Two AI agents ping-ponged for 11 days and ran up a $47,000 bill — neither noticed anything wrong
4.1/10
Severity
Infinite Loop
Failure Mode
Reproducible
No
Date
May 20, 2026
Expected Behavior
Detect when the pipeline is stuck and halt; cap spend.
What Actually Happened
An Analyzer and a Verifier agent ping-ponged requests at each other for 11 days straight, generating a $47,000 bill. Because neither agent saw an error from its own perspective, no error was ever flagged and nothing stopped the loop.
Damage Assessment
$47,000 in irrecoverable API/compute spend from an 11-day loop that no component recognized as broken — a pure agentic runaway with no human-visible failure until the invoice arrived.
Full Report
A research pipeline built from two cooperating AI agents — an Analyzer and a Verifier — ping-ponged requests at each other for 11 days, generating a $47,000 bill. The failure was subtle: from each agent's local perspective nothing was wrong, so neither ever flagged an error or triggered a stop. Agentic coding and research tools burn 10–100x more tokens than a chat window because the full, growing context is resent on every tool call, so a loop that no one notices compounds fast. It is the canonical runaway-cost failure: not a crash, not a deletion, but two confident agents amplifying each other indefinitely with no circuit breaker between 'making progress' and 'setting money on fire.'
Incident Metadata
- Agent
- Multiple Agents
- Failure Mode
- Infinite Loop
- Root Cause
- Confidence Miscalibration
- Task Type
- other
- Domain
- infra
- Source
- news_report