---
phase: 12-phase-task-decomposition
plan: 03
subsystem: agent
tags: [agent-mode, json-schema, mock-manager, typescript, decompose]

# Dependency graph
requires:
  - phase: 12-phase-task-decomposition
    plan: 01
    provides: decomposeOutputSchema, decomposeOutputJsonSchema, TaskBreakdown type
provides:
  - Mode-aware agent spawning handles 'decompose' mode with decomposeOutputJsonSchema
  - ClaudeAgentManager.handleDecomposeOutput() method for decompose completion handling
  - MockAgentManager supports decompose_complete scenarios for E2E testing
  - AgentStoppedEvent.reason extended with 'decompose_complete'
affects: [12-05, 12-08]

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "Decompose mode follows same handler dispatch pattern as discuss/breakdown modes"
    - "MockAgentScenario discriminated union extended for all four agent modes"

key-files:
  created: []
  modified:
    - src/agent/manager.ts
    - src/agent/mock-manager.ts
    - src/events/types.ts

key-decisions:
  - "Task 3 executed first as Tasks 1-2 depend on AgentStoppedEvent reason type"
  - "handleDecomposeOutput follows exact pattern of handleBreakdownOutput for consistency"

patterns-established:
  - "Mode handler extension: new modes add handler method + switch case + JSON schema mapping"

# Metrics
duration: 7min
completed: 2026-02-01
---

# Phase 12 Plan 03: Agent Manager Decompose Mode Summary

**Updated ClaudeAgentManager and MockAgentManager to support decompose mode with decomposeOutputJsonSchema for phase-to-task decomposition**

## Performance

- **Duration:** 7 min
- **Started:** 2026-02-01T10:38:18Z
- **Completed:** 2026-02-01T10:45:07Z
- **Tasks:** 3
- **Files modified:** 3

## Accomplishments

- Extended AgentStoppedEvent.reason type with 'decompose_complete' for event typing
- Added decompose mode support to ClaudeAgentManager (schema selection, handler method, switch routing)
- Added decompose_complete scenario support to MockAgentManager for E2E testing
- All 402 tests pass with no regressions

## Task Commits

Each task was committed atomically:

1. **Task 3: Extend AgentStoppedEvent reason type** - `fe3fed0` (feat) - executed first as dependency
2. **Task 1: Update ClaudeAgentManager for decompose mode** - `8754cde` (feat)
3. **Task 2: Update MockAgentManager for decompose mode** - `2bd0bc5` (feat)

## Files Created/Modified

- `src/events/types.ts` - Added 'decompose_complete' to AgentStoppedEvent reason union
- `src/agent/manager.ts` - Added decompose imports, getJsonSchemaForMode case, handleDecomposeOutput method, switch case routing
- `src/agent/mock-manager.ts` - Added TaskBreakdown import, decompose_complete scenario type, completeAgent handler case

## Decisions Made

1. **12-03: Task execution order** - Task 3 (AgentStoppedEvent) executed first since Tasks 1-2 depend on 'decompose_complete' reason type
2. **12-03: Handler pattern consistency** - handleDecomposeOutput follows exact structure of handleBreakdownOutput for maintainability

## Deviations from Plan

None - plan executed exactly as written. Task order adjusted for dependency correctness.

## Issues Encountered

None

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness

- Decompose mode fully supported in both agent managers
- Ready for 12-04 (Plan tRPC Procedures) and 12-05 (Decompose tRPC Procedures)
- MockAgentManager can simulate decompose_complete scenarios for E2E testing in 12-08

---
*Phase: 12-phase-task-decomposition*
*Completed: 2026-02-01*
