🧪 Vitest MCP Server

MCP Vitest runner with LLM-optimized test output, log capturing, and line-by-line coverage analysis.

Table of Contents

• 😢 The Problem with LLMs and Testing
• ✨ Key Features
• 🚀 Quick Start
• 📋 Requirements
• 🧰 Tools
• 🔄 Multi-Repository Support
• 🪝 Claude Code Hook
• 🤖 LLM instructions
• ⚙️ Configuration
• 🔍 Development Mode & Debugging
• 🔧 Troubleshooting
• 🤝 Contributing
• 📜 License

😢 The Problem with LLMs and Testing 😢

• Noisy test output - Raw Vitest output can be extremely verbose eating up tokens/context with useless information.
• Full test suite runs - LLMs sometimes forget to limit the scope of the test run, causing full test suite runs to be executed.
• Buried console logs - Console logs can be hidden in test output, making it inefficient for LLMs to debug test failures.
• Raw coverage files - Raw coverage files are too large for AI to parse.
• Watch mode - LLMs get stuck when vitest runs in watch mode.

✨ Key Features ✨

• Smart Test Results with adaptive, structured output to limit noise.
• Console Log Capture to prevent logs from getting lost in test output.
• Coverage Analysis with line-by-line gap insights.
• Multi-Repository Support in a single session with context switching.
• Safety Guards prevent full project runs, watch mode, invalid vitest commands, and context hogging.

🚀 Quick Start 🚀

The Vitest MCP server can be used with any MCP-compatible IDE or tool and works with all Javascript or Typescript Vitests. The basic configuration is:

{
  "mcpServers": {
    "vitest": {
      "command": "npx",
      "args": ["-y", "@djankies/vitest-mcp"]
    }
  }
}

⚠️ Note: The above example may not be valid for all MCP clients. Verify your client’s specific setup instructions.

🛠️ Client-Specific Setup

Select your preferred IDE or tool from the setup guides below:

Configuration Methods

Claude Code supports multiple configuration approaches:

Method 1: CLI Wizard (Interactive)

# Add server with interactive prompts
claude mcp add vitest -- npx -y @djankies/vitest-mcp

# Add to project scope (shareable with team)