---
phase: 04-agent-lifecycle
plan: 01
subsystem: database
tags: [drizzle, sqlite, agents, repository, persistence]

# Dependency graph
requires:
  - phase: 02-data-layer
    provides: Database setup, Drizzle ORM, repository patterns
provides:
  - agents table in database schema
  - AgentRepository port interface
  - DrizzleAgentRepository adapter
affects: [04-agent-lifecycle, agent-manager]

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "Port-adapter pattern for AgentRepository (same as TaskRepository)"
    - "CreateAgentData interface for explicit optional fields"

key-files:
  created:
    - src/db/repositories/agent-repository.ts
    - src/db/repositories/drizzle/agent.ts
    - src/db/repositories/drizzle/agent.test.ts
  modified:
    - src/db/schema.ts
    - src/db/repositories/index.ts
    - src/db/repositories/drizzle/index.ts
    - src/db/repositories/drizzle/test-helpers.ts

key-decisions:
  - "Agent name is unique human-readable identifier"
  - "taskId nullable with onDelete: 'set null' (agent may outlive task)"
  - "sessionId nullable - populated from CLI JSON output after first run"
  - "waiting_for_input status for agents paused on AskUserQuestion"

# Metrics
duration: 3 min
completed: 2026-01-30
---

# Phase 04 Plan 01: Agent Schema & Repository Summary

**Agents table with AgentRepository port and DrizzleAgentRepository adapter for agent state persistence**

## Performance

- **Duration:** 3 min
- **Started:** 2026-01-30T18:58:15Z
- **Completed:** 2026-01-30T19:01:08Z
- **Tasks:** 3
- **Files modified:** 7

## Accomplishments

- Added agents table to database schema with full lifecycle status tracking
- Created AgentRepository port interface with comprehensive lookup methods
- Implemented DrizzleAgentRepository adapter with 22 passing tests
- Established CreateAgentData interface pattern for explicit optional fields

## Task Commits

Each task was committed atomically:

1. **Task 1: Add agents table to database schema** - `dfaa510` (feat)
2. **Task 2: Create AgentRepository port interface** - `eec5f13` (feat)
3. **Task 3: Create DrizzleAgentRepository adapter with tests** - `25f98fc` (feat)

## Files Created/Modified

- `src/db/schema.ts` - Added agents table, agentsRelations, Agent/NewAgent types
- `src/db/repositories/agent-repository.ts` - AgentRepository port interface with CreateAgentData
- `src/db/repositories/drizzle/agent.ts` - DrizzleAgentRepository implementation
- `src/db/repositories/drizzle/agent.test.ts` - 22 tests covering all operations
- `src/db/repositories/index.ts` - Export AgentRepository, AgentStatus, CreateAgentData
- `src/db/repositories/drizzle/index.ts` - Export DrizzleAgentRepository
- `src/db/repositories/drizzle/test-helpers.ts` - Added agents table SQL

## Decisions Made

- **Agent name unique:** Human-readable identifier (e.g., 'gastown', 'chinatown')
- **taskId nullable with SET NULL:** Agent may outlive the task it was assigned to
- **sessionId nullable:** Populated from Claude CLI JSON output after first run
- **waiting_for_input status:** For agents paused on AskUserQuestion checkpoints
- **CreateAgentData interface:** Explicit optional fields instead of Omit<> for cleaner API

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 3 - Blocking] Fixed CreateAgentData type definition**
- **Found during:** Task 3 (DrizzleAgentRepository tests)
- **Issue:** Using `Omit<Agent, ...>` made optional fields required in TypeScript
- **Fix:** Created explicit `CreateAgentData` interface with optional fields
- **Files modified:** src/db/repositories/agent-repository.ts, src/db/repositories/index.ts
- **Verification:** Build succeeds, 22 tests pass
- **Committed in:** 25f98fc (combined with Task 3)

---

**Total deviations:** 1 auto-fixed (blocking)
**Impact on plan:** Type system fix required for usable API. No scope creep.

## Issues Encountered

None

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness

- Agent persistence layer ready for AgentManager adapter (04-03)
- All verification checks pass:
  - npm run build succeeds
  - npm test passes 221 tests (22 new for agent repository)
  - agents table has correct columns and relations
  - AgentRepository interface exported
  - DrizzleAgentRepository exported from drizzle/index.ts

---
*Phase: 04-agent-lifecycle*
*Completed: 2026-01-30*
