thelawin.dev Documentation
Welcome to the thelawin.dev API documentation. Generate EU-compliant ZUGFeRD and Factur-X invoices with a simple REST API.
Quick Start
New to thelawin.dev? Start with the Getting Started Guide.
What is thelawin.dev?
thelawin.dev is a developer-first API for generating electronic invoices that comply with European standards:
- EN 16931 - EU Core Invoice specification
- ZUGFeRD 2.3 - German e-invoice standard
- Factur-X 1.0 - French/EU standard
Key Features
| Feature | Description |
|---|---|
| Truly Stateless | Your invoice data is never stored. PDF returned as Base64. |
| 3 Templates | Minimal, Classic, and Compact designs |
| Built-in Validation | Validate existing PDFs for compliance |
| 8 Official SDKs | TypeScript, Python, Ruby, Kotlin, Java, Swift, Dart, C# |
| MCP Server | AI integration for Claude, GPT, and more |
API Overview
Generate Invoice
bash
curl -X POST https://api.thelawin.dev/v1/generate \
-H "X-API-Key: env_live_..." \
-H "Content-Type: application/json" \
-d '{
"template": "minimal",
"invoice": {
"number": "2026-001",
"date": "2026-01-15",
"seller": {"name": "Acme GmbH", "vat_id": "DE123456789", "city": "Berlin", "country": "DE"},
"buyer": {"name": "Customer AG", "city": "München", "country": "DE"},
"items": [{"description": "Consulting", "quantity": 8, "unit": "HUR", "unit_price": 150, "vat_rate": 19}]
}
}'Validate PDF
bash
curl -X POST https://api.thelawin.dev/v1/validate \
-H "X-API-Key: env_live_..." \
-F "file=@invoice.pdf"Next Steps
- Getting Started - Create your first invoice
- Authentication - API key management
- API Reference - Full endpoint documentation
- SDKs - Official client libraries