GST E-Invoicing Software | E-Invoice API
REST API for IRN generation. Webhooks for status post-back.
Programmatic IRN, e-way bill, cancellation and CDNR via a REST API. OAuth-style authentication per GSTIN. Idempotency keys built in. Webhooks fire on IRN success, failure and cancellation.
What the system does
Capability, input, output.
| Capability | Input | Output |
|---|---|---|
| IRN endpoint | POST invoice JSON | IRN + signed QR + EWB |
| Cancellation endpoint | POST IRN + reason within 24h | Cancellation confirmation |
| CDNR endpoint | POST credit/debit note JSON | CDNR IRN |
| Webhooks | Configured webhook URL | Event push on IRN, EWB, cancellation |
| Idempotency | Idempotency-Key header | Repeated calls return original response |
-
IRN endpoint
- Input
- POST invoice JSON
- Output
- IRN + signed QR + EWB
-
Cancellation endpoint
- Input
- POST IRN + reason within 24h
- Output
- Cancellation confirmation
-
CDNR endpoint
- Input
- POST credit/debit note JSON
- Output
- CDNR IRN
-
Webhooks
- Input
- Configured webhook URL
- Output
- Event push on IRN, EWB, cancellation
-
Idempotency
- Input
- Idempotency-Key header
- Output
- Repeated calls return original response
Compliance + integrations
Programmatic, with the same compliance.
The API is a thin layer over the same authorised GSP integration. Every API call respects the GSTN schema and the rate-limit policy. Audit trail is per-call.
Regulations we work within
-
Rule 48(4), CGST Rules
API calls produce IRN-stamped invoices in the prescribed format.
Connects to
- OAuth 2.0 Per-GSTIN authentication
- Webhooks Event-driven status
E-Invoice API FAQ
What buyers ask.
What happens on rate limit?
The API returns 429 with retry-after. The GSP rate limit is shared across the GSTIN; the system queues and retries automatically when called via the in-product flow. Direct API calls should respect retry-after.
Idempotency key. How long is it valid?
Idempotency keys are valid for 24 hours. Same key + same payload returns the original response. Same key + different payload returns 400.
Webhooks. Reliable delivery?
Webhooks have at-least-once delivery with retries (1m, 5m, 30m, 1h, 6h). Each webhook carries a signature; verify with the shared secret.
More in GST E-Invoicing Software
Related features
Get an API key. Generate your first IRN programmatically.
API access free for one GSTIN. Generate an OAuth client; call POST /irn with a sample payload; receive IRN in under 2 seconds.