Fail-open is the default failure mode of agent hooks I'm the author of Handrail, a free, MIT-licensed hook pack for Claude Code and other agent-CLI hook systems. Handrail works with Claude Code and other agent CLIs in plain text only; it is not affiliated with, endorsed by, or a product of Anthropic. This post is about one specific design bug I keep finding in hook scripts, including early drafts of my own: they fail open. What "fail open" means here An agent-CLI hook is a...