majiayu000 Codex Assistant
Execute tasks using OpenAI Codex CLI and analyze results.
Important Limitations
Codex runs in read-only sandbox mode. It cannot:
- Create or modify files
- Execute scripts or commands that write to disk
- Run generated code
Always ask Codex to output results directly to stdout. Do not request file creation or modification - instead, ask Codex to print/output the code or results, which Claude can then save if needed.
Command
codex exec --model gpt-5.2-codex "PROMPT"
Prompt Format
Structure prompts with three sections:
# Role
[Describe the role/persona for the task]
# Context
[Include relevant information:]
- File paths and links to documentation
- Memory files or conversation context
- Additional task-relevant details
# Task
[Clear task description]
[Expected deliverables]
Workflow
- Construct prompt - Build structured prompt with Role, Context, Task
- Execute codex - Run command with the formatted prompt
- Analyze output - Review results for:
- Completeness of task execution
- Quality and accuracy of output
- Issues or recommendations identified
- Actionable items to address
Example
codex exec --model gpt-5.2-codex "# Role
Senior code reviewer with expertise in security and best practices.
# Context
Repository: /path/to/project
Files changed: src/auth.py, src/api.py
Branch: feature/user-auth
# Task
Review changes against develop branch.
Search for security issues, bugs, and suggest improvements.
Output your findings and recommendations to stdout."
Note: Always phrase tasks to output results rather than create/modify files. For code generation, ask Codex to "print the code" or "output the script" instead of "create a file".
Output Analysis
After codex completes, evaluate:
- Findings - Key issues or insights discovered
- Recommendations - Suggested improvements or fixes
- Action items - Concrete next steps to implement
- Quality - Overall assessment of the analysis