Across our last set of inventories, the number of AI systems actually in production consistently exceeded the number on the client's own register. The gap was not shadow IT in the old sense. It was teams doing exactly what leadership asked for, quickly, with the credentials they had to hand.
The first thing we do on an AI governance engagement is ask for the register. Almost every client has one now. It is usually a spreadsheet, maintained by someone in risk or architecture, and it usually lists between four and nine systems.
The second thing we do is go and look. Code search across the repositories, inspection of the cloud accounts, egress patterns on the network, and, most productively, the expense records. Somebody paid for it. That trail is almost always the one that finds the tool the security team never saw.
The register is never right. That is not a criticism of the person maintaining it, and it is not the old story about shadow IT either. What we find is teams that did exactly what leadership asked them to do, at the speed leadership asked for it, using the access they already had.
Models get noticed. Somebody signs a contract, procurement gets involved, there is a line in the budget. A model tends to arrive through a process, and processes leave records.
Agents arrive differently. An engineer wires a model to a tool, gives it a credential so the demo works, and shows it to their manager on a Thursday. It saves four hours a week. It stays. Nobody filled in a form because nothing was bought, and the thing that changed was a few dozen lines in a repository nobody outside that team reads.
By the time we arrive, that agent has been writing into a production system for eight months, still using the credential that was convenient on day one.
Here is the shape of it, repeated across engagements with different names attached.
None of the individual decisions there is unreasonable. The engineer who built it was solving the problem in front of them with the tools they had. The compounding is what makes it dangerous, and compounding is invisible to everyone except somebody looking at the whole path at once.
We stopped describing this in terms of vulnerabilities some time ago, because it did not land. A board hearing that an agent is vulnerable to prompt injection reasonably asks how likely that is and moves on.
Blast radius lands better. For each agent we map what it can read, what it can write, what it can trigger, and what the worst outcome is if someone talks it into doing the wrong thing. Then we put that next to the task the agent was actually built to do. The gap between those two is the finding, and it is usually enormous.
A board that hears an agent built to categorise tickets can modify any customer record and issue refunds does not need a probability estimate. They can see the problem, and more importantly they can see the fix.
Almost everything in this category is inexpensive to remediate relative to what it costs when it surfaces on its own. Scope the credential to the minimum the task requires. Log every action with its originating context so a bad write can be traced. Put a human approval step on anything irreversible, which in practice means anything involving money, deletion or an external party.
For a typical estate that is a few weeks of work per agent and it does not require replacing anything. The hard part is not the engineering. The hard part is knowing which agents exist, which is why the inventory comes first and why we do it by looking rather than by asking.
You do not need an assessment to start. Search your repositories for the model provider SDKs you have accounts with. Pull the last twelve months of expense records and look for anything AI-shaped under a few hundred dollars a month, which is where these things live. Ask each engineering team leader, privately and without a form, what they have running that is not on the register. You will find things.
Then, for each one, ask a single question: if someone hostile controlled the input to this, what is the most damaging thing it could do with the access it currently holds. That question alone will reorder your priorities.
Discovery is the first week of an AI governance assessment, and it is usually the week that changes the conversation.