v0.7.0 - Centralized Session Management

What's New

Phase 5: Centralized Session Management

This release introduces a dedicated SessionManager service for thread-safe session lifecycle management with automatic cleanup.

New Features

SessionManager (services/session_manager.py)

• Thread-safe Operations: All session operations protected by Lock
• Automatic TTL: Sessions expire after 30 minutes of inactivity (configurable)
• Background Cleanup: Async task removes expired sessions every 5 minutes
• Session Statistics: Monitor active sessions, messages, and cleanup metrics
• Singleton Pattern: App-wide shared instance via get_session_manager()
• Lifecycle Callbacks: Optional hooks for session created/expired events

New Commands

Command	Description
/stats	Display session statistics
/session-stats	Alias for /stats

FastAPI Lifecycle Integration

• Cleanup task starts automatically on app startup
• Graceful shutdown stops cleanup task and closes resources

Architecture

User Request
     ↓
Orchestrator → ChatAgent → SessionManager
                               ↓
                    ┌──────────┴──────────┐
                    │  Background Task    │
                    │  (cleanup every 5m) │
                    └─────────────────────┘

Changes

• New services/session_manager.py with full session lifecycle management
• Updated agents/chat_agent.py to delegate session ops to SessionManager
• Updated agents/orchestrator.py with /stats command
• Updated main.py with FastAPI startup/shutdown events

Configuration

Environment Variable	Default	Description
SESSION_TIMEOUT_MINUTES	30	Session TTL
MAX_HISTORY_LENGTH	20	Max messages per session

---

ADK Migration Complete

All 5 phases of the ADK migration are now complete:

1. ✅ Phase 1: Install ADK & Refactor Tools (v0.3.0)
2. ✅ Phase 2: ChatAgent with LINE Integration (v0.4.0)
3. ✅ Phase 3: Specialized Agents (v0.5.0)
4. ✅ Phase 4: Orchestrator with A2A (v0.6.0)
5. ✅ Phase 5: Session Management (v0.7.0)

Full Changelog: v0.6.0...v0.7.0