YNAB MCP Server

A comprehensive Model Context Protocol (MCP) server for YNAB (You Need A Budget) that enables AI assistants like Claude Desktop to read your budget, analyze spending patterns, detect subscriptions, and provide personalized financial insights—all through natural conversation.

Why YNAB MCP?

Traditional YNAB integrations require manual API calls or custom scripting. This MCP server lets you:

• Talk to your budget naturally — Ask Claude "Am I overspending on dining out?" and get instant insights
• Get AI-powered financial analysis — Subscription detection, spending trends, savings recommendations, and budget health scores
• Stay safe by default — Read-only mode protects against accidental changes
• Access everything — 55 tools covering 100% of the YNAB API plus 22 custom analytics tools

Features

| Feature | Description | |---------|-------------| | Complete API Coverage | 55 MCP tools spanning all YNAB API endpoints | | Advanced Analytics | 22 tools for spending analysis, trend detection, and financial insights | | Read-Only by Default | Write operations require explicit opt-in (YNAB_READ_ONLY=false) | | Smart Rate Limiting | Token bucket algorithm with 180 req/hour budget (10% safety margin) | | Intelligent Caching | Reduces API calls for infrequently changing data | | Type-Safe | Full TypeScript implementation with Zod schema validation |

Quick Start

Prerequisites

• Node.js 20 or later
• A YNAB account with API access
• A YNAB Personal Access Token (get one here)

Installation

# Clone the repository
git clone https://github.com/auzroz/ynab-mcp.git
cd ynab-mcp

# Install dependencies
npm install

# Copy environment template
cp .env.example .env

# Edit .env and add your YNAB_ACCESS_TOKEN

Configuration

Edit .env with your settings:

# Required: Your YNAB Personal Access Token
YNAB_ACCESS_TOKEN=your_personal_access_token

# Optional: Default budget UUID (uses "last-used" if not set)
YNAB_BUDGET_ID=optional_default_budget_uuid

# Optional: Set to false to enable write operations (default: true)
YNAB_READ_ONLY=true

Build & Run

# Build TypeScript
npm run build

# Run the server
npm start

Claude Desktop Integration

Add to your Claude Desktop configuration:

macOS/Linux: ~/.config/claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "ynab": {
      "command": "node",
      "args": ["/path/to/ynab-mcp/dist/index.js"],
      "env": {
        "YNAB_ACCESS_TOKEN": "your_token_here"
      }
    }
  }
}

Example Conversations

Once connected, try asking Claude:

| Question | Tool Used | |----------|-----------| | "What's my current net worth?" | ynab_net_worth | | "How much did I spend on dining out this month?" | ynab_list_category_transactions | | "What subscriptions do I have?" | ynab_detect_recurring | | "Is my budget in good shape?" | ynab_budget_health | | "Where can I cut back on spending?" | ynab_savings_opportunities | | "Am I on track this month?" | ynab_spending_pace | | "Compare this month to last month" | ynab_monthly_comparison |

Available Tools (55 Total)

Analytics Tools (22)

These tools provide AI-powered financial insights beyond basic YNAB functionality:

| Tool | Description | |------|-------------| | ynab_detect_recurring | Find subscription patterns and recurring payments | | ynab_spending_analysis | Analyze spending trends by category | | ynab_budget_health | Assess overall budget health with score and alerts | | ynab_savings_opportunities | Identify potential areas to save money | | ynab_budget_vs_actuals | Compare budgeted vs actual spending | | ynab_quick_summary | At-a-glance budget status overview | | ynab_income_expense | Income vs expense breakdown and trends | | ynab_net_worth | Calculate total net worth from all accounts | | ynab_goal_progress | Track goal funding progress with projections | | ynab_spending_by_payee | Analyze spending by merchant/payee | | ynab_unused_categories | Find inactive or unused categories | | ynab_monthly_comparison | Month-over-month spending comparison | | ynab_spending_trends | Multi-month trend analysis with projections | | ynab_cash_flow_forecast | Project future cash flow based on scheduled transactions | | ynab_reconciliation_helper | Help with account reconciliation | | ynab_budget_suggestions | Get budget suggestions based on history | | ynab_overspending_alerts | Quick check for overspent categories | | ynab_transaction_search | Powerful multi-filter transaction search | | ynab_spending_pace | Track daily spending rate vs target | | ynab_category_balances | Quick category balance lookup | | ynab_credit_card_status | Credit card balances vs payment categories | | ynab_age_of_money | Age of money metric with explanation |

Core YNAB API Tools (33)

Complete coverage of all YNAB API endpoints:

• ynab_get_user — Get authenticated user information

• ynab_list_budgets — List all accessible budgets
• ynab_get_budget — Get detailed budget information
• ynab_get_budget_settings — Get budget settings (currency format, etc.)

• ynab_list_accounts — List all accounts with balances
• ynab_get_account — Get specific account details
• ynab_create_account — Create a new account (write mode)

• ynab_list_categories — List all category groups and categories
• ynab_get_category — Get category details
• ynab_get_month_category — Get category budget for specific month
• ynab_update_category — Update category budgeted amount (write mode)

• ynab_list_payees — List all payees (merchants/vendors)
• ynab_get_payee — Get specific payee details
• ynab_list_payee_locations — List all payee locations for mapping
• ynab_get_payee_location — Get specific payee location
• ynab_list_payee_locations_by_payee — List locations for a specific payee

• ynab_list_months — List all budget months
• ynab_get_month — Get detailed month summary with categories

• ynab_list_transactions — List transactions with filters
• ynab_get_transaction — Get transaction details
• ynab_create_transaction — Create a new transaction (write mode)
• ynab_create_transactions — Bulk create transactions (write mode)
• ynab_update_transaction — Update a transaction (write mode)
• ynab_delete_transaction — Delete a transaction (write mode)
• ynab_list_account_transactions — List transactions for a specific account
• ynab_list_category_transactions — List transactions for a specific category
• ynab_list_payee_transactions — List transactions for a specific payee
• ynab_import_transactions — Trigger import from linked banks (write mode)

• ynab_list_scheduled_transactions — List scheduled/recurring transactions
• ynab_get_scheduled_transaction — Get scheduled transaction details

• ynab_rate_limit_status — Check API rate limit status
• ynab_audit_log — View write operation audit log
• ynab_health_check — Test API connectivity

Development

# Run with hot reload
npm run dev

# Run tests
npm test

# Run tests in watch mode
npm run test:watch

# Lint code
npm run lint

# Fix lint issues
npm run lint:fix

# Type check only
npm run typecheck

Testing with MCP Inspector

npx @modelcontextprotocol/inspector node dist/index.js

Architecture

src/
├── index.ts              # Entry point (stdio server)
├── server.ts             # Tool registration
├── config/               # Environment configuration
├── services/             # Core services
│   ├── ynab-client.ts    # YNAB API wrapper with rate limiting
│   ├── rate-limiter.ts   # Token bucket rate limiter
│   └── cache.ts          # In-memory TTL cache
├── tools/                # MCP tool implementations
│   ├── user/
│   ├── budgets/
│   ├── accounts/
│   ├── categories/
│   ├── payees/
│   ├── months/
│   ├── transactions/
│   ├── scheduled-transactions/
│   └── analytics/
└── utils/                # Helpers (currency, dates, errors)

Security

| Feature | Description | |---------|-------------| | Read-Only Default | Write operations disabled unless YNAB_READ_ONLY=false | | Token Security | Never commit your YNAB_ACCESS_TOKEN; use environment variables | | Input Validation | All tool parameters validated with Zod schemas | | Rate Limiting | Built-in protection against API quota exhaustion | | Audit Logging | All write operations logged for review |

Contributing

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Make your changes
4. Run tests and linting: npm test && npm run lint
5. Commit your changes (git commit -m 'Add amazing feature')
6. Push to the branch (git push origin feature/amazing-feature)
7. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• YNAB for their excellent budgeting platform and API
• Anthropic for Claude and the Model Context Protocol
• Model Context Protocol for the MCP specification

Related Projects

• YNAB API Documentation
• Model Context Protocol
• Claude Desktop