Does the brake really stop a CrewAI crew?

Yes. A live run on real OpenAI confirmed it halts crew.kickoff(). CrewAI's retry loop used to swallow the brake; AgentBrakeError is now a BaseException, so it can't be caught by the framework's except Exception.

When do I call install()?

Right before crew.kickoff(), after your agents and LLMs are constructed — CrewAI lazy-loads provider classes, so installing late guarantees they're patched.

How accurate is the cost ceiling?

It reads real token usage the provider reports. Loop, step, tool-call and duration limits are exact regardless.

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Stop runaway CrewAI agents in real time

CrewAI 1.x routes LLM calls through provider classes and wraps execution in retry loops, so naive guards silently no-op. AgentBrake patches the real provider call path plus ToolUsage, and raises a BaseException the retry loop can't catch — verified live against a real crew.kickoff().

$pip install agentbrake-sdk

GitHub

One line to wire it in

from agentbrake import CrewAIBrake

# right before crew.kickoff()
CrewAIBrake(max_cost_usd=3.00, repeat_tool_limit=5).install()

CrewAI runaway patterns it catches

Pattern	How it stops
Identical-tool loops	Loop detector patches ToolUsage and trips after N identical tool calls in a row.
Cost blowouts	Per-instance token-delta accounting from each provider call drives a live cost ceiling.
Retry-swallowed brakes	CrewAI wraps execution in except-Exception retry loops. AgentBrakeError is a BaseException, so it sails past them and actually halts crew.kickoff().
Provider drift	CrewAI 1.x routes calls through a provider factory; AgentBrake patches the real provider classes, not the dead LLM.call entry point.

Add the brake to your CrewAI agent

One line of code. Open source. Works on LangChain 1.x, CrewAI 1.x, and the classic AgentExecutor.

$pip install agentbrake-sdk

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Frequently asked questions

Does the brake really stop a CrewAI crew?: Yes. A live run on real OpenAI confirmed it halts crew.kickoff(). CrewAI's retry loop used to swallow the brake; AgentBrakeError is now a BaseException, so it can't be caught by the framework's except Exception.
When do I call install()?: Right before crew.kickoff(), after your agents and LLMs are constructed — CrewAI lazy-loads provider classes, so installing late guarantees they're patched.
How accurate is the cost ceiling?: It reads real token usage the provider reports. Loop, step, tool-call and duration limits are exact regardless.