A Model Context Protocol (MCP) server that provides AI-powered code review using Google Gemini 3 Pro. LGTMCP reviews your code changes and either commits them automatically (if approved) or provides detailed feedback for improvements.

• AI Code Review: Leverages Google Gemini 3 Pro for intelligent code analysis
• Automatic Commit: Commits changes when code passes review (optional)
• Security Scanning: Built-in secret detection using Gitleaks
• Gitignore Protection: Prevents access to gitignored files during review
• MCP Integration: Works seamlessly with Claude Desktop and other MCP clients
• Review-Only Mode: Option to get feedback without automatic commits

git clone https://msrl.dev/lgtmcp.git
cd lgtmcp
make build

make install

This installs the binary to ~/bin by default. You can customize the installation directory:

make install INSTALL_PATH=/usr/local/bin

Note: Ensure ~/bin is in your shell's PATH. Add this to your shell configuration file if needed:

# For bash/zsh
export PATH="$HOME/bin:$PATH"

1. Get a Google API key from Google AI Studio.

2. Create configuration directory:

   mkdir -p ~/.config/lgtmcp

3. Create configuration file from example:

   cp config.example.yaml ~/.config/lgtmcp/config.yaml

4. Edit the configuration file with your settings:

   google:
     api_key: "your-gemini-api-key-here"
   gemini:
     model: "gemini-3-pro-preview"
     fallback_model: "gemini-2.5-pro" # Default; set to "none" to disable
   logging:
     level: "info"

The fallback_model is use when we run into quota exhaustion on the primary model. While Gemini 3 Pro is in preview, it has very low daily rate limits.

1. Set up configuration file as described above

2. Configure LGTMCP with Claude Code:

claude mcp add lgtmcp -- lgtmcp

The MCP server exposes two tools:

Reviews code changes and returns feedback without committing.

Parameters:

• directory: Path to the git repository

Reviews code changes and commits if approved. This is a separate tool so that you can set tool permissions on it differently from review.

Parameters:

• directory: Path to the git repository
• commit_message: Message for the commit if approved

Review only (no commit):

review_only("/path/to/repo")

Review and commit if approved:

review_and_commit("/path/to/repo", "Add new feature")

1. Security check: Scans files for secrets using Gitleaks
2. Diff generation: Creates diff of all staged and unstaged changes
3. AI review: Sends diff to Gemini 3 Pro for analysis
   • Gemini can request file contents for context
   • Gitignored files are automatically blocked from access
4. Decision:
   • If approved (LGTM): Returns approval message (review_only) or commits changes (review_and_commit)
   • If not approved: Returns detailed feedback

All configuration is managed through the YAML configuration file located at:

• $XDG_CONFIG_HOME/lgtmcp/config.yaml (if XDG_CONFIG_HOME is set)
• ~/.config/lgtmcp/config.yaml (default)

See config.example.yaml for all available configuration options.

LGTMCP logs are written to platform-specific default locations:

• macOS: ~/Library/Logs/lgtmcp/lgtmcp.log
• Linux: ~/.local/share/lgtmcp/logs/lgtmcp.log (or $XDG_DATA_HOME/lgtmcp/logs/lgtmcp.log)
• Windows: %LOCALAPPDATA%\lgtmcp\logs\lgtmcp.log

You can configure logging in your config.yaml:

logging:
  output: "directory" # Options: none, stdout, stderr, directory, mcp
  level: "info" # Options: debug, info, warn, error
  # directory: "/custom/log/path"  # Optional custom directory

To view logs on macOS:

# View the log file
tail -f ~/Library/Logs/lgtmcp/lgtmcp.log

# Or open in Console.app
open ~/Library/Logs/lgtmcp/lgtmcp.log

make build

make test

make lint

make coverage

"Not a git repository" error

• Ensure you're in a git repository with a .git directory

"Secrets detected" error

• Review and remove any exposed secrets from your changes

"Gemini API error"

• Verify your API key is valid and has quota remaining
• Check network connectivity

"No changes to review"

• Make sure you have staged or unstaged changes in your repository