E-invoicing API for developers: send invoices, get the NBR result
Integrate your POS, ERP or custom software with a small REST API. Send an invoice, receive validation results and the NBR status, and print the QR code at the point of sale.
What the API offers
- POST an invoice with a required Idempotency-Key header, so a retry never creates a duplicate.
- Sign immediately (sign=now) and receive the QR code to print on the receipt.
- GET one invoice or a list with its NBR status.
- API keys per integration with read and write abilities, and a per-key rate limit.
- Signed webhooks for inbound events and signed callbacks when the NBR answers.
- A machine-readable OpenAPI description at /api/v1/openapi.json.
Security
- HTTPS only; keys are shown once and stored as a fingerprint.
- Webhook and callback signatures use HMAC-SHA256 over the timestamp and body, with a short validity window.
- Callback addresses must be public https addresses and are protected against requests to internal networks.
- Cross-origin browser access is closed unless you list your origins.
Test before you go live
Use the dry-run endpoint to see the full validation result for a payload without saving or sending anything, and the NBR sandbox for end-to-end tests.