🌮 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.

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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.

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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.

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Cursor

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

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

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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"
      }
    }
  }
}

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Running from source

git clone https://github.com/madtaco-dev/mcp.git
cd mcp
npm install
npm run build
npm test
npm start

Stdio transport only. The server calls the public MadTaco HTTP API — no database, no secrets beyond an optional API key.

New tools ship as minor releases (1.1, 1.2, …) as the API grows. See llms.txt for the current tool list.

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Links

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

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MIT © 🌮 MadTaco · Built for agents, literally.