MCP YNAB Server

An MCP server implementation that provides access to YNAB (You Need A Budget) functionality through the Model Context Protocol.

Features

View account balances and transactions
Create new transactions
Access YNAB data through standardized MCP resources

Installation

uv pip install -e .

Configuration

The server requires a YNAB API key to function. You can obtain one from your YNAB Developer Settings.

The API key can be provided through:

Environment variable: YNAB_API_KEY=your_api_key
MCP secret management system
.env file in project root

Usage

Running the Server

# Development mode with hot reload and browser launch
task dev

# Production install for Claude Desktop, Goose, or any other MCP-supported environment
task install

Available Resources

ynab://accounts - List all YNAB accounts
ynab://transactions/{account_id} - Get recent transactions for a specific account

Available Tools

create_transaction - Create a new transaction
get_account_balance - Get the current balance of an account

Example Usage

# Create a new transaction
result = await create_transaction(
    account_id="your_account_id",
    amount=42.50,  # in dollars
    payee_name="Coffee Shop",
    category_name="Dining Out",
    memo="Morning coffee"
)

# Get account balance
balance = await get_account_balance("your_account_id")

# List accounts
accounts = await ctx.read_resource("ynab://accounts")

# Get recent transactions
transactions = await ctx.read_resource(f"ynab://transactions/{account_id}")

Development

# Install dependencies (uses uv)
task deps

# Run all tests including integration tests (you will need a YNAB API key for this)
task test:all

# Generate coverage report
task coverage

# Format and lint code
task fmt  # Should add this to Taskfile

Project Tasks

This project uses a Taskfile for common operations. Key commands:

task dev       # Start dev server with auto-reload
task test      # Run unit tests
task coverage  # Generate test coverage report
task install   # Install production build
task deps      # Synchronize dependencies

See Taskfile.yml for all available tasks.