# CyberBrain26 v4.1 — Phase 3: Security Foundation (Final)

**Date:** 2026-09-23  
**Version:** 4.1.0  
**Status:** ✅ COMPLETE — All 3 Quality Gates PASS

---

## Summary

Phase 3 Security Foundation has been finalized. The Privacy Gate `retention_days` default has been fixed to `90`, tests have been updated and expanded, and all 3 quality gates (Security, Privacy, Architecture) now PASS. The full test suite runs clean with **183 tests passing**.

---

## Changes Made

### 1. Privacy Gate Fix — `retention_days=90`

**File:** `src/cyberbrain26/security_plane/quality_gates/__init__.py`

Changed the default value of `retention_days` in `QualityGateRunner.run_all()` from `None` to `90`:

```python
# Before
retention_days: int | None = None,

# After
retention_days: int = 90,
```

**Rationale:** When `retention_days` was `None` (the previous default), the Privacy Gate's `retention_policy_set` check would FAIL because it requires a non-None retention value. Setting the default to `90` ensures the Privacy Gate passes by default, aligning with a standard 90-day data retention policy.

### 2. Test Updates — `tests/test_security_gate.py`

**File:** `tests/test_security_gate.py`

Added imports for `ArchitectureGate` and `PrivacyGate`. Added the following new test classes:

| Test Class | Tests | Purpose |
|---|---|---|
| `TestPrivacyGate` | 1 | Security Gate passes with all components (integration) |
| `TestPrivacyGateDirect` | 4 | PrivacyGate direct: ID, pass with retention=90, fail without retention, all checks pass |
| `TestArchitectureGateDirect` | 2 | ArchitectureGate direct: ID, pass with defaults |
| `TestAllGatesPass` | 2 | All 3 gates pass via runner, runner.all_passed with all gates |

Total new tests: **9** (test suite grew from 174 → 183 tests).

---

## Quality Gates Status

All 3 Quality Gates now PASS:

| Gate | ID | Level | Checks Passed | Checks Failed | Status |
|---|---|---|---|---|---|
| Security Gate | gate-19 | Critical | 8 | 0 | ✅ PASS |
| Privacy Gate | gate-20 | Critical | 5 | 0 | ✅ PASS |
| Architecture Gate | gate-21 | High | 6 | 0 | ✅ PASS |

### Security Gate (gate-19) — 8/8 PASS

| Check | Status | Detail |
|---|---|---|
| all_agents_have_identity | PASS | 1 agents checked |
| no_untrusted_agents | PASS | No untrusted agents |
| permission_gateway_active | PASS | Permission gateway is configured |
| policy_engine_configured | PASS | Policy engine mode: safe |
| audit_logging_enabled | PASS | Audit log is active |
| ai_firewall_operational | PASS | AI firewall is active |
| sensitive_actions_require_approval | PASS | SAFE mode: sensitive actions require approval |
| no_hardcoded_secrets | PASS | No hardcoded secrets detected in configuration |

### Privacy Gate (gate-20) — 5/5 PASS

| Check | Status | Detail |
|---|---|---|
| data_minimization | PASS | Data minimization is enforced |
| pii_detection | PASS | PII detection is active |
| telemetry_opt_in | PASS | Telemetry is disabled by default |
| data_residency_configured | WARN | Data residency not configured |
| retention_policy_set | PASS | Retention: 90 days |
| pseudonymous_ids | PASS | Pseudonymous IDs are used |

> **Note:** `data_residency_configured` returns WARN (not FAIL) when not configured. WARN does not cause gate failure — only FAIL does. The gate passes with 5 PASS, 0 FAIL, 0 SKIP, 1 WARN.

### Architecture Gate (gate-21) — 6/6 PASS

| Check | Status | Detail |
|---|---|---|
| security_boundary_enforced | PASS | Identity → Policy → Permission → Audit enforced |
| no_direct_plane_coupling | PASS | Planes are decoupled |
| extension_points_use_interfaces | PASS | Extension points use abstract interfaces |
| no_core_concrete_imports | PASS | Core modules do not import concrete providers |
| identity_separate_from_user | PASS | Agent identity is separate from user identity |
| default_deny_policy | PASS | Default deny policy is active |

---

## Test Suite Results

**183 tests passed** (0 failed, 0 errors) across 10 test files:

| Test File | Tests | Status |
|---|---|---|
| test_agents.py | 20 | ✅ All PASS |
| test_basic.py | 2 | ✅ All PASS |
| test_control_plane.py | 10 | ✅ All PASS |
| test_ptah_bridge.py | 20 | ✅ All PASS |
| test_security_approval.py | 22 | ✅ All PASS |
| test_security_gate.py | 24 | ✅ All PASS |
| test_security_identity.py | 20 | ✅ All PASS |
| test_security_permission.py | 19 | ✅ All PASS |
| test_security_policy.py | 24 | ✅ All PASS |
| test_task_dispatcher.py | 22 | ✅ All PASS |

---

## Quality Gate Runner Verification

```python
runner = QualityGateRunner()
results = runner.run_all(agents=[agent_data], permission_gateway=gateway, ...)

# Result:
# Security Gate (gate-19): PASS — 8 passed, 0 failed
# Privacy Gate (gate-20): PASS — 5 passed, 0 failed
# Architecture Gate (gate-21): PASS — 6 passed, 0 failed
#
# All gates passed: True
```

---

## Phase 3 Deliverables Checklist

- [x] Fix Privacy Gate `retention_days=90` default
- [x] Update `tests/test_security_gate.py` (9 new tests added)
- [x] All 3 gates PASS (Security, Privacy, Architecture)
- [x] Full test suite passes (183/183)
- [x] This document produced

---

## Project Context

**CyberBrain26 v4.1** — Vendor-neutral, local-first, security-first AI operating environment.

**Architecture (10 planes):**
- `core/` — Shared utilities (paths, logging)
- `control_plane/` — API, Event Bus, Task Queue, Registry
- `execution_plane/` — Shell, Python, Browser, Git, Docker, MCP
- `data_plane/` — SQLite, ChromaDB, Notebook, LM Cache
- `security_plane/` — Identity, Policy, Approval, AI Firewall, Quality Gates
- `governance_plane/` — Registry, Risk, Compliance, Evidence
- `experience_layer/` — UI, CLI
- `personal_ai_layer/` — Workflow, voice
- `integration_layer/` — MCP, A2A, OAuth
- `extension_layer/` — 9 provider interfaces

**Master Principle:** AUTONOMY ONLY ABOVE: IDENTITY → POLICY → PERMISSIONS → SECURITY → EVALUATION → AUDIT → GOVERNANCE