invowerk — Claude Code MCP server: invoices and setup
Validates ZUGFeRD, Factur-X, XRechnung and Peppol BIS e-invoices. Use it from Claude Code and other MCP clients over HTTP.
claude mcp add --transport http xrechnung-e-invoice-validator https://api.invowerk.dev/mcp/What invowerk does
invowerk validates ZUGFeRD and Factur-X PDFs, XRechnung in UBL or CII form, and Peppol BIS Billing. XRechnung checks use the KoSIT validator, while PDF files also go through PDF/A validation. Results include the verdict, applied rule sets and the document SHA-256.
The server is available through https://api.invowerk.dev/mcp/, a REST API and a browser tool. Files are handled in memory rather than stored. The anonymous tier works without an API key but has a lower rate limit; adding X-API-Key raises plan limits, with 500 free credits per month for the API and MCP service.
It supports Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Cline, Zed and Windsurf (Devin Desktop). A failed validation still returns a response with valid: false and individual findings.
What it helps with
- validate a ZUGFeRD or Factur-X PDF
- check an XRechnung UBL or CII file
- inspect a Peppol BIS Billing invoice
- return the document hash and rule results
- identify findings in an e-invoice
Example prompts for the agent
- Validate
beispiel-xrechnung.xmland list any business-rule findings. - Check this ZUGFeRD PDF for PDF/A compliance and return its SHA-256.
- Detect the invoice format and explain every validation problem.
How to install invowerk
Platform CLI: remote server
claude mcp add --transport http xrechnung-e-invoice-validator https://api.invowerk.dev/mcp/Platform CLI: remote server
codex mcp add invowerk --url https://api.invowerk.dev/mcp/Config file
{
"mcpServers": {
"invowerk": {
"url": "https://api.invowerk.dev/mcp/"
}
}
}Config file
{
"servers": {
"invowerk": {
"type": "http",
"url": "https://api.invowerk.dev/mcp/"
}
}
}Platform CLI: remote server
gemini mcp add -t http invowerk https://api.invowerk.dev/mcp/Step by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about invowerk
How do I install invowerk in Claude Code?
Run claude mcp add --transport http xrechnung-e-invoice-validator https://api.invowerk.dev/mcp/, then run claude mcp add --transport http invowerk https://api.invowerk.dev/mcp/.
What does invowerk do?
This MCP server validates ZUGFeRD, Factur-X, XRechnung and Peppol BIS Billing invoices. It returns the verdict, findings and the document SHA-256.
Can I use invowerk without an API key?
Yes. The anonymous tier works without a key at a lower rate limit; an X-API-Key header applies your plan limits.
