Codex Analysis
Run the Codex CLI to get deep analysis using gpt-5.2-codex with high reasoning effort.
IMPORTANT: This skill MUST spawn subagents for parallel exploration. Always include subagent instructions in the prompt.
When to Use
- User asks for "Codex analysis" or "Codex help"
- User wants a second opinion on code or architecture
- User needs deep reasoning on a complex problem
Running the Analysis (MUST spawn subagents)
Execute this command, replacing {PROMPT} with the user's question or analysis request.
Always append subagent instructions to the prompt:
codex exec -m gpt-5.2-codex \
--config model_reasoning_effort="high" \
--sandbox read-only \
--skip-git-repo-check \
"{PROMPT} Spawn subagents to explore different aspects in parallel."
Command Parameters
| Flag | Purpose |
|------|---------|
| -m gpt-5.2-codex | Use gpt-5.2-codex model (spawns subagents for parallel work) |
| --config model_reasoning_effort="high" | Maximum reasoning depth |
| --sandbox read-only | Safe read-only sandbox |
| --skip-git-repo-check | Skip git repository validation |
Subagent Requirements
MANDATORY: Every prompt MUST include instructions to spawn subagents. This enables:
- Parallel exploration of different code areas
- Concurrent analysis of multiple concerns (security, performance, architecture)
- Faster and more thorough analysis
Template suffix to append to every prompt:
"Spawn subagents to explore different aspects in parallel."
After Running
- Summarize the Codex analysis output
- Highlight key suggestions and findings
- Ask if the user wants to:
- Implement any suggested changes
- Get more details on specific points
- Run additional analysis
Example Usage
User asks: "Use Codex to analyze the authentication flow"
Run (note: subagent spawning is REQUIRED):
codex exec -m gpt-5.2-codex \
--config model_reasoning_effort="high" \
--sandbox read-only \
--skip-git-repo-check \
"Analyze the authentication flow in this codebase. Spawn subagents to explore security issues, improvement opportunities, and best practices in parallel."
User asks: "Get Codex help with performance issues"
Run:
codex exec -m gpt-5.2-codex \
--config model_reasoning_effort="high" \
--sandbox read-only \
--skip-git-repo-check \
"Identify performance bottlenecks in this codebase. Spawn subagents to analyze database queries, API endpoints, and frontend rendering in parallel."
Then summarize findings and offer follow-up actions.