validate_xrechnung uploads an XRechnung XML file (UBL or CII) or a ZUGFeRD PDF to POST https://checkxrechnung.com/v1/validate (file_path or xml).
validate_zugferd uploads a PDF to POST https://checkxrechnung.com/v1/zugferd/validate (file_path). PDF/A-3 check, profile, EN 16931 CII Schematron, rule_url.
extract_zugferd uploads a PDF to POST https://checkxrechnung.com/v1/zugferd/extract (file_path) and returns the raw XML plus a JSON summary.

The free limit is shared: 50 requests per IP per UTC day, 10 per minute. XML validation is 5 MB. The ZUGFeRD tools are 10 MB.

validate_xrechnung takes exactly one of file_path or xml. validate_zugferd and extract_zugferd take file_path only.

Validation output is valid plus errors[]. Each error has rule_id, severity, location, message, hint, and rule_url when a rule code is present. rule_url is the API value when the response includes rule_url or ruleUrl; otherwise https://checkxrechnung.com/fehler/<code> (lowercase). extract_zugferd returns ok, summary, and xml.

The service reports persisted: false. The tools call the network, so they are not a local read-only check. Batch volume: https://checkxrechnung.com/api-waitlist

Package name: xrechnung-validator-mcp. Registry name in server.json: io.github.wenboteng/xrechnung-validator (mcpName matches). Not submitted to the MCP registry yet. Build with npm run build (node dist/index.js) or, after publish, npx -y xrechnung-validator-mcp.

Claude Desktop

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

{
  "mcpServers": {
    "xrechnung-validator": {
      "command": "npx",
      "args": ["-y", "xrechnung-validator-mcp"]
    }
  }
}

Cursor

~/.cursor/mcp.json or the project file .cursor/mcp.json:

{
  "mcpServers": {
    "xrechnung-validator": {
      "command": "npx",
      "args": ["-y", "xrechnung-validator-mcp"]
    }
  }
}

From a checkout, before the npm publish:

{
  "mcpServers": {
    "xrechnung-validator": {
      "command": "node",
      "args": ["mcp/dist/index.js"]
    }
  }
}

VS Code

.vscode/mcp.json:

{
  "servers": {
    "xrechnung-validator": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "xrechnung-validator-mcp"]
    }
  }
}