OpenMeter is transitioning from a subject-based to a customer-centric approach for usage metering and billing, set to fully deprecate subject APIs by December 1, 2025. The update facilitates automatic mapping of usage events to customers based on Customer ID or Key, while allowing the assignment of multiple subjects to a single customer for consolidated billing. The existing Stripe integration will migrate to an OpenMeter Stripe App, supporting multiple accounts and enhanced customer-level control. Although manual mapping of subjects to customers remains optional, any subject without a linked customer will automatically convert into a customer, maintaining synchronization until the deprecation deadline. The change introduces customer-level entitlements, which consolidate usage from assigned subjects for billing calculations, though subject-level entitlements will eventually be phased out. Users are encouraged to transition to customer APIs promptly to ensure continuity, with the option to link subjects to customers remaining available post-migration.