A hacked account + no hard spending cap = a six-figure AI bill. Here's the failure mode nobody's protecting against.

Saw a story recently that stuck with us: someone's cloud account got compromised, the attacker spun up new projects to dodge the free-tier limits, and ran image generation at scale. Tbill came in north of $80K. Provider offered a "courtesy" partial write-off. User's still on the hook for five figures. What got us thinking isn't the hack itself, we all know credential theft happens. It's this: none of the major AI providers let you put a hard, absolute cap on spend. You can set alerts. You can set soft budgets. But nothing stops a request at the door once a limit is hit, not for a malicious actor abusing stolen credentials, and not for your own code running an agentic loop that goes sideways at 2am. We have seen the "internal" version of this constantly: a retry loop with no backoff limit, a prompt that occasionally spirals into a 40-turn agent chain, a bug that reprocesses the same batch five times. Nobody's hacking you; your own code just doesn't know when to stop, and the provider's dashboard tells you about it a day later, after the damage is done. The uncomfortable part: "alert me when spend crosses X" and "stop the request before it happens" are completely different guarantees, and right now almost every provider only offers the first one. Curious how others here handle this: are you relying on provider-side alerts, or has anyone actually built a hard-stop layer in front of their AI calls?