmanager --install` aborts on unaccepted per-package licenses
#    (e.g. the Google APIs system image) if licenses aren't accepted first.
#    The system-image arch must match your host: `arm64-v8a` for Apple
#    Silicon (M1/M2/M3), `x86_64` for Intel Macs. Check with `uname -m`.
yes | sdkmanager --licenses
sdkmanager --install "platform-tools" "emulator" "system-images;android-34;google_apis;arm64-v8a"

Persist ANDROID_HOME and put the SDK binaries on your PATH by appending to ~/.zshrc (or ~/.bashrc):

export ANDROID_HOME="$HOME/Library/Android/sdk"
export PATH="$ANDROID_HOME/platform-tools:$ANDROID_HOME/emulator:$PATH"

</details>

Installation

npm install -g replicant-mcp

After installation, run the built-in diagnostics to verify your environment:

replicant doctor

Updating

npm update -g replicant-mcp

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Setup

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "replicant": {
      "command": "npx",
      "args": ["-y", "replicant-mcp"]
    }
  }
}

Claude Code

claude mcp add replicant -- npx -y replicant-mcp

Cursor

Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json (project):

{
  "mcpServers": {
    "replicant": {
      "command": "npx",
      "args": ["-y", "replicant-mcp"]
    }
  }
}

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "replicant": {
      "command": "npx",
      "args": ["-y", "replicant-mcp"]
    }
  }
}

OpenAI Codex CLI

Add to ~/.codex/config.toml:

[mcp_servers.replicant]
command = "npx"
args = ["-y", "replicant-mcp"]

Or via CLI:

codex mcp add replicant -- npx -y replicant-mcp

Note: Ensure adb and emulator are in your PATH, or set ANDROID_HOME environment variable. On macOS: ~/Library/Android/sdk, on Linux: ~/Android/Sdk.

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Example

You: "I just changed the checkout flow. Build the app, go through checkout
      with a test product, and make sure the confirmation screen shows up."

Claude: [Builds debug APK, installs on emulator, launches app]
        [Taps "Electronics" category → "Wireless Headphones" → "Add to Cart"]
        [Navigates to cart, taps "Checkout"]
        [Fills shipping form, taps "Place Order"]

        Confirmation screen is showing:
        - Order #38291
        - "Wireless Headphones" × 1
        - Total: $79.99
        - Estimated delivery: Jan 30

        The flow works. Want me to test the edge cases—empty cart,
        invalid address, payment failure?

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Design

replicant-mcp uses progressive disclosure (summaries first, details on demand) to minimize token usage, and accessibility-first UI automation for faster, cheaper, more reliable interactions than screenshot-based approaches. See docs/architecture.md for details.

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More Info

• Configuration: Set REPLICANT_CONFIG for advanced options. See docs/configuration.md.
• Logging: Set REPLICANT_LOG_LEVEL (error, warn, info, debug) and REPLICANT_LOG_FORMAT (json for structured output) to control server logging. Logs are written to stderr.
• Troubleshooting: Common issues and solutions in docs/troubleshooting.md.
• Tool documentation: Ask Claude to call rtfm with a category like "build", "adb", "emulator", or "ui".

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Documentation

| Document | Description | |----------|-------------| | Architecture | Design overview and progressive disclosure pattern | | Configuration | Config file reference, environment variables, Gradle setup | | API Stability | Tool API versioning policy and deprecation process | | Security Model | adb-shell safety model, command denylist, threat boundaries | | Support Matrix | Tested OS, Node.js, Android SDK, and emulator versions | | Known Limitations | Accessibility gaps, timeouts, single-device focus, and more | | Artifacts | .replicant/ directory contents and privacy considerations | | Troubleshooting | Common issues and solutions | | Changelog | Version history | | Security Policy | Vulnerability reporting process | | Support / Getting Help | How to report bugs and ask questions | | Contributing | Development setup and guidelines |

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Contributing

See CONTRIBUTING.md for development setup and guidelines.

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Acknowledgments

• Inspired by xc-mcp for iOS
• Built on the Model Context Protocol

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License

MIT

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Questions? Open an issue