ynab-mcp-server

A personal MCP server that gives Claude native access to YNAB budget data.

Architecture

Layer 1: FastMCP reads YNAB's official OpenAPI spec at startup and auto-generates one MCP tool per endpoint.

Layer 2: Custom tools for higher-level workflows: spending summaries by category, payee consolidation/renaming.

Related MCP server: monarch-mcp

Setup

Prerequisites

• uv — Python package manager

• A YNAB Personal Access Token from app.ynab.com/settings/developer

Install

uv sync

Configure

Create a .env file (never committed):

YNAB_API_TOKEN=your_token_here
YNAB_READ_ONLY=false

Run

YNAB_API_TOKEN=your_token uv run ynab-mcp-server

Connecting to Claude Desktop

Edit ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "ynab": {
      "command": "/absolute/path/to/.venv/bin/ynab-mcp-server",
      "env": {
        "YNAB_API_TOKEN": "your_token_here",
        "YNAB_READ_ONLY": "false"
      }
    }
  }
}

Use the absolute path from which ynab-mcp-server after uv sync.

Environment Variables

Testing

npx @modelcontextprotocol/inspector