YNAB MCP Server

A Model Context Protocol (MCP) server for interacting with YNAB (You Need A Budget) via their API.

Features

• Get budgets, accounts, and categories
• Get, create and update transactions
• Create new categories
• Update budgeted amounts for categories
• Get budget summaries

Prerequisites

• Python 3.13 or higher
• A YNAB account with an API token (Get your token here)
• UV package manager (optional but recommended)

Installation

1. Clone this repository

   git clone https://github.com/ntdef/ynab-mcp.git
   cd ynab-mcp
   

2. Create a virtual environment

   uv venv
   

3. Activate the virtual environment

   • Windows:

     venv\Scripts\activate
     

   • Unix/MacOS:

     source venv/bin/activate
     

4. Install dependencies using UV

   # python -m pip install uv
   uv sync
   

5. Copy .env.example to .env and add your YNAB API token

   cp .env.example .env
   # Edit .env with your favorite editor
   

Usage

Running the server

uv run ynab-mcp

The server will start in stdio mode, so you won't see any output.

Available tools

The YNAB MCP Server provides the following tools:

Budget management

• get_budgets: Retrieve all budgets for the authenticated user
• get_budget_summary: Get a summary of the budget, optionally for a specific month

Account management

• get_accounts: Retrieve all accounts for a specific budget

Category management

• get_categories: Retrieve all categories for a specific budget
• create_category: Create a new category in the specified budget group
• update_category_budgeted: Update the budgeted amount for a category in a specific month

Transaction management

• get_transactions: Retrieve transactions for a specific budget, optionally filtered by date, account, or category
• create_transaction: Create a new transaction in the specified budget
• update_transaction: Update one or more fields of a specific transaction

Development

Running tests

uv run pytest

Code style

This project uses Black and isort for code formatting. To format your code:

uv run isort src tests
uv run black src tests

License

MIT License

Acknowledgements

• Some of the code was written with the assistance of aider
• YNAB API Documentation
• fastmcp by Anthropic