# Sd0xdev Sd0x Dev Flow Codex Explain

> Codex Explain Skill

- Skill: `tomevault-io/sd0xdev-sd0x-dev-flow-codex-explain` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/sd0xdev-sd0x-dev-flow-codex-explain`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/sd0xdev-sd0x-dev-flow-codex-explain/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/sd0xdev-sd0x-dev-flow-codex-explain

---


# 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

Use `mcp__codex__codex` with explanation prompt. See `references/codex-prompt-explain.md`.

Config: `sandbox: 'read-only'`, `approval-policy: 'never'`

## 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
```

---
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<!-- tomevault:4.0:skill_md:2026-04-11 -->