Codex System — Deep Reasoning Partner
Codex CLI (gpt-5.3-codex) is your highly capable supporter for deep reasoning tasks
詳細ルール:
.claude/rules/codex-delegation.md
Context Management (CRITICAL)
サブエージェント経由を推奨。 メインオーケストレーターのコンテキストを節約するため。
| 状況 | 方法 |
|---|---|
| 詳細な設計相談 | サブエージェント経由（推奨） |
| デバッグ分析 | サブエージェント経由（推奨） |
| 短い質問 (1-2文回答) | 直接呼び出しOK |
When to Consult (MUST)
| Situation | Trigger Examples |
|---|---|
| Design decisions | 「どう設計？」「アーキテクチャ」 / "How to design?" |
| Debugging | 「なぜ動かない？」「エラー」 / "Debug" "Error" |
| Trade-off analysis | 「どちらがいい？」「比較して」 / "Compare" "Which?" |
| Complex implementation | 「実装方法」「どう作る？」 / "How to implement?" |
| Refactoring | 「リファクタ」「シンプルに」 / "Refactor" "Simplify" |
| Code review | 「レビューして」「確認して」 / "Review" "Check" |
When NOT to Consult
- •Simple file edits, typo fixes
- •Following explicit user instructions
- •git commit, running tests, linting
- •Tasks with obvious single solutions
How to Consult
Recommended: Subagent Pattern
Use Task tool with subagent_type='general-purpose' to preserve main context
code
Task tool parameters:
- subagent_type: "general-purpose"
- run_in_background: true (optional, for parallel work)
- prompt: |
Consult Codex about: {topic}
codex exec --model gpt-5.3-codex --sandbox read-only --full-auto "
{question for Codex}
" 2>/dev/null
Return CONCISE summary (key recommendation + rationale).
Direct Call (Short Questions Only)
For quick questions expecting 1-2 sentence answers:
bash
codex exec --model gpt-5.3-codex --sandbox read-only --full-auto "Brief question" 2>/dev/null
Workflow (Subagent)
- •Spawn subagent with Codex consultation prompt
- •Continue your work → Subagent runs in parallel
- •Receive summary → Subagent returns concise insights
Sandbox Modes
| Mode | Use Case |
|---|---|
read-only | Analysis, review, debugging advice |
workspace-write | Implementation, refactoring, fixes |
Language Protocol
- •Ask Codex in English
- •Receive response in English
- •Execute based on advice (or let Codex execute)
- •Report to user in Japanese
Task Templates
Design Review
bash
codex exec --model gpt-5.3-codex --sandbox read-only --full-auto "
Review this design approach for: {feature}
Context:
{relevant code or architecture}
Evaluate:
1. Is this approach sound?
2. Alternative approaches?
3. Potential issues?
4. Recommendations?
" 2>/dev/null
Debug Analysis
bash
codex exec --model gpt-5.3-codex --sandbox read-only --full-auto "
Debug this issue:
Error: {error message}
Code: {relevant code}
Context: {what was happening}
Analyze root cause and suggest fixes.
" 2>/dev/null
Code Review
See: references/code-review-task.md
Refactoring
See: references/refactoring-task.md
Integration with Gemini
| Task | Use |
|---|---|
| Need research first | Gemini → then Codex |
| Design decision | Codex directly |
| Library comparison | Gemini research → Codex decision |
Why Codex?
- •Deep reasoning: Complex analysis and problem-solving
- •Code expertise: Implementation strategies and patterns
- •Consistency: Same project context via
context-loaderskill - •Parallel work: Background execution keeps you productive