openhuman/docs/tinyagents-full-migration-plan/05-events/02-bridge-consolidation.md

05.2 — One event bridge; delete engine/

Two progress paths remain: OpenhumanEventBridge (tinyagents/observability.rs) and scattered direct publish_global calls in session/turn code. The old shared harness/engine/ progress/checkpoint seams are gone.

Steps

1. Done for the reusable engine module: ProgressReporter/TurnProgress moved under session/tool_progress.rs, leaving no shared harness/engine/ surface. The old session-local agent_tool_exec compatibility shim is deleted.
2. Done: engine/checkpoint.rs is gone. CapPauser owns the graceful max-iteration stop, and the remaining sub-agent checkpoint summary is localized in subagent_runner/ops/checkpoint.rs.
3. Sweep direct agent-run/tool/subagent lifecycle DomainEvent publishes on turn paths (session/turn, orchestration tools) — emit through the bridge or a typed helper so ordering/rate-limiting is single-owner.
4. Current finding (2026-07-02): agent/progress_tracing.rs (722) plus agent/progress_tracing/tests.rs (616) are not currently redundant. The root module is the opt-in observability.agent_tracing exporter fed by the web progress bridge's AgentProgress stream. Retain it until the 05.1 journal path can produce the same metadata-only OTel/Langfuse spans and append/export contract.

Deletions

• Deleted: src/openhuman/agent/harness/engine/ (checkpoint + progress seams).
• Redundant publishes found in step 3.
• Retain agent/progress_tracing.rs + sibling tests for now; delete only after journal-backed span export proves parity with the current config contract.

Acceptance

• Progress-event parity fixture: same AgentProgress sequence for a scripted turn before/after (tool timeline, thinking, cost footer).
• No engine:: imports remain.