Agent skill

Swift Expert

A skill your agent uses when building iOS/macOS applications with Swift 5.9+, SwiftUI, or async/await concurrency.

AGPL-3.0Auto-check passedMobile

Install Swift Expert

skills CLI

$ npx skills add FNOSP/FlyNarwhal --skill swift-expert -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install FNOSP/FlyNarwhal swift-expert --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/FNOSP/FlyNarwhal.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/swift-expert .claude/skills/swift-expert && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "swift-expert" agent skill from https://github.com/FNOSP/FlyNarwhal/tree/master/.agents/skills/swift-expert into .claude/skills/swift-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "swift-expert", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/FNOSP/FlyNarwhal/tree/master/.agents/skills/swift-expert

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add FNOSP/FlyNarwhal --skill swift-expert -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install FNOSP/FlyNarwhal swift-expert --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/FNOSP/FlyNarwhal.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/swift-expert .agents/skills/swift-expert && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "swift-expert" agent skill from https://github.com/FNOSP/FlyNarwhal/tree/master/.agents/skills/swift-expert into .agents/skills/swift-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "swift-expert", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add FNOSP/FlyNarwhal --skill swift-expert -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install FNOSP/FlyNarwhal swift-expert --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/FNOSP/FlyNarwhal.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/swift-expert .cursor/skills/swift-expert && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "swift-expert" agent skill from https://github.com/FNOSP/FlyNarwhal/tree/master/.agents/skills/swift-expert into .cursor/skills/swift-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "swift-expert", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/FNOSP/FlyNarwhal.git --path .agents/skills/swift-expert

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add FNOSP/FlyNarwhal --skill swift-expert -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install FNOSP/FlyNarwhal swift-expert --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/FNOSP/FlyNarwhal.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/swift-expert .gemini/skills/swift-expert && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "swift-expert" agent skill from https://github.com/FNOSP/FlyNarwhal/tree/master/.agents/skills/swift-expert into .gemini/skills/swift-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "swift-expert", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install FNOSP/FlyNarwhal swift-expert

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add FNOSP/FlyNarwhal --skill swift-expert -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/FNOSP/FlyNarwhal.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/swift-expert .github/skills/swift-expert && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "swift-expert" agent skill from https://github.com/FNOSP/FlyNarwhal/tree/master/.agents/skills/swift-expert into .github/skills/swift-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "swift-expert", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add FNOSP/FlyNarwhal --skill swift-expert -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install FNOSP/FlyNarwhal swift-expert --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/FNOSP/FlyNarwhal.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/swift-expert .opencode/skills/swift-expert && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "swift-expert" agent skill from https://github.com/FNOSP/FlyNarwhal/tree/master/.agents/skills/swift-expert into .opencode/skills/swift-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "swift-expert", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: swift-expert
GitHub stars: 496
Token cost: ~813 tokens
SKILL.md length: 332 words
Files: 6 (incl. references)
Skills in repo: 8
Repo updated: Oct 8, 2026
First seen: Oct 7, 2026
Licence: AGPL-3.0

At a glance

A skill your agent uses when building iOS/macOS applications with Swift 5.9+, SwiftUI, or async/await concurrency.

Works in 5 steps: Architecture Analysis - Identify… → Design Protocols - Create protocol-first… → Implement - Write type-safe code with… → …
Building iOS/macOS applications with Swift 5.9+
SKILL.md covers Role Definition, When to Use This Skill, Core Workflow and Reference Guide, plus 3 more sections
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Swift Expert is an agent skill from FNOSP/FlyNarwhal. Use when building iOS/macOS applications with Swift 5.9+, SwiftUI, or async/await concurrency. Invoke for protocol-oriented programming, SwiftUI state management, actors, server-side Swift.

Its SKILL.md is about 810 tokens, which your agent loads only when the skill is triggered. The skill folder holds 6 other files, including reference files (for example `references/async-concurrency.md`, `references/memory-performance.md` and `references/protocol-oriented.md`).

It sits in Mobile, covering iOS development and Async programming. It works with SwiftUI, iOS and macOS. The repository describes itself as: 基于 Flutter 框架开发的适用于飞牛影视的跨平台客户端. The licence is AGPL-3.0.

When your agent uses it

Building iOS/macOS applications with Swift 5.9+
Async/await concurrency

Example prompts

“/swift-expert”

Workflow steps

5 steps, taken from the first numbered list in SKILL.md.

Architecture Analysis - Identify platform targets, dependencies, design patterns
Design Protocols - Create protocol-first APIs with associated types
Implement - Write type-safe code with async/await and value semantics
Optimize - Profile with Instruments, ensure thread safety
Test - Write comprehensive tests with XCTest and async patterns

What it can do on your machine

Read from SKILL.md and the folder at commit c94d847. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Swift Expert loads about 813 tokens when it runs, and up to ~11k if it reads all its reference files. Until then it costs about 51 tokens; SKILL.md has 332 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~51
When it runs · the whole SKILL.md, loaded when a task matches: ~813
With references · SKILL.md plus every file in references/, read only if the agent opens them: ~11k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from FNOSP/FlyNarwhal at commit c94d847, republished under its AGPL-3.0 licence (© FNOSP). 332 words, ~813 tokens.

Download SKILL.mdSave it as .claude/skills/swift-expert/SKILL.md (or your agent's skills folder). This skill also uses 5 other files; get the full folder from GitHub.

name: swift-expert
description: Use when building iOS/macOS applications with Swift 5.9+, SwiftUI, or async/await concurrency. Invoke for protocol-oriented programming, SwiftUI state management, actors, server-side Swift.

Swift Expert

Senior Swift developer with mastery of Swift 5.9+, Apple's development ecosystem, SwiftUI, async/await concurrency, and protocol-oriented programming.

Role Definition

You are a senior Swift engineer with 10+ years of Apple platform development. You specialize in Swift 5.9+, SwiftUI, async/await concurrency, protocol-oriented design, and server-side Swift. You build type-safe, performant applications following Apple's API design guidelines.

When to Use This Skill

Building iOS/macOS/watchOS/tvOS applications
Implementing SwiftUI interfaces and state management
Setting up async/await concurrency and actors
Creating protocol-oriented architectures
Optimizing memory and performance
Integrating UIKit with SwiftUI

Core Workflow

Architecture Analysis - Identify platform targets, dependencies, design patterns
Design Protocols - Create protocol-first APIs with associated types
Implement - Write type-safe code with async/await and value semantics
Optimize - Profile with Instruments, ensure thread safety
Test - Write comprehensive tests with XCTest and async patterns

Reference Guide

Load detailed guidance based on context:

Topic	Reference	Load When
SwiftUI	`references/swiftui-patterns.md`	Building views, state management, modifiers
Concurrency	`references/async-concurrency.md`	async/await, actors, structured concurrency
Protocols	`references/protocol-oriented.md`	Protocol design, generics, type erasure
Memory	`references/memory-performance.md`	ARC, weak/unowned, performance optimization
Testing	`references/testing-patterns.md`	XCTest, async tests, mocking strategies

Constraints

MUST DO

Use type hints and inference appropriately
Follow Swift API Design Guidelines
Use async/await for asynchronous operations
Ensure Sendable compliance for concurrency
Use value types (struct/enum) by default
Document APIs with markup comments
Use property wrappers for cross-cutting concerns
Profile with Instruments before optimizing

MUST NOT DO

Use force unwrapping (!) without justification
Create retain cycles in closures
Mix synchronous and asynchronous code improperly
Ignore actor isolation warnings
Use implicitly unwrapped optionals unnecessarily
Skip error handling
Use Objective-C patterns when Swift alternatives exist
Hardcode platform-specific values

Output Templates

When implementing Swift features, provide:

Protocol definitions and type aliases
Model types (structs/classes with value semantics)
View implementations (SwiftUI) or view controllers
Tests demonstrating usage
Brief explanation of architectural decisions

Knowledge Reference

Swift 5.9+, SwiftUI, UIKit, async/await, actors, structured concurrency, Combine, property wrappers, result builders, protocol-oriented programming, generics, type erasure, ARC, Instruments, XCTest, Swift Package Manager, Vapor

Files

SKILL.md and 5 other files (references) in .agents/skills/swift-expert of FNOSP/FlyNarwhal.

SKILL.md
references/async-concurrency.md
references/memory-performance.md
references/protocol-oriented.md
references/swiftui-patterns.md
references/testing-patterns.md

Open the folder on GitHubat commit c94d847

Compare with similar skills

Swift Expert next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Swift Expert compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Swift Expert this skillFNOSP/FlyNarwhal	496	—	~813	Automated safety check: Pass	AGPL-3.0	today
Swift ExpertJeffallan/claude-skills	12k	—	~1.5k	Automated safety check: Pass	MIT	5 days ago
Swiftui Expert Skillomarshahine/HomeClaw	175	4 repos	~2.8k	Automated safety check: Pass	MIT	yesterday
Hig Project Contextraintree-technology/hig-doctor	143	5 repos	~1.2k	Automated safety check: Pass	MIT	28 days ago
Swiftui Expert SkillEslzzyl/Pixiv-SwiftUI	111	1 repos	~2.9k	Automated safety check: Pass	AGPL-3.0	yesterday
Hig Components Contentraintree-technology/hig-doctor	143	5 repos	~1.3k	Automated safety check: Pass	MIT	28 days ago

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Questions about Swift Expert

What does Swift Expert do?

A skill your agent uses when building iOS/macOS applications with Swift 5.9+, SwiftUI, or async/await concurrency. Swift Expert is an agent skill from FNOSP/FlyNarwhal.9+, SwiftUI, or async/await concurrency.

When should I use Swift Expert?

Swift Expert fits situations like: building iOS/macOS applications with Swift 5.9+; async/await concurrency.

How do I install Swift Expert in Claude Code?

Run `npx skills add FNOSP/FlyNarwhal --skill swift-expert -a claude-code`. Or copy the skill folder (.agents/skills/swift-expert in FNOSP/FlyNarwhal) into .claude/skills/swift-expert in your project. Claude Code loads it when a task matches its description.

How do I install Swift Expert in Codex?

Run `npx skills add FNOSP/FlyNarwhal --skill swift-expert -a codex`. Or copy the skill folder (.agents/skills/swift-expert in FNOSP/FlyNarwhal) into .agents/skills/swift-expert in your project. Codex loads it when a task matches its description.

Can I use Swift Expert in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add FNOSP/FlyNarwhal --skill swift-expert -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/swift-expert, .gemini/skills/swift-expert, .github/skills/swift-expert and .opencode/skills/swift-expert in your project.

What does Swift Expert need to run?

SKILL.md names no scripts, command-line tools or credentials: Swift Expert is instructions for the agent only.

Does Swift Expert access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Swift Expert safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Swift Expert use?

Swift Expert is published under the AGPL-3.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Swift Expert use?

About 813 tokens (SKILL.md is roughly 3.3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 10k tokens, read only when the agent opens those files.

What are the alternatives to Swift Expert?

Skills that share tags, products or a category with Swift Expert: Swift Expert (Jeffallan/claude-skills, 12k stars), Swiftui Expert Skill (omarshahine/HomeClaw, 175 stars), Hig Project Context (raintree-technology/hig-doctor, 143 stars) and Swiftui Expert Skill (Eslzzyl/Pixiv-SwiftUI, 111 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Swift Expert?

FNOSP (a GitHub organization) maintains it in FNOSP/FlyNarwhal, which has 496 GitHub stars. The repository holds 8 skills in this directory. The repository was last updated on October 8, 2026.

Source: FNOSP/FlyNarwhal on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Swift Expert

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Swift Expert

Role Definition

When to Use This Skill

Core Workflow

Reference Guide

Constraints

MUST DO

MUST NOT DO

Output Templates

Knowledge Reference

Files

Compare with similar skills

Similar skills

More from FNOSP/FlyNarwhal

Related

Questions about Swift Expert