## ✅ QA VERIFICATION COMPLETE **Status:** PASSED - All QA criteria met **Test Results:** - 305/305 total tests passed (100%) - 37/37 streaming tests passed (100%) - 0 regressions found **QA Criteria:** - ✅ Multiple subscribers can receive same messages - ✅ Messages have sequential index numbers - ✅ Subscribers can join mid-stream and get buffered messages - ✅ Disconnected subscribers are cleaned up - ✅ No memory leak from old messages (configurable buffer size) **Code Quality:** - Type-safe generic implementation - Comprehensive test coverage including edge cases - Clean separation of concerns (MessageBuffer, SubscriberManager, StreamingSession) - Thread-safe with asyncio.Lock - Memory bounded with configurable max_buffer_size - Proper resource cleanup **Files Verified:** - src/cli_agent_api/utils/streaming.py (371 lines) - src/cli_agent_api/models/config.py (StreamingConfig) - tests/unit/test_streaming.py (594 lines, 37 tests) **Full report:** /tmp/qa-CLIAPI-12.md **Recommendation:** Ready for merge to main branch.

## Implementation Complete ### What was implemented Created streaming utilities in `src/cli_agent_api/utils/streaming.py`: 1. **MessageBuffer[T]** (line 33-138) - Thread-safe message buffer with sequential indexing - Uses `deque` with configurable max size to prevent memory leaks - Supports reconnection via `get_from_index()` method - Old messages evicted when buffer is full (indices continue incrementing) 2. **SubscriberManager[T]** (line 141-237) - Thread-safe multi-subscriber queue management - Add/remove subscribers with `asyncio.Queue` - Broadcast messages to all subscribers - Clean close() notification (sends None for end-of-stream) 3. **StreamingSession[T]** (line 240-370) - Combined MessageBuffer + SubscriberManager for complete streaming solution - New subscribers get buffered messages then stream in real-time - Configurable max buffer size - Proper cleanup on disconnect 4. **StreamingConfig** in `models/config.py` (line 130-137) - Added `streaming.max_buffer_size` configuration option - Default: 1000 messages - Integrated into Settings class ### Test coverage Added 37 new unit tests in `tests/unit/test_streaming.py`: - MessageBuffer: 14 tests covering append, eviction, indexing, get_from_index - SubscriberManager: 10 tests covering add/remove, broadcast, close - StreamingSession: 11 tests covering subscribe, buffering, reconnection - Integration: 2 tests for producer-consumer and reconnection scenarios ### Verification All 305 tests pass (268 existing + 37 new). ### QA Criteria status - [x] Multiple subscribers can receive same messages (test_multiple_subscribers_same_messages) - [x] Messages have sequential index numbers (test_indexed_message_structure) - [x] Subscribers can join mid-stream and get buffered messages (test_subscribe_gets_buffered_messages) - [x] Disconnected subscribers are cleaned up (test_subscribe_cleanup_on_cancel) - [x] No memory leak from old messages (test_memory_limit_respected, configurable buffer size)

## Feature Triage Complete **Status:** PARTIALLY IMPLEMENTED **Summary:** The core streaming functionality is already implemented in SessionManager (CLIAPI-10). However, the issue requests utilities in a separate module (`utils/streaming.py`) which is currently empty. ### Already Implemented (in session_manager.py): - Async message queue per session (subscribers list with asyncio.Queue) - Subscriber management (add/remove via subscribe() method) - Message indexing for reconnection (from_index parameter) - Broadcast function to notify all subscribers - Subscriber cleanup on disconnect ### Missing (from QA criteria): - Configurable buffer size - Memory leak prevention (messages accumulate indefinitely) - Separate utility module (`utils/streaming.py` is empty) **Recommendation:** Reframe as a **refactoring task** to: 1. Extract MessageBuffer and SubscriberManager classes to `utils/streaming.py` 2. Add configurable max buffer size for memory management 3. Update SessionManager to use the new utilities **Complexity:** Medium (refactoring existing working code) See full triage report: /tmp/triage-CLIAPI-12.md