Codex ThinkDeep Skill

Multi-step investigation and deep reasoning with Codex (gpt-5.2) using extra-high reasoning.

When to Use

• Complex problems requiring step-by-step analysis
• Architecture decisions
• Performance deep-dives
• Security analysis
• When user asks for "deep", "thorough", or "comprehensive" Codex analysis

Reasoning Level

xhigh (always - this skill is for deep analysis)

Execution

1. Understand the problem fully
2. Gather all relevant files and context
3. Formulate a structured prompt:

   Investigate this step by step. Form hypotheses, test them, and build confidence.
   
   Question: <user's question>
   
   Context:
   <relevant file contents>
   
   Please:
   1. Break down the problem
   2. Form initial hypotheses
   3. Analyze each hypothesis
   4. Reach a well-reasoned conclusion
   

4. Run: codex exec -c model_reasoning_effort="xhigh" "<prompt>"
5. Return the comprehensive analysis

Response Format

**Deep Analysis from Codex:**

**Problem Breakdown:**
[Step-by-step analysis]

**Hypotheses Explored:**
[Each hypothesis and findings]

**Conclusion:**
[Final recommendation with confidence level]

**Session ID:** [id]