Feature/async iterator sse streaming #35
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Implements Server-Sent Events (SSE) streaming for tool results that return async iterators, enabling real-time streaming of tool outputs through POST requests. Key Features: - Detects async iterators using Symbol.asyncIterator - Automatic response type selection (JSON vs SSE) - Streams each yielded chunk as separate SSE event - Maintains backward compatibility with immediate JSON responses - Robust error handling during streaming - Per-session event ID tracking for SSE events Files Added: - test/async-iterator-streaming.test.ts: Comprehensive test suite (5 tests) - examples/streaming-demo.ts: Working demonstration server Files Modified: - src/types.ts: Extended types for async generator support - src/handlers.ts: Added streaming response detection and interface - src/routes/mcp.ts: Implemented SSE streaming logic for POST responses Testing: - All 281 tests passing including 5 new streaming-specific tests - Tests cover immediate responses, streaming, error handling, and event sequencing - Demo server with curl examples for manual verification 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <[email protected]>
Fixes critical MCP specification compliance issue where event IDs were assigned per-session instead of per-stream, breaking Last-Event-ID resumability. Key Changes: - Updated SessionStore interface to support per-stream tracking with StreamMetadata - Added stream ID generation and management for each SSE connection - Implemented per-stream event ID sequences starting from 1 - Modified message storage to organize by streamId, not just sessionId - Updated replay logic to work with per-stream cursors - Maintained backwards compatibility with legacy session-level methods Per MCP Transport Specification: - Line 169: "event IDs should be assigned by servers on a per-stream basis" - Line 143: "client MAY remain connected to multiple SSE streams simultaneously" - Line 145: "server MUST send each message on only one of the connected streams" Files Modified: - src/stores/session-store.ts: Added per-stream interface methods - src/stores/memory-session-store.ts: Implemented per-stream storage - src/stores/redis-session-store.ts: Added Redis per-stream support - src/routes/mcp.ts: Per-stream SSE implementation with stream IDs - test/per-stream-event-ids.test.ts: Test suite for per-stream compliance Testing: - 284/286 tests passing (2 Redis integration test failures to address) - New per-stream test suite covering event ID architecture - Fixed async iterator streaming test expectations - Updated all session creation to include streams Map 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <[email protected]>
Updates Redis integration tests to work with the new per-stream event ID architecture while maintaining backward compatibility. Key Changes: - Modified sendSSEToStreams to detect broadcast notifications and elicitation requests - Added isBroadcast logic to use legacy session-level storage for notifications - Updated sendSSEToStreamsLegacy to store messages in session history for backward compatibility - Fixed tests expecting session-level message storage for broadcast/elicitation messages Per-stream messages use per-stream storage, while broadcast notifications and elicitation requests use session-level storage to maintain compatibility with existing tests and expected behavior. Testing: - All 286 tests now passing - Redis integration tests (7/7) passing - Broadcast notifications properly stored in session history - Elicitation requests properly stored in session history 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <[email protected]>
The broadcast system is a core feature, not legacy. Updates terminology throughout: - sendSSEToStreamsLegacy → sendSSEToStreamsBroadcast - 'Legacy' comments → 'Broadcast' comments - Clarifies that broadcast messages are session-wide by design - Maintains same functionality with clearer naming 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <[email protected]>
Adds detailed documentation for the new async iterator streaming feature: Key additions: - Async Iterator Streaming section with complete examples - Basic streaming tool implementation patterns - Advanced streaming examples (file processing, error handling) - Client usage examples with curl commands - Streaming response format explanation - Key features and benefits overview Documentation covers: - Automatic async iterator detection - Real-time SSE streaming capabilities - Error handling during streaming - Backward compatibility guarantees - MCP specification compliance - Performance and resumability features Updated Features section to highlight: - Async Iterator Streaming as a key feature - Per-Stream Event IDs for MCP compliance - Real-time streaming capabilities 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <[email protected]>
Signed-off-by: Matteo Collina <[email protected]>
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