Someone Left Claude Code /loop Running Overnight and Woke Up to a $6,000 Bill

805 upvotes. 255 comments. The highest-engagement story on r/ClaudeAI yesterday. A developer ran /loop before bed and burned approximately $6,000 in Claude usage by morning.

I use /loop regularly. This story hit home.

The problem isn't that /loop is dangerous. It's that there's no hard spending cap, no token limit, and no auto-stop when the task completes. The agent just keeps going. If it hits a wall, it tries harder. If it succeeds, it finds more work. Without explicit boundaries, an autonomous coding agent is a money printer running in reverse.

The community response was immediate and practical. Three guardrails emerged: First, set a max_turns or iteration limit before stepping away from the machine. Second, use ScheduleWakeup with bounded delays rather than unbounded infinite loops. Third, add a pre-iteration hook that checks cumulative token usage and exits if a budget threshold is exceeded. The Ralph plugin provides circuit-breaker functionality for exactly this purpose.

This is the second high-profile cost runaway since Uber's reported Claude Code bill, and it won't be the last. The pattern is predictable: developers discover autonomous agents are powerful, trust them with unsupervised execution, and learn the hard way that "autonomous" means "will keep spending your money until something stops it."

Here's my take: this is a tooling gap, not a user error. Every cloud service that can run up unlimited bills has spending alerts and hard caps. AWS will email you at $50 and shut off services at $100 if you configure it. Claude Code should ship with a max_spend configuration that hard-stops execution. The fact that it doesn't is a product decision Anthropic needs to revisit.

What to do about it: If you're running any autonomous agent loop (Claude Code, Codex, Devin, anything), set explicit bounds before execution. Add this to your ~/.claude/settings.json or use hooks. Don't assume the agent will know when to stop. It won't.