Scaffold Exercises

Create exercise directory structures with sections, problems, solutions, and explainers that pass linting. Use when user wants to scaffold exercises, create exercise stubs, or set up a new course section.

This skill is imported from mattpocock/skills (MIT) and is model-invoked upstream.

When to use this skill

• Create exercise directory structures with sections, problems, solutions, and explainers that pass linting.
• Use when user wants to scaffold exercises, create exercise stubs, or set up a new course section.

Instructions

Scaffold Exercises

Create exercise directory structures that pass pnpm ai-hero-cli internal lint, then commit with git commit.

Directory naming

• Sections: XX-section-name/ inside exercises/ (e.g., 01-retrieval-skill-building)
• Exercises: XX.YY-exercise-name/ inside a section (e.g., 01.03-retrieval-with-bm25)
• Section number = XX, exercise number = XX.YY
• Names are dash-case (lowercase, hyphens)

Exercise variants

Each exercise needs at least one of these subfolders:

• problem/ - student workspace with TODOs
• solution/ - reference implementation
• explainer/ - conceptual material, no TODOs

When stubbing, default to explainer/ unless the plan specifies otherwise.

Required files

Each subfolder (problem/, solution/, explainer/) needs a readme.md that:

• Is not empty (must have real content, even a single title line works)
• Has no broken links

When stubbing, create a minimal readme with a title and a description:

# Exercise Title

Description here

If the subfolder has code, it also needs a main.ts (>1 line). But for stubs, a readme-only exercise is fine.

Workflow

1. Parse the plan - extract section names, exercise names, and variant types
2. Create directories - mkdir -p for each path
3. Create stub readmes - one readme.md per variant folder with a title
4. Run lint - pnpm ai-hero-cli internal lint to validate
5. Fix any errors - iterate until lint passes

Lint rules summary

The linter (pnpm ai-hero-cli internal lint) checks:

• Each exercise has subfolders (problem/, solution/, explainer/)
• At least one of problem/, explainer/, or explainer.1/ exists
• readme.md exists and is non-empty in the primary subfolder
• No .gitkeep files
• No speaker-notes.md files
• No broken links in readmes
• No pnpm run exercise commands in readmes
• main.ts required per subfolder unless it's readme-only

Moving/renaming exercises

When renumbering or moving exercises:

1. Use git mv (not mv) to rename directories - preserves git history
2. Update the numeric prefix to maintain order
3. Re-run lint after moves

Example:

git mv exercises/01-retrieval/01.03-embeddings exercises/01-retrieval/01.04-embeddings

Example: stubbing from a plan

Given a plan like:

Section 05: Memory Skill Building
- 05.01 Introduction to Memory
- 05.02 Short-term Memory (explainer + problem + solution)
- 05.03 Long-term Memory

Create:

mkdir -p exercises/05-memory-skill-building/05.01-introduction-to-memory/explainer
mkdir -p exercises/05-memory-skill-building/05.02-short-term-memory/{explainer,problem,solution}
mkdir -p exercises/05-memory-skill-building/05.03-long-term-memory/explainer

Then create readme stubs:

exercises/05-memory-skill-building/05.01-introduction-to-memory/explainer/readme.md -> "# Introduction to Memory"
exercises/05-memory-skill-building/05.02-short-term-memory/explainer/readme.md -> "# Short-term Memory"
exercises/05-memory-skill-building/05.02-short-term-memory/problem/readme.md -> "# Short-term Memory"
exercises/05-memory-skill-building/05.02-short-term-memory/solution/readme.md -> "# Short-term Memory"
exercises/05-memory-skill-building/05.03-long-term-memory/explainer/readme.md -> "# Long-term Memory"

Examples

• Apply this skill to one narrow scope first, confirm the output matches the shape described above, then widen to the full task.
• When a step needs a fact from the repository or the environment, look it up instead of asking the user for it.

Best practices

• Keep the upstream procedure intact; record deviations explicitly instead of silently improvising.
• Stop and hand control back to the user at every decision point this skill marks as theirs.
• Prefer small reversible changes, and state assumptions rather than burying them.

References

• Upstream skill: mattpocock/skills skills/misc/scaffold-exercises/SKILL.md (commit 3cca18b, MIT)
• Project standards: .agent-skills/skill-standardization/SKILL.md
• Validator script: .agent-skills/skill-standardization/scripts/validate_skill.sh