# tinker.types.SamplingPrefillBillingEvent *Generated from tinker 0.30.4 at commit [`1e5777e`](https://github.com/thinking-machines-lab/tinker/tree/1e5777ef1e0bb2bae6d9b8d63a6144eec405377d). Source links point at that snapshot.* ## *class* [**tinker.types.SamplingPrefillBillingEvent**](https://github.com/thinking-machines-lab/tinker/blob/1e5777ef1e0bb2bae6d9b8d63a6144eec405377d/src/tinker/types/billing_usage_response.py#L31)(*[StrictBase](https://github.com/thinking-machines-lab/tinker/blob/1e5777ef1e0bb2bae6d9b8d63a6144eec405377d/src/tinker/_models.py#L76)*) Prompt (prefill) tokens processed while sampling. **Fields:** - [**type**](https://github.com/thinking-machines-lab/tinker/blob/1e5777ef1e0bb2bae6d9b8d63a6144eec405377d/src/tinker/types/billing_usage_response.py#L34) (*Literal['sampling_prefill']*) - [**cached**](https://github.com/thinking-machines-lab/tinker/blob/1e5777ef1e0bb2bae6d9b8d63a6144eec405377d/src/tinker/types/billing_usage_response.py#L36) (*bool*) – True when the tokens were served from the prefill cache (billed at the discounted cached rate); False for full-rate prefill - [**token_count**](https://github.com/thinking-machines-lab/tinker/blob/1e5777ef1e0bb2bae6d9b8d63a6144eec405377d/src/tinker/types/billing_usage_response.py#L40) (*int*) – Prefill token count for the bucket