# 12 Block Self

> §2.4 / §2.5. Self-blocker skill. Its frontmatter PreToolUse:Skill hook returns a JSON block decision for any Skill tool call to 11-block-target. Must be invoked BEFORE 11-block-target so the hook is registered.

- Skill: `kazukinagata/12-block-self` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add kazukinagata/12-block-self`
- Raw SKILL.md: https://api.skillmd.com/api/skills/kazukinagata/12-block-self/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: kazukinagata (https://skillmd.com/u/kazukinagata)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/kazukinagata/12-block-self

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# 12-block-self

§2.4 — frontmatter `PreToolUse:Skill` で **11-block-target だけ**を block する。

## step 1: alive-check

```bash
proj="${CLAUDE_PROJECT_DIR:-$PWD}"
ver="${VERIFIER_VERSION_DIR:-v-unknown}"
sid="${CLAUDE_SESSION_ID:-no-sid}"
out_dir="$proj/findings/$ver/$sid"
mkdir -p "$out_dir"
printf '[12-BODY %s] tag=alive-check (self-blocker registered)\n' "$(date -Iseconds)" | tee -a "$out_dir/probe.log"
```

次のプロンプトで、**自然文で**「`11-block-target` skill を起動してください」とユーザに依頼してもらう（slash 経由は §1.9 によると Skill tool が呼ばれないので block 経路にならない）。