Bearer keys, prefixed ULIDs, cursor pagination, idempotency on every mutation, signed webhooks. Learn it once for SK Billing; it holds across all of Softknack.
Invoices reference CRM contacts and Catalog items by ID; payments post to the ledger atomically. Bearer keys, prefixed ULIDs, idempotency on every mutation, signed webhooks.
Get a test key, make one authenticated call, and listen for the webhook. The same three moves work for every endpoint in the suite.
Test and live keys are separate environments. Build against sk_test_ without touching a real customer.
One authenticated POST with an idempotency key. Same key + same body always returns the same result.
A signed invoice.created event hits your endpoint — verify the HMAC, act on it, return 200.
curl -X POST https://api.softknack.com/billing/v1/invoices \ -H "Authorization: Bearer sk_live_..." \ -H "Idempotency-Key: 9f2c-4d1a-...-e7b3" \ -H "Content-Type: application/json" \ -d '{ "contact_id": "ctc_01J9X...", "items": [{ "catalog_item_id": "itm_01J9X...", "qty": 1 }], "due_in_days": 7 }'
Signed with HMAC-SHA256, delivered at-least-once, retried on a fixed schedule, and replayable from a dead-letter queue. You will never miss an event because a deploy was mid-flight.
| Event | When it fires |
|---|---|
invoice.created | Drafted — from an agent flow, the API, or by hand. |
invoice.sent | Delivered with its payment link; reminder sequence armed. |
payment.recorded | Razorpay webhook or manual entry — posted to the ledger atomically. |
invoice.overdue | The chase begins via SK Notifications. |
invoice.paid | Settled in full; ledger balanced. |
credit_note.issued | A first-class reversing posting. |
The platform conventions every SK product obeys — learn them once, rely on them everywhere.
Every mutation takes an Idempotency-Key. Same key + body returns the original result; a conflicting body gets 409.
Sortable, debuggable IDs like inv_01J9X... — you can read the type and the time right off the wire.
Stable cursors that never skip or repeat a row when data changes mid-list. No page-offset drift.
Isolation enforced in the database. 404-over-403, so the existence of another tenant's record never leaks.
HMAC-SHA256 on every delivery, with the full retry schedule and dead-letter replay above.
The OpenAPI spec is generated from the code's validators and checked in CI — the docs can't lie.
Drive billing from your own systems: create invoices over REST, subscribe to payment events, and let SK Notifications handle the chase. Or expose invoicing to your own AI agents over MCP with scoped permissions — the same tools SUKI uses to bill from a call.
Generate a hosted payment link for any amount over the API, drop it in a message, and collect via Razorpay — the payment still posts to the ledger and fires payment.recorded.
Auth, errors, pagination, every endpoint and schema — written once for the platform, shared by every product.
docs.softknack.com/billing See pricing →