OPAL is an administration layer for policy engines such as Open Policy Agent and AWS Cedar that detects changes to policy and policy data in real-time and pushes live updates to deployed agents.
OPAL solves the problem of keeping authorization data synchronized across distributed policy engines as application state changes. It monitors policy and data sources—including APIs, databases, git repositories, S3, and third-party services—and automatically propagates updates to all connected agents. The tool uses a server-client architecture where the OPAL server detects changes and pushes them via WebSocket to OPAL clients running alongside policy engines, ensuring services stay synchronized with the authorization data they need.
Teams should adopt OPAL when running multiple policy engines in microservice or cloud-native environments where authorization data changes frequently and must be reflected immediately across services. It works well for fine-grained authorization implementations, Google-Zanzibar-style permission models, and hybrid architectures with centralized policy but decentralized data sources. The tool is policy-engine agnostic, supporting OPA, Cedar, and other compatible engines, making it suitable for organizations that want to avoid vendor lock-in while maintaining real-time policy synchronization.
The project maintains active test coverage and publishes both server and client packages to package repositories. Development activity shows consistent engagement with the codebase through regular updates and community contributions.
