My First MCP

NextFlow AI Internship — Submission 3 (Module 1.5 & 1.6)

This is my first working MCP (Model Context Protocol) server. The goal of this submission is to build the smallest possible end-to-end MCP pipeline — one server, one tool — and prove it actually works by connecting to it with MCP Inspector.

What this server does

The server exposes a single tool called greet:

• greet(name) — takes a person's name as input and returns a friendly greeting, e.g. Hello, Ada!

It's intentionally simple. The point of this step isn't a useful tool — it's confirming that the server starts, registers a tool correctly, validates input with Zod, and responds over stdio the way a real MCP host would expect.

Tech stack

• @modelcontextprotocol/sdk — official MCP server SDK
• zod — schema validation for tool input
• TypeScript + tsx — run TS directly without a separate build step

Project structure

my-first-mcp/
├── src/
│   └── index.ts      # server setup + the "greet" tool
├── package.json
├── package-lock.json
├── tsconfig.json
├── README.md
└── .gitignore

Setup

npm install

Running the server

npm run dev

If it stays running with no crash and no visible output, that's expected — the server is just waiting for input over stdio. Stop it with Ctrl+C.

Testing with MCP Inspector

Since this server talks over stdio, it needs a host or inspector to actually call it. To verify it manually:

npx @modelcontextprotocol/inspector npx tsx src/index.ts

Then, in the browser UI that opens:

1. Go to the Tools tab and confirm greet is listed with its description and input schema.
2. Call it with valid input (name: "Ada") → returns Hello, Ada!.
3. Call it with invalid input (empty or wrong type) → rejected by Zod before the handler code runs, confirming input validation is working.

A screenshot of both the tool listing and a successful call is included with this submission.

Notes

• All logging in this server uses console.error, never console.log or process.stdout.write — the stdio transport uses standard output to talk to the host, so anything else written there would corrupt the connection.
• node_modules/ and dist/ are excluded via .gitignore and are not part of this repo.