YNAB MCP

YNAB Model Context Protocol (MCP) server for Claude Code integration with You Need A Budget (YNAB).

Overview

This repository contains a Docker-based MCP server that enables Claude Code to interact with YNAB (You Need A Budget) accounts. It implements the OAuth flow and provides a comprehensive API for budget management, transaction tracking, and financial insights.

Known Issues

MCP Tool Availability

The following issues have been identified:

1. Transactions API - The list_transactions endpoint fails with "invalid date" errors when using the sinceDate parameter
2. Missing API Tools - Several endpoints that are defined in the source code are not available in the MCP integration
3. Inconsistent Behavior - Some tools work in testing with test-mcp.js but fail in the actual MCP integration

Issue Tracking

We're actively working on the following fixes:

• fix-transactions-api branch: Addressing the date format handling in the transactions API
• fix-mcp-registration branch: Ensuring all API tools are properly registered and available

Features

• OAuth-based authentication with YNAB API
• Complete budget and account management
• Transaction creation and categorization
• Advanced category management with bulk allocation and recommendations
• Support for multiple budgets (personal and family)
• Rate limit handling (YNAB API limit: 200 requests/hour)
• Caching for improved performance

New Category Management Features

This MCP includes advanced category management capabilities:

• Assign to Categories: Allocate funds from Ready to Assign to multiple categories in one operation
• Recommended Allocations: Get AI-powered suggestions for budget distribution based on goals and spending patterns

See Category Management Documentation for details.

Getting Started

Prerequisites

• Docker
• Node.js v18+ (for development)
• Claude Code CLI
• YNAB account

Installation

1. Clone this repository
2. Copy config/config.example.js to config/config.js and add your YNAB API credentials
3. Build the Docker image: docker build -t ynab-mcp:latest .
4. Create a JSON configuration for Claude:

   {
     "command": "docker",
     "args": [
       "run",
       "--rm",
       "-i",
       "-v",
       "/path/to/data:/app/data",
       "-v",
       "/path/to/config:/app/config",
       "-e",
       "NODE_ENV=production",
       "ynab-mcp:latest"
     ]
   }

5. Register the MCP with Claude Code CLI:

   claude mcp add-json ynab '{"command": "docker", "args": ["run", "--rm", "-i", "-v", "/path/to/data:/app/data", "-v", "/path/to/config:/app/config", "-e", "NODE_ENV=production", "ynab-mcp:latest"]}'

   You can also save the JSON to a file and use:

   claude mcp add-json ynab "$(cat config.json)"

6. Authenticate with your YNAB account when prompted by Claude

Integration with Claude

This MCP integrates seamlessly with Claude, allowing:

• Viewing budgets and transactions
• Getting financial insights
• Managing your budget through natural conversation

Security

• Tokens are stored securely in a mounted Docker volume
• No sensitive data is logged
• Authentication uses OAuth 2.0 standards
• Support for read-only mode

Implementation Details

The implementation follows the Model Context Protocol standard using:

• Node.js and the official MCP SDK
• Docker for containerization and deployment
• YNAB JavaScript SDK for API operations
• OAuth 2.0 for authentication

License

MIT

Acknowledgements

• YNAB API
• YNAB JavaScript Library
• Anthropic Claude