swift-concurrency

Guide Swift Concurrency patterns including async/await, actors, tasks, and Sendable conformance.

62|5|Updated Jan 21, 2026

Search Tags:#async/await #actors #sendable #swift concurrency #structured concurrency #swift 6 migration

Ready to run

npx skills add https://github.com/wendylabsinc/claude-skills --skill swift-concurrency-wendylabsinc

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: swift-concurrency
Source: https://github.com/wendylabsinc/claude-skills/tree/main/swift-concurrency
Command: npx skills add https://github.com/wendylabsinc/claude-skills --skill swift-concurrency-wendylabsinc

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill helps developers navigate the complexities of Swift's modern concurrency model, ensuring they write safe, performant, and maintainable asynchronous code.

Core Features & Use Cases

Best Practices: Provides expert guidance on Swift Concurrency, async/await, actors, tasks, and Sendable conformance.
Migration: Assists in migrating to Swift 6 and strict concurrency checking.
Debugging: Helps identify and resolve data races, thread safety issues, and concurrency-related linter warnings.
Use Case: A developer is struggling with "Main actor-isolated property cannot be used from a nonisolated context" errors. This Skill can analyze their code, explain actor isolation, and suggest appropriate solutions like using nonisolated or refactoring to pass data safely.

Quick Start

Use the swift-concurrency skill to understand how to protect shared mutable state using actors.

Frequently Asked Questions about swift-concurrency

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I fix "Main actor-isolated property cannot be used from a nonisolated context" errors in Swift?▼

Swift concurrency errors involving main actor isolation require adjusting your async context or using the `nonisolated` keyword. You can resolve these Swift concurrency warnings by analyzing actor isolation boundaries and refactoring the code to pass data safely across actors or applying appropriate isolation attributes.

What is the best way to protect shared mutable state using Swift concurrency?▼

Protecting shared mutable state in Swift concurrency is best achieved using actors. Actors serialize access to their mutable properties, preventing data races and ensuring thread-safe concurrent code execution without manual locking mechanisms.

How do I migrate an existing project to Swift 6 strict concurrency checking?▼

Migrating to Swift 6 strict concurrency involves incrementally adopting Sendable conformance and resolving data race warnings. You can transition your codebase by updating asynchronous patterns, ensuring type safety across tasks, and systematically addressing linter warnings generated by the compiler.

When do I need to use Sendable conformance in Swift async/await code?▼

Sendable conformance is needed in Swift async/await code when passing types across actor boundaries or concurrent tasks. Marking types as Sendable guarantees thread-safe data transfer, allowing the compiler to enforce concurrency safety and prevent data races during asynchronous execution.

How does structured concurrency work in Swift?▼

Structured concurrency in Swift works by linking task lifetimes to hierarchical scopes, ensuring child tasks complete before their parent. This pattern uses async/await and tasks to manage concurrent operations predictably, enforcing cancellation and error handling automatically.

Why am I getting concurrency-related linter warnings after adopting async/await?▼

Concurrency-related linter warnings after adopting async/await usually indicate potential data races or improper actor isolation. These warnings highlight missing Sendable conformance or unsafe shared mutable state access, requiring you to refactor asynchronous code to meet strict thread safety standards.