Codex Runtime

Use the installed Codex companion from Claude Code. The caller owns routing and review; the companion performs one bounded task.

Preamble

Resolve the helper from the active plugin first, then the stable marketplace installation:

if [ -n "${CLAUDE_PLUGIN_ROOT:-}" ] && [ -f "$CLAUDE_PLUGIN_ROOT/scripts/codex-companion.mjs" ]; then
  COMPANION="$CLAUDE_PLUGIN_ROOT/scripts/codex-companion.mjs"
else
  COMPANION="$HOME/.claude/plugins/marketplaces/openai-codex/plugins/codex/scripts/codex-companion.mjs"
fi
[ -f "$COMPANION" ] && echo "CODEX_COMPANION: $COMPANION" || echo "CODEX_COMPANION: missing"

CODEX_COMPANION: missing → stop and report the missing runtime. Do not guess a versioned cache path.