Open Policy Agent (OPA) is a powerful, open source policy engine. It decouples policy decision-making from application logic. With OPA, you write policies in Rego, a high-level language designed for fine-grained control. Instead of scattering authorization logic across services, you centralize it. This makes policies easier to audit, test, and maintain.
A self-hosted OPA deployment gives you full control. You run the binary, you own the environment, and no third party touches your data. It runs as a sidecar, as a daemon, or as an embedded library. You decide where and how to scale. You can integrate with Kubernetes admission controllers, service meshes like Istio, CI/CD pipelines, or custom microservices.
Self-hosting OPA means you can enforce security and compliance without exposing sensitive policies or decision logs to external APIs. You choose the storage backend. You choose when to update. You can run air-gapped or in high-security networks. You can test changes locally before pushing to production.
Configuration is simple. You download the OPA binary. You run it with your policy bundle. You expose its REST API for policy queries. You can point your services to it for real-time decisions or precompute answers. You can load policies from Git repos, object storage, or direct file mounts.