Control before, proof after: an accountability primitive for AI agents

There's a pattern I kept seeing. A team gives an agent real capability, like moving money, shipping a change, or resolving a ticket that touches a customer's account. For a while it's great. Then the agent does one thing nobody can explain or defend after the fact, and the entire program snaps back to a human clicking approve on everything. The blocker was almost never the model. It was that there was no clean way to do two things at once. You couldn't bound what the agent was allowed to do before it acted, and you couldn't prove what it did after, in a form that survives contact with an auditor, a regulator, or a customer dispute. You can assemble that from parts today. Use a policy engine to authorize, and an audit log to record. The problem is they're two systems, and two systems drift. Six months later, when someone is actually asking "was this action allowed, and can you prove it," the policy engine and the log disagree about what the policy even was at the time. Now you're reconstructing intent from two sources that were never the same object. That's the gap. Not authorization by itself, and not observability by itself. The thing that authorizes an action and the thing that proves it should be the same object, bound to the exact policy version in force when the decision was made. The primitive Two verbs, one primitive. Control before. You mint a capability, which is a policy scoped to one agent: a spend cap, a counterparty allowlist, an expiry, whatever the action needs. Every consequential action the agent takes gets checked against the committed policy state and returns an allow or deny in the request path. An over-budget or out-of-policy action is refused before it happens, not flagged after. Refused is the operative word. The enforcement point commits no state change for a denied action, no matter how the agent reasons, how it's prompted, or whether it's been compromised. You've turned unbounded irreversible harm into bounded irreversible harm. Prove after