MCP example & Demo

What is MCP example & Demo?

MCP example & Demo is a simple MCP server that demonstrates the Model Context Protocol. It implements a basic "add" tool and shows how to communicate with an MCP server over STDIN using JSON‑RPC messages.

How to use MCP example & Demo?

Run the server with mcp run server.py and send JSON‑RPC messages over STDIN. Alternatively, use mcp dev server.py to launch the MCP inspector for interactive testing.

Key features of MCP example & Demo

• Provides a single "add" tool that sums two numbers
• Demonstrates the full MCP initialization handshake
• Supports tools/list and tools/call JSON‑RPC methods
• Includes an example of an error response from a tool call
• Uses STDIN transport by default
• Works with the MCP inspector in dev mode

Use cases of MCP example & Demo

• Learning how the MCP protocol works end‑to‑end
• Testing a client’s ability to handle initialize, ping, and tool calls
• A minimal reference implementation for developing custom MCP servers
• Demonstrating error handling in tool execution

FAQ from MCP example & Demo

What does the server do?

It provides an "add" tool that accepts two numeric arguments (a and b) and returns their sum.

How do I run the server?

Use mcp run server.py to start it on STDIN, or mcp dev server.py to open the MCP inspector.

What transport does the server use?

It communicates over STDIN using JSON‑RPC 2.0.

What protocol version does it support?

The server uses the MCP protocol version 2025-03-26.

Does the server support any other tools?

No, it only includes the single "add" tool demonstrated in the README.