Embedded GST Automation for Vertical SaaS — White-Label GSP Gateway, OAuth-Per-Tenant, No GSP License Needed
Add GST + e-Invoice + e-Way Bill to your SaaS in a sprint. Multi-tenant by design. Per-customer OAuth scopes.
Read the multi-tenant guide — how to plug WhiteBooks into your tenant model in 2 hours
The problem
For CTO / Head of Product at a vertical SaaS (clinic-management, restaurant POS SaaS, salon SaaS, EdTech billing). Your customers want to send GST invoices from inside your product. You don't want to be a GSP. You want to embed.
How WhiteBooks solves it
- Multi-tenant OAuth: one parent client_credentials registers your SaaS; child OAuth scopes provision per-tenant tokens — each tenant's data is isolated.
- Per-tenant DPDP consent flow: consent grant + retention metadata logged on every fetch, retrievable by tenant.
- White-label branding option: customer-facing PDFs, emails, and IRN responses can carry your SaaS brand instead of WhiteBooks.
- Webhook fan-out per tenant: each tenant's subscription delivers only its own events.
Key APIs
| Tool / Endpoint | What it does | Path |
|---|---|---|
oauth.provision_tenant | Mint child token per tenant | /api/v1/oauth/provision |
gst.verify_gstin | Tenant onboarding | /api/v1/gstin/{gstin} |
einvoice.generate_irn | Per-tenant IRN | /api/v1/generate-irn |
eway.generate | Per-tenant EWB | /api/v1/generate |
webhooks.subscribe | Per-tenant event subscription | /api/v1/webhooks/subscribe |
Compliance angle
Tenant data isolation (per-tenant encryption keys), DPDP consent flow per tenant, white-label branding (optional), billing pass-through (you bill your customer, we bill you on aggregated volume).
Live numbers
- Throughput: 1,000 invoices / EWBs per single API call (bulk mode).
- Latency: p50 87 ms IRN, p95 312 ms — live at whitebooks.in/status.
- Uptime: 99.994% rolling 30-day; 99.99% SLA with credits on Enterprise.
- Region: Mumbai + Hyderabad active-active; KSA in
me-south-1.
Sample architecture
Sample customer pattern
A clinic-management SaaS with 12,000 SMB clinics on the platform embeds WhiteBooks to issue GST invoices for clinic billing. Each clinic has its own tenant-scoped OAuth token; the clinic UI carries the SaaS brand; the SaaS receives a monthly volume bill from WhiteBooks.
Frequently asked questions
How does the multi-tenant OAuth model work?
You register your SaaS once as a parent client. For every customer on your platform you call oauth.provision_tenant which returns a child token scoped to that tenant's GSTIN. Tokens are independently revocable and auto-rotate.
Do we have to become a GSP ourselves?
No. The GSP licence remains with WhiteBooks. You consume our API as a regular OAuth client; the GSP-to-GSTN connectivity, certification, and audit overhead stays on our side.
Can our brand show on the customer-facing PDF / IRN?
Yes, with the white-label add-on. The IRN response carries your SaaS brand in the public-facing fields; the audit log retains the GSP relationship for regulator inspection.
How is billing done?
Pass-through: you bill your customer at whatever you charge; we bill you on aggregated monthly volume across all tenants. Volume tiers start at 1,000 IRN/month with discounts at 10K, 100K, 1M.
What about DPDP consent for each tenant?
Consent is logged per-tenant per-fetch with a consent reference (typically your customer ID + workflow). Tenants can request their own audit log via your support flow; we never expose tenant-A data to tenant-B.
Get started
Related use cases: Logistics · Retail · Manufacturing · Fintech · Pharma · E-Commerce · SaaS · CA Firms · ERP Providers
Reference: All APIs hub · /docs/gst · /docs/einvoice · /docs/eway · Pricing · Architecture · Status · Changelog