Denial of wallet

Denial of wallet is an attack on metered systems that aims to exhaust budget rather than capacity: forcing an AI application into expensive model calls, tool invocations, or loops until the bill, not the server, becomes the casualty. Agents raise the stakes because one instruction can trigger thousands of billable actions.

A classic denial of service fills a pipe; a denial of wallet drains an account at normal request rates, which is why rate limiting alone misses it. Agentic systems add a self-inflicted variant: a mis-planned loop or a runaway delegation tree consumes budget with no attacker at all. Controls are the same for both: per-agent action budgets, cost ceilings tied to declared scope, and circuit breakers that turn "unusually expensive" into a decision for a human.

Related

• Agent scope
• Blast radius
• All glossary terms