* [Lago v1.44.0](https://github.com/getlago/lago) – Programmable API for usage-based billing designed for product-led SaaS.

* [Flexprice v2.0.10](https://github.com/flexprice/flexprice) – Usage metering and billing infrastructure designed for AI companies to streamline pricing models and track usage.

* [usage_credits v0.5.0](https://github.com/rameerez/usage_credits) – Add usage-based credits to Rails apps with operations, subscription refills, booster packs, rollovers, expirations, and transaction audit trails.

* [YETI 1.14.71](https://github.com/yeti-switch/yeti-web) – Admin interface for managing SIP SBC with billing and multiple database support.