MCP Lab

What is MCP Lab?

MCP Lab is a personal experimentation repository for learning and testing the Model Context Protocol (MCP) using the TypeScript SDK. It contains multiple sub-projects: a basic MCP server (mcp-server-dummies), a Text-to-SQL server for SQLite (mcp-lab-text2sql), and a client that integrates MCP with OpenAI’s Responses API.

How to use MCP Lab?

Each sub‑project is installed and run separately. Navigate to a project (e.g. mcp-server-dummies) and run npm i, then npm run build (compiles with tsc) and npm run dev (runs with ts-node). Debug with npm run test which launches the MCP Inspector at http://localhost:6274. Servers can be added to Claude Desktop via claude_desktop_config.json under AppData/Roaming/Claude on Windows.

Key features of MCP Lab

• Basic MCP server for learning and quick testing.
• Text‑to‑SQL server letting you chat with SQLite databases in natural language.
• MCP client that bridges MCP tools with OpenAI’s Responses API.
• Supports debugging via the MCP Inspector visual interface.
• All projects require Node.js >= v20.
• Licensed under MIT.

Use cases of MCP Lab

• Experimenting with the MCP SDK and understanding protocol mechanics.
• Building and testing a Text‑to‑SQL assistant over a local SQLite database.
• Connecting MCP servers to an OpenAI‑powered agent (via the provided client).
• Prototyping and debugging MCP tools before production deployment.

FAQ from MCP Lab

What runtime does MCP Lab require?

All projects need Node.js version 20 or higher.

How can I debug an MCP server in this lab?

Run npm run test inside a server project – this launches the MCP Inspector at http://localhost:6274 for interactive testing.

Can I use these MCP servers with Claude Desktop?

Yes. Edit claude_desktop_config.json (located in AppData/Roaming/Claude on Windows) and add entries with the node command pointing to the compiled dist/index.js of each server. Remember to run npm run build first.

Are these MCP servers directly compatible with OpenAI?

No. MCP tool schemas differ from OpenAI’s function‑calling format. MCP Lab includes a client project (mcp-client) that transforms tools for use with the OpenAI Responses API. When defining tool arguments with Zod, OpenAI requires all params be required, forbids min/max on integers, and disallows default values.

What data does the Text‑to‑SQL server work with?

The mcp-lab-text2sql server interacts with a SQLite database, but the README does not specify which database or its location; the server is designed to chat with your own SQLite data.