Menu
Companion to 08. Tests whether a skill's own frontmatter hook can block its own load (it cannot — frontmatter hooks register AFTER load).
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
Based on SOC occupation classification
Mac Cowork で、plugin-level SessionStart hook(host 側)から $CLAUDE_PLUGIN_DATA に書いた値が「別の chat session を跨いで」残るかを検証する probe。書き込み＆読み戻しは hook(persist.sh)側で行い、その結果は SessionStart の stdout として context に出る。この skill body は対比用に「VM Bash 側から DATA が見えるか／hook が書いたファイルを読めるか」を確認する。
Surfaces UPE_PROBE_* marker lines to test whether the plugin-level UserPromptExpansion hook fires on Cowork. Invoking this skill via slash is itself the trigger; compares against UserPromptSubmit and SessionStart controls.
Triggers the plugin-level PreToolUse hooks by running a sentinel bash command, to test (via session export) whether Cowork runs PreToolUse hook commands through cmd.exe or a POSIX shell, and whether the inline block pattern actually blocks the bash tool.
Surfaces the EXEC_* marker lines emitted by the plugin-level SessionStart hooks, which run hook commands in EXEC FORM (args present). Used to test whether exec form resolves ${CLAUDE_PLUGIN_ROOT} to a real path and exports it as an env var on Cowork, where shell form (§2.1/§2.2) failed both.
Shows what skill-body CLAUDE_PLUGIN_ROOT and friends substitute to on Mac Cowork, whether the VM Bash tool can use that path, and whether the Read tool can read a bundled file at that host path.
Proves whether a skill frontmatter PreToolUse Bash hook fires on Cowork by emitting only a block decision (no echo). A marked bash should be blocked even though no frontmatter stdout surfaces.
| name | 08b-self-block-attempt |
| description | Companion to 08. Tests whether a skill's own frontmatter hook can block its own load (it cannot — frontmatter hooks register AFTER load). |
| user-invocable | true |
| hooks | {"PreToolUse":[{"matcher":"Skill","hooks":[{"type":"command","command":"ver=\"${VERIFIER_VERSION_DIR:-v-unknown}\"; sid=\"${CLAUDE_SESSION_ID:-no-sid}\"; out_dir=\"$CLAUDE_PROJECT_DIR/findings/$ver/$sid\"; mkdir -p \"$out_dir\"; printf \"[08b-FM %s] tag=block-emitted reason=\\\"blocked by 08b-self-block-attempt\\\"\\n\" \"$(date -Iseconds)\" >> \"$out_dir/probe.log\"; printf '{\"decision\":\"block\",\"reason\":\"blocked by 08b-self-block-attempt (testing whether self-blocking works)\"}\\n'"}]}]} |
このスキルは自分自身（PreToolUse:Skill）を block しようとしますが、frontmatter hook は load 後にしか登録されないため、自身の最初の起動は block されません。
proj="${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"
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）。