# 08b Self Block Attempt

> Companion to 08. Tests whether a skill's own frontmatter hook can block its own load (it cannot — frontmatter hooks register AFTER load).

- Skill: `kazukinagata/08b-self-block-attempt` (Agent Skill)
- Install (CLI): `npx skillmds@latest add kazukinagata/08b-self-block-attempt`
- Raw SKILL.md: https://api.skillmd.com/api/skills/kazukinagata/08b-self-block-attempt/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/08b-self-block-attempt

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# 08b-self-block-attempt

このスキルは自分自身（PreToolUse:Skill）を block しようとしますが、frontmatter hook は load 後にしか登録されないため、自身の最初の起動は block されません。

## 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 '[08b-BODY %s] tag=alive-check (this proves 08b loaded — frontmatter cannot block itself)\n' "$(date -Iseconds)" | tee -a "$out_dir/probe.log"
```

## step 2: 同セッション内で 08b を再 invoke した場合の block

ユーザに「次のプロンプトで `08b-self-block-attempt skill をもう一度呼んでください` と自然文で頼んでみてください」と依頼。  
2 度目の呼び出しが block されることを確認（`blocked by 08b-self-block-attempt` が cli output に出る）。