REST · JSON · v1

Control your billing stack from anywhere

The same data you use in the dashboard-clients, invoices, quotations, debit notes, inventory, expenses, email sendouts, and analytics-available over a versioned API. Authenticate with your account API key and build integrations without scraping the UI.

Developer guide Interactive reference Cursor skill (.md)

Base URL

Use this URL in integrations (production). On localhost you still call your dev server; this is the public endpoint customers use.

https://api.onestopinvoice.com/v1

What you can do

Clients & documents

Client CRUD with dedupe, plus invoices, quotations, and debit notes with line items.

Inventory & expenses

Keep stock and costs aligned with your books and PDFs.

Send & analytics

Email document PDFs and pull summary analytics for dashboards.

Secure by API key

Per-account keys; same subscription and suspension rules as the web app.

Authentication

Send your key as Authorization: Bearer <api_key> or X-API-Key: <api_key> . Create or rotate it under Dashboard → API Key.

?api_key= is for quick tests only-not for production.

Response shape

Responses use {"ok": true, "data": …} or {"ok": false, "error": {"code", "message", "details"}}.

Endpoints overview

GET /v1/me account summary
GET|POST /v1/clients, GET|PATCH|DELETE /v1/clients/{id} dedupe on phone / email / GSTIN
GET|POST /v1/invoices, GET|PATCH|DELETE /v1/invoices/{id}
GET|POST /v1/quotations, GET|PATCH|DELETE /v1/quotations/{id}
GET|POST /v1/debit-notes, GET|PATCH|DELETE /v1/debit-notes/{id}
GET|POST /v1/inventory, GET|PATCH|DELETE /v1/inventory/{id}
GET|POST /v1/expenses, GET|PATCH|DELETE /v1/expenses/{id}
POST /v1/sendouts email PDF
GET /v1/analytics/summary

Read the developer guide Raw README.md Download Cursor skill

Reference appendix error codes, file map, and notes for AI assistants