automationsmanufaktur-labs/open-invoice-germany

Why? From 2025 German B2B must be able to receive structured e-invoices; from 2027/2028 sending becomes mandatory. Many freelancers and SMEs pay a monthly fee just to stay compliant. This project makes it free and open — you host it yourself, your data stays with you.

⚠️ Not tax or legal advice. GoBD compliance additionally requires the user’s own process documentation (Verfahrensdokumentation). All legal references with sources live in COMPLIANCE.md (single source of truth). No warranty.

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🗣️ Talk to it with Claude Code (MCP)

Connect your local instance to Claude Code or Claude Desktop and create legally sound invoices just by describing them:

“Create an invoice to Müller GmbH for 3 hours of consulting at €95, delivered today, finalise it and export the XRechnung.”

Claude calls the right tools in order (create customer/service → invoice → finalise → PDF + XRechnung). Finalising enforces the § 14 UStG mandatory fields — non-compliant invoices are rejected. The invoice is created and stored locally. Setup + examples: docs/MCP.md.

npm run mcp   # start the MCP server (stdio) / wire it into Claude Code via .mcp.json

🔒 Data protection (GDPR). The app core runs 100% locally, but the MCP feature is optional and not automatically GDPR-compliant: when you let a cloud LLM (e.g. Claude) create the invoice, the data you describe (customer name, items, amounts = personal data) is sent to that provider and processed on your behalf (Art. 28 GDPR). For business use with real personal data, either use a local model (the MCP server is model-agnostic) or a commercial API with a DPA — note that Claude Code/Desktop always use Anthropic’s cloud and the consumer Pro/Max subscription has no DPA. List the provider as a sub-processor in your records and privacy policy. Details: docs/MCP.md. Not legal advice.

Features

• Voice control via MCP (Claude Code/Desktop) — see above.
• GoBD core: finalisation (draft → immutable), gapless number ranges, append-only audit hash-chain, cancellation instead of deletion.
• § 14 UStG: mandatory-field check blocks finalisation when data is missing.