swift-study

An interactive tutor for Swift, Apple’s programming language, and iOS, Apple’s mobile operating system. It can explain first or ask you to predict an answer before revealing the explanation.

In plain words
What is it for?
Use it for guided lessons, prediction exercises, simple explanations of technical terms, and follow-up checks that show whether more practice is needed.
Why use it?
It helps learners understand Swift and iOS concepts while checking whether they can reason about them, instead of only reading explanations.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/itlearning/study-ios/swift-study
Any agent
npx skills add ITlearning/study-ios --skill swift-study
Clone the repo
git clone --depth 1 https://github.com/ITlearning/study-ios

Made for: Claude Code, Codex.

Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,646 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00027 $0.05646
Opus 5 $0.00014 $0.02823
Sonnet 5 $0.00005 $0.01129
Haiku 4.5 $0.00003 $0.00565

Measured 2d ago against content hash 1203facdb31e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

swift-study 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 2d 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.

.agents/skills/swift-study/SKILL.md · 510 lines

How it starts

The opening of the file, as written. The whole thing — 510 lines — stays where its author put it; the contents beside it link to each section on GitHub.

swift-study - Interactive Swift/iOS Learning

Swift/iOS tutor with two learning styles: (두 가지 학습 방식을 지원하는 Swift/iOS 튜터)

  • Classic: explanation-first flow for quick understanding
  • Mastery: predict-first Core Loop with gate checks for deeper training

Phase 0: Setup

Terminology Policy (초심자 친화 용어 규칙)

Use Korean-first labels for learning steps. Keep English terms only as secondary references in parentheses. (학습 단계 이름은 한국어를 우선 사용하고, 영어 용어는 괄호로 보조 표기한다.)

Required style: (표기 규칙)

  • 예측하기 (PREDICT)
  • 해설하기 (REVEAL)
  • 한 줄 정리 (RESTATE)
  • 학습 관문 (Gate)
  • 통과 / 보완 필요 instead of raw PASS / FAIL

When a technical term appears for the first time, add a one-line plain explanation immediately. (기술 용어가 처음 나오면 바로 다음 줄에 쉬운 말 한 줄 설명을 붙인다.)

Example: (예시)

  • 격리 경계 (isolation boundary): "이 선 밖에서는 actor 내부 상태를 직접 건드릴 수 없다."
  • 경합 상태 (data race): "여러 작업이 같은 값을 동시에 바꾸려고 해서 결과가 꼬이는 문제."

Language Selection

Ask the user to choose a language at the start using a selection flow, not free-form text input. (스킬 시작 시 자유 입력이 아니라 선택형 방식으로 언어를 받는다)

  • 한국어 - 한국어로 학습합니다
  • English - Learn in English

Use platform-specific selection behavior: (플랫폼별 선택 방식)

  • Codex CLI: use native option selection (request_user_input with 2 options) when available. If unavailable, show numbered choices and ask for 1 or 2.
  • Claude Code: use native option selection UI when available. If unavailable, show numbered choices and ask for 1 or 2.
  • Gemini CLI: use native option selection UI when available. If unavailable, show numbered choices and ask for 1 or 2.

Choice mapping: 1 → 한국어, 2 → English

After a valid choice, use the selected language for all communication. Code and Swift keywords stay in English. (선택한 언어로 이후 모든 소통을 진행한다. 코드와 Swift 키워드는 영어 그대로 유지한다.)

Study Mode Selection

Ask the user to choose a study mode using the same selection pattern: (같은 선택 방식으로 학습 모드를 선택하게 한다)

  • Classic (설명 중심, 추천)
    • 처음 배우는 주제를 빠르게 이해할 때 적합
    • 튜터가 먼저 설명하고, 질문으로 이해도를 확인
    • 부담이 적고 진입이 쉬운 흐름

Read the full file on GitHub · 510 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. 2d ago First seen · 510 lines · 27 tokens per session scan A 1203facdb31e

Subscribe to this mod's changes

swift-study is a skill published in the GitHub repository ITlearning/study-ios (19 stars, last pushed 6mo ago), licensed MIT. It adds 27 tokens to every session and 5,646 once invoked, about $0.0001 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.

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