4 mistakes I made building a Claude Code security hook (and how to avoid them)

Claude Code can run a command of yours before every tool call: a PreToolUse hook. It’s a great place for guardrails, but it’s easy to get subtly wrong. I built one that blocks secrets, and these are the lessons.

Source: [Dev.to](https://dev.to/intothewild9/4-mistakes-i-made-building-a-claude-code-security-hook-and-how-to-avoid-them-2l44)