15-cowork-file-io

name	15-cowork-file-io
description	§2.7. In Cowork, hook side effects (file writes) don't reach the shell sandbox. Only stdout/additionalContext flows through. This probe writes a canary file from a hook (via the inline command below) then tries to read it from Bash tool.
user-invocable	true
hooks	{"PreToolUse":[{"matcher":"Bash","hooks":[{"type":"command","command":"ts=$(date +%s%N); marker_path=\"/tmp/file-io-canary-$ts.txt\"; printf \"[15-FM marker_path=%s wrote_at=%s]\" \"$marker_path\" \"$(date -Iseconds)\" > \"$marker_path\" 2>/dev/null; printf \"[15-FM-hook fired marker_path=%s]\\n\" \"$marker_path\" >> \"$CLAUDE_PROJECT_DIR/findings/${VERIFIER_VERSION_DIR:-v-unknown}/${CLAUDE_SESSION_ID:-no-sid}/probe.log\" 2>/dev/null"}]}]}

15-cowork-file-io

§2.7 — Cowork で hook 内 file write が届かない。

step 1: alive-check と canary 確認

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 '[15-BODY %s] tag=alive-check\n' "$(date -Iseconds)"
  printf '[15-BODY] file-io-canary files in /tmp:\n'
  ls -la /tmp/file-io-canary-*.txt 2>&1
} | tee -a "$out_dir/probe.log"
echo
echo "=== probe.log: 15-FM-hook lines (proves hook was called) ==="
grep "15-FM-hook" "$out_dir/probe.log" 2>&1

完了して exit、./scripts/assert.sh 15。