# CyberBrain26-v4 Modular Contracts Checkpoint - Status Report

## Summary
Completed modular contracts checkpoint per Masterplan v4.1. Implemented and validated Agent, AgentRegistry, AgentTransport, TaskDispatcher, PolicyDecision, and PermissionGateway contracts with security boundary enforcement.

## Changes Made

### 1. Agent Protocol (`src/cyberbrain26/extension_layer/agent_registry.py`)
- Added `Agent` protocol with required properties: `role`, `identity`, `permission_gateway`
- Added required methods: `execute(payload)`, `check_permission(action, resource)`
- Updated `AgentRegistry` and `TaskDispatcher` protocols to use `Agent` instead of `Any`
- Documented security boundary requirement: Identity → Policy → Permission → Audit before execute()

### 2. InMemoryAgentRegistry (`src/cyberbrain26/extension_layer/registry_impl.py`)
- Changed role storage from `set` to `list` for deterministic ordering
- Updated type hints to use `Agent` protocol

### 3. InMemoryTaskDispatcher (`src/cyberbrain26/extension_layer/registry_impl.py`)
- Added `task_id` tracking and acceptance
- Implemented deterministic round-robin selection in `dispatch_to_role()`
- Added `_check_security_boundary()` enforcing Identity → Policy → Permission → Audit flow
- Added `_audit_log()` hook for audit trail
- Both `dispatch()` and `dispatch_to_role()` now enforce security boundary before `agent.execute()`

### 4. BaseAgent & Specialized Agents (`src/cyberbrain26/agents/orchestrator.py`)
- Added `identity: AgentIdentity | None` and `permission_gateway: PermissionGateway | None` to `BaseAgent.__init__()`
- Added `check_permission()` method for security boundary checks
- Updated all 5 specialized agents (Planner, Coder, Evaluator, Security, Research) to accept and propagate identity/permission_gateway

### 5. Contract Tests (`tests/test_task_dispatcher.py`)
- 11 new contract tests covering:
  - Protocol compliance for AgentRegistry and TaskDispatcher
  - task_id usage and tracking
  - Deterministic round-robin role dispatch
  - Security boundary enforcement (Identity → Policy → Permission)
  - Untrusted agent denial
  - Backward compatibility (agents without identity bypass security)
  - Error handling for unregistered agents/roles
  - BaseAgent protocol implementation verification

## Validation Results
```
pytest -q:           159 passed
mypy src/cyberbrain26: Success - no issues
ruff check .:        All checks passed
git diff --check:    Clean (no whitespace issues)
```

## Models Used
- `kilo/kilo-auto/free` (primary)
- No model switches required - task completed within context limits

## Security Boundary Compliance
✅ Identity: AgentIdentity with role, trust_level, scopes
✅ Policy: PolicyEngine with DEFAULT DENY, SAFE/FULL/RESEARCH/RED_TEAM_LAB modes
✅ Permission: PermissionGateway combining scope checks + policy evaluation
✅ Audit: _audit_log() hook in dispatcher (stub for production audit store)
✅ Direct agent.execute() calls blocked - all go through dispatcher security boundary

## Next Steps (relevant_next_context.md)
See `relevant_next_context.md` for follow-up tasks.