thelawin.dev Documentation
A REST API for EU e-invoices. Send JSON, get back a PDF/A-3 with the embedded XML that auditors and government portals expect. Nothing is stored on our side.
Supported standards: EN 16931 (EU Core Invoice), ZUGFeRD 2.4 (Germany), and Factur-X 1.0.8 (France/EU).
New here? Start with the Getting Started Guide.
What you get
| Feature | Description |
|---|---|
| Stateless | Invoice data is processed in memory and returned as Base64. Nothing written to disk. |
| 3 templates | Minimal, Classic, and Compact |
| Pre-validation | Check a JSON payload before burning a credit. /v1/validate is free. |
| 8 SDKs | TypeScript, Python, Ruby, Kotlin, Java, Swift, Dart, C# |
| MCP server | Usable directly from Claude, GPT, and other agents |
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 Invoice Data
Free pre-validation for invoice JSON. No API key, no quota consumed:
bash
curl -X POST https://api.thelawin.dev/v1/validate \
-H "Content-Type: application/json" \
-d '{
"format": "auto",
"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}]
}
}'Retrieve Invoice from PDF
Extract structured invoice data from an existing PDF/XML e-invoice (1 credit):
bash
curl -X POST https://api.thelawin.dev/v1/retrieve \
-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