datum-agent

datum-agent is the local operations satellite for Datum. It provides an embeddable job registry actor for named, supervised, materialized streams, including graceful drain, hard stop, restart with backoff, lifecycle status snapshots, and a stream-native event feed.

It also provides the Datum Control Protocol (DCP) server/client layer used by the daemon, CLI, TUI, and future cluster control plane. DCP is prost over length-prefixed TCP/QUIC frames: QUIC with mTLS is the remote deployment path, and plaintext TCP is accepted only for loopback local development.

StartJob in v0.9.1 uses a registered-factory model: StartJob { factory_name, instance_name, params }. The daemon registers named JobSpec factories at startup; closures and stream blueprints do not cross the wire. Dynamic blueprint upload is out of scope until cluster placement work in v0.10.