# Modern Swift writing guide (/write-swift)

/write-swift is a Claude Code skill in the Code section. It is maintained by emilkowalski and published under the MIT license. A guide for writing, reviewing or migrating Swift 6: value types, data-race-safe concurrency, protocols, performance and Swift Testing.

- Web version: https://skills.sgomez.dev/en/s/write-swift
- Section: [Code](https://skills.sgomez.dev/en/code.md)
- Author: emilkowalski
- License: MIT
- Source: https://github.com/emilkowalski/skills/tree/d16ebe60d09a5ba2afcb7054ede9d0a10c9f6128/skills/write-swift
- Updated 23 Sept 2026

## How to ask for it

- `Review this Swift code for concurrency issues`
- `Help me migrate this class to value types in Swift 6`
- `Fix this retain cycle in my Swift code`

## Install

macOS · Linux:

```
curl -fsSL https://raw.githubusercontent.com/sgomez-dev/claude-skills/main/install.sh | bash
```

Windows:

```
irm https://raw.githubusercontent.com/sgomez-dev/claude-skills/main/install.ps1 | iex
```


## Author's description

How to write modern Swift well — modeling with value types, Swift 6 data-race safety and approachable concurrency (@concurrent, main-actor-by-default, actors, task groups), protocols and generics (some vs any), API design, performance and ARC, Swift Testing, macros, and the modern language features agents don't know about yet. Use when writing, reviewing, or migrating Swift, or when a concurrency error, a hang, a data race, a retain cycle, or a performance problem needs fixing.

- [How we review this](https://skills.sgomez.dev/en/methodology.md)