LeaveManager – MCP Server with Claude Integration

LeaveManager is a custom Model Context Protocol (MCP) server built using FastMCP.
It allows Claude to interact with a backend Leave Management System using natural language.

This project demonstrates how Claude can automatically select and execute backend tools based on user queries.

🚀 Features

• Check employee leave balance
• Apply leave for specific dates
• View leave history
• In-memory state management
• Claude Desktop integration via MCP
• Automatic tool selection from natural language

🧠 Tech Stack

• Python 3.10+
• FastMCP
• MCP CLI
• Claude Desktop (for tool invocation)
• uv (Python package manager)

📂 Project Structure

my-first-mcp-server/ │ ├── main.py ├── pyproject.toml ├── README.md ├── .gitignore ├── uv.lock └── .venv/

🛠️ MCP Tools

1️⃣ get_leave_balance

Checks remaining leave days for an employee.

Input:

• employee_id (string)

2️⃣ apply_leave

Applies leave for given dates and updates balance.

Input:

• employee_id (string)
• leave_dates (list of YYYY-MM-DD)

3️⃣ get_leave_history

Returns all leave dates taken by an employee.

Input:

• employee_id (string)

💡 Example Claude Queries

• “Check leave balance for employee E001”
• “Apply leave for employee E001 on 2025-04-17 and 2025-05-01”
• “Show leave history for employee E001”

Claude automatically selects and executes the correct MCP tool.

⚠️ Important Note on Data Storage

• This project uses in-memory storage
• Data resets when the MCP server restarts
• This is intentional for simplicity
• Can be extended with SQLite for persistence

▶️ Running Locally (Without Claude)

uv run main.py


🎯 Learning Outcomes

Built a real MCP server

Exposed backend tools to Claude

Understood stateful MCP behavior

Integrated Python backend with LLM tool calling

📌 Future Improvements

SQLite persistence

Date validation & duplicate checks

Employee creation & reset tools

FastAPI + MCP hybrid architecture

🧑‍💻 Author

Uma Maheswara Rao
Aspiring AI Engineer / Data Analyst