Claude Code Hooks

Shell commands that fire at specific points in Claude Code's lifecycle.

Hooks enforce mechanically what prose cannot: a model can reason its way past an instruction, but it cannot reason its way past an exit 2 — which is exactly why every hook must be narrow, silent, and reversible.

Named failure mode — chatty happy path: a hook that emits stdout on exit 0 corrupts the tool call it was guarding; silence on success is part of the contract, not a style preference.

Prompt

Add a PreToolUse hook to fleet-router/.claude/settings.json that blocks `git push --force` on the main branch. Keep it silent on exit 0, exit 2 with a message on block, and confirm it fires with a manual test invocation before committing the change.

It's working if