YNAB MCP Server

An MCP (Model Context Protocol) server for the YNAB (You Need A Budget) API, built with FastMCP.

This server automatically exposes all YNAB API endpoints as MCP tools, allowing AI assistants like Claude to interact with your YNAB budgets, accounts, transactions, and more.

Prerequisites

• Python 3.11 or higher
• uv package manager
• A YNAB account with API access

Setup

1. Clone the Repository

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

2. Get Your YNAB API Token

1. Log in to your YNAB account at app.ynab.com
2. Go to Account Settings → Developer Settings
3. Click New Token under "Personal Access Tokens"
4. Give your token a name and click Generate
5. Copy the token (you won't be able to see it again!)

3. Install Dependencies

uv sync

Running the Server

With Claude Desktop

Add the following to your Claude Desktop configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "ynab": {
      "command": "/absolute/path/to/this/project/.venv/bin/ynab-mcp-server",
      "args": [],
      "env": {
        "YNAB_API_TOKEN": "your-token-here"
      }
    }
  }
}

With Cursor

Add the following to your Cursor MCP settings (~/.cursor/mcp.json for global or .cursor/mcp.json in your project):

{
  "mcpServers": {
    "ynab": {
      "command": "/absolute/path/to/this/project/.venv/bin/ynab-mcp-server",
      "args": [],
      "env": {
        "YNAB_API_TOKEN": "your-token-here"
      }
    }
  }
}

With OpenCode

Add the following to your OpenCode configuration file (~/.config/opencode/opencode.json):

{
  "mcp": {
    "ynab": {
      "type": "local",
      "command": ["/absolute/path/to/this/project/.venv/bin/ynab-mcp-server"],
      "enabled": true,
      "environment": {
        "YNAB_API_TOKEN": "your-token-here"
      }
    }
  }
}

Available Tools

The server automatically exposes all YNAB API endpoints as MCP tools. Here are some of the available operations:

User

• getUser - Get authenticated user information

Budgets

• getBudgets - List all budgets
• getBudgetById - Get a single budget with all related entities
• getBudgetSettingsById - Get budget settings

Accounts

• getAccounts - List all accounts for a budget
• getAccountById - Get a single account
• createAccount - Create a new account

Categories

• getCategories - List all categories for a budget
• getCategoryById - Get a single category
• updateCategory - Update a category
• getMonthCategoryById - Get a category for a specific month
• updateMonthCategory - Update a category for a specific month

Transactions

• getTransactions - List transactions
• getTransactionById - Get a single transaction
• createTransaction - Create a new transaction
• updateTransaction - Update a transaction
• deleteTransaction - Delete a transaction
• importTransactions - Import transactions
• getTransactionsByAccount - List transactions for an account
• getTransactionsByCategory - List transactions for a category
• getTransactionsByPayee - List transactions for a payee

Payees

• getPayees - List all payees
• getPayeeById - Get a single payee
• updatePayee - Update a payee

Scheduled Transactions

• getScheduledTransactions - List scheduled transactions
• getScheduledTransactionById - Get a single scheduled transaction
• createScheduledTransaction - Create a new scheduled transaction
• updateScheduledTransaction - Update a scheduled transaction

Months

• getBudgetMonths - List budget months
• getBudgetMonth - Get a single budget month

Example Usage

Once connected, you can ask Claude things like:

• "Show me my YNAB budgets"
• "What's my current balance in my checking account?"
• "List my transactions from last week"
• "Create a transaction for $50 at the grocery store"
• "How much have I spent on dining out this month?"

Creating Custom Skills for Your YNAB Workflow

YNAB workflows are personal. Everyone has their own conventions for handling transactions, categorizing expenses, and managing duplicates. This repo includes a skill system that lets you encode your personal conventions so Claude can learn and apply them consistently.

Step 1: Explore Your Budget

Start by asking Claude to do something useful with your YNAB data:

"Show me all my unapproved transactions"
"Help me categorize my uncategorized transactions"
"Find duplicate transactions in my budget"

Work through the task interactively. As you do, you'll naturally develop conventions. For example:

• "Venmo transactions always have a matching withdrawal in my checking account - I delete the Venmo one and keep the bank record"
• "Transactions from 'AMZN' should be categorized as 'Shopping' unless the memo mentions 'Kindle'"
• "Any transaction over $500 should be flagged for review"

Step 2: Create a Skill to Encode Your Conventions

Once you've established patterns you want to reuse, create a skill to encode them. This repo includes the skill-creator skill in .skills/skill-creator/ to help you build custom skills.

Ask Claude:

"Load the skill-creator skill and help me create a ynab skill that encodes
the conventions we just used for processing transactions"

The skill-creator will guide you through:

1. Identifying the reusable patterns from your workflow
2. Creating a SKILL.md file with your conventions
3. Structuring the skill for future use

Step 3: Use Your Skills

Once created, your skills live in .skills/ and Claude will automatically apply them when relevant. You can:

• Add more conventions as you discover them
• Share skills with others who have similar YNAB setups
• Build on the included examples

Included Skills

• .skills/skill-creator/ - Claude's official guide for creating new skills, included for convenience

Development

Project Structure

.
├── pyproject.toml
├── README.md
├── uv.lock
└── src/
    └── ynab_mcp_server/
        ├── __init__.py
        └── server.py

How It Works

This server uses FastMCP's from_openapi() method to automatically generate MCP tools from YNAB's OpenAPI specification. When the server starts, it:

1. Fetches the YNAB OpenAPI spec from https://api.ynab.com/papi/open_api_spec.yaml
2. Parses the specification
3. Creates an authenticated HTTP client with your API token
4. Generates MCP tools for each API endpoint

Resources

• YNAB API Documentation
• FastMCP Documentation
• MCP Protocol Specification

License

MIT