| name | explain |
| description | Deep-dive into complex code using Codex CLI. Traces call chains, maps dependencies, and explains how code works. Use when asked to understand, unwind, or explain tangled or unfamiliar code. |
Codex Explain
Use Codex CLI to do a thorough, read-only deep-dive into code and report back a clear explanation.
1) Build the prompt
From the user's request, construct a focused prompt for Codex. The prompt should ask Codex to:
- Trace the relevant code paths end-to-end
- Identify key abstractions, data flow, and control flow
- Surface non-obvious dependencies or side effects
- Call out anything surprising or fragile
Include the target (file path, function name, module, or concept) in the prompt.
2) Run Codex
codex --sandbox read-only -a never exec "$PROMPT"
Do not use | tee unless the output is likely to be very large.
3) Follow response contract
Structure the explanation as:
- What it does — high-level purpose
- How it works — key code paths and flow
- Connections — dependencies, callers, side effects
- Gotchas — anything surprising, fragile, or easy to misunderstand
Keep it concrete. Reference specific files and lines, not abstract descriptions.
