@trailfolio/mcp

Canadian financial calculator tools for AI assistants, via the Model Context Protocol.

Mortgage affordability, income tax, closing costs, Canada Child Benefit, Smith Manoeuvre, and more — powered by the Trailfolio API.

Setup

1. Get an API key

Create one at trailfolio.com/settings/api-keys.

2. Configure your MCP client

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "Trailfolio": {
      "command": "npx",
      "args": ["-y", "@trailfolio/mcp"],
      "env": {
        "TRAILFOLIO_API_KEY": "tf_live_..."
      }
    }
  }
}

Windows: Use cmd as the command:

{
  "mcpServers": {
    "Trailfolio": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "@trailfolio/mcp"],
      "env": {
        "TRAILFOLIO_API_KEY": "tf_live_..."
      }
    }
  }
}

Claude Code

claude mcp add trailfolio -- npx -y @trailfolio/mcp

Then set your API key as an environment variable or in your shell profile:

export TRAILFOLIO_API_KEY="tf_live_..."

Environment Variables

| Variable | Required | Default | Description | |----------|----------|---------|-------------| | TRAILFOLIO_API_KEY | Yes | — | API key from trailfolio.com/settings/api-keys | | TRAILFOLIO_API_URL | No | https://api.trailfolio.com/v1 | API base URL override |

Available Tools

| Tool | Description | |------|-------------| | calculate_mortgage_affordability | Max purchase price with stress test (CMHC/OSFI rules) | | calculate_buyer_closing_costs | Land transfer tax, CMHC insurance, legal fees | | calculate_seller_closing_costs | Realtor commission, legal fees, discharge fee | | calculate_canadian_income_tax | Federal + provincial tax, CPP/EI, dividends, capital gains | | get_tax_constants | CPP/EI rates, RRSP/FHSA limits, dividend gross-up rates | | calculate_mortgage_timeline | Amortization schedule with renewal/refinance events | | calculate_canada_child_benefit | CCB monthly payments with income phaseout | | calculate_heloc_interest | Interest split: tax-deductible vs personal | | calculate_smith_manoeuvre | Convert mortgage debt to deductible investment debt |

All tools use snake_case parameters (MCP convention). The server translates to camelCase for the API.

License

MIT