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

code

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.