Estuary Flow derivations [1], I suspect (I work here)? You write a program which has messages pushed to it, which maintains and updates an internal state, and w

Estuary Flow derivations [1], I suspect (I work here)? You write a program which has messages pushed to it, which maintains and updates an internal state, and which publishes output messages. You can build cyclic data-flows [2] - not just DAGs - which seems a key ingredient. You can also write contract-based tests that verify the end-to-end behaviors of your "agents" [3]. Today, you're limited to SQLite or TypeScript. Looking forward, we aim to open it up to any program packaged in a docker container. [1] https://docs.estuary.dev/concepts/derivations/ https://docs.estuary.dev/concepts/derivations/ [2] https://docs.estuary.dev/concepts/derivations/#approving-transfers https://docs.estuary.dev/concepts/derivations/#approving-tra... [3] https://docs.estuary.dev/concepts/tests/ https://docs.estuary.dev/concepts/tests/