gate.cat is an essential developer tool designed to protect your systems from irreversible mistakes made by AI coding agents. Even without malicious intent, giving an AI agent shell access combined with a single confident miscalculation can spell disaster for your codebase and infrastructure.

Operating as a deterministic, fail-closed veto, gate.cat inspects tool calls directly at the boundary. It intercepts and refuses high-risk, irreversible commands—such as rm -rf, DROP TABLE, or terraform destroy—before they are ever executed. Built for flexibility, it supports Claude Code hooks, gated shells, and OpenAI-API proxies.

Backed by extensive testing, the creators replayed over 826,644 real agent commands with zero misses, and they transparently publish their own bypass map. Best of all, gate.cat is completely free forever and open-source under the Apache 2.0 license.

Pros of gate.cat

Blocks irreversible commands like rm -rf and DROP TABLE before execution
Deterministic, fail-closed veto security model at the boundary
Supports Claude Code hooks, gated shells, and OpenAI-API proxies
Free forever and open-source under the Apache 2.0 license

Cons of gate.cat

Focused specifically on blocking destructive commands rather than full agent orchestration
Requires proper integration setup (hooks, proxies, or shells) to function
Relies on boundary inspection which must cover all potential execution paths

Frequently Asked Questions

What does gate.cat do?

gate.cat acts as a deterministic, fail-closed veto that inspects tool calls at the boundary. It blocks irreversible commands—such as rm -rf, DROP TABLE, and terraform destroy—before an AI coding agent can execute them.