---
name: Codex Explain
slug: codex-explain-2
category: AI Engineering
description: Codex Explain produces structured explanations of code at a chosen depth. Use it to understand complex logic, trace data flow, or onboard to unfamiliar code.
github: "https://github.com/sd0xdev/sd0x-harness/tree/main/skills/codex-explain"
language: JavaScript
stars: 188
forks: 24
install: "npx degit https://github.com/sd0xdev/sd0x-harness/tree/main/skills/codex-explain ~/.claude/skills/codex-explain"
installs_to: ~/.claude/skills/codex-explain
source_path: skills/codex-explain/SKILL.md
collection_size: 25
category_size: 3278
collection_url: "https://dirskills.com/collections/sd0xdev/sd0x-harness"
added: 2026-09-06T05:20:13.578Z
last_synced: 2026-09-06T05:20:13.578Z
canonical_url: "https://dirskills.com/skills/codex-explain-2"
---

# Codex Explain

Codex Explain produces structured explanations of code at a chosen depth. Use it to understand complex logic, trace data flow, or onboard to unfamiliar code.

**Install:**

```bash
npx degit https://github.com/sd0xdev/sd0x-harness/tree/main/skills/codex-explain ~/.claude/skills/codex-explain
```

## README

# Codex Explain Skill

## Trigger

- Keywords: explain code, what does this do, how does this work, code walkthrough

## When NOT to Use

- Code review (use `codex-code-review`)
- Bug investigation (use `bug-fix` or `issue-analyze`)
- Architecture overview (use `code-explore`)

## Workflow

```
Read target → [Collect context] → Codex explain → Output explanation
```

### Step 1: Read Target File

Read file content. If `--lines` specified, extract only that range.

### Step 2: Codex Explanation

Dispatch per `@skills/codex-code-review/references/codex-transport.md` § Start with the explanation prompt. See `references/codex-prompt-explain.md`.


## Depth Levels

| Level  | Description                                          |
| ------ | ---------------------------------------------------- |
| brief  | One-sentence summary                                 |
| normal | Functional overview + execution flow + key concepts (default) |
| deep   | + Design patterns + complexity + issues + dependencies |

## Output

```markdown
## Code Explanation: <target>
- **Depth**: brief / normal / deep
- **Summary**: <functional overview>
- **Execution flow**: <key paths>
- **Key concepts**: <patterns, abstractions>
```

## Verification

- [ ] Codex independently researched project context (imports, callers)
- [ ] Explanation matches requested depth level
- [ ] Key concepts are identified and explained

## References

- Explanation prompt: `references/codex-prompt-explain.md`

## Examples

```
Input: /codex-explain src/service/order/order.service.ts
Action: Read file → Codex explain (normal) → Functional summary + detailed explanation

Input: /codex-explain src/service/xxx.ts --depth deep
Action: Read file → Codex explain (deep) → Patterns + complexity + issues

Input: /codex-explain src/xxx.ts --lines 50-100
Action: Read lines 50-100 → Codex explain → Focused explanation
```