> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nozle.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Create Credit Top-up Purchase

> Start checkout for a fixed product-credit package

**Auth:** secret key only. Publishable keys are rejected. `Idempotency-Key` is required.

```json theme={null}
{
  "customer_id": "customer_123",
  "credit_system_code": "ai_credits",
  "top_up_package_code": "starter_pack"
}
```

The response returns the pending purchase snapshot and hosted `payment_url`. Navigate the same page to that URL.

<Warning>
  Creating checkout does not grant credits. Credits are materialized only after Nozle records and validates a confirmed successful payment.
</Warning>