mutmut-mcp

Mutmut MCP brings mutation testing into your AI coding workflow. It wraps mutmut as an MCP server so Claude and other AI assistants can run mutation tests, inspect surviving mutations, and recommend where your test coverage needs work.

Features

• Run Mutation Tests: Execute mutation testing across Python projects from your AI assistant
• Inspect Survivors: See which mutations survived your test suite
• Coverage Recommendations: Get specific suggestions for improving test coverage
• Retest Mutations: Retest individual or batch survivors after fixing tests
• Cache Management: Manage the mutmut cache system
• Six MCP Tools: Full mutation testing workflow exposed as tools

Installation

# Direct
uvx --from git+https://github.com/wdm0006/mutmut-mcp mutmut-mcp

# Via Smithery
npx -y @smithery/cli install @wdm0006/mutmut-mcp --client claude

# Or clone and run locally
git clone https://github.com/wdm0006/mutmut-mcp
cd mutmut-mcp
uv sync
uv run mutmut-mcp

Usage

Add to your MCP client configuration, then ask your AI assistant to run mutation tests on your project. It will execute mutmut, report results, and help you identify and fix test coverage gaps.