E

---
name: e
description: "Explain a file, error, design, diff, or concept like a helpful engineering colleague: grounded in evidence, concise, and with useful follow-up threads. Use when the user asks for a clear explanation of the current work or codebase."
---

# Explain

Use this as the Codex and Pi equivalent of `/up:e`.

1. If the user named a file, error, diff, or behavior, inspect it before explaining. If they did not, infer the most recent clear topic and state what you selected; ask once only if no target is clear.
2. Lead with the mechanism that answers the question. Assume the reader only vaguely remembers surrounding context.
3. Give evidence in plain language, normally one to four paragraphs. Avoid doc dumps, invented terminology, and unexplained shorthand.
4. End with up to three deeper follow-up threads only when they would add real value.