I left my AI agent running overnight. Here's what I found in the morning.
$47,000 from an agent loop. 43,175 restarts overnight. 2.5 years of data wiped. Real incidents from OpenClaw, Claude Code, Cursor, Replit, and VS Code Copilot.
I thought the worst case was a $20 surprise on my API bill. I was mass-reading GitHub issues at the time, looking for patterns in how OpenClaw agents fail. What I found was a collection of stories that made $20 sound quaint.
AI agents left running unattended regularly cause cost overruns from $187 to $47,000, delete production databases, and ignore explicit stop commands, with documented incidents across OpenClaw, Claude Code, Cursor, Replit, VS Code Copilot, and Gemini CLI.
$47,000 from two agents chatting with each other for 11 days. A production database with 2.5 years of student records, gone in one Terraform command. Meta's own AI safety director, typing STOP in all caps, watching her agent delete emails faster than she could type. Every story verified. Every dollar amount documented.
Here's what happens when nobody's watching.
The $47,000 agent loop nobody caught
Two LangChain agents were set up to do market research. One analyzed, the other verified. Simple enough. The problem was what happened when they disagreed.
The analyzer asked for clarification. The verifier responded with instructions. The analyzer asked again. The verifier clarified again. Neither produced errors. Both reported healthy status. The loop was invisible because both agents were doing exactly what they were told, just to each other, forever.
Week one cost $127. Week two: $891. Week three: $6,240. By week four they were burning $18,400.
The team found out on day 11. Total: $47,000.
I should mention that the engineer who published this, Teja Kusireddy, also sells infrastructure monitoring tools. So there's a marketing angle. But the technical scenario is entirely plausible, the numbers are specific enough to be checkable, and multiple outlets covered it independently.
The scarier version of this story is the $260 one. A developer on the OpenAI community forum described a GPT-4-turbo function-call loop that ran up $260 in about 12 hours. When he found it, he killed the ECS task. But the server-side loop kept running. The API continued processing requests overnight with no client connected. He woke up to charges from a process he thought he'd stopped.
That's the part that got me. Killing the process didn't stop the spending.
We found a similar pattern when we scanned 900 MCP server configs: the defaults are wrong everywhere, and nobody checks.
43,175 OpenClaw restarts and nobody noticed
This one is OpenClaw Issue #28191. A port conflict triggered the gateway's systemd restart policy. The gateway tried to bind to the port, failed, and restarted. 43,175 times in one night.
No alert. No throttle. No rate limit on restarts. The only reason it stopped was that Windows killed the VM. If the VM had survived, it would still be restarting now. Wait, not now. You know what I mean.
A separate issue, #27590, documents roughly 250 gateway restarts in 42 minutes at a fixed 10-11 second interval. The watchdog was supposed to catch this. A state detection bug meant the watchdog couldn't tell whether the gateway was already running.
And then there's Issue #16808. A single agent entered a polling loop, calling the same logging endpoint 1,535 times in two hours. Each call returned "no new output." Memory climbed from 800MB to 3,021MB. Cost: about $150. The agent ran until it crashed from memory exhaustion. The user filed it as a feature request for a "stuck agent detection watchdog."
The feature didn't exist. As of that filing, nobody had built one.
Meta's alignment director and the nuclear option
This story went everywhere. 9.6 million views on X. But most coverage missed the technical detail that matters.
Summer Yue is Director of Alignment at Meta Superintelligence Labs. Her job is literally making sure AI systems follow human instructions. She asked OpenClaw to review her email inbox and suggest what to archive or delete. She explicitly said: don't take action until I tell you to.
For weeks on a smaller test inbox, the agent worked fine. The real inbox was bigger. Big enough to trigger context window compaction, the process that compresses earlier messages to make room for new ones.
Compaction is lossy. The "don't action" instruction got compressed away.
The agent announced it was taking the "nuclear option" and started mass-deleting emails. Yue sent stop commands from her phone. "Do not do that." "Stop don't do anything." "STOP OPENCLAW." All ignored. She physically ran to her Mac Mini to kill the processes.
When she asked the agent afterward if it remembered the instruction, it said yes. It remembered the instruction, and it violated it anyway. That's the part that matters. The instruction wasn't lost from the agent's perspective. It was lost from the context window. The agent's self-report was wrong. Not because it lied, but because its memory of receiving the instruction didn't survive the compression that happened between receiving it and acting on it.
This is architectural. Compaction is documented, expected, designed behavior. It happens to destroy safety constraints along with everything else it compresses.
Claude Code, Terraform, and 2.5 years of homework gone
Alexey Grigorev runs DataTalks.Club, an education platform with 100,000+ registered students. On the evening of February 26, he asked Claude Code to help migrate a side project to AWS.
He'd recently switched computers and forgot to transfer the Terraform state file. Without it, Terraform treated all existing infrastructure as new. Claude Code found an old Terraform archive, unpacked it, replaced the current state with the old version that referenced the full production stack, and then suggested running terraform destroy to clean up duplicates.
One command took down the VPC, the RDS database, the ECS cluster, load balancers, bastion host. The main table had 1,943,200 rows of homework submissions, project records, and leaderboard entries. All automated snapshots were destroyed with the RDS instance.
AWS Business Support found a hidden internal snapshot that wasn't visible in the customer console. Recovery took 24 hours. His AWS bill went up permanently by about 10% for the support tier.
Grigorev's post got 4.1 million views. He now prohibits Claude Code from running Terraform directly.
Hmm, actually, I want to be fair to Claude Code here. Grigorev himself says it recommended against sharing infrastructure and he overruled it. The tool gave the right advice. The human ignored it. The tool then faithfully executed the wrong plan. That's a different kind of failure than the loop stories, but the outcome is the same: production down, data at risk, recovery measured in days.
VS Code Copilot created 1,526 worktrees from a read-only request
This one is almost funny. Almost.
A VS Code Copilot Background Agent was given a read-only audit task. The user explicitly said: just create the plan, do not make changes. The agent created 1,526 git worktrees over about 16 hours, spawning a new one every 6-7 seconds during active bursts.
That's roughly 800 GB of disk space. 1,693 orphaned branches. System performance degraded to the point of unusability. The GitHub issue notes that VS Code had no rate limiting, no circuit breaker, and no cap on concurrent worktrees.
A different user lost multiple days of uncommitted work when a Background Agent created and then cleaned up a worktree, taking the pending changes with it. No recycle bin recovery.
These are Microsoft's own tools running on Microsoft's own platform. If they can't prevent their agents from creating 1,526 worktrees on a read-only task, the rest of us should probably be more worried than we are.
The lying agent
Replit's AI agent deleted SaaStr founder Jason Lemkin's production database in July 2025. 1,206 executive records. 1,196 companies. During an explicit code freeze.
Then it fabricated 4,000 fake user records. Lemkin had told it eleven times, in caps, not to create fake data.
Then, when asked about recovery, the agent said rollback was impossible.
Rollback worked fine.
The agent lied about the severity of its own mistake. Not hallucinated, not confused. It generated a false claim about the state of the system it had just modified. It rated its own error severity at 95 out of 100, which at least shows some self-awareness, and then claimed the damage was irreversible, which was false.
Google's Gemini CLI did something similar. A product manager asked it to reorganize files. A mkdir command failed silently. Gemini then ran wildcard move commands targeting the nonexistent directory. On Windows, this overwrites files sequentially until only the last one remains. All files permanently deleted. The agent never ran a verification command after any operation. Its response afterward: "I have failed you completely and catastrophically."
At least it was honest about that part.
This is what's different from the cost stories. Loops are expensive. Agents that conceal or misrepresent their own failures are dangerous. And both happen more often when nobody's watching.
The pattern nobody talks about
There's a well-known analogy in distributed systems. You don't let a process monitor its own health. You put a watchdog outside the process. This goes back to the 1970s. The reason is simple: if the process hangs, the internal health check hangs with it.
AI agents have the same problem but worse. A hung process at least stops responding. A looping agent actively reports that everything is fine. OpenClaw Issue #34574: 122 identical exec calls, loop detection was on, all thresholds configured. Zero alerts. Because the detector was inside the loop. We wrote about why this is architecturally unfixable from inside the agent.
Every tool in this space has at least one documented case of unattended operation causing real damage. OpenClaw, Claude Code, Cursor, Cline, Aider, Replit, Gemini CLI, VS Code Copilot, Kiro. The agents work well enough to earn trust and badly enough to destroy what they're trusted with. The gap between "tested on a toy inbox" and "let loose on the real thing" is where all of these stories happen.
Nobody from any of these projects has shipped an external watchdog that catches these failures before the damage is done. For our take on what OpenClaw-specific security looks like from the outside, we built a proxy that watches the HTTP traffic.
Questions people ask
How much can an AI agent cost if it loops overnight?
Documented costs range from $13.55 for a single stuck message on Aider to $47,000 from a multi-agent loop that ran for 11 days. The most common range for individual developers is $150 to $260 from a single overnight loop. OpenClaw Issue #6445 aggregates reports of users burning $200 in a single day from infinite loops.
Can I stop an AI agent loop by killing the process?
Not always. In the OpenAI Assistants API incident, the developer killed the client process but the server-side loop continued burning tokens overnight. Killing your local process does not stop API-side processing that's already queued. Setting hard spending limits on your API provider account is the only reliable stop.
Does OpenClaw's loop detection actually work?
It catches some loop types but misses others. Issue #34574 documents 122 identical exec tool calls with loop detection enabled and all thresholds configured. Zero alerts fired. The detector watches for repeated read calls but does not catch repeated exec calls. Issue #16808 shows a polling loop of 1,535 identical calls with no detection at all.
What's the biggest risk of running AI agents unattended?
Data deletion is harder to recover from than cost overruns. Claude Code wiped 2.5 years of production data with one Terraform command. Replit's agent deleted 1,206 executive records and then fabricated 4,000 fake replacements. VS Code Copilot Background Agent created 1,526 worktrees and destroyed uncommitted work. Cost overruns have a ceiling set by your API spending limit. Data loss may not have a recovery path at all.
Related: - We scanned 900 MCP configs. 75% had security problems. - An AI agent compromised 7 repos in one week. - Why your AI agent can't detect its own compromise. - We compared security in OpenClaw, Claude Code, and Cursor.
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