https://github.com/AvdLee/Swift-Concurrency-Agent-Skill
Add expert Swift Concurrency guidance to your AI coding tool (Agent Skills open format): safe concurrency, performance optimization, and Swift 6 migration.
https://github.com/AvdLee/Swift-Concurrency-Agent-Skill
agent-skills async-await swift swift-actor swift-concurrency
Last synced: 6 months ago
JSON representation
Add expert Swift Concurrency guidance to your AI coding tool (Agent Skills open format): safe concurrency, performance optimization, and Swift 6 migration.
- Host: GitHub
- URL: https://github.com/AvdLee/Swift-Concurrency-Agent-Skill
- Owner: AvdLee
- License: mit
- Created: 2026-01-07T09:19:00.000Z (6 months ago)
- Default Branch: main
- Last Pushed: 2026-01-30T13:34:40.000Z (6 months ago)
- Last Synced: 2026-01-31T07:06:38.537Z (6 months ago)
- Topics: agent-skills, async-await, swift, swift-actor, swift-concurrency
- Homepage: https://www.swiftconcurrencycourse.com
- Size: 645 KB
- Stars: 750
- Watchers: 5
- Forks: 42
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- Funding: .github/FUNDING.yml
- License: LICENSE
Awesome Lists containing this project
- awesome-ios-ai - Swift Concurrency - Async/await, actors, Sendable, and strict concurrency for Swift 6. (Skills / Swift Concurrency)
- awesome-agent-skills - AvdLee/Swift-Concurrency-Agent-Skill - references` 📚 `has-scripts` 📜 `spec-compliant` ✅ (🎯 Individual Skills)
- awesome-openclaw-skills - AvdLee/Swift-Concurrency-Agent-Skill
- awesome-agent-skills - Swift-Concurrency-Agent-Skill - Swift Concurrency skill for Claude Code, focused on async/await, actors, Sendable, tasks, and modern Swift patterns. (Framework Skills)
- awesome-claude-code - **Swift-Concurrency-Agent-Skill** - (1.6k ⭐) - Expert Swift Concurrency guidance for AI coding agents working on Swift projects. (🧠 Agent Skills)
README
# Swift Concurrency Agent Skill
Expert guidance for any AI coding tool that supports the [Agent Skills open format](https://agentskills.io/home) — safe concurrency, performance, and Swift 6+ migration.
Based on the comprehensive [Swift Concurrency Course](https://www.swiftconcurrencycourse.com?utm_source=github&utm_medium=agent-skill&utm_campaign=swift-concurrency-skill), distilled into actionable, concise references for agents.
## Who this is for
- Teams migrating to Swift 6 / strict concurrency who need safe defaults and quick triage.
- Developers debugging data races, isolation errors, or flaky async tests.
- Anyone wanting performance-minded concurrency patterns (actors, tasks, Sendable, async streams).
## See also my other skills:
- [SwiftUI Expert](https://github.com/AvdLee/SwiftUI-Agent-Skill)
- [Core Data Expert](https://github.com/AvdLee/Core-Data-Agent-Skill)
## How to Use This Skill
### Option A: Using skills.sh (recommended)
Install this skill with a single command:
```bash
npx skills add https://github.com/avdlee/swift-concurrency-agent-skill --skill swift-concurrency
```
For more information, visit the [skills.sh platform page](https://skills.sh/avdlee/swift-concurrency-agent-skill/swift-concurrency).
Then use the skill in your AI agent, for example:
> Use the swift concurrency skill and analyze the current project for Swift Concurrency improvements
### Option B: Claude Code Plugin
#### Personal Usage
To install this Skill for your personal use in Claude Code:
1. Add the marketplace:
```bash
/plugin marketplace add AvdLee/Swift-Concurrency-Agent-Skill
```
2. Install the Skill:
```bash
/plugin install swift-concurrency@swift-concurrency-agent-skill
```
#### Project Configuration
To automatically provide this Skill to everyone working in a repository, configure the repository's `.claude/settings.json`:
```json
{
"enabledPlugins": {
"swift-concurrency@swift-concurrency-agent-skill": true
},
"extraKnownMarketplaces": {
"swift-concurrency-agent-skill": {
"source": {
"source": "github",
"repo": "AvdLee/Swift-Concurrency-Agent-Skill"
}
}
}
}
```
When team members open the project, Claude Code will prompt them to install the Skill.
### Option C: Manual install
1) **Clone** this repository.
2) **Install or symlink** the `swift-concurrency/` folder following your tool’s official skills installation docs (see links below).
3) **Use your AI tool** as usual and ask it to use the “swift-concurrency” skill for Swift Concurrency tasks.
#### Where to Save Skills
Follow your tool’s official documentation, here are a few popular ones:
- **Codex:** [Where to save skills](https://developers.openai.com/codex/skills/#where-to-save-skills)
- **Claude:** [Using Skills](https://platform.claude.com/docs/en/agents-and-tools/agent-skills/overview#using-skills)
- **Cursor:** [Enabling Skills](https://cursor.com/docs/context/skills#enabling-skills)
**How to verify**:
Your agent should reference the triage/playbook in `swift-concurrency/SKILL.md` and jump into the relevant reference file for your error or task.
## What This Skill Offers
This skill gives your AI coding tool comprehensive Swift Concurrency guidance. It can:
### Guide Your Concurrency Decisions
- Choose the right tool for the job (async/await, actors, tasks, task groups)
- Understand when to use `@MainActor`, custom actors, or `nonisolated`
- Navigate isolation domains and prevent data races at compile time
- Apply `Sendable` conformance correctly for value and reference types
### Write Safe Concurrent Code
- Avoid common pitfalls like actor reentrancy and retain cycles
- Prevent data races with proper isolation
- Handle task cancellation and error propagation correctly
- Manage memory safely in concurrent contexts
### Optimize Performance
- Choose between serialized, asynchronous, and parallel execution
- Reduce actor contention and unnecessary suspension points
- Understand the tradeoffs of parallelism
### Migrate to Swift 6
- Step-by-step migration strategies for existing codebases
- Enable strict concurrency checking incrementally
- Rewrite closure-based code to async/await
- Migrate from Combine/RxSwift to Swift Concurrency
- Use migration tooling for upcoming Swift features
### Test Concurrent Code
- Write reliable tests using Swift Testing (recommended) or XCTest
- Handle `@MainActor` isolation in tests
- Use `withMainSerialExecutor` for deterministic testing
- Avoid flaky tests with proper async handling
### Integrate with Core Data
- Safely pass data between isolation domains using `NSManagedObjectID`
- Implement the Data Access Object (DAO) pattern
- Use custom actor executors when needed
- Avoid common Core Data concurrency pitfalls
## What Makes This Skill Different
**Expert Knowledge**: Based on real-world experience migrating large production codebases to Swift 6, distilled from the comprehensive [Swift Concurrency Course](https://www.swiftconcurrencycourse.com?utm_source=github&utm_medium=agent-skill&utm_campaign=swift-concurrency-skill).
**Non-Opinionated**: Focuses on industry-standard best practices and compile-time safety, not architectural preferences. Works with any Swift project, coding style, or architecture.
**Swift 6.2 Ready**: Covers the latest Swift Concurrency features including:
- Default Actor Isolation
- `isolated deinit`
- Global Actor Conformance for protocols
- `nonisolated(nonsending)` and `@concurrent`
- Approachable Concurrency build settings
- Concurrency-safe notifications (iOS 26+)
**Practical & Concise**: Assumes your AI agent is already smart. Focuses on what developers need to know, not what they already understand. Includes code examples for every pattern.
## See it in action
[](https://www.youtube.com/watch?v=khekVi1PK3o)
## Skill Structure
```
swift-concurrency/
├── SKILL.md # Main skill file with decision trees
└── references/
├── async-await-basics.md # Fundamentals of async/await syntax
├── tasks.md # Task lifecycle, cancellation, priorities
├── sendable.md # Isolation domains and Sendable conformance
├── actors.md # Actor isolation, global actors, reentrancy
├── async-sequences.md # AsyncSequence and AsyncStream patterns
├── threading.md # Threads vs tasks, suspension points
├── memory-management.md # Retain cycles, weak self, isolated deinit
├── core-data.md # Core Data integration patterns
├── performance.md # Optimization with Xcode Instruments
├── testing.md # Testing concurrent code
├── migration.md # Step-by-step Swift 6 migration guide
├── glossary.md # Terms & concepts for Swift Concurrency
└── linting.md # Linting rules for strict concurrency
```
## Contributing
Contributions are welcome! This repository follows the [Agent Skills open format](https://agentskills.io/home), which has specific structural requirements.
**We strongly recommend using AI assistance for contributions:**
- Use the [skill-creator skill](https://github.com/anthropics/skills/tree/main/skills/skill-creator) with Claude to ensure proper formatting
- This helps maintain the Agent Skills format and ensures your contribution works correctly with AI agents
**Please read [CONTRIBUTING.md](CONTRIBUTING.md) for:**
- How to use the skill-creator skill for contributions
- Agent Skills format requirements
- Quality standards and best practices
- Pull request process
This skill is maintained to reflect the latest Swift Concurrency best practices and will be updated as the language evolves.
## About the Author
Created by [Antoine van der Lee](https://www.avanderlee.com), a Swift Concurrency expert and creator of the [Swift Concurrency Course](https://www.swiftconcurrencycourse.com?utm_source=github&utm_medium=agent-skill&utm_campaign=swift-concurrency-skill). With years of experience in Swift & Swift Concurrency, this skill distills practical knowledge into actionable guidance for AI assistants. He [published tens of articles on Swift Concurrency](https://www.avanderlee.com/category/concurrency/) on his blog called SwiftLee.
## License
This skill is open-source and available under the MIT License. See [LICENSE](LICENSE) for details.