# WhiteBooks e-Invoice API for Developers

> WhiteBooks e-Invoice API: GSP-certified REST API for real-time IRN (Invoice Reference Number) generation, signed JSON retrieval, QR code embedding, and cancellation. Connects to the official GST IRP. Sub-100ms latency.

URL: https://whitebooks.in/api/e-invoice-api-for-developers

## Key facts
- Endpoints: Generate IRN, Cancel IRN, Fetch IRN, Get GSTIN details, Get e-Way Bill from IRN
- Response time: <100 ms typical · 200-400 ms p95 for single invoice · 2-4 s for 100-invoice batch
- Bulk IRN: up to 1,000 invoices per call with per-row error codes
- Signed JSON + QR code returned in every successful response
- 24-hour cancellation window supported via Cancel endpoint
- Webhook callbacks for asynchronous IRN generation on IRP recovery
- Base URLs: Sandbox apisandbox.whitebooks.in/einvoice · Production api.whitebooks.in/einvoice
- SDKs: Java, Node.js, Python · OpenAPI 3.0 spec · Postman collection
- KSA ZATCA Phase 2 e-invoicing also supported via separate endpoint

## Contact
- Sales: +91 9032111788 · sales@whitebooks.in
- Technical support: +91 9032111388 · support@whitebooks.in
- Address: 8-2-682/3/A/24, Road No 12, Banjara Hills, Hyderabad, Telangana 500034, India
- Parent company: BVM IT Consulting Services India Private Limited (www.bvmcs.com)

## Machine-readable resources
- Site-wide index: https://whitebooks.in/llms.txt
- Full content: https://whitebooks.in/llms-full.txt
- AI crawler policy: https://whitebooks.in/.well-known/ai.txt
- Sitemap: https://whitebooks.in/sitemap-index.xml
- Robots: https://whitebooks.in/robots.txt