# Keys and spend

Who may call, and what it cost.

A key carries its own rate and its own ceiling. The log keeps every attempt made behind a request. Usage is those attempts added up against what is left.

Issue one key per surface, give it its own rate and ceiling, and revoke it without touching the others. Point a provider's own secret at it instead and those calls never reach the balance.

Two limits and a refusal: a ceiling on any single call, a cap on the project, and a call that would cross either is rejected pre-flight.

HTML: https://hopscotchlabs.ai/control