Turn Claude into your AI-powered API testing lab. Test, debug, and document APIs through natural conversation with support for authentication, response validation, and performance metrics.

Installation

NPM Global

npm install -g api-lab-mcp

NPX (no installation)

npx -y api-lab-mcp

From source

git clone https://github.com/atototo/api-lab-mcp.git
cd api-lab-mcp
npm install && npm run build
node dist/mcp/server.js

Docker

FROM node:20-alpine
RUN npm install -g api-lab-mcp
EXPOSE 3000
CMD ["api-lab-mcp", "--http-mode"]

docker build -t api-lab-mcp .
docker run -p 3000:3000 api-lab-mcp

Configuration

Claude Desktop (macOS/Linux)

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

Claude Desktop (Windows)

{
  "mcpServers": {
    "api-lab-mcp": {
      "command": "npx.cmd",
      "args": ["-y", "api-lab-mcp"]
    }
  }
}

Available Tools

Tool	Description
`test_http_endpoint`	Test any HTTP endpoints with full customization, including all HTTP methods, custom headers, authentication...
`test_with_assertions`	Advanced testing with intelligent response validation using JSONPath expressions, regex patterns,...
`test_with_session`	Session-based authentication for complex flows with cookie jar management, CSRF token handling and...
`batch_test`	Efficient execution of multiple API tests with parallel or sequential execution and aggregated results
`analyze_api_spec`	Extract and understand OpenAPI/Swagger specifications, parse specs, list endpoints and understand...
`generate_test_scenarios`	AI-generated tests from specifications, create comprehensive test suites from OpenAPI documentation with...

Features

Universal authentication - Bearer tokens, API keys, OAuth2, session cookies and CSRF tokens
Intelligent response analysis - Automatic validation of status codes, headers and JSON paths
Real-time performance metrics - Response time, payload sizes and Core Web Vitals
Conversational testing - Test complex scenarios through natural dialogue
Specification-based test generation - Automatic test suite creation from OpenAPI/Swagger documentation
Batch testing - Run multiple APIs in parallel or sequentially
MCP server testing - Test tools and resources of other MCP servers
Environment management - Seamless switching between dev, staging and production
Automatic documentation - Generate API documentation from test conversations
Smart assertions - Claude understands intent and creates appropriate tests

Environment Variables

Optional

PORT - Server port for HTTP mode (default: 3001)
LOG_LEVEL - Logging verbosity level - ERROR, WARN, INFO, DEBUG (default: INFO)

Usage Examples

Test the GitHub API to get my user information

Why is my login endpoint returning 401?

Test my application with session cookie JSESSIONID=ABC123

Check if all my endpoints respond in less than 200ms

Create tests from my OpenAPI specification at /api/docs

Notes

Works with both Claude Desktop and Claude Code. Supports zero-configuration and works out of the box. Includes comprehensive authentication support, session management and AI-powered test generation from OpenAPI specifications.

API Lab MCP Server