my-mcp-server

A playground and experimentation project for building an MCP (Model Context Protocol) server using TypeScript. It demonstrates how to expose tools and resources to AI agents and language models via the stdio transport.

The server manages a user database backed by PostgreSQL (via Drizzle ORM) and exposes tools and resources that an AI agent can call to read, create, update, and delete user records.

Features

• Tool — create_user: Creates a new user from name, email, address, and phone fields (all required) and returns the created record with its database id.

• Tool — update_user: Updates an existing user by id; at least one field must be provided and only the provided fields are changed.

• Tool — delete_user: Deletes a user by id and returns the deleted record.

• Resource — users://all: Returns the full list of users from the database as JSON.

• Resource — users://{userId}/profile: Returns the profile of a single user identified by userId.

Related MCP server: FastMCP Example Server

Prerequisites

• Node.js v18 or later

• npm v9 or later

• Docker (for the local Postgres database)

Setup

1. Install dependencies:

   npm install

2. Configure the database connection. Copy .env.example to .env and adjust the values if needed:

   cp .env.example .env

3. Start the Postgres container:

   npm run db:up   # or: docker compose up -d db

4. Apply the database schema:

   npm run db:migrate

On startup the server connects to the database and seeds it from data/users.json the first time (the seed is skipped once the table has data). The schema is managed by Drizzle migrations in src/db/migrations/: after changing src/db/schema.ts, run npm run db:generate to emit a new migration and npm run db:migrate to apply it.

Running the Server

Development mode (using tsx, no build step)

npm run server:dev

Build & run compiled output

npm run server:build   # compiles TypeScript → JavaScript
npm start              # run the compiled server

Watch mode (auto-recompile on changes)

npm run server:build:watch

Inspect with MCP Inspector UI

The MCP Inspector lets you interactively call tools and browse resources in a browser UI:

npm run server:inspect

Note: server:inspect sets DANGEROUSLY_OMIT_AUTH=true — use this only for local development.

Loading the MCP Server in Agent Environments

Agent CLI (e.g. Claude Code CLI)

Existence of .mcp.json should be picked up by the agent and prompted to load the server. Otherwise it's a simple MCP server config that needs to be added to the configuration with other servers.

Project Structure

my-mcp-server/
├── src/
│   ├── server.ts        # MCP server entry point (tools & resources)
│   ├── db.ts            # Postgres connection, startup checks, and seeding
│   └── db/
│       ├── schema.ts    # Drizzle table definitions
│       └── migrations/  # Generated SQL migrations (committed)
├── data/
│   ├── users.json       # Seed data imported into Postgres on first start
│   └── env.ts           # Env validation used by drizzle-kit
├── drizzle.config.ts    # drizzle-kit configuration
├── docker-compose.yml   # Local Postgres container
├── package.json
└── tsconfig.json

Tech Stack

License

ISC