@madtaco/mcp

🌮 MadTaco — MCP Server

Verification & utility API for AI agents. Tax-ID validation, sanctions screening, company verification, and more — one API, prepaid credits, priced per call. Failed checks cost $0.

The MadTaco API is live. This package exposes it as MCP tools for Claude, Cursor, and any MCP-compatible agent.

npx @madtaco/mcp

No API key required for the tools in v1.0.0 — they map to MadTaco's free endpoints (50 requests/day per IP on the API). Set MADTACO_API_KEY later when paid tools ship in 1.1+ for higher limits.

Tools (v1.0.0)

Tool	API endpoint	Description
validate_tax_id	POST /v1/validate/tax-id	Format/checksum — CL RUT, MX RFC
validate_iban	POST /v1/validate/iban	IBAN checksum and parsing
get_cl_indicator	GET /v1/data/cl/{indicator}	UF, UTM, USD, EUR, IPC (CMF source)

Every response includes credits_charged (always 0 for these tools).

Coming in 1.1+ (same package, grows with the API): create_account, verify_account, get_balance, get_usage, screen_sanctions, verify_company, inspect_domain, validate_email, validate_phone, screen, propose_check.

Quick start — Claude Desktop

Add to claude_desktop_config.json:

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

{
  "mcpServers": {
    "madtaco": {
      "command": "npx",
      "args": ["-y", "@madtaco/mcp"]
    }
  }
}

Restart Claude Desktop. You should see madtaco under MCP tools with the three validators above.

Example prompts in Claude

Validate the Chilean RUT 11.111.111-1 using MadTaco.

Check whether IBAN DE89 3704 0044 0532 0130 00 is valid.

What's today's UF value in Chile?

Get the UF for 2026-07-01.

Claude will call validate_tax_id, validate_iban, or get_cl_indicator and return the JSON from the API.

Cursor

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

{
  "mcpServers": {
    "madtaco": {
      "command": "npx",
      "args": ["-y", "@madtaco/mcp"]
    }
  }
}

Environment variables

Variable	Required	Default	Description
MADTACO_API_BASE	No	https://api.madtaco.dev/v1	API base URL (override for staging)
MADTACO_API_KEY	No	—	Optional X-Api-Key header; not needed for v1.0.0 tools

Example with a custom base (local/staging):

{
  "mcpServers": {
    "madtaco": {
      "command": "npx",
      "args": ["-y", "@madtaco/mcp"],
      "env": {
        "MADTACO_API_BASE": "https://api.madtaco.dev/v1"
      }
    }
  }
}

Development

This directory is developed inside the private MadTaco API repo and published to the public madtaco-dev/mcp repository.

cd mcp
npm install
npm run build
npm test
npm start

Stdio transport only. The server talks exclusively to the MadTaco HTTP API — no database, no secrets beyond an optional API key.

Publish checklist

# From mcp/ after copying to madtaco-dev/mcp
npm login
npm publish --access public

Bump minor versions (1.1.0, 1.2.0, …) as new API endpoints get MCP tools. Update llms.txt when the tool list changes.

Links

• madtaco.dev — product site
• API docs — OpenAPI reference
• Pricing — machine-readable per-operation prices
• llms.txt — agent-oriented overview
• Health — API status

MIT © 🌮 MadTaco · Built for agents, literally.