Pattern: Policy Card

Layer 01 · Govern-as-Code In the chapter 05 catalogue Build one: Policy Card builder

One working control on the engineering side of AI governance.

Summary: Express a governance rule as a machine-readable artefact that travels with the model or agent and is evaluated in the pipeline and at runtime, rather than as prose a human must apply. The Policy Card encodes permitted and prohibited actions, obligations and evidentiary requirements for one AI system, and links to the enforcement and audit pipelines that act on it¹.

Objectives

Turn a policy from a statement of intent into an executing control, versioned and testable, so that a rule change is a reviewable diff and every evaluation leaves a verdict.

Target users

AI governance engineer, platform team, policy owner.

Impacted stakeholders

Model owners, deployers, auditors, regulators.

Relevant principles

Build the control at the earliest point it can block; make the governed path the easiest path.

Context

An organisation with more than a handful of AI systems and a governance function that cannot review every change by hand. Rules exist but live in documents no pipeline can read.

Problem

Prose policy cannot be enforced automatically, drifts from the systems it governs, and leaves no evidence that it was applied. A rule that can only be remembered is violated the moment someone forgets.

Solution

Write each rule as a Policy Card: a structured, machine-readable artefact (for example expressed for an OPA/Rego or Cedar engine, or as a Policy Cards document) that states allow/deny logic, the failure mode it addresses and the framework clauses it maps to. Store it with the system it governs. Evaluate it pre-merge, at deploy, and (where the rule is a runtime constraint) at the point of action. Emit a verdict (rule id, input hash, decision, timestamp) on every evaluation.

Illustrative schema for the verdict:

{
  "rule_id": "residency.eu-only.v3",
  "decision": "deny",
  "input_hash": "sha256:9f2b…",
  "timestamp": "2026-09-18T14:07:11Z"
}

Consequences

Rules become enforceable and auditable, and the crosswalk generates itself. The cost is authoring and maintaining cards, and the discipline to keep the executable version authoritative over the prose.

Related patterns

Framework Crosswalk; Eval Gate in CI; Runtime Guardrail; Machine-Readable Evidence (OSCAL); Agent Identity & Scoped Credentials.

Maps to: EU AI Act Art. 9 · ISO/IEC 42001 · NIST AI RMF (Govern) · CSA AICM · OWASP Agentic ASI02/ASI03 · Layer 01 Govern-as-Code.

Threat IDs follow the OWASP Top 10 for Agentic Applications 2026 ² and function labels the NIST AI RMF³. Mappings are illustrative, not a claim of conformity.

Sources

1. [1] Policy Cards: machine-readable, deployment-layer governance artefacts for AI agents, linked to enforcement and audit pipelines (arXiv 2510.24383). 2025-10. https://arxiv.org/abs/2510.24383 (verified: primary)
2. [2] Top 10 for Agentic Applications 2026 (ASI IDs). OWASP GenAI Security Project. 2025-12-09. https://genai.owasp.org/resource/owasp-top-10-for-agentic-applications-for-2026/ (verified: primary)
3. [3] AI Risk Management Framework (AI RMF 1.0; Govern, Map, Measure, Manage). NIST. 2023-01-26. https://www.nist.gov/itl/ai-risk-management-framework (verified: primary)