Agent skill

Swift Concurrency Expert

Swift Concurrency review and remediation for Swift 6.2+. An agent skill from Dimillian/Skills.

MITAuto-check passedDevelopment

Install Swift Concurrency Expert

skills CLI

$ npx skills add Dimillian/Skills --skill swift-concurrency-expert -a claude-code

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

GitHub CLI

$ gh skill install Dimillian/Skills swift-concurrency-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/Dimillian/Skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/swift-concurrency-expert .claude/skills/swift-concurrency-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-concurrency-expert" agent skill from https://github.com/Dimillian/Skills/tree/main/swift-concurrency-expert into .claude/skills/swift-concurrency-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "swift-concurrency-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/Dimillian/Skills/tree/main/swift-concurrency-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 Dimillian/Skills --skill swift-concurrency-expert -a codex

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

GitHub CLI

$ gh skill install Dimillian/Skills swift-concurrency-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/Dimillian/Skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/swift-concurrency-expert .agents/skills/swift-concurrency-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-concurrency-expert" agent skill from https://github.com/Dimillian/Skills/tree/main/swift-concurrency-expert into .agents/skills/swift-concurrency-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "swift-concurrency-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 Dimillian/Skills --skill swift-concurrency-expert -a cursor

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

GitHub CLI

$ gh skill install Dimillian/Skills swift-concurrency-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/Dimillian/Skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/swift-concurrency-expert .cursor/skills/swift-concurrency-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-concurrency-expert" agent skill from https://github.com/Dimillian/Skills/tree/main/swift-concurrency-expert into .cursor/skills/swift-concurrency-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "swift-concurrency-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/Dimillian/Skills.git --path swift-concurrency-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 Dimillian/Skills --skill swift-concurrency-expert -a gemini-cli

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

GitHub CLI

$ gh skill install Dimillian/Skills swift-concurrency-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/Dimillian/Skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/swift-concurrency-expert .gemini/skills/swift-concurrency-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-concurrency-expert" agent skill from https://github.com/Dimillian/Skills/tree/main/swift-concurrency-expert into .gemini/skills/swift-concurrency-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "swift-concurrency-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 Dimillian/Skills swift-concurrency-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 Dimillian/Skills --skill swift-concurrency-expert -a github-copilot

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

Manual copy

$ git clone --depth 1 https://github.com/Dimillian/Skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/swift-concurrency-expert .github/skills/swift-concurrency-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-concurrency-expert" agent skill from https://github.com/Dimillian/Skills/tree/main/swift-concurrency-expert into .github/skills/swift-concurrency-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "swift-concurrency-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 Dimillian/Skills --skill swift-concurrency-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 Dimillian/Skills swift-concurrency-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/Dimillian/Skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/swift-concurrency-expert .opencode/skills/swift-concurrency-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-concurrency-expert" agent skill from https://github.com/Dimillian/Skills/tree/main/swift-concurrency-expert into .opencode/skills/swift-concurrency-expert/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "swift-concurrency-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-concurrency-expert
GitHub stars: 4k
Token cost: ~1.1k tokens
SKILL.md length: 295 words
Files: 5 (incl. references)
Skills in repo: 12
Repo updated: Mar 29, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Swift Concurrency review and remediation for Swift 6.2+. An agent skill from Dimillian/Skills.

Works in 3 steps: Triage the issue → Apply the smallest safe fix → Verify the fix
Asked to review Swift Concurrency usage
SKILL.md covers Overview, Workflow and Reference material
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Swift Concurrency Expert is an agent skill from Dimillian/Skills. Swift Concurrency review and remediation for Swift 6.2+. Use when asked to review Swift Concurrency usage, improve concurrency compliance, or fix Swift concurrency compiler errors in a feature or file. Concrete actions include adding Sendable conformance, applying @MainActor annotations, resolving actor isolation warnings, fixing data race diagnostics, and migrating completion handlers to async/await.

Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 6 other files, including reference files (for example `agents/openai.yaml`, `references/approachable-concurrency.md` and `references/swift-6-2-concurrency.md`).

It sits in Development, covering Async programming. It works with Swift. The licence is MIT.

When your agent uses it

Asked to review Swift Concurrency usage
Improve concurrency compliance
Fix Swift concurrency compiler errors in a feature

Example prompts

“/swift-concurrency-expert”

Workflow steps

3 steps, taken from the step headings in SKILL.md.

Triage the issue
Apply the smallest safe fix
Verify the fix

What it can do on your machine

Read from SKILL.md and the folder at commit 05ba982. 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 (its code samples are swift).
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 Concurrency Expert loads about 1.1k tokens when it runs, and up to ~4.8k if it reads all its reference files. Until then it costs about 107 tokens; SKILL.md has 295 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~107
When it runs · the whole SKILL.md, loaded when a task matches: ~1.1k
With references · SKILL.md plus every file in references/, read only if the agent opens them: ~4.8k

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 Dimillian/Skills at commit 05ba982, republished under its MIT licence (© Dimillian). 295 words, ~1,086 tokens.

Download SKILL.mdSave it as .claude/skills/swift-concurrency-expert/SKILL.md (or your agent's skills folder). This skill also uses 4 other files; get the full folder from GitHub.

name: swift-concurrency-expert
description: Swift Concurrency review and remediation for Swift 6.2+. Use when asked to review Swift Concurrency usage, improve concurrency compliance, or fix Swift concurrency compiler errors in a feature or file. Concrete actions include adding Sendable conformance, applying @MainActor annotations, resolving actor isolation warnings, fixing data race diagnostics, and migrating completion handlers to async/await.

Swift Concurrency Expert

Overview

Review and fix Swift Concurrency issues in Swift 6.2+ codebases by applying actor isolation, Sendable safety, and modern concurrency patterns with minimal behavior changes.

Workflow

1. Triage the issue

Capture the exact compiler diagnostics and the offending symbol(s).
Check project concurrency settings: Swift language version (6.2+), strict concurrency level, and whether approachable concurrency (default actor isolation / main-actor-by-default) is enabled.
Identify the current actor context (@MainActor, actor, nonisolated) and whether a default actor isolation mode is enabled.
Confirm whether the code is UI-bound or intended to run off the main actor.

2. Apply the smallest safe fix

Prefer edits that preserve existing behavior while satisfying data-race safety.

Common fixes:

UI-bound types: annotate the type or relevant members with @MainActor.
Protocol conformance on main actor types: make the conformance isolated (e.g., extension Foo: @MainActor SomeProtocol).
Global/static state: protect with @MainActor or move into an actor.
Background work: move expensive work into a @concurrent async function on a nonisolated type or use an actor to guard mutable state.
Sendable errors: prefer immutable/value types; add Sendable conformance only when correct; avoid @unchecked Sendable unless you can prove thread safety.

3. Verify the fix

Rebuild and confirm all concurrency diagnostics are resolved with no new warnings introduced.
Run the test suite to check for regressions — concurrency changes can introduce subtle runtime issues even when the build is clean.
If the fix surfaces new warnings, treat each one as a fresh triage (return to step 1) and resolve iteratively until the build is clean and tests pass.

Examples

UI-bound type — adding @MainActor

swift

// Before: data-race warning because ViewModel is accessed from the main thread
// but has no actor isolation
class ViewModel: ObservableObject {
    @Published var title: String = ""
    func load() { title = "Loaded" }
}

// After: annotate the whole type so all stored state and methods are
// automatically isolated to the main actor
@MainActor
class ViewModel: ObservableObject {
    @Published var title: String = ""
    func load() { title = "Loaded" }
}

Protocol conformance isolation

swift

// Before: compiler error — SomeProtocol method is nonisolated but the
// conforming type is @MainActor
@MainActor
class Foo: SomeProtocol {
    func protocolMethod() { /* accesses main-actor state */ }
}

// After: scope the conformance to @MainActor so the requirement is
// satisfied inside the correct isolation context
@MainActor
extension Foo: SomeProtocol {
    func protocolMethod() { /* safely accesses main-actor state */ }
}

Background work with @concurrent

swift

// Before: expensive computation blocks the main actor
@MainActor
func processData(_ input: [Int]) -> [Int] {
    input.map { heavyTransform($0) }   // runs on main thread
}

// After: hop off the main actor for the heavy work, then return the result
// The caller awaits the result and stays on its own actor
nonisolated func processData(_ input: [Int]) async -> [Int] {
    await Task.detached(priority: .userInitiated) {
        input.map { heavyTransform($0) }
    }.value
}

// Or, using a @concurrent async function (Swift 6.2+):
@concurrent
func processData(_ input: [Int]) async -> [Int] {
    input.map { heavyTransform($0) }
}

Reference material

See references/swift-6-2-concurrency.md for Swift 6.2 changes, patterns, and examples.
See references/approachable-concurrency.md when the project is opted into approachable concurrency mode.
See references/swiftui-concurrency-tour-wwdc.md for SwiftUI-specific concurrency guidance.

Files

SKILL.md and 4 other files (references) in swift-concurrency-expert of Dimillian/Skills.

SKILL.md
agents/openai.yaml
references/approachable-concurrency.md
references/swift-6-2-concurrency.md
references/swiftui-concurrency-tour-wwdc.md

Open the folder on GitHubat commit 05ba982

Compare with similar skills

Swift Concurrency 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 Concurrency Expert compared with similar skills
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Swift Concurrency Expert this skillDimillian/Skills	4k	—	~1.1k	Automated safety check: Pass	MIT	6 mo ago
Swift Concurrencyhenrypldev/react-native-nitro-mlx	100	3 repos	~3.1k	Automated safety check: Pass	MIT	1 mo ago
Swift Concurrencysupabitapp/supaterm	172	—	~3.3k	Automated safety check: Pass	Custom licence	15 days ago
Swift Concurrencynimblehq/ios-templates	110	—	~1.7k	Automated safety check: Pass	MIT	2 mo ago
cmux Swift Package Architecturemanaflow-ai/cmux	28k	1 repos	~4.2k	Automated safety check: Pass	Custom licence	today
Swift Concurrency 6 2affaan-m/ECC	276k	4 repos	~2k	Automated safety check: Pass	MIT	today

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Questions about Swift Concurrency Expert

What does Swift Concurrency Expert do?

Swift Concurrency review and remediation for Swift 6.2+. An agent skill from Dimillian/Skills. Swift Concurrency Expert is an agent skill from Dimillian/Skills.2+.

When should I use Swift Concurrency Expert?

Swift Concurrency Expert fits situations like: asked to review Swift Concurrency usage; improve concurrency compliance; fix Swift concurrency compiler errors in a feature.

How do I install Swift Concurrency Expert in Claude Code?

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

How do I install Swift Concurrency Expert in Codex?

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

Can I use Swift Concurrency 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 Dimillian/Skills --skill swift-concurrency-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-concurrency-expert, .gemini/skills/swift-concurrency-expert, .github/skills/swift-concurrency-expert and .opencode/skills/swift-concurrency-expert in your project.

What does Swift Concurrency Expert need to run?

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

Does Swift Concurrency 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 Concurrency 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 Concurrency Expert use?

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

How many tokens does Swift Concurrency Expert use?

About 1.1k tokens (SKILL.md is roughly 4.3k 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 3.7k tokens, read only when the agent opens those files.

What are the alternatives to Swift Concurrency Expert?

Skills that share tags, products or a category with Swift Concurrency Expert: Swift Concurrency (henrypldev/react-native-nitro-mlx, 100 stars), Swift Concurrency (supabitapp/supaterm, 172 stars), Swift Concurrency (nimblehq/ios-templates, 110 stars) and cmux Swift Package Architecture (manaflow-ai/cmux, 28k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Swift Concurrency Expert?

Dimillian (a GitHub user) maintains it in Dimillian/Skills, which has 3,989 GitHub stars. The repository holds 12 skills in this directory. The repository was last updated on March 29, 2026.

Source: Dimillian/Skills 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 Concurrency 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 Concurrency Expert

Overview

Workflow

1. Triage the issue

2. Apply the smallest safe fix

3. Verify the fix

Examples

Reference material

Files

Compare with similar skills

Similar skills

More from Dimillian/Skills

Related

Questions about Swift Concurrency Expert