Use when the user asks to run Codex CLI (codex exec, codex resume) or references OpenAI Codex for code analysis, refactoring, or automated editing
Installation
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.
When continuing a previous session, use codex exec resume --last via stdin. IMPORTANT: When resuming, you CANNOT specify model, reasoning effort, or other flagsโthe session retains all settings from the original run. Resume syntax: echo "your prompt here" | codex exec resume --last
Run the command, capture stdout/stderr, and summarize the outcome for the user.
Quick Reference
Use case
Sandbox mode
Key flags
Read-only review or analysis
read-only
--sandbox read-only
Apply local edits
workspace-write
--sandbox workspace-write --full-auto
Permit network or broad access
danger-full-access
--sandbox danger-full-access --full-auto
Resume recent session
Inherited from original
echo "prompt" | codex exec resume --last (no flags allowed)
Run from another directory
Match task needs
-C <DIR> plus other flags
Following Up
After every codex command, immediately use AskUserQuestion to confirm next steps, collect clarifications, or decide whether to resume with codex exec resume --last.
When resuming, pipe the new prompt via stdin: echo "new prompt" | codex exec resume --last. The resumed session automatically uses the same model, reasoning effort, and sandbox mode from the original session.
Restate the chosen model, reasoning effort, and sandbox mode when proposing follow-up actions.
Error Handling
Stop and report failures whenever codex --version or a codex exec command exits non-zero; request direction before retrying.
Before you use high-impact flags (--full-auto, --sandbox danger-full-access, --skip-git-repo-check) ask the user for permission using AskUserQuestion unless it was already given.
When output includes warnings or partial results, summarize them and ask how to adjust using AskUserQuestion.