# formkorrekt

> API for German e-invoices: validate XRechnung (UBL/CII) and ZUGFeRD against XRechnung / EN 16931 with rule codes and German fix hints, deterministic XML repair, generation from JSON. Servers in Nuremberg; documents are processed in memory and not stored. Monthly free allowance, then prepaid credit. No tax advice.

## Docs

- [Quickstart](https://formkorrekt.com/quickstart): first API call with curl, error codes
- [API reference](https://formkorrekt.com/docs): interactive reference
- [OpenAPI](https://formkorrekt.com/openapi.json): OpenAPI 3.1 description of the REST API
- [MCP server](https://formkorrekt.com/docs/mcp): remote MCP endpoint https://formkorrekt.com/mcp (Streamable HTTP, API key as 'Authorization: Bearer sk_…'), setup for Claude, Cursor, VS Code
- [MCP server card](https://formkorrekt.com/.well-known/mcp/server-card.json): tools and input schemas

## Articles

- [Wissen](https://formkorrekt.com/wissen)

## Optional

- [Sign up](https://formkorrekt.com/signup): free allowance, no payment details
- [Terms](https://formkorrekt.com/agb)
- [Privacy](https://formkorrekt.com/datenschutz)