Swift Writer
Writes clean, modern Swift and SwiftUI.
What it does
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.
Install in under a minute
Mac or Linux, after you download
unzip swift-writer.zip -d ~/.claude/skills/Windows PowerShell
Expand-Archive swift-writer.zip -DestinationPath $HOME\.claude\skills- Start a new Claude Code session so it sees the skill.
- Ask in plain words, for example: "Use Swift Writer on this project."
- Unzip the download, then zip just the swift-writer folder if your computer added an extra folder.
- In Claude.ai, open Settings, then Capabilities, and upload it under Skills.
- Turn the skill on and ask Claude to use it.
Swift Writer uses the open SKILL.md format, so it also works in agents like Cursor, Gemini CLI, GitHub Copilot and Codex. Copy the swift-writer folder into that agent's skills folder, for example .cursor/skills/ or .github/skills/ in your project.
What's inside
The 16 main sections of the SKILL.md, in order.
- Initial Response
- Model data with value types
- Errors and optionals, make the failure paths visible
- Concurrency: stay single-threaded until profiling says otherwise
- Sendable and sharing data
- Structured concurrency
- Concurrency in SwiftUI
- Protocols and generics
- API design, clarity at the point of use
- Performance, measure, then choose
- ARC and object lifetime
- Testing, Swift Testing by default
- Macros
- Logging and debugging
- Unsafe code and interop
- Modern syntax you should be using
In the download: LICENSE, NOTICE.md, SKILL.md
Credit and license
Swift Writer is a renamed, packaged copy of write-swift by Emil Kowalski (github.com/emilkowalski/skills), used under the MIT license. The license and a list of changes ship inside the download.
Questions
Does Swift Writer work in Claude.ai, not just Claude Code?
Yes. In Claude.ai, upload the swift-writer folder as a zip in Settings under Capabilities. It also works in other agents that support Agent Skills, like Cursor, Gemini CLI and GitHub Copilot.
What do I get?
A zip with the swift-writer folder: its SKILL.md (6,522 words) and its license files. One payment, instant download.
Who made Swift Writer?
It's a renamed, packaged copy of write-swift by Emil Kowalski, used under the MIT license. The license and a list of changes ship inside the download.