Pattern Proposal: Service Layer Application Facade

Summary

Orchestrates complex multi-engine operations behind high-level application service interfaces.

Candidate Pattern

• ID: service-layer-facade
• Classification: governance
• Maturity: established
• Type: implemented

Observed Signals

No specific signals listed.

Evidence

Supporting Evidence

• src/cas_runner/governance/governance_action_service.py (GovernanceActionService) - Coordinates governance action resolution and execution logic.
• src/cas_runner/runner.py (FlowRunner) - Main execution coordinator wrapping flow execution.
• src/cas_runner/cli.py (main) - Entry point dispatching user commands directly into service facades.

Scope Assessment

• Evidence Strength: high
• Confidence: high
• Applies to: ideas-to-life-cas

Rationale

• Intent: Provide a clean boundary between external callers (CLI, automated workflows) and underlying compliance/governance engines.
• Context: A single governance invocation requires inspecting inventories, verifying compliance, and executing actions.
• Force: Clients should not need to instantiate and coordinate multiple internal engines.
• Force: Workflow scripts and CLI handlers must remain lightweight.

Traceability

Artifact source: proposed-patterns