Codex Skill
Priorities
Correctness > Security > Efficiency
Goal
Execute OpenAI Codex CLI for automated code analysis, refactoring, and editing tasks. Default to gpt-5.3-codex model with user-specified reasoning effort. Suppress stderr thinking tokens by default unless debugging is needed.
Constraints
- Default model:
gpt-5.3-codex(ask user for reasoning effort: high, medium, or low) - Sandbox mode:
--sandbox read-only(default),workspace-write(for edits),danger-full-access(network/broad access) - Always use
--skip-git-repo-checkflag - Suppress stderr by default: append
2>/dev/nullto allcodex execcommands - Resume sessions:
echo "prompt" | codex exec --skip-git-repo-check resume --last 2>/dev/null(no config flags between exec and resume unless user specifies) - Ask permission before using high-impact flags (
--full-auto,--sandbox danger-full-access) - Stop and report on non-zero exit codes
- Inform user after completion: "You can resume this Codex session at any time by saying 'codex resume'"
Model Options
| Model | Best for | Context window | Key features |
|---|---|---|---|
gpt-5.3-codex ⭐⭐ | Flagship model: Software engineering, code review, agentic coding | 400K input / 128K output | 25% faster, best agentic coding, $1.75/$14.00 |
gpt-5.3-codex-spark | Research preview: ultra-fast inference via Cerebras | 400K input / 128K output | 1000+ tokens/s, experimental |
gpt-5.2-codex | Code review, security analysis | 400K input / 128K output | 79% SWE-bench Pro |
gpt-5.1-codex ⭐ | Software engineering, agentic coding workflows | 400K input / 128K output | 76.3% SWE-bench, $1.25/$10.00 |
gpt-5.1-codex-mini | Cost-efficient coding (4x more usage allowance) | 400K input / 128K output | Near SOTA performance, $0.25/$2.00 |
gpt-5.1-thinking | Ultra-complex reasoning, deep problem analysis | 400K input / 128K output | Adaptive thinking depth, runs 2x slower on hardest tasks |
References
Load CLI reference and code review patterns:
Glob(pattern: "**/sdlc/**/skills/codex/references/codex-cli-reference.md", path: "~/.claude/plugins")→ Read result
Arguments
$ARGUMENTS