openhuman/docs/tinyagents-full-migration-plan/05-events/03-domainevent-projection.md

05.3 — DomainEvent & AgentProgress as projections

DomainEvent (core event bus) and AgentProgress (UI vocabulary) stay — as compatibility projections fed from crate events, never as primary state.

Steps

1. Catalog current agent-domain DomainEvent publishers/subscribers (agent/bus.rs, triage, task_dispatcher, orchestration background_delivery/run_ledger_finalize). Current high-volume lifecycle publishers still include Agent::run_single, SpawnSubagentTool::execute, ContinueSubagentTool::execute, dispatch_subagent, project_spawn_parallel_spawned, and project_spawn_parallel_result. RunLedgerFinalizeSubscriber::handle remains a real global-bus subscriber: it consumes SubagentCompleted/SubagentFailed as authoritative detached-run terminal signals until journal/status-store replay covers those paths. For each event that mirrors a crate AgentEvent/GraphEvent, source it from the journal/bridge. Events with no crate analogue (triage decisions, channel routing) stay native DomainEvents — they are product semantics.
2. agent/bus.rs native handler agent.run_turn stays (transport into the turn), but its progress mirroring moves to the bridge. Current live bridge symbols are OpenhumanEventBridge::on_event plus ThinkingForwarder for the non-streaming/tool-argument gaps that do not yet have crate event parity.
3. Document the rule in core/event_bus README: new agent-run telemetry reads crate events/status first; DomainEvent is for cross-domain product signals.
4. Do NOT remove DomainEvent variants until every subscriber is re-pointed (spec non-goal) — track per-variant status in this file as work lands.

Deletions

• Duplicate mirroring blocks identified in step 1 (list them here when cataloged).

Acceptance

• Existing subscribers receive identical DomainEvents (bus tests).
• New run-inspection RPCs read journals/status, not the bus.