diff --git a/.planning/phases/07-chat-infrastructure/07-01-SUMMARY.md b/.planning/phases/07-chat-infrastructure/07-01-SUMMARY.md
new file mode 100644
index 000000000..870ee2508
--- /dev/null
+++ b/.planning/phases/07-chat-infrastructure/07-01-SUMMARY.md
@@ -0,0 +1,110 @@
+---
+phase: 07-chat-infrastructure
+plan: 01
+type: tdd
+status: completed
+completedAt: 2026-01-27
+---
+
+# Phase 7 Plan 1: Redux Slice & Core Reducers Summary
+
+**Created sessionChatSlice with all reducers using TDD methodology**
+
+## Accomplishments
+
+- Created sessionChatSlice.js with complete initial state structure matching CHAT_REDUX_DESIGN.md
+- Implemented 7 reducers using strict TDD approach (RED-GREEN-REFACTOR):
+  - `addMessageFromWebSocket`: Message handling with deduplication and unread logic
+  - `setActiveChannel`: Channel selection for viewing
+  - `openChatWindow`: Opens window and resets unread count
+  - `closeChatWindow`: Closes window without affecting unread counts
+  - `markAsRead`: Explicitly marks channel as read with timestamp
+  - `incrementUnreadCount`: Manual unread count increment
+  - `setWindowPosition`: UI position persistence
+- Comprehensive unit test suite with 40 tests and 100% reducer coverage
+- Message deduplication logic validated (critical for WebSocket + REST scenario)
+- Unread tracking system tested and working across multi-channel scenarios
+- 3 integration tests validate complete message flows and multi-channel behavior
+- Registered sessionChat slice in Redux store configuration
+
+## Files Created/Modified
+
+### Created Files
+- `jam-ui/src/store/features/sessionChatSlice.js` - Redux slice with 7 reducers and helper function
+- `jam-ui/src/store/features/__tests__/sessionChatSlice.test.js` - Comprehensive unit and integration tests (40 tests)
+
+### Modified Files
+- `jam-ui/src/store/store.js` - Added sessionChat reducer to store configuration
+
+## Test Coverage
+
+**40 total tests passing:**
+- 13 tests for initial state structure
+- 8 tests for addMessageFromWebSocket (including deduplication)
+- 2 tests for setActiveChannel
+- 3 tests for openChatWindow
+- 2 tests for closeChatWindow
+- 3 tests for markAsRead
+- 3 tests for incrementUnreadCount
+- 3 tests for setWindowPosition
+- 3 integration tests for complete flows
+
+## Decisions Made
+
+### Channel Key Construction
+Implemented `getChannelKey()` helper function to construct channel keys:
+- Session messages: Use `sessionId` directly (not prefixed with 'session-')
+- Lesson messages: Use `lessonSessionId` directly
+- Global messages: Use 'global' string
+
+This matches the design doc specification where channel keys are used directly as IDs rather than prefixed strings.
+
+### Message Deduplication Strategy
+Used `Array.some()` to check for existing message by `id` before insertion. This is efficient for typical chat message counts and prevents duplicate messages when the same message arrives via both WebSocket and REST API.
+
+### Unread Count Logic
+Unread count increments when:
+- Window is closed (regardless of active channel)
+- Window is open BUT viewing a different channel
+
+This ensures users see unread counts for background channels while preventing increments for the currently visible channel.
+
+### Timestamp Handling
+All timestamps use `new Date().toISOString()` for consistency with server-side timestamps. This ensures proper sorting and display across time zones.
+
+## Issues Encountered
+
+None. TDD approach caught all issues early:
+- Initial tests validated state structure
+- Core reducer tests validated message handling and deduplication
+- Integration tests validated multi-reducer interactions
+- All tests passed on first GREEN phase implementation
+
+## Commit History
+
+Task 1 commits:
+- `fd44d1255` - test(07-01): add failing tests for sessionChatSlice initial state
+- `e98504eba` - feat(07-01): implement sessionChatSlice with initial state structure
+
+Task 2 commits:
+- `60a559e58` - test(07-01): add failing tests for core reducers with message deduplication
+- `15a658a5d` - feat(07-01): implement core reducers with message deduplication logic
+
+Task 3 commits:
+- `96d7188a4` - test(07-01): add failing tests for unread tracking and integration flows
+- `7bafb3c69` - feat(07-01): implement unread tracking reducers and complete slice
+
+## Next Phase Readiness
+
+**Ready for Plan 07-02 (Async Thunks & API Integration):**
+- State structure complete and tested
+- All reducers implemented and validated
+- Integration tests prove multi-reducer coordination works
+- Message deduplication strategy validated
+- Unread tracking foundation ready for WebSocket integration
+
+**Phase 7 Plan 2 will implement:**
+- `fetchChatHistory` async thunk for REST API
+- `sendChatMessage` async thunk for sending messages
+- WebSocket message handler integration
+- Loading/error state management via extraReducers