The Hisabi Developer API v1 — Invoices and Clients, Programmatically
A REST API for the things you already do in the dashboard: create clients, issue invoices, send them, mark them paid, pull the PDFs. Bearer-key auth, an OpenAPI 3.1 spec, and it's included on every plan.
If your business issues invoices from its own system — a booking platform, a store backend, an internal tool — you shouldn't have to retype them into a dashboard. The Developer API v1 exposes Hisabi's core objects over plain REST so your code can do it instead.
What You Can Do
The v1 API covers four resource areas:
- Clients — list, create, fetch, update, and delete the people and companies you bill.
- Invoices — create and list invoices, fetch one, update a draft, send it by email, mark it paid, and download the finished PDF.
- Batch — create up to 100 invoices in one call, with per-row error reporting.
- Brand assets — fetch pre-signed URLs for your logo and signature to reuse in your own flows.
Designed to Be Boring
Auth is a Bearer API key you create in your workspace settings. Responses follow the same shape as the rest of Hisabi: { data } on success, { error } on failure. The full machine-readable contract lives at /api/v1/openapi.json — an OpenAPI 3.1 document you can drop into Postman, Scalar, or your codegen tool of choice.
Everything is scoped to your workspace. A key can only ever see and touch the data of the workspace that issued it.
Included on Every Plan
The API is part of the product, not an enterprise add-on — it's available on every plan, including Free. Your plan's existing invoice and AI quotas apply to API-created objects the same way they apply in the dashboard.
Start at the developer page for the quickstart, endpoint reference, and example requests.