Open Policy Agent

Visit site Alternatives

Score7.3

Rank#2 of 24

PriceFree

Free planYes

Runs onAPI, Linux, macOS, Self-hosted, Web, Windows

Summary

Open Policy Agent (OPA) is a free, open-source policy engine for separating policy decisions from the systems that enforce them. It evaluates policies against structured input and can return structured data, making it applicable to microservices, Kubernetes, CI/CD pipelines and API gateways. Policies are written in Rego, a declarative language designed for complex hierarchical data. Applications can request evaluations through a REST API, Go API, WebAssembly runtimes or custom evaluators using OPA's intermediate representation. Bundles distribute policy and data to OPA instances, while discovery bundles carry flexible configuration. Management interfaces support policy distribution, health and status checks, and decision logs. The project lists integrations for Kubernetes, Terraform, Envoy and code editors, and recommends OPA Gatekeeper for Kubernetes admission control. Installation documentation covers macOS, Linux/Unix, Windows and Docker. OPA is a graduated Cloud Native Computing Foundation project. Its security guidance says authentication and authorization are off by default and recommends configuring TLS, authentication and authorization when securing the API.

Who it is for

OPA suits teams that need policy decisions across services, Kubernetes, CI/CD pipelines or API gateways, and can work with Rego and its evaluation interfaces. Those exposing its API should account for the fact that authentication and authorization are off by default.

What is good

Separates policy decisions from enforcement.
Supports REST, Go API and WebAssembly evaluation.
Bundles distribute policy and data.
Integrates with Kubernetes, Terraform and Envoy.
Free and open source under Apache License 2.0.

What to know first

API authentication and authorization are off by default.
Policies use the Rego language.

Verdict

OPA offers multiple ways to evaluate and distribute policies across software systems. Its API security settings need attention because authentication and authorization are disabled by default.

Open Policy Agent plans and pricing

All plans

Open Policy Agent Free Open-source policy engine · Apache License, Version 2.0 openpolicyagent.org · 3 Oct 2026

Compared on infrastructure policy as code tools

Policy language: Regoopenpolicyagent.org
IaC formats: Terraform plan JSON, JSON, YAMLopenpolicyagent.org
Policy testing: Yesopenpolicyagent.org
Admission control: Yesopenpolicyagent.org
Runtime enforcement: Yesopenpolicyagent.org
CI/CD integration: Yesopenpolicyagent.org
Policy reporting: Yesopenpolicyagent.org

Facts

Policy engine: OPA is an open source, general-purpose policy engine that separates policy decision-making from policy enforcement.openpolicyagent.org · 2 Oct 2026
Use cases: OPA can enforce policies in microservices, Kubernetes, CI/CD pipelines, and API gateways.openpolicyagent.org · 2 Oct 2026
Integration options: OPA supports policy evaluation through a REST API, a Go API, WebAssembly, and custom evaluators using its intermediate representation.openpolicyagent.org · 2 Oct 2026
Policy management: OPA provides management interfaces for distributing policies, checking status and health, and collecting decision logs.openpolicyagent.org · 2 Oct 2026
Kubernetes: The OPA documentation recommends OPA Gatekeeper for Kubernetes admission control.openpolicyagent.org · 2 Oct 2026
Downloads: The official installation guide provides options for macOS, Linux/Unix, Windows, and Docker.openpolicyagent.org · 2 Oct 2026
Binary checksums: The installation guide says binary checksums are available by appending .sha256 to the binary filename.openpolicyagent.org · 2 Oct 2026
API security: OPA's security guidance describes TLS, authentication, and Rego-based authorization, and says authentication and authorization are off by default.openpolicyagent.org · 2 Oct 2026
Security reporting: The security policy asks users to report suspected security issues to the OPA security team by email.openpolicyagent.org · 2 Oct 2026
Community support: The official site links to an OPA Slack community for users to talk with other users and maintainers.openpolicyagent.org · 2 Oct 2026
Project status: OPA is a graduated Cloud Native Computing Foundation project.openpolicyagent.org · 2 Oct 2026
Purpose: OPA is an open-source, general-purpose policy engine that unifies policy enforcement across software systems.openpolicyagent.org · 3 Oct 2026
Decision input and output: OPA evaluates policies against arbitrary structured input and can return arbitrary structured data as output.openpolicyagent.org · 3 Oct 2026
Policy evaluation: Policies can be evaluated through a REST API, the Go API, WebAssembly runtimes, or custom evaluators using OPA's intermediate representation.openpolicyagent.org · 3 Oct 2026
Integrations: The project lists integrations for Kubernetes, Terraform, Envoy, and code editors.openpolicyagent.org · 3 Oct 2026
Policy distribution: OPA bundles distribute policy and data to OPA instances, while discovery bundles distribute flexible configuration.openpolicyagent.org · 3 Oct 2026
Deployment: The documentation describes installing OPA on macOS, Linux/Unix, and Windows, and running it with Docker.openpolicyagent.org · 3 Oct 2026
Security configuration: Authentication and authorization are off by default, and the security guide recommends configuring TLS, authentication, and authorization when securing the API.openpolicyagent.org · 3 Oct 2026
Support: The project lists third-party companies offering commercial support and says the listings are not vetted endorsements.openpolicyagent.org · 3 Oct 2026
Governance: OPA is a graduated Cloud Native Computing Foundation project.openpolicyagent.org · 3 Oct 2026