ADR 0003 — One log

Status: accepted · 2026-09-13

Context. Earlier designs sketched a separate events.jsonl event stream for other tools alongside the Logbook, and a future reader ("Aion") consuming it.

Decision. There is one log: the Logbook. Any other tool that wants to record an event writes a line here through an adapter or as a manual line. Readers read the Logbook. No parallel event stream exists.

Consequences. Every derived system is a consumer of the Logbook, never a peer of it. Adapters are the only way in; Logbook.append is the only write.