---
id: review/reactive-and-hosts
name: Review reactive execution and host configs — signal graph, preconditions, HostConfig implementations
status: pending
depends_on:
  - reactive/workflow-root
  - reactive/node-status
  - reactive/max-concurrency
  - reactive/retry-semantics
  - host/graphology
  - host/reactive
  - component/operation
  - component/sequential
  - component/parallel
  - component/conditional
  - component/map
  - review/foundation
scope: broad
risk: medium
impact: phase
level: review
---

## Description

Review the reactive execution layer and host config implementations before final integration. Verify signal-backed state management is correct, preconditions drive proper state transitions, failure propagation follows dependency edges, and both HostConfig implementations render templates correctly.

## Acceptance Criteria

- [ ] WorkflowReactiveRoot initializes signals correctly for all DAG nodes
- [ ] EventLogProjection correctly derives status and results from event log per ADR-005
- [ ] Computed preconditions: correct for Sequential, Parallel, Conditional, and join scenarios
- [ ] blockedByFailure: correctly propagates failures along dependency edges, NOT structural scope
- [ ] GraphologyHostConfig: Sequential → sequential edges, Parallel → no inter-child edges, Conditional → conditional edges with dataFlow
- [ ] ReactiveHostConfig: creates WorkflowNodes with correct signal references
- [ ] Conditional as error boundary: then-branch skipped, else-branch activated, downstream sees completed
- [ ] maxConcurrency semaphore limits parallel starts correctly
- [ ] Retry semantics: new requestId, projection reflects latest attempt
- [ ] dispose() cleans up all signals and effects — no leaks
- [ ] All tests pass: `npm test`
- [ ] TypeScript strict mode compilation succeeds: `npx tsc --noEmit`

## References

- docs/architecture/reactive-execution.md, docs/architecture/host-configs.md, docs/architecture/workflow-templates.md

## Notes

> To be filled by implementation agent

## Summary

> To be filled on completion