---
phase: 03-lifecycle-management
plan: 01
subsystem: infra
tags: [asyncio, python, session-management, lifecycle]

# Dependency graph
requires:
  - phase: 02-telegram-integration
    provides: Session management and persistent subprocess architecture
provides:
  - SessionIdleTimer class for per-session timeout detection
  - Session metadata with idle_timeout field for lifecycle configuration
  - ClaudeSubprocess.pid property for process tracking
affects: [03-lifecycle-management]

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "Asyncio-based timer with reset() cancellation pattern"
    - "Session metadata defaults for configurable behavior"

key-files:
  created:
    - telegram/idle_timer.py
  modified:
    - telegram/session_manager.py
    - telegram/claude_subprocess.py

key-decisions:
  - "Default 600s (10 min) idle timeout per session"
  - "Timer reset via task cancellation + new task creation"
  - "PID property returns live process ID only (None if terminated)"

patterns-established:
  - "Timer pattern: cancel existing task, create new background sleep task"
  - "Metadata defaults: provide sensible values in create_session()"

# Metrics
duration: 2min
completed: 2026-02-04
---

# Phase 03 Plan 01: Idle Timer Foundation Summary

**Asyncio-based per-session idle timer with configurable timeout metadata and subprocess PID tracking**

## Performance

- **Duration:** 2 min
- **Started:** 2026-02-04T23:27:29Z
- **Completed:** 2026-02-04T23:29:00Z
- **Tasks:** 2
- **Files modified:** 3

## Accomplishments
- Created SessionIdleTimer class with asyncio timer management
- Extended session metadata to include idle_timeout field (default 600s)
- Added PID property to ClaudeSubprocess for process tracking
- Foundation ready for suspend/resume lifecycle implementation

## Task Commits

Each task was committed atomically:

1. **Task 1: Create SessionIdleTimer module** - `488d94e` (feat)
2. **Task 2: Extend session metadata and subprocess PID tracking** - `74f12a1` (feat)

## Files Created/Modified
- `telegram/idle_timer.py` - SessionIdleTimer class with reset(), cancel(), and activity tracking properties
- `telegram/session_manager.py` - Added idle_timeout to metadata, get_session_timeout() helper method
- `telegram/claude_subprocess.py` - Added pid property returning live process ID

## Decisions Made
- Default idle timeout: 600 seconds (10 minutes) - balances responsiveness with resource conservation
- Timer reset pattern: Cancel existing asyncio task and create new one (clean slate approach)
- PID property returns None for terminated processes - prevents stale PID references

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered

None

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness

Ready for next plan (03-02: Suspend/Resume Implementation):
- Idle timer module complete and tested
- Session metadata supports timeout configuration
- Subprocess exposes PID for lifecycle tracking
- All imports verified, no blockers

---
*Phase: 03-lifecycle-management*
*Completed: 2026-02-04*