It’s an open-source cost attribution tool for Kafka systems that supports both identity-level and topic-level attribution. The original version focused only on identity-level attribution using Confluent Cloud API and metrics data. In v2, I expanded it to support topic-level attribution as well.

The backend is Python/FastAPI, and the frontend is React. Compared to v1, which was fully in-memory and depended on Prometheus and Grafana for retention and visualization, v2 adds SQLite-backed persistence, an evolving REST API, and a plugin-based architecture for extending to other ecosystems.

No signups, free to use, and fully open source. I’d appreciate feedback, especially from people who deal with Kafka platform ownership, multi-tenancy, or chargeback/showback problems. I’m actively working on it, and I’d be glad to hear about bugs, gaps, or features that would make it more useful.