# tinker.types.BillingUsageSession

## *class* [**tinker.types.BillingUsageSession**](https://github.com/thinking-machines-lab/tinker/blob/main/src/tinker/types/billing_usage_response.py#L121)(*[BaseModel](https://github.com/thinking-machines-lab/tinker/blob/main/src/tinker/_models.py#L88)*)

Session-level attributes tied to a session.

**Fields:**

- [**user_metadata**](https://github.com/thinking-machines-lab/tinker/blob/main/src/tinker/types/billing_usage_response.py#L124) (*dict[str, str] | None*) – The session's customer-supplied user_metadata (as passed to CreateSessionRequest.user_metadata); None when the session has none.

## Referenced by

- [tinker.types.BillingUsageResponse](https://tinker-docs.thinkingmachines.ai/tinker/api-reference/types/billingusageresponse/index.md)