Codex

Codex CLI Integration

This skill enables multi-turn conversations with OpenAI Codex CLI for:

• Plan refinement and review
• Code review and debugging
• Research and brainstorming
• Getting a second opinion on approaches

How to Use

Starting a Conversation

Run the script with a JSON prompt via stdin:

echo '{"prompt": "Review this implementation plan and suggest improvements..."}' | python3 scripts/codex_chat.py

Continuing a Conversation

The script stores session IDs automatically. To continue the last conversation:

echo '{"prompt": "What about edge cases?", "continue_session": true}' | python3 scripts/codex_chat.py

Reasoning Selection

Always uses gpt-5.4. Reasoning effort strategy:

• First message of a conversation: always use high
• Follow-up messages: choose based on conversation complexity so far
  • high — Complex threads, deep analysis, architecture decisions
  • medium — Simple follow-ups, clarifications, quick questions

echo '{"prompt": "...", "reasoning": "medium"}' | python3 scripts/codex_chat.py

Background Execution

For long-running Codex tasks, use the Task tool with background mode:

When Codex might take a while:
1. Use Task tool with run_in_background: true
2. Pass the Bash command that runs the script
3. Continue other work
4. Check TaskOutput when ready

Input JSON Schema

{
  "prompt": "Required - the prompt to send to Codex",
  "reasoning": "Optional - 'medium' or 'high' (default: high)",
  "continue_session": "Optional - true to continue last conversation",
  "working_directory": "Optional - project directory for context"
}

Output JSON Schema

{
  "response": "Codex's response text",
  "session_id": "ID for continuing this conversation",
  "model": "Model that was used",
  "reasoning": "Reasoning level that was used",
  "success": true
}

Session Management

Sessions are stored in ~/.codex-claude-session.json. Each new conversation creates a new session unless continue_session: true is passed.

Important: Session continuation requires being in a git repository. New sessions can start anywhere, but to continue a session you need to be in a git repo (use working_directory to specify a project path).

Exit Codes

• 0: Success
• 1: Input/configuration error
• 2: Codex CLI error
• 3: Codex not installed

Examples

Basic plan review

echo '{"prompt": "Review this plan for implementing user authentication. Look for security issues and suggest improvements."}' | python3 scripts/codex_chat.py

Quick question with medium reasoning

echo '{"prompt": "What are the pros and cons of this approach?", "reasoning": "medium"}' | python3 scripts/codex_chat.py

Continue a conversation

echo '{"prompt": "What about the error handling I mentioned earlier?", "continue_session": true}' | python3 scripts/codex_chat.py