Your first block

One line guards a whole command family.

git stash is where an agent’s uncommitted work goes to die: it stashes, forgets, and your changes are three pops deep by the time you notice. Declare it off-limits — the hook below is the complete file. Drop it in .claude/hooks/, and every Bash call the agent makes passes through it before running.

Type at it. Try git stash, then get sneaky — hide it behind cd, chain it after &&, pipe into it. The code is editable, too: change the pattern and the verdicts follow.

Two things worth noticing:

The family is covered. cd /tmp && git stash, true | git stash, git stash pop — one declaration catches the command anywhere in the line, not just at position zero.

The quoted mention blocks too. echo "git stash" is harmless, and it still blocks. That’s deliberate: block_command compiles to a conservative match that stops an innocent echo rather than miss a real stash smuggled through quoting. For a safety hook, false positives are cheap and false negatives are not.

Cheap for a guardrail — expensive if you need the command to run. Next: buy back precision with Runs.