> ## 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.

# Check Credit Usage

> Calculate an advisory credit decision without mutation

**Auth:** secret key only.

```json theme={null}
{
  "customer_id": "customer_123",
  "feature_code": "agent_execution",
  "credit_system_code": "ai_credits",
  "properties": {},
  "occurred_at": "2026-07-20T12:00:00.750Z"
}
```

The response includes `advisory: true`, exact `metric_amount`,
`credits_required`, the available balance, and the projected source
selection:

```json theme={null}
{
  "advisory": true,
  "allowed": true,
  "metric_amount": "1",
  "credit_system": "ai_credits",
  "credits_required": "2",
  "available": "625",
  "projected_remaining": "623",
  "projected_deductions": [
    {
      "balance_source_id": "0f89...",
      "source_type": "subscription_grant",
      "amount": "2",
      "remaining": "373"
    }
  ]
}
```

Projected deductions follow the same deterministic expiry, priority, creation
time, and ID ordering as an authoritative consume, but no source or ledger row
is changed. Another request can spend credits before a later track call, so
this endpoint is not authorization to perform irreversible work.