# swiftui-design-principles

A skill that hands your coding agent fixed rules for spacing, type and color in SwiftUI and WidgetKit, so the UI reads as a native app instead of generated markup.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 1300 installs · ★ 32
- Author: arjitj2
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/arjitj2/swiftui-design-principles/tree/HEAD/SKILL.md
- Updated: 2026-03-16
- HTML: https://affpapa.org/en/nevibecode/skills/swiftui-design-principles

## What it does

The skill comes out of comparing well-built SwiftUI apps with ones where margins and text sizes look slightly off. Your agent gets a rule set and applies it whenever it creates or edits views, WidgetKit widgets, or any native Apple UI.

The rules are concrete. Spacing must come from a base-4/base-8 grid: 4, 8, 12, 16, 20, 24, 32, 40, 48, and arbitrary values like 26 or 34 are called out as wrong. The type scale shrinks to five roles with distinct weights, and large headings use light weights. Colors come from semantic system values such as `Color(.systemBackground)`, `Color(.separator)` and `.foregroundStyle(.secondary)` rather than white with a dozen opacity steps. Consistency is spelled out too: one font design across app and widgets, at most two tracking values, and years rendered without locale grouping.

This is worth installing if your agent already writes SwiftUI but you keep fixing the result by hand. One command through `npx skills add` drops the file at `~/.claude/skills/swiftui-design-principles/SKILL.md`. Expect friction if your project has its own design system with different spacing, because the skill will argue with it.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add arjitj2/swiftui-design-principles --skill swiftui-design-principles -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/swiftui-design-principles/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/swiftui-design-principles/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add arjitj2/swiftui-design-principles --skill swiftui-design-principles -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/swiftui-design-principles/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add arjitj2/swiftui-design-principles --skill swiftui-design-principles -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/swiftui-design-principles/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install arjitj2/swiftui-design-principles swiftui-design-principles
```

2. **Manually: put the files in place**
- File: `.github/skills/swiftui-design-principles/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add arjitj2/swiftui-design-principles --skill swiftui-design-principles -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/arjitj2/swiftui-design-principles
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/swiftui-design-principles/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add arjitj2/swiftui-design-principles --skill swiftui-design-principles -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/arjitj2/swiftui-design-principles/tree/HEAD/SKILL.md

## When to use it
- pull view padding onto a single grid
- cut the number of font sizes down to a clear scale
- swap hardcoded colors for semantic system ones
- match a WidgetKit widget to the app's visual style
- strip gradients and decorative borders out of a screen

## Example prompts
- build the stats screen following swiftui-design-principles
- check my padding and font sizes against the skill
- make the WidgetKit widget match the main app's style

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: d797e0c0977a83c8.

BEGIN THIRD-PARTY FILE d797e0c0977a83c8
````text
---
name: swiftui-design-principles
description: Design principles for building polished, native-feeling SwiftUI apps and widgets. Use this skill when creating or modifying SwiftUI views, iOS widgets (WidgetKit), or any native Apple UI. Ensures proper spacing, typography, colors, and widget implementations that look and feel like quality apps rather than AI-generated slop.
license: MIT
metadata:
  author: arjitj2
  version: "1.1.1"
---

This skill encodes design principles derived from comparing polished, production-quality SwiftUI apps against poorly-built ones. The patterns here represent what separates an app that feels "right" from one where the margins, spacing, and text sizes just look "off."

Apply these principles whenever building or modifying SwiftUI interfaces, WidgetKit widgets, or any native Apple UI.

## Core Philosophy

**Restraint over decoration.** Every pixel must earn its place. A polished app uses fewer colors, fewer font sizes, fewer spacing values, and fewer words — but uses them consistently. Over-engineering visual elements (custom gradients, decorative borders, bespoke dividers) creates visual noise. Native components and system colors create harmony.

**Attention is scarce.** Keep UI copy shorter than you think it needs to be. Prefer one clear headline and one compact supporting block over repeated explanation in the title, subtitle, body, and footer. If a screen needs rationale, put it in one purposeful place instead of scattering it across the page.

---

## 1. Spacing System: Use a Consistent Grid

**CRITICAL**: Use spacing values from a base-4/base-8 grid. Never use arbitrary values.

### Allowed spacing values
```
4, 8, 12, 16, 20, 24, 32, 40, 48
```

### Bad (arbitrary values that create visual dissonance)
```swift
// WRONG - these numbers have no relationship to each other
.padding(.bottom, 26)
.padding(.bottom, 34)
.padding(.bottom, 36)
HStack(spacing: 18)
.padding(14)
```

### Good (values from a consistent grid)
```swift
// RIGHT - predictable rhythm the eye can follow
.padding(.horizontal, 20)
.padding(.top, 8)
Spacer().frame(height: 32)
HStack(spacing: 4)  // or 8, 12, 16
.padding(.vertical, 12)
.padding(.horizontal, 16)
```

### Standard padding assignments
- **Outer content padding**: 16-20pt horizontal
- **Between major sections**: 24-32pt vertical
- **Within grouped components**: 4-12pt
- **Card/row internal padding**: 12-16pt vertical, 16pt horizontal

---
````
END THIRD-PARTY FILE d797e0c0977a83c8

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