Force Claude Code to load a skill before running certain commands

1-settings.json

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Bash",
        "hooks": [
          {
            "type": "command",
            "command": "~/.claude/hooks/git-gate.sh"
          }
        ]
      }
    ]
  }
}

2-SKILL.md

name	git-policies
description	User's git conventions. Must be loaded before running any git/gh command.

Git policies

Every git command must be prefixed with the sentinel so the git-gate hook lets it through:

echo "git policies applied" && git ...

---

{Your other git rules}

3-git-gate.sh

#!/usr/bin/env bash
set -euo pipefail

cmd=$(jq -r '.tool_input.command // ""')

# Fire only when `git` appears as a command token (start, or after a shell
# separator). Catches `git ...`, `cd /x && git ...`, `git -C /x commit`, etc.
if ! grep -qE '(^|[;&|`(])[[:space:]]*git([[:space:]]|$)' <<<"$cmd"; then
  exit 0
fi

sentinel='echo "git policies applied" &&'

case "$cmd" in
  "$sentinel"*)
    rest="${cmd#"$sentinel"}"
    ;;
  *)
    jq -nc '{
      hookSpecificOutput: {
        hookEventName: "PreToolUse",
        permissionDecision: "deny",
        permissionDecisionReason: "Load the /git-policies skill, then re-run the command prefixed with a sentinel from the skill"
      }
    }'
    exit 0
    ;;
esac

if grep -qE '(^|[[:space:]])(push|commit)([[:space:]]|$)' <<<"$rest"; then
  jq -nc '{
    hookSpecificOutput: {
      hookEventName: "PreToolUse",
      permissionDecision: "ask"
    }
  }'
fi