ai-engineering-from-scratch-zh: Skill for Claude Code

.claude/skills/check-understanding/SKILL.md

check-understanding is a skill for Claude Code from fancyboi999/ai-engineering-from-scratch-zh. It costs 71 tokens per session (2,224 once invoked), scanned A, original, MIT.

A quiz tool for testing knowledge from the AI Engineering from Scratch course. It can test a numbered phase or a named subject such as deep learning or computer vision.

In plain words
What is it for?
Use it when you want to be quizzed on a phase, test your understanding of a topic, or check whether you are ready for the next phase.
Why use it?
It helps learners find out whether they understand a completed course phase before moving on. It also provides a structured way to check weak areas.

Skill for Claude Code

Written for Claude Code: installed under .claude/. Also seen: names the AskUserQuestion tool.

This is fancyboi999/ai-engineering-from-scratch-zh's own configuration. It tells Claude Code how to work on ai-engineering-from-scratch-zh itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything ai-engineering-from-scratch-zh configures →

About the project

ai-engineering-from-scratch-zh is a Chinese-language adaptation of a course that teaches AI engineering by implementing algorithms, tools, and agents from the ground up. It is for learners following a 20-stage path across mathematics, machine learning, agent systems, and production topics, with lessons using Python, TypeScript, Rust, and Julia. The catalogue entries provide agent skills and instructions associated with the course.

fancyboi999/ai-engineering-from-scratch-zh · 1,056 stars · on GitHub · aieng-zh.cn

Reuse

Borrowing it

Nothing to install: this file belongs to fancyboi999/ai-engineering-from-scratch-zh. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/fancyboi999/ai-engineering-from-scratch-zh/main/.claude/skills/check-understanding/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/fancyboi999/ai-engineering-from-scratch-zh

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for check-understanding

README.md
[![agentmods](https://agentmods.dev/badge/skills/fancyboi999/ai-engineering-from-scratch-zh/check-understanding/github.svg)](https://agentmods.dev/skills/fancyboi999/ai-engineering-from-scratch-zh/check-understanding)
Your own site
<a href="https://agentmods.dev/skills/fancyboi999/ai-engineering-from-scratch-zh/check-understanding"><img src="https://agentmods.dev/badge/skills/fancyboi999/ai-engineering-from-scratch-zh/check-understanding/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for check-understanding

Your own site · 80×15
<a href="https://agentmods.dev/skills/fancyboi999/ai-engineering-from-scratch-zh/check-understanding"><img src="https://agentmods.dev/badge/skills/fancyboi999/ai-engineering-from-scratch-zh/check-understanding.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 71 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,224 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00071 $0.02224
Opus 5 $0.00036 $0.01112
Sonnet 5 $0.00014 $0.00445
Haiku 4.5 $0.00007 $0.00222

Measured 8d ago against content hash f7c341b72ca0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

check-understanding scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/check-understanding/SKILL.md · 165 lines

How it starts

The opening of the file, as written. The whole thing — 165 lines — stays where its author put it; the contents beside it link to each section on GitHub.

检查理解程度

测试学习者对 AI Engineering from Scratch 已完成阶段的掌握情况。

触发方式

当用户说出类似下面的话时启用此 skill:

  • /check-understanding 3/check-understanding deep-learning
  • “测验一下我对第 2 阶段的掌握情况”
  • “测试第 1 阶段”
  • “检查我对 transformer 的理解”
  • “我掌握第 3 阶段了吗”
  • “我准备好进入下一阶段了吗”

输入

接受阶段编号(0-19)或阶段名称作为参数。如果没有参数,列出全部 20 个阶段,并询问用户希望测试哪一阶段。

阶段映射

将参数映射到 phases/ 下正确的阶段目录:

输入 目录 阶段名称
0, setup, tooling 00-setup-and-tooling 环境设置与工具
1, math, math-foundations 01-math-foundations 数学基础
2, ml, ml-fundamentals 02-ml-fundamentals 机器学习基础
3, deep-learning, dl 03-deep-learning-core 深度学习核心
4, cv, computer-vision, vision 04-computer-vision 计算机视觉
5, nlp 05-nlp-foundations-to-advanced NLP:从基础到进阶
6, speech, audio 06-speech-and-audio 语音与音频
7, transformers 07-transformers-deep-dive Transformer 深入剖析
8, generative, gen-ai, genai 08-generative-ai 生成式 AI
9, rl, reinforcement-learning 09-reinforcement-learning 强化学习
10, llms, llm, llms-from-scratch 10-llms-from-scratch 从零构建 LLM
11, llm-engineering, llm-eng 11-llm-engineering LLM 工程
12, multimodal 12-multimodal-ai 多模态 AI
13, tools, protocols, mcp 13-tools-and-protocols 工具与协议
14, agents, agent-engineering 14-agent-engineering Agent 工程
15, autonomous 15-autonomous-systems 自主系统
16, multi-agent, swarms 16-multi-agent-and-swarms 多 Agent 与群体
17, infrastructure, production, infra 17-infrastructure-and-production 基础设施与生产环境
18, ethics, safety, alignment 18-ethics-safety-alignment 伦理、安全与对齐
19, capstone, projects 19-capstone-projects 综合项目

流程

第 1 步:解析阶段

解析参数。若为数字,验证它是否在 0 到 19(含)之间。数字超出范围时,告诉用户:阶段 [N] 不存在。有效阶段为 0-19。然后展示完整列表供其选择。若为名称或关键词,在上方阶段映射中查找。关键词不匹配任何条目时,告诉用户:未知阶段“[keyword]”。请从下面列表中选择:,并展示全部 20 个阶段。未提供参数时,要求用户从完整列表中选择。

第 2 步:读取阶段内容

如果仓库已克隆(当前目录或其父目录存在 phases/),找出 phases/<phase-dir>/ 下全部课程目录并读取每课的 docs/zh.md。如果未克隆,从 README 的 Contents 部分获取该阶段课程列表(获取 https://raw.githubusercontent.com/fancyboi999/ai-engineering-from-scratch-zh/main/README.md),再从同一 raw base URL 获取每课的 docs/zh.md。这些文档就是出题依据。

Read the full file on GitHub · 165 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago Changed · +6 lines · +27 tokens per session f7c341b72ca0
  2. 13d ago First seen · 159 lines · 44 tokens per session scan A fa402e64e58d

Subscribe to this mod's changes

check-understanding is a skill published in the GitHub repository fancyboi999/ai-engineering-from-scratch-zh (1,056 stars, last pushed 4d ago), licensed MIT. It adds 71 tokens to every session and 2,224 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.