MCP Testing Library

What is MCP Testing Library?

A CLI tool for running Model Context Protocol (MCP) tests, written in TypeScript with full type support and compatible with the MCP SDK. It is designed for developers who need to validate MCP server implementations.

How to use MCP Testing Library?

Install as a development dependency via npm install --save-dev mcp-testing-library. Use the mcpt command to run test files matching the default pattern **/*.test.{js,ts}, with options for timeout, exclusion, and color output. The library also provides a programmatic API via import { mcpt, expect } for custom test scripts.

Key features of MCP Testing Library

• CLI tool for running MCP tests
• Configurable test timeout and exclusion patterns
• Verbose mode for detailed output
• Colorful test output for readability
• Support for individual test files or glob patterns
• Programmatic usage with mcpt and expect utilities

Use cases of MCP Testing Library

• Validate an MCP server’s tools, prompts, and resources after deployment
• Run automated CI/CD tests for MCP server updates
• Quickly test different MCP server configurations with custom timeouts and exclusions

FAQ from MCP Testing Library

How do I run all tests in my project?

Execute mcpt with no arguments; it will find test files matching the default glob pattern **/*.test.{js,ts}.

How can I set a custom test timeout?

Use the --timeout option followed by milliseconds, e.g., mcpt --timeout 10000.

Can I exclude certain directories or files?

Yes, use --exclude <patterns> with comma-separated glob patterns. Defaults exclude node_modules/ and dist/.

How do I use MCP Testing Library programmatically?

Import { mcpt, expect } from mcp-testing-library and call mcpt with a server configuration and a callback that receives tools, prompts, resources, and isMethodExist.

What test file pattern does the CLI use by default?

The default pattern is **/*.test.{js,ts}, but you can override it with --pattern <glob>.