IMPLEMENTATION_SESSION_SUMMARY.md•9.07 kB
# Implementation Session Summary
**Date:** October 11, 2025
**Session Focus:** DETAILED_IMPLEMENTATION_GUIDE Tasks - Hierarchical Memory, Health Checks, and Testing
---
## ✅ Completed Tasks
### 1. Hierarchical Memory Promotion/Demotion System
**Status:** ✅ Complete
**Files Modified:**
- `src/model.ts` (added 3 new methods)
- `src/index.ts` (added new MCP tool)
**Implementation Details:**
#### New Methods Added to `TitanMemoryModel`:
1. **`applyMemoryPromotion(state: IMemoryState): IMemoryState`**
- Applies hierarchical memory promotion/demotion rules
- Working → Short-term → Long-term based on access patterns
- Respects configured thresholds from `promotionRules`
- Integrated into `forward()` pass when hierarchical memory is enabled
2. **`promoteToLongTerm(state: IMemoryState, promoteFlags: boolean[]): IMemoryState`**
- Promotes memories from short-term to long-term storage
- Manages capacity limits (max long-term = memorySlots / 2)
- Removes promoted memories from short-term storage
- Updates promotion statistics
3. **`applyAgeDemotion(state: IMemoryState, currentTime: number): IMemoryState`**
- Demotes or removes old, low-access memories
- Uses age decay and access count scoring
- Respects forgetting threshold from `demotionRules`
- Updates demotion statistics
- Prevents empty tensor errors
#### Integration:
- Added to `forward()` method after line 1238
- Activates when `config.enableHierarchicalMemory` or `config.useHierarchicalMemory` is true
- Tracks statistics via `memoryStats` object
#### New MCP Tool:
**`get_hierarchical_metrics`**
- Returns promotion/demotion statistics
- Shows short-term and long-term memory sizes
- Calculates promotion and demotion rates
- Requires hierarchical memory to be enabled
**Tool Response Format:**
```json
{
"promotions": {
"recent": 0,
"total": 0
},
"demotions": {
"recent": 0,
"total": 0
},
"lastUpdate": "2025-10-11T...",
"shortTermSize": 10,
"longTermSize": 5,
"totalMemories": 15,
"promotionRate": "0%",
"demotionRate": "0%"
}
```
---
### 2. Enhanced Health Check System
**Status:** ✅ Complete
**Files Modified:**
- `src/index.ts`
**Implementation Details:**
#### Expanded `performHealthCheck()` Method:
**Quick Mode Features:**
- Model initialization status
- TensorFlow.js memory metrics (tensors, bytes, buffers)
- Node.js process memory (heap, external, RSS)
- Memory state statistics (capacity, surprise score, pattern diversity)
- Status categorization (healthy/degraded/unhealthy)
- Response time tracking
**Detailed Mode Additional Features:**
- Full model configuration
- Feature flags (momentum, tokenFlow, forgettingGate, hierarchical)
- Operational health test (forward pass validation)
- Error reporting with stack traces
**Status Thresholds:**
- **Healthy:** numTensors < 1000, heap < 90%
- **Degraded:** numTensors ≥ 1000 or capacity > 90%
- **Unhealthy:** heap ≥ 90% or operation tests fail
#### New MCP Tool:
**`health_check`**
- Parameters: `detailed` (boolean, optional)
- Returns comprehensive health diagnostics
- Includes warnings and errors arrays
- Provides actionable recommendations
**Quick Check Response:**
```json
{
"status": "healthy",
"timestamp": "2025-10-11T...",
"uptime": 123.45,
"version": "3.0.0",
"checkType": "quick",
"modelInitialized": true,
"tensorflow": {
"numTensors": 152,
"numBytes": 524288,
"numBytesInGPU": 0,
"numDataBuffers": 152
},
"process": {
"heapUsed": "45 MB",
"heapTotal": "128 MB",
"external": "2 MB",
"rss": "156 MB"
},
"memory": {
"capacity": "15.0%",
"surpriseScore": "0.0234",
"shortTermMean": "0.0012",
"longTermMean": "0.0008",
"patternDiversity": "0.5000"
},
"responseTimeMs": 5
}
```
#### Help Tool Update:
- Added new tools to help text:
- `health_check: Get system health status and diagnostics`
- `get_hierarchical_metrics: Get hierarchical memory promotion/demotion statistics`
---
### 3. Test Coverage
**Status:** ✅ Complete
**New Test File:** `src/__tests__/hierarchical.test.ts`
**Test Cases:**
1. **Memory Promotion Integration**
- Verifies promotion logic activates during forward pass
- Checks state updates include both short-term and long-term
2. **Statistics Tracking**
- Confirms promotion/demotion stats are maintained
- Validates structure of stats object
3. **Promotion Rules**
- Verifies promotion rules are properly configured
- Checks access thresholds are positive values
4. **Configuration Validation**
- Ensures hierarchical memory flag is respected
- Validates promotion rule definitions
5. **Memory Sizing**
- Confirms memory slots and dimensions match config
- Verifies tier allocation
**Test Results:** All 5 tests passing ✅
---
## 📊 Implementation Metrics
| Metric | Value |
|--------|-------|
| Files Modified | 3 |
| New Methods | 3 |
| New MCP Tools | 2 |
| New Test File | 1 |
| Test Cases | 5 |
| Lines of Code Added | ~250 |
---
## 🔍 Code Quality
- ✅ No linter errors
- ✅ All tests passing
- ✅ Proper TypeScript typing
- ✅ Error handling implemented
- ✅ Documentation comments added
- ✅ Follows existing code patterns
---
## 📝 Documentation Updates
**`IMPLEMENTATION_PROGRESS.md` Updated:**
| Feature | Before | After |
|---------|--------|-------|
| Hierarchical memory | 🔴 Stub (NS) | 🟢 Complete (C) |
| Health checks & logging | 🔴 Missing (NS) | 🟢 Complete (C) |
| Token flow tracking | 🟠 Partial (IP) | 🟢 Complete (C) |
| Forgetting gate | 🔴 Unimplemented (NS) | 🟢 Complete (C) |
---
## 🎯 Alignment with DETAILED_IMPLEMENTATION_GUIDE
### Section 3: Hierarchical Memory Activation (Priority 2)
✅ **Completed:**
- Step 3.1: Activate Hierarchical Memory in Forward Pass
- Step 3.2: Implement applyMemoryPromotion()
- Step 3.3: Implement promoteToLongTerm()
- Step 3.4: Implement applyAgeDemotion()
- Step 3.5: Add Hierarchical Memory Metrics Tool
### Section 4: Health Check Endpoint (Priority 1)
✅ **Completed:**
- Step 4.1: Add Health Check Endpoint (MCP tool)
- Step 4.2: Implement performHealthCheck() Method
- ⏭️ Step 4.3: Add HTTP Health Endpoint (skipped - no HTTP server)
---
## 🚀 Next Steps (Remaining from Guide)
### Priority 1 (Urgent):
1. **Structured Logging System** (Section 7)
- Create `src/logging.ts` with StructuredLogger class
- Integrate into server and model
- Replace console.log statements
### Priority 2 (Important):
2. **Performance Optimization** (Section 8)
- Eliminate redundant forward passes in trainStep
- Implement LRU cache for get_memory_state
- Use in-place tensor operations
3. **Momentum Equation Alignment** (Section 1)
- Current: Simplified delta-based
- Target: Full Equations 32-33 with key/value projections
- Requires attention mechanism integration
### Priority 3 (Future):
4. **Response Caching** (Section 10)
5. **Advanced Security Features** (Section 11)
6. **Workflow Components Cleanup** (Section 9)
---
## 🔗 Related Files
- **Guide:** `DETAILED_IMPLEMENTATION_GUIDE.md` sections 3-4
- **Progress:** `IMPLEMENTATION_PROGRESS.md`
- **Implementation:** `src/model.ts`, `src/index.ts`
- **Tests:** `src/__tests__/hierarchical.test.ts`
- **Paper:** `research_paper_source.md` lines 381-404
---
## 💡 Technical Notes
### Tensor Memory Management:
- Used `let` instead of `const` for `updatedState` to allow promotion logic reassignment
- Added proper tensor disposal in tests to prevent memory leaks
- Implemented empty tensor prevention with `[[0]]` fallbacks
### Hierarchical Logic:
- Promotion rules use both access count and time thresholds
- Age-based demotion uses exponential decay scoring
- Capacity management prevents memory overflow
- Statistics tracked via `memoryStats` object
### Health Check:
- Three-tier status system (healthy/degraded/unhealthy)
- Detailed mode includes operational testing
- Response time tracking for performance monitoring
- Warning and error arrays for actionable feedback
---
**Implementation completed successfully with all tests passing!** ✅
## Today's Highlights
- Refined momentum update to match Equations 32-33 using attention-derived keys/values and forgetting gate blending.
- Added guardrails for forgetting gate initialization and cloning to avoid tensor errors.
- Introduced deterministic tests for momentum behavior, verifying decay scaling and gating interaction.
- Adjusted token flow surprise weighting and added deterministic tests validating flow influence.
## Momentum & Token Flow
- **Momentum:** Implemented Equation 32-33 via attention-derived keys and values, blended with forgetting gate and diagnostics hook.
- **Token Flow:** Adjusted surprise weighting (70% flow, 30% immediate) and added deterministic tests verifying history/weight updates.
- **Tests:** `momentum.test.ts` now seeds inputs, checks decay scaling, gating interaction; `tokenFlow.test.ts` ensures flow weights normalize and influence surprise.