NestDaddy

invowerk

dev.invowerk/xrechnung-e-invoice-validator · v1.0.1

E-invoice checker for ZUGFeRD, Factur-X, XRechnung and Peppol BIS. Free web tool, API and MCP.

Connect Remote server

Terminal
claude mcp add --transport http xrechnung-e-invoice-validator https://api.invowerk.dev/mcp/ --header "X-API-Key: <X_API_KEY>"
~/.cursor/mcp.json
{
  "mcpServers": {
    "xrechnung-e-invoice-validator": {
      "url": "https://api.invowerk.dev/mcp/",
      "headers": {
        "X-API-Key": "<X_API_KEY>"
      }
    }
  }
}
.vscode/mcp.json
{
  "servers": {
    "xrechnung-e-invoice-validator": {
      "type": "http",
      "url": "https://api.invowerk.dev/mcp/",
      "headers": {
        "X-API-Key": "<X_API_KEY>"
      }
    }
  }
}
Claude Desktop
Settings > Connectors > Add custom connector
URL: https://api.invowerk.dev/mcp/

Replace the values in angle brackets with your own. Keys stay on your machine; we never see them.

Tools 6 found in our last check

  • validate_invoice

    Check an e-invoice against EN 16931 and German rules. Input: `invoice_base64` is the base64 of an XML invoice (UBL or CII) or a ZUGFeRD / Factur-X PDF, at most 4 MB decoded; or pass the file as a download link in `file`. `explain=true` adds an explanation to findings whose rule…

  • render_invoice

    Render an XML e-invoice (UBL or CII, e.g. XRechnung) as a readable HTML page. invowerk uses the KoSIT XRechnung visualization. Use it to show a person what an e-invoice contains. Input: `invoice_base64` is the base64 of the XML, at most 4 MB decoded, or pass the file as a downlo…

  • explain_errors

    Explain rule codes in plain language. Works without an API key. Covers the codes of `validate_invoice` findings and hints: EN 16931, XRechnung, ZUGFeRD and invowerk's own hint codes (IW-*). Input: `codes` is a list of one or more codes, e.g. ["BR-CO-18", "BR-DE-21"]. Duplicates…

  • generate_invoice

    Create a valid EN 16931 e-invoice (UBL or CII XML) from JSON. Input: `invoice` is a JSON object keyed on EN 16931 Business Terms, the same schema as `POST /v1/generate`, at most 4 MB. Main fields: `syntax` ("ubl" default, or "cii"), `flavor` ("en16931" default, or "xrechnung", w…

  • parse_invoice

    Read an existing e-invoice into JSON keyed on EN 16931 Business Terms. The JSON is the input format of `generate_invoice`, so you can edit it and create the invoice again. Input: `invoice_base64` is the base64 of an XML invoice (UBL or CII) or a ZUGFeRD / Factur-X PDF, at most 4…

  • convert_invoice

    Convert an e-invoice to UBL or CII. The result is checked before it is returned. Input: `invoice_base64` is the base64 of an XML invoice or a ZUGFeRD / Factur-X PDF, at most 4 MB decoded; or pass the file as a download link in `file`. `target_syntax` is "ubl" or "cii". `target_f…

Headers

NameDescription
X-API-Key
Optional, secret
Optional API key; the anonymous tier works without it

Details

Endpointhttps://api.invowerk.dev/mcp/ (Streamable HTTP)
First published4 Oct 2026
Last updated4 Oct 2026
Registry namedev.invowerk/xrechnung-e-invoice-validator

More finance and crypto servers See all

Listing data from the official MCP registry. Status and tools from NestDaddy's daily check. Browse all MCP servers.