Decoupled Reasoning and Orchestration
Intent
Separate orchestration, reasoning, and knowledge access responsibilities through explicit contracts to enable implementation-agnostic workflow execution.
Context
The CAS framework requires a clear separation between the orchestration layer (Runner), reasoning logic (Workflows), and data access layer (Knowledge Providers). This separation is essential for systems adopting the CAS workflow model to ensure modularity and portability across different execution environments.
Agentic Profile
The CAS Runner orchestrates execution and validates compliance, while Workflows encapsulate reasoning logic and Knowledge Providers supply context. Agents must adhere to prompt-based contracts to maintain decoupling.
Forces
The pattern balances portability, modularity, and governance requirements through explicit contracts.
Drivers
- Portability across execution environments
- Modular evolution of reasoning capabilities
- Implementation-agnostic workflow design
Constraints
- Strict separation of reasoning logic from orchestration runners
- Prompt-based contracts for data access abstraction
Tradeoffs
- Additional contract management overhead
- Potential latency from abstraction layers
Solution
Implement a decoupled execution model where the CAS Runner handles orchestration and validation, Workflows contain pure reasoning logic, and Knowledge Providers abstract data access. Communication between layers is enforced via prompt-based contracts, ensuring that reasoning logic remains independent of storage and execution infrastructure.
Operationalisation
Adopting this pattern requires restructuring workflow implementations to enforce layer separation and integrating automated validation into the CI/CD pipeline.
Workflow Implications
- Refactor existing workflows to isolate reasoning logic from orchestration calls
- Define and version prompt-based contracts for Knowledge Provider interactions
- Update onboarding specifications to reference the decoupled execution model
Automation Opportunities
- Implement CI/CD validation to detect violations of the decoupled execution model
- Automate compliance checks through architecture alignment reviews
- Generate runtime-native AW artifacts to monitor pattern adherence
Implementation Signals
Signals include the presence of distinct Runner, Workflow, and Knowledge Provider components, explicit prompt-based contracts between layers, and CI/CD guardrails enforcing decoupling.
Evidence
High confidence based on recurring architecture work, current state support, and cross-project applicability.
Signals
- recurring_architecture_work
- current_architecture_state_support
- cross_project_applicability
Supporting Evidence
- aw-ideas-to-life-cas-20260605-04
- aw-ideas-to-life-cas-20260605-03
Confidence Basis
High confidence due to successful implementation in the ideas-to-life-cas project, strong evidence from multiple architecture work items, and alignment with the CAS framework's foundational execution model.
Consequences
Adopting this pattern increases modularity and portability but requires strict adherence to contract definitions and governance validation.
Benefits
- Increased modularity and portability of reasoning logic
- Implementation-agnostic execution across different environments
- Clear separation of concerns simplifies maintenance and evolution
Risks
- Contract maintenance overhead if prompt interfaces change frequently
- Potential performance overhead from abstraction layers
Governance Implications
- Mandatory compliance for all CAS-based workflows
- Requires structured YAML ADRs for future execution model changes
- CI/CD validation and architecture alignment reviews are required for enforcement
Reuse Notes
Applies to all CAS-based workflow implementations requiring separation between reasoning logic and orchestration runners. Reference this pattern from future workflow onboarding specifications.
Confidence
High confidence in the pattern's effectiveness and maturity.
Level: high
Rationale
The pattern defines the foundational execution model for the CAS framework, is implementation-agnostic, and has been validated through recurring architecture work and cross-project applicability.