Open Policy Agent / Rego the cloud-native third of the policy-language triad

Why it matters for NETEVO

OPA is the most-adopted general-purpose policy engine in the cloud-native stack. It decouples policy decision-making from application logic: policy is authored in the Rego declarative language and evaluated by the engine, separately from the services it governs. In agentic-AI architectures it serves, alongside AWS Cedar, as the runtime engine that consumes policy and returns ALLOW / DENY / OBLIGATE decisions per agent action. Any organisation running Kubernetes, microservices, or a modern cloud architecture is likely to have an OPA decision point somewhere in the stack already.

OPA pairs with Cedar and Catala as the policy-language triad that the Law-to-Code Methodology can target. Where Cedar emphasises formal analysability and Catala emphasises law-as-DSL fidelity, OPA / Rego emphasises operational ubiquity and cloud-native integration. The choice between the three is positional rather than absolute, and the Methodology itself is engine-agnostic.

OPA is anchored by an open-source project rather than a peer-reviewed paper. The stable reference is the project documentation at its canonical URL, and the project's versioned history is maintained through its GitHub releases.