What Is Cerbos and What Does It Do?

Cerbos is an authorization management platform for enterprise software and AI systems. It answers the question that comes after login: not "who is this user?" but "what is this identity actually allowed to do, right now, to this specific resource?" It enforces fine-grained, contextual, and continuous authorization across applications, gateways, workloads, and AI agents — and it does so from a single set of centrally managed policies rather than scattered code.

If you already have an identity provider handling authentication and an IGA tool provisioning roles, Cerbos fills the runtime gap between them: it controls what identities do at the resource level while requests are happening.

The problem Cerbos addresses

Authentication tells you an identity is who it claims to be. It does not tell you whether that identity should be able to read a particular record, call a particular endpoint, or have an AI agent act on its behalf. Cerbos frames this as the authorization gap, and highlights four failure modes it is built to close:

• Over-permissioned access — agents and services can do more than they should, so a single mistake can expose sensitive data or trigger unauthorized actions.
• Blurred identity lines — AI agents act on behalf of users through MCP clients and other interfaces, masking who initiated an action. When the system can't tell them apart, agents inherit permissions they should never have.
• Standing access that never expires — long-lived tokens and shared credentials stay valid long after they're needed, increasing compromise risk.
• No fine-grained kill switch — if an agent exceeds its scope, access continues until someone rotates credentials or restarts systems, instead of being revoked in seconds.

What Cerbos actually does

Centralizes authorization logic

Instead of scattering if statements across services, you define, approve, and update policies centrally and replace that logic with a single function call. Cerbos supports RBAC, ABAC, ReBAC, and PBAC out of the box, and its materials state you can deploy roles and permissions without code changes.

Governs every identity type

Policies cover users, service accounts, non-human identities (NHIs), and AI agents in one place, so the same control plane manages access across your identity fabric.

Secures AI agents with guardrails

You define what each AI agent can access before it goes live, and revoke that access in seconds through policy if something changes. This is the "define boundaries before launch, revoke after" model rather than relying on credential rotation.

Provides visibility and audit evidence

Cerbos logs every decision — who, what, when, and which policy — so you can see what every identity can access and produce audit-ready records. Its materials cite alignment with SOC 2, ISO 27001, HIPAA, GDPR, NIS2, DORA, and FedRAMP.

Scales across architectures

It handles millions of authorization decisions per second across distributed systems and AI agents, is stateless, and can be deployed in cloud, on-prem, or air-gapped environments.

Where it fits in your stack

Cerbos positions itself explicitly as the layer that closes the gap in an existing IAM stack, not a replacement for the IdP or IGA you already run.

When Cerbos is a fit

Cerbos is worth evaluating if you recognize one or more of these conditions:

• Authorization logic is duplicated across services and creating blind spots.
• You are deploying AI agents or MCP-based integrations and need to bound what they can reach before launch.
• You need a fast, policy-driven way to revoke a single agent's or service's access without rotating credentials.
• You need per-decision audit logs to satisfy compliance frameworks.
• You run distributed or air-gapped infrastructure and need authorization that scales independently of your application code.

If your needs stop at authentication and coarse role assignment, the runtime layer Cerbos targets may be more than you need.

Getting started

The site offers a demo booking path and a "Try Cerbos" option for hands-on evaluation. Pricing is published on a dedicated pricing page, so check that page directly for current tiers and terms rather than assuming a free or self-serve tier.