Claude Code /loop Billing Failure: User Spent $6,000 via Cache Miss

A user running Claude Code /loop every 30 minutes on Opus 4.7 accumulated a $6,000 bill over 26 hours because the 30-minute interval exceeds the 5-minute prompt cache TTL, guaranteeing a cache miss on every iteration and full re-write charges as conversation history grew to 800K tokens.

1 min read|agenticonsult Intelligence

Claude Code /loop Billing Failure: User Spent $6,000 via Cache Miss

A developer using Claude Code's /loop command to check open PRs every 30 minutes on Opus 4.7 accumulated approximately $6,000 in API charges over 26 hours (46 iterations). Root cause: the prompt cache TTL is 5 minutes; a 30-minute loop interval guarantees the cache expires between every cycle, forcing a full re-write at expensive write rates. By hour 20, conversation history reached 800K tokens, with each iteration paying full re-write cost. Anthropic's dashboard has a multi-day reporting lag, so the user had no real-time cost visibility until a limit notification arrived.

Why It Matters

Any /loop interval beyond 5 minutes structurally defeats Anthropic's prompt cache. Developers running unattended loops on long conversations should either keep intervals under 5 minutes to stay warm, or start fresh sessions per cycle.

This breaking-news item was assembled from the cited primary source with AI assistance. It is intended for rapid situational awareness — refer to the original publication for the definitive statement.

Claude Code /loop Billing Failure: User Spent $6,000 via Cache Miss

Claude Code /loop Billing Failure: User Spent $6,000 via Cache Miss

Why It Matters

Live Intel Feed