---
title: "Authorization-specific platform or general-purpose policy engine"
description: "OPA is a general-purpose policy engine that evaluates Rego policies over structured data. Cerbos is purpose-built for fine-grained authorization across applications, APIs, agents, services, and workloads. The comparison covers both engines and the lifecycle tooling around them."
competitor: "OPA"
canonical: "https://www.cerbos.dev/cerbos-vs-opa"
source: "https://www.cerbos.dev/cerbos-vs-opa"
---

# Authorization-specific platform or general-purpose policy engine

OPA is a general-purpose policy engine that evaluates Rego policies over structured data. Cerbos is purpose-built for fine-grained authorization across applications, APIs, agents, services, and workloads. The comparison covers both engines and the lifecycle tooling around them.

## Verdict

**Choose Cerbos when**

- The scope is application authorization and teams want principals, resources, actions, roles, conditions, tests, audit, and query planning as product primitives.
- Operating Rego conventions, bundle infrastructure, decision-log collection, or application-specific query adapters creates material maintenance work.
- Policy reviewers prefer an authorization-specific YAML or JSON schema with CEL conditions over a general-purpose language.

**Consider OPA when**

- One engine must cover Kubernetes admission, infrastructure, CI/CD, and policy shapes outside application authorization.
- An existing platform is stable and its Rego expressiveness or ecosystem is a verified requirement.

## General engine, specific product

OPA is a CNCF-graduated, general-purpose policy engine. It evaluates Rego over structured data and has documented use cases across Kubernetes admission control, Terraform, CI/CD, gateways, and application or API authorization. Cerbos provides authorization-specific primitives through its Apache 2.0 PDP, managed lifecycle options through Cerbos Hub, and context and integration capabilities through Cerbos Synapse.

Cerbos reports that its first prototype used OPA and that its replacement engine was up to 17 times faster on the application-authorization workloads Cerbos tested. Treat that as a scoped internal comparison and benchmark representative policies in the intended deployment.

In August 2025, OPA's creators and many Styra team members joined Apple. The OPA project said its CNCF governance and Apache 2.0 licensing were unchanged. OPA remains community governed with active releases and documented production adopters; verify the support provider and lifecycle product your deployment will rely on.

**OPA** — Fits teams that need a programmable, general-purpose policy engine across infrastructure and application domains. OPA has mature use cases for Kubernetes admission control, Terraform, CI/CD, gateways, and application or API authorization. Rego supports a broader range of policy shapes than Cerbos' authorization-specific model.

**Cerbos** — Fits teams that want authorization-specific principals, resources, actions, roles, conditions, tests, audit, and query planning. The open source Cerbos PDP is self-hosted as a service. For supported JavaScript environments, Cerbos Hub's commercial ePDP downloads Cerbos Hub-managed bundles and evaluates them in-process through WebAssembly, without a per-decision service call. Cerbos Hub also adds managed lifecycle workflows and is available as an enterprise on-premise deployment for restricted and air-gapped environments. Cerbos Synapse adds decision-time data and integrations from customer-controlled infrastructure.

- **What your team maintains** — Choose an authorization-specific product with managed lifecycle options, or assemble and operate OPA's general-purpose components, including the self-hosted OPA Control Plane, around the application model. Both are valid; operational ownership and product roadmaps differ.
- **Policy authoring** — Rego is broader and more programmable. Cerbos' authorization-specific YAML or JSON schema with CEL conditions may be easier for some application teams to review. Test both languages with representative policies and the intended reviewers.
- **List filtering** — Cerbos PlanResources returns a query plan, with reference adapters for six data layers. OPA's Compile API returns partially evaluated queries or an AST; use or build an adapter for the target query layer.

## What application teams ask for

Verified against public documentation on 24 July 2026. The links beside each row point to Cerbos or neutral foundation and standards sources; competitor sources informed the research but are not linked here.

| Requirement | Cerbos | OPA |
| --- | --- | --- |
| Application authorization primitives | NATIVE — Models principals, resources, actions, roles, and derived roles directly in policy. | GENERAL PURPOSE — Models anything expressible in Rego, with authorization conventions left to your team. |
| Policy testing and CI | BUILT IN — Ships a first class test format and compile checks designed for authorization policies. | BUILT IN — Provides mature testing through opa test and surrounding tooling. Genuine parity on this row. |
| Decision logging and audit | BUILT IN + HUB — Provides configurable decision logging to file, Kafka, local storage, or Cerbos Hub. Cerbos Hub adds managed collection and search. | BUILT IN + CONFIGURABLE — Provides configurable decision logging. OPA core requires a collector or control plane for durable storage and search. |
| List filtering and query planning | BUILT IN — PlanResources returns a query plan, with reference adapters for Prisma, Drizzle, Mongoose, Convex, LangChain/ChromaDB, and SQLAlchemy. | PARTIAL — The Compile API returns partially evaluated queries or a JSON AST. Use an ecosystem adapter or build translation for the target query layer. |
| Managed policy distribution | VIA HUB — Cerbos Hub builds, tests, signs, and distributes policies from Git and other policy-store workflows. The open source Cerbos PDP also supports disk, Git, object storage, database, and Cerbos Hub stores. | CORE + SELF-HOSTED OCP — OPA core supports bundle distribution. The Apache 2.0 OPA Control Plane adds self-hosted Git-based policy management, bundle building, external data sources, and object-storage distribution. |
| SDK language coverage | 8 LANGUAGES + LARAVEL — Provides REST and gRPC APIs with official clients for Go, Java, JavaScript, Python, Ruby, Rust, .NET, and PHP, plus Laravel. | BROAD ECOSYSTEM — Exposes REST, a Go API, WebAssembly, and a broad ecosystem of language SDKs and integrations. Maturity varies, so verify the specific package. |
| AuthZEN compatibility | INTEROP READY — The Cerbos PDP partially implements AuthZEN Authorization API 1.0. Alex Olivier is one of the current AuthZEN Working Group cochairs. | VERIFY — OPA core does not document native AuthZEN endpoints. OPA participated as a PDP in the 2025 OpenID interoperability event; verify the adapter, gateway, and specification version required. |
| Infrastructure and platform policy | AUTHORIZATION FOCUS — Focuses on authorization decisions and can integrate with infrastructure systems through Cerbos Synapse. It is not a general-purpose admission-policy engine. | NATIVE — Has mature ecosystem projects for infrastructure policy. Gatekeeper is the OPA project's recommended Kubernetes admission-control integration. |

### Sources

- [Cerbos resource policies](https://docs.cerbos.dev/cerbos/latest/policies/resource_policies.html)
- [Cerbos derived roles](https://docs.cerbos.dev/cerbos/latest/tutorial/06_derived-roles.html)
- [Cerbos policy testing](https://docs.cerbos.dev/cerbos/latest/tutorial/04_testing-policies.html)
- [Cerbos compile](https://docs.cerbos.dev/cerbos/latest/cli/cerbos.html)
- [Cerbos audit configuration](https://docs.cerbos.dev/cerbos/latest/configuration/audit.html)
- [Cerbos Hub audit collection](https://docs.cerbos.dev/cerbos-hub/audit-log-collection.html)
- [Cerbos query-plan adapters](https://docs.cerbos.dev/cerbos/latest/recipes/query-plan-adapters/index.html)
- [Cerbos Hub](https://docs.cerbos.dev/cerbos-hub/index.html)
- [Cerbos Hub policy stores](https://docs.cerbos.dev/cerbos-hub/policy-stores.html)
- [Cerbos PDP storage](https://docs.cerbos.dev/cerbos/latest/configuration/storage.html)
- [Cerbos APIs and SDKs](https://docs.cerbos.dev/cerbos/latest/api/index.html)
- [Cerbos AuthZEN API](https://docs.cerbos.dev/cerbos/latest/api/index.html)
- [AuthZEN Working Group](https://openid.net/wg/authzen/)
- [OpenID AuthZEN interoperability datasheet](https://openid.net/wp-content/uploads/2025/04/OpenID-AuthZEN-Datasheet-Gartner-London.pdf)
- [Cerbos Synapse](https://docs.cerbos.dev/synapse/latest/)
- [OPA CNCF project](https://www.cncf.io/projects/open-policy-agent-opa/)

Compiled from public documentation in July 2026. Details change, so verify current capabilities before you decide.

## The policy model trades breadth for application structure

OPA evaluates arbitrary Rego over structured data. Cerbos fixes the outer model around application authorization and uses CEL for conditions.

OPA can express application, infrastructure, admission, configuration, and pipeline policy. The team defines its own input schema, package conventions, decision shape, and reusable libraries.

Cerbos models principals, resources, actions, roles, derived roles, scopes, conditions, and structured outputs directly. This is less general than Rego and makes more authorization conventions common across services.

Migration should start by identifying the application-authorization subset of the Rego estate. Infrastructure and admission policies can remain on OPA while application decisions move to Cerbos.

## Both engines are open source; the surrounding ownership differs

OPA core provides engine primitives and bundle support. Cerbos packages authorization-specific runtime and lifecycle mechanisms across Cerbos PDP, Cerbos Hub, and Cerbos Synapse.

OPA provides policy evaluation, testing, bundles, decision logging, partial evaluation, REST, Go, and WebAssembly integration. The self-hosted OPA Control Plane adds Git-based management, bundle building, external data, and object-storage distribution.

The Apache 2.0 Cerbos PDP provides authorization APIs, policy tests, decision logging, and query planning. Cerbos Hub adds managed build, test, signed distribution, and audit aggregation. For supported JavaScript environments, Cerbos Hub's commercial ePDP downloads Cerbos Hub-managed bundles and evaluates them in-process through WebAssembly, without a per-decision service call. Cerbos Hub Enterprise can run on-premise in restricted and air-gapped environments.

Cerbos Synapse is a separate commercial component for decision-time data and protocol or integration extensions. It runs in customer-controlled infrastructure. Neither Cerbos Hub nor Cerbos Synapse changes the open source licence of the Cerbos PDP.

## List filtering exposes the integration cost

OPA can partially evaluate policy. Cerbos returns an authorization-specific query plan with reference data-layer adapters.

OPA's Compile API can return partially evaluated queries or a JSON AST. The application still needs a safe translation layer for its ORM, database, or search system.

Cerbos PlanResources returns a datastore-agnostic query plan for the requested principal, action, and resource kind. Reference adapters translate supported plan shapes for selected data layers.

Neither approach removes the need to validate query semantics and unsupported expressions. Compare the real adapter code, generated predicate, and returned records for representative policies.

## Separate reusable authorization intent from Rego implementation

Translate the input contract and decision table before translating expressions. Keep OPA for policy domains that require its general-purpose model.

| OPA or Rego concept | Cerbos | Notes |
| --- | --- | --- |
| input.subject or input.user | request.principal | Normalize the principal ID, roles, and attributes at the enforcement point. |
| input.resource | request.resource | Assign a resource kind and ID, then pass domain attributes under resource.attr. |
| input.action and allow rule | Rule actions and EFFECT_ALLOW or EFFECT_DENY | Derive an explicit action-by-scenario decision table before modeling rules. |
| Rego helper rule | Derived role, scoped policy, or CEL condition | Choose the construct by domain meaning. Do not mechanically inline every helper into CEL. |
| Partial evaluation or Compile API | PlanResources query plan | Replace and test the data-layer translation separately from single-resource checks. |

### An owner-or-editor document policy

`document.yaml`

```yaml
apiVersion: api.cerbos.dev/v1
resourcePolicy:
  version: default
  resource: document
  rules:
    - actions: ["view", "edit"]
      effect: EFFECT_ALLOW
      condition:
        match:
          expr: request.resource.attr.ownerId == request.principal.id
    - actions: ["view", "edit"]
      effect: EFFECT_ALLOW
      roles: ["editor"]
```

The enforcement point sends the principal, document resource, and requested action to CheckResources. Add deny cases, missing-attribute cases, and scope variants to the Cerbos policy test suite before comparing with the Rego result.

## Where OPA remains the stronger fit

Cerbos is purpose-built for authorization. It is not a replacement for every Rego policy domain.

| Capability | Cerbos approach | Guidance |
| --- | --- | --- |
| General-purpose policy evaluation | Cerbos models application and service authorization through fixed principal, resource, action, and policy concepts. | Keep OPA for admission control, infrastructure, CI/CD, and policy shapes outside the Cerbos model. |
| Rego expressiveness and ecosystem | Cerbos uses YAML or JSON policy schemas with CEL conditions and authorization-specific APIs. | Inventory custom functions, recursive logic, ecosystem integrations, and packages outside authorization before considering migration. |
| Existing stable OPA platform | Cerbos can reduce authorization-specific platform work, but migration still requires policy, integration, and operational changes. | Do not migrate solely to change engines. Quantify current maintenance cost and test coexistence first. |

## Coexistence, and where the standards are going

OPA and Cerbos can coexist, for example with OPA handling infrastructure policy and Cerbos handling application authorization. Admission control often benefits from a general policy engine. Application teams may prefer authorization-specific primitives, query adapters, and managed lifecycle tooling, although OPA also supports application authorization and lifecycle components.

AuthZEN Authorization API 1.0 defines an interoperable PEP-to-PDP interface. Services can use the same API against PDPs that implement the relevant endpoints and capabilities. The Cerbos PDP partially implements documented AuthZEN endpoints. An OPA deployment currently requires a compatible adapter or gateway. Alex Olivier of Cerbos is one of the current AuthZEN Working Group cochairs.

For an existing OPA application-authorization stack, compare the cost of OCP or other control-plane components and application-specific data or query adapters with Cerbos PDP, Cerbos Hub, and Cerbos Synapse. The Cerbos platform packages authorization-specific policy, tests, audit, distribution, enrichment, and query-planning mechanisms while retaining an Apache 2.0 Cerbos PDP.

## Use Cerbos for application authorization and keep OPA where it fits

Cerbos is the stronger overall choice for application authorization because its PDP, policy model, tests, audit, query planning, Cerbos Hub distribution, and optional Cerbos Synapse enrichment are designed around that problem. Prove the boundary with one Rego package that performs single-resource checks and list filtering. Run both engines in parallel and compare decisions, data predicates, latency, memory, rollout, and operational work. Keep OPA for admission, infrastructure, and other general-purpose policy domains.

## Questions you are probably asking

### Is Rego not more expressive than YAML and CEL?

Rego offers broader policy expressiveness. Cerbos' constrained authorization model may be easier for some application teams to review. Test both against representative policies and reviewers, including someone outside the authoring team.

### OPA is CNCF graduated and everywhere. Why bet on Cerbos?

OPA remains CNCF graduated and community governed. Its creators and many Styra team members joined Apple in 2025; OPA said governance and licensing were unchanged, and several tools moved toward the OPA organization. Both OPA and the Cerbos PDP are Apache 2.0. Cerbos' commercial roadmap is focused on authorization management across Cerbos PDP, Cerbos Hub, and Cerbos Synapse. Verify the support provider and lifecycle tooling each deployment depends on.

### We already built application authorization on OPA. Is migration worth it?

Sometimes no. If the OPA deployment is stable and inexpensive to maintain, keep it. A migration case appears when application-specific policy conventions, query adapters, data integration, or lifecycle operations carry material engineering cost. Cerbos reports up to 17 times faster evaluation than its own earlier OPA-based prototype on the workloads it tested; benchmark your policies and topology in a parallel run.

### Can OPA and Cerbos coexist?

Yes. One possible split is OPA for infrastructure or admission policy and Cerbos for application authorization, but both products have broader integration surfaces. AuthZEN defines a standard interface for compatible PDPs. Cerbos partially implements it; an OPA deployment currently needs a compatible adapter or gateway.

## The short version

**Cerbos strengths**

- Packages authorization-specific primitives, tests, audit, query planning, distribution, and enrichment across Cerbos PDP, Cerbos Hub, and Cerbos Synapse
- Uses an authorization-specific YAML or JSON schema with CEL conditions, which some teams may find easier to review
- Returns datastore-agnostic query plans with six reference adapters
- Distributes signed policies through Cerbos Hub from Git and source-agnostic policy stores
- Partially implements AuthZEN Authorization API 1.0; Alex Olivier is a current Working Group cochair
- Provides an Apache 2.0 Cerbos PDP that is free to self-host, with published Cerbos Hub pricing

**Weigh with OPA**

- Rego expresses logic that purpose built policy languages cannot
- Infrastructure policy, Kubernetes admission control, and CI gates are OPA's home ground
- The engine is CNCF graduated, community governed, and healthy
- Mature testing tooling and a broad documented ecosystem
- An existing, stable OPA deployment may not justify a migration
- OPA's creators and many Styra team members joined Apple in 2025; verify the current support provider and product lifecycle

Send us one of your real authorization scenarios, however messy. We will model it in Cerbos policies and run it with you.