# Sprint 45 Status Report

**Sprint**: 45 - Brain Architecture
**Duration**: 10 Days
**Authority**: ADR-009 Brain Architecture
**Status**: COMPLETE ✅

---

## Executive Summary

Sprint 45 delivered the complete Brain Architecture for EndiorBot - a persistent, LLM-agnostic knowledge storage system following the "iceberg" 4-layer model.

### Key Deliverables

| Component | LOC | Tests | Status |
|-----------|-----|-------|--------|
| ADR-009 + Types + Storage | ~1,200 | 31 | ✅ |
| Layer 1: Events | ~620 | 47 | ✅ |
| Layer 2: Patterns | ~730 | 43 | ✅ |
| Layer 3: Structures | ~660 | 37 | ✅ |
| Layer 4: Mental Models + Digest | ~1,140 | 62 | ✅ |
| CEO Profile | ~948 | 55 | ✅ |
| Evolution + Versioning + Checkpoint | ~597 | 23 | ✅ |
| CLI Brain Commands | ~583 | 17 | ✅ |
| **Total** | **~6,478** | **315** | ✅ |

---

## Architecture

### Iceberg 4-Layer Model

```
┌─────────────────────────────────────┐
│ Layer 1: Events (Realtime)          │ ← Append-only session logs
│   sessions, fix_attempts, escalations │
├─────────────────────────────────────┤
│ Layer 2: Patterns (Active)          │ ← Upsert by signature
│   error_patterns, fix_hints          │
├─────────────────────────────────────┤
│ Layer 3: Structures (Reference)     │ ← Replace by project+type
│   module_maps, file_trees, api_specs │
├─────────────────────────────────────┤
│ Layer 4: Mental Models (Archive)    │ ← Heuristics + rules
│   ceo_preferences, derived_rules     │
└─────────────────────────────────────┘
```

### Storage Location

```
~/.endiorbot/brain/
├── version.json         # Brain version + layer versions
├── events.json          # Layer 1: Session events
├── patterns.json        # Layer 2: Error patterns
├── structures.json      # Layer 3: Project structures
├── mental-models.json   # Layer 4: Decision rules
└── ceo-profile.json     # CEO preferences
```

### BrainDigest for Checkpoint Provenance

```typescript
interface BrainDigest {
  hash: string;           // SHA-256 of combined layers (16 chars)
  computedAt: string;     // ISO timestamp
  layerHashes: {
    events: string;
    patterns: string;
    structures: string;
    mentalModels: string;
    ceoProfile: string;
  };
}
```

---

## API Summary

### Layer Operations

| Layer | Key Operations |
|-------|----------------|
| Events | `appendEvent()`, `getAllEvents()`, `getEventsSince()` |
| Patterns | `addPattern()`, `findFixHint()`, `addOrIncrementPattern()` |
| Structures | `setStructure()`, `getStructure()`, `setModuleMap()` |
| Mental Models | `setModel()`, `getModelsByDomain()`, `searchModels()` |

### CEO Profile

| Category | Operations |
|----------|------------|
| Style | `setIndentPreference()`, `setQuotePreference()` |
| Development | `setTestingPreference()`, `setDocumentationPreference()` |
| Conventions | `setNamingConvention()`, `updateConventions()` |
| Custom Rules | `addCustomRule()`, `removeCustomRule()` |

### Checkpoint Integration

```typescript
// Get brain reference for checkpoint
const ref = getBrainCheckpointReference();
// Returns: { brainVersion, brainDigest, layerHashes, capturedAt }

// Verify brain matches checkpoint
const matches = verifyBrainCheckpoint(ref);

// Compare changes
const diff = compareBrainCheckpoint(ref);
// Returns: { matches, changedLayers, currentDigest, checkpointDigest }
```

### CLI Commands

| Command | Description |
|---------|-------------|
| `endiorbot brain status` | Show brain health, version, layers |
| `endiorbot brain export [--output]` | Export brain to JSON |
| `endiorbot brain layers [layerId]` | List layers or show entries |
| `endiorbot brain init` | Initialize brain storage |

---

## Test Coverage

| Test Suite | Tests |
|------------|-------|
| storage.test.ts | 31 |
| events.test.ts | 47 |
| patterns.test.ts | 43 |
| structures.test.ts | 37 |
| mental-models.test.ts | 36 |
| digest.test.ts | 26 |
| ceo-profile.test.ts | 55 |
| evolution.test.ts | 23 |
| brain CLI tests | 17 |
| **Brain Total** | **315** |
| **Full Suite** | **2,463+** |

---

## ADR Compliance

### ADR-009 Brain Architecture ✅

- [x] 4-layer iceberg model implemented
- [x] File-based JSON storage at `~/.endiorbot/brain/`
- [x] Atomic writes with temp file + rename
- [x] BrainDigest with per-layer SHA-256 hashes
- [x] CEO Profile with preferences and conventions
- [x] Versioning with layer-level version counters
- [x] Export/import functionality

### ADR-006 Checkpoint Integration ✅

- [x] `getBrainCheckpointReference()` captures brain state
- [x] `CheckpointState.brain` includes version, digest, layerHashes
- [x] Graceful fallback when brain not initialized
- [x] `verifyBrainCheckpoint()` for state verification
- [x] `compareBrainCheckpoint()` for layer-level diff

---

## Sprint Timeline

| Day | Task | Status |
|-----|------|--------|
| 1 | ADR-009 + Types + Storage | ✅ |
| 2 | Layer 1: Events | ✅ |
| 3 | Layer 2: Patterns | ✅ |
| 4 | Layer 3: Structures | ✅ |
| 5 | Layer 4: Mental Models + Digest | ✅ |
| 6-7 | CEO Profile | ✅ |
| 8 | Evolution + Versioning + Checkpoint | ✅ |
| 9 | CLI Brain Commands | ✅ |
| 10 | G-Sprint-45 Gate | ✅ |

---

## G-Sprint-45 Gate

| # | Criterion | Status |
|---|-----------|--------|
| 1 | ADR-009 approved, 4 layers in `~/.endiorbot/brain/` | ✅ |
| 2 | CEO Profile load/save works | ✅ |
| 3 | Brain version + digest; checkpoint records both | ✅ |
| 4 | `layerHashes` in checkpoint state | ✅ |
| 5 | `verifyBrainCheckpoint` detects state change | ✅ |
| 6 | `loadBrainContext` / `restoreBrainContext` round-trip | ✅ |
| 7 | CLI commands: status, export, layers, init | ✅ |
| 8 | `pnpm build` clean | ✅ |
| 9 | `pnpm test` 2,463+ passing | ✅ |

**Gate Result**: PASS ✅

---

## Files Created/Modified

### New Files

```
src/brain/
├── types.ts              # Core type definitions
├── storage.ts            # File I/O, version, digest
├── evolution.ts          # Versioning + checkpoint integration
├── ceo-profile.ts        # CEO preferences
├── digest.ts             # Digest comparison utilities
└── layers/
    ├── events.ts         # Layer 1
    ├── patterns.ts       # Layer 2
    ├── structures.ts     # Layer 3
    └── mental-models.ts  # Layer 4

src/cli/commands/brain.ts  # CLI commands

docs/02-design/01-ADRs/ADR-009-Brain-Architecture.md

tests/brain/
├── storage.test.ts
├── evolution.test.ts
├── ceo-profile.test.ts
├── digest.test.ts
└── layers/
    ├── events.test.ts
    ├── patterns.test.ts
    ├── structures.test.ts
    └── mental-models.test.ts

tests/cli/commands/brain.test.ts
```

### Modified Files

```
src/sessions/checkpoint/types.ts      # BrainLayerHashes, enhanced BrainReference
src/sessions/checkpoint/checkpoint.ts # getBrainCheckpointReference integration
src/cli/commands/index.ts             # registerBrainCommand export
src/cli/index.ts                      # registerBrainCommand call
```

---

## Next Sprint

Sprint 46 will focus on:
- GitHub Models Provider integration
- Brain → routing intelligence
- Cross-layer pattern extraction

---

*Sprint 45 Complete*
*Brain Architecture Delivered*
*2026-02-24*
