API Reference

The Summa API enables direct integration with your POS system. After each sale, an API call creates a receipt stamp — a one-time URL that’s printed as a QR code on the receipt.

Authentication

Every API call requires an API key. The key is sent as a Bearer token in the Authorization header.

Create an API key under Settings → API Keys in your shop dashboard. Settings → API Keys
Copy the key immediately — it’s only shown once.
Send the key as a header: Authorization: Bearer YOUR_KEY

Create Receipt Stamp

POST /api/receipt-stamp

Creates a single-use receipt stamp. The returned URL is printed as a QR code on the receipt. Each code is single-use and expires after 48 hours.

Request body

The request body is optional. If your shop has only one program, it’s selected automatically. With multiple programs, use programId to specify which program should receive the stamp.

Response body

url: Full URL for the QR code — the customer scans this with their phone.
code: The stamp code (part of the URL). Useful for logging or debugging.
expiresAt: Expiry timestamp in ISO 8601 format. After this time, the code can no longer be redeemed.

Example

curl -X POST https://your-domain.com/api/receipt-stamp \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{}'

Error Codes

Status Code	Meaning
`401`	API key missing or invalid. Check the Authorization header.
`400`	Invalid program. The programId doesn’t exist or doesn’t belong to your shop.
`403`	No active subscription. Receipt stamps require an active Summa subscription.

Limits

Receipt stamps require an active Summa subscription. During the free trial (30 days), the API works without restrictions. After that, an expired or cancelled subscription blocks access (HTTP 403).