What can an AI governance layer not do?

A governance layer works on requests and responses. That is where its strength comes from, and it is also where its limits are. Knowing them is the quickest way to judge a vendor's claims and to see which risks still need a separate answer.

It cannot verify a perception

A control point sees requests and responses. It can enforce rules about them and record what happened. It cannot determine whether the model's judgment about the world was right. If a system concludes that a document is authentic, a governance layer can log that conclusion, constrain what follows from it, and make it reviewable. It cannot make it true.

That limit belongs to every system that acts on perception, people included, and no product removes it. The reasoning is in what can and cannot be guaranteed.

It cannot govern what it does not see

Traffic routed around the control point is ungoverned. A personal account on a consumer chatbot, an application calling a model provider directly with its own key, a tool a team adopted last month: if the request never crosses the point, it is never checked and never recorded.

Coverage is therefore a real question, and the first one to ask of any deployment. Which AI traffic passes the point, how is that share measured, and what happens to a request that tries to go around it? A credible answer names the gaps.

It does not address how a model was trained

Governing what a deployed system may do at runtime and governing what data went into building it are separate problems with separate remedies. A runtime layer sees nothing of a model's training data. That question belongs to who built the model, and on what, and it is answered from documents before deployment.

The claim to walk away from

Any vendor claiming to detect all synthetic media, guarantee no incorrect output, or eliminate hallucination is claiming to have solved the perception half of the problem. Nobody has. A vendor who makes that claim has also told you how carefully the rest of the pitch was checked.

What a governance layer can honestly promise is narrower and testable: a defined set of permitted actions, enforced while the system runs, and a record of everything that crossed the point. Each of those can be demonstrated live.