CPEX#

A policy enforcement runtime for AI agents.

CPEX is a deterministic reference monitor between an agent and every capability it invokes: tools, prompts, resources, inference providers, and A2A methods. Every operation is evaluated against security state the model cannot observe or influence, including identity, delegation and escalation chains, information-flow labels, and an audit log.

CPEX composes authorization, delegation, redaction, information-flow tracking, and auditing into a single policy-defined pipeline. Each capability an agent can invoke defines its own enforcement pipeline; APL is the configuration that defines it, executed in two phases: before the operation and after its result.

CPEX mediates every operation an untrusted LLM triggers, evaluating APL policy against identity, delegation, taint, and audit state the model cannot forge

Existing authorization systems (RBAC, ABAC, Cedar, OPA, AuthZEN) answer whether a request should be allowed. CPEX answers a broader question: what security pipeline should execute for this agent operation. It invokes those engines for the decision and enforces the result.

  • Get started#

    Stand up CPEX as an enforcement point and run your first policy.

    Quick Start →

  • Write policy#

    Learn APL: predicates, effects, sequencing, PDPs, delegation, and tainting.

    APL →

  • Why CPEX#

    The reference-monitor model and where CPEX sits in an agent stack.

    Vision →

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