Integration API

Bill from your own systems

Connect a POS, e-commerce checkout, or custom app to Simple Bills. Create GST invoices, record payments, download PDFs, and keep books in sync — without retyping into the web UI.

Open interactive docs Download OpenAPI spec

API base URL: https://api.simplebills.in/api · Auth: X-Api-Key: ensk_live_… on every integration request · Rate limit: 60 requests/minute per key (default)

What you can do

Create sale invoices with customers, line items, extra charges, and inline payments
Fetch, list, and download invoice PDFs
Record and void payments on existing invoices
Record refunds on credit notes (sale returns)
List company bank accounts for bank-mode payments

Customers are matched by phone within your company. New customers and line-item products are created automatically when needed.

Quick start

1. Generate an API key

Sign in to Simple Bills as a company admin, then generate a key from the app (or call the key-management endpoint with your Sanctum token and X-Company-Id). Copy data.api_key immediately — it is shown only once.

2. Create an invoice

curl -X POST https://api.simplebills.in/api/integration/v1/invoices \
  -H "X-Api-Key: ensk_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "invoice_date": "2026-07-03",
    "customer": { "name": "Rahul Sharma", "phone": "9876543210" },
    "lines": [
      { "name": "Service fee", "quantity": 1, "unit_price": 1000, "gst_rate": 18 }
    ],
    "payments": [
      { "paid_amount": 1180, "payment_date": "2026-07-03", "payment_mode": "cash" }
    ],
    "external_reference": "order-9912"
  }'

3. Fetch or download

# Get invoice JSON
curl https://api.simplebills.in/api/integration/v1/invoices/101 \
  -H "X-Api-Key: ensk_live_YOUR_KEY"

# Download PDF
curl -o invoice-101.pdf \
  https://api.simplebills.in/api/integration/v1/invoices/101/download \
  -H "X-Api-Key: ensk_live_YOUR_KEY"

Endpoints

Method	Path	Description
GET	`/integration/v1/bank-accounts`	List payable bank accounts
POST	`/integration/v1/invoices`	Create sale invoice
GET	`/integration/v1/invoices/{id}`	Fetch invoice
GET	`/integration/v1/invoices/{id}/download`	Download invoice PDF
GET	`/integration/v1/invoices`	List or search invoices
POST	`/integration/v1/invoices/{id}/payments`	Record payment
POST	`/integration/v1/invoices/{id}/void`	Void invoice
POST	`/integration/v1/payments/{id}/void`	Void payment
GET	`/integration/v1/credit-notes/{id}/refunds`	Refund summary
POST	`/integration/v1/credit-notes/{id}/refunds`	Record refund

Company admins manage keys via /api/integration-key/generate, index, and revoke (Sanctum auth). See the interactive docs for request/response schemas.

Authentication

Integration calls — X-Api-Key: ensk_live_… or Authorization: Bearer ensk_live_…
Key management — Sanctum user token + X-Company-Id header

No X-Financial-Year-Id header is required — the active financial year for your company is selected automatically.

Response format

All responses use a standard envelope:

{
  "status": true,
  "message": null,
  "data": {},
  "meta": null,
  "errors": null,
  "code": null
}

OpenAPI documentation

Full request/response schemas, examples, and error codes are available as OpenAPI 3.0:

Swagger UI — try endpoints in the browser
openapi.yaml — machine-readable spec for code generators

Interactive docs must be enabled on the API server (ENSO_OPENAPI_ENABLED=true in production).

Common error codes

INVALID_API_KEY (401) — missing, invalid, or revoked key
ACCOUNTING_NOT_CONFIGURED (422) — company setup incomplete
INSUFFICIENT_STOCK (422) — tracked product without stock
INVOICE_NOT_FOUND / PAYMENT_NOT_FOUND (404)

Building an integration?

We can help you map fields from your POS or platform. Contact us or call +91 70961 20201.