--- name: building-native-ui-v2 description: "Expo UI Guidelines workflow skill. Use this skill when the user needs Complete guide for building beautiful apps with Expo Router. Covers fundamentals, styling, components, navigation, animations, patterns, and native tabs and the operator should preserve the upstream workflow, copied support files, and provenance before merging or handing off." version: "0.0.1" category: frontend tags: ["building-native-ui-v2", "building-native-ui", "complete", "guide", "for", "building", "beautiful", "apps"] complexity: advanced risk: caution tools: ["codex-cli", "claude-code", "cursor", "gemini-cli", "opencode"] source: community author: "sickn33" date_added: "2026-04-19" date_updated: "2026-04-25" --- # Expo UI Guidelines ## Overview This public intake copy packages `plugins/antigravity-awesome-skills/skills/building-native-ui` from `https://github.com/sickn33/antigravity-awesome-skills` into the native Omni Skills editorial shape without hiding its origin. Use it when the operator needs the upstream workflow, support files, and repository context to stay intact while the public validator and private enhancer continue their normal downstream flow. This intake keeps the copied upstream files intact and uses the `external_source` block in `metadata.json` plus `ORIGIN.md` as the provenance anchor for review. # Expo UI Guidelines Imported source sections that did not map cleanly to the public headings are still preserved below or in the support files. Notable imported sections: Running the App, Code Style, Routes, Responsiveness, Behavior, Text Styling. ## When to Use This Skill Use this section as the trigger filter. It should make the activation boundary explicit before the operator loads files, runs commands, or opens a pull request. - You are building a native-feeling Expo Router application and need guidance on navigation, controls, effects, or platform-specific UI. - You need to decide whether Expo Go is sufficient or a custom native build is actually required. - The task involves modern Expo UI patterns across animations, tabs, headers, storage, media, or visual effects. - Use when the request clearly matches the imported source intent: Complete guide for building beautiful apps with Expo Router. Covers fundamentals, styling, components, navigation, animations, patterns, and native tabs. - Use when the operator should preserve upstream workflow detail instead of rewriting the process from scratch. - Use when provenance needs to stay visible in the answer, PR, or review packet. ## Operating Table | Situation | Start here | Why it matters | | --- | --- | --- | | First-time use | `metadata.json` | Confirms repository, branch, commit, and imported path through the `external_source` block before touching the copied workflow | | Provenance review | `ORIGIN.md` | Gives reviewers a plain-language audit trail for the imported source | | Workflow execution | `SKILL.md` | Starts with the smallest copied file that materially changes execution | | Supporting context | `SKILL.md` | Adds the next most relevant copied source file without loading the entire package | | Handoff decision | `## Related Skills` | Helps the operator switch to a stronger native skill when the task drifts | ## Workflow This workflow is intentionally editorial and operational at the same time. It keeps the imported source useful to the operator while still satisfying the public intake standards that feed the downstream enhancer flow. 1. Confirm the user goal, the scope of the imported workflow, and whether this skill is still the right router for the task. 2. Read the overview and provenance files before loading any copied upstream support files. 3. Load only the references, examples, prompts, or scripts that materially change the outcome for the current request. 4. Execute the upstream workflow while keeping provenance and source boundaries explicit in the working notes. 5. Validate the result against the upstream expectations and the evidence you can point to in the copied files. 6. Escalate or hand off to a related skill when the work moves out of this imported workflow's center of gravity. 7. Before merge or closure, record what was used, what changed, and what the reviewer still needs to verify. ### Imported Workflow Notes #### Imported: Running the App **CRITICAL: Always try Expo Go first before creating custom builds.** Most Expo apps work in Expo Go without any custom native code. Before running `npx expo run:ios` or `npx expo run:android`: 1. **Start with Expo Go**: Run `npx expo start` and scan the QR code with Expo Go 2. **Check if features work**: Test your app thoroughly in Expo Go 3. **Only create custom builds when required** - see below ### When Custom Builds Are Required You need `npx expo run:ios/android` or `eas build` ONLY when using: - **Local Expo modules** (custom native code in `modules/`) - **Apple targets** (widgets, app clips, extensions via `@bacons/apple-targets`) - **Third-party native modules** not included in Expo Go - **Custom native configuration** that can't be expressed in `app.json` ### When Expo Go Works Expo Go supports a huge range of features out of the box: - All `expo-*` packages (camera, location, notifications, etc.) - Expo Router navigation - Most UI libraries (reanimated, gesture handler, etc.) - Push notifications, deep links, and more **If you're unsure, try Expo Go first.** Creating custom builds adds complexity, slower iteration, and requires Xcode/Android Studio setup. ## Examples ### Example 1: Ask for the upstream workflow directly ```text Use @building-native-ui-v2 to handle . Start from the copied upstream workflow, load only the files that change the outcome, and keep provenance visible in the answer. ``` **Explanation:** This is the safest starting point when the operator needs the imported workflow, but not the entire repository. ### Example 2: Ask for a provenance-grounded review ```text Review @building-native-ui-v2 against metadata.json and ORIGIN.md, then explain which copied upstream files you would load first and why. ``` **Explanation:** Use this before review or troubleshooting when you need a precise, auditable explanation of origin and file selection. ### Example 3: Narrow the copied support files before execution ```text Use @building-native-ui-v2 for . Load only the copied references, examples, or scripts that change the outcome, and name the files explicitly before proceeding. ``` **Explanation:** This keeps the skill aligned with progressive disclosure instead of loading the whole copied package by default. ### Example 4: Build a reviewer packet ```text Review @building-native-ui-v2 using the copied upstream files plus provenance, then summarize any gaps before merge. ``` **Explanation:** This is useful when the PR is waiting for human review and you want a repeatable audit packet. ## Best Practices Treat the generated public skill as a reviewable packaging layer around the upstream repository. The goal is to keep provenance explicit and load only the copied source material that materially improves execution. - Prefer flex gap over margin and padding styles - Prefer padding over margin where possible - Always account for safe area, either with stack headers, tabs, or ScrollView/FlatList contentInsetAdjustmentBehavior="automatic" - Ensure both top and bottom safe area insets are accounted for - Inline styles not StyleSheet.create unless reusing styles is faster - Add entering and exiting animations for state changes - Use { borderCurve: 'continuous' } for rounded corners unless creating a capsule shape ### Imported Operating Notes #### Imported: General Styling Rules - Prefer flex gap over margin and padding styles - Prefer padding over margin where possible - Always account for safe area, either with stack headers, tabs, or ScrollView/FlatList `contentInsetAdjustmentBehavior="automatic"` - Ensure both top and bottom safe area insets are accounted for - Inline styles not StyleSheet.create unless reusing styles is faster - Add entering and exiting animations for state changes - Use `{ borderCurve: 'continuous' }` for rounded corners unless creating a capsule shape - ALWAYS use a navigation stack title instead of a custom text element on the page - When padding a ScrollView, use `contentContainerStyle` padding and gap instead of padding on the ScrollView itself (reduces clipping) - CSS and Tailwind are not supported - use inline styles ## Troubleshooting ### Problem: The operator skipped the imported context and answered too generically **Symptoms:** The result ignores the upstream workflow in `plugins/antigravity-awesome-skills/skills/building-native-ui`, fails to mention provenance, or does not use any copied source files at all. **Solution:** Re-open `metadata.json`, `ORIGIN.md`, and the most relevant copied upstream files. Check the `external_source` block first, then restate the provenance before continuing. ### Problem: The imported workflow feels incomplete during review **Symptoms:** Reviewers can see the generated `SKILL.md`, but they cannot quickly tell which references, examples, or scripts matter for the current task. **Solution:** Point at the exact copied references, examples, scripts, or assets that justify the path you took. If the gap is still real, record it in the PR instead of hiding it. ### Problem: The task drifted into a different specialization **Symptoms:** The imported skill starts in the right place, but the work turns into debugging, architecture, design, security, or release orchestration that a native skill handles better. **Solution:** Use the related skills section to hand off deliberately. Keep the imported provenance visible so the next skill inherits the right context instead of starting blind. ## Related Skills - `@00-andruia-consultant` - Use when the work is better handled by that native specialization after this imported skill establishes context. - `@00-andruia-consultant-v2` - Use when the work is better handled by that native specialization after this imported skill establishes context. - `@10-andruia-skill-smith` - Use when the work is better handled by that native specialization after this imported skill establishes context. - `@10-andruia-skill-smith-v2` - Use when the work is better handled by that native specialization after this imported skill establishes context. ## Additional Resources Use this support matrix and the linked files below as the operator packet for this imported skill. They should reflect real copied source material, not generic scaffolding. | Resource family | What it gives the reviewer | Example path | | --- | --- | --- | | `references` | copied reference notes, guides, or background material from upstream | `references/n/a` | | `examples` | worked examples or reusable prompts copied from upstream | `examples/n/a` | | `scripts` | upstream helper scripts that change execution or validation | `scripts/n/a` | | `agents` | routing or delegation notes that are genuinely part of the imported package | `agents/n/a` | | `assets` | supporting assets or schemas copied from the source package | `assets/n/a` | ### Imported Reference Notes #### Imported: References Consult these resources as needed: ``` references/ animations.md Reanimated: entering, exiting, layout, scroll-driven, gestures controls.md Native iOS: Switch, Slider, SegmentedControl, DateTimePicker, Picker form-sheet.md Form sheets in expo-router: configuration, footers and background interaction. gradients.md CSS gradients via experimental_backgroundImage (New Arch only) icons.md SF Symbols via expo-image (sf: source), names, animations, weights media.md Camera, audio, video, and file saving route-structure.md Route conventions, dynamic routes, groups, folder organization search.md Search bar with headers, useSearch hook, filtering patterns storage.md SQLite, AsyncStorage, SecureStore tabs.md NativeTabs, migration from JS tabs, iOS 26 features toolbar-and-headers.md Stack headers and toolbar buttons, menus, search (iOS only) visual-effects.md Blur (expo-blur) and liquid glass (expo-glass-effect) webgpu-three.md 3D graphics, games, GPU visualizations with WebGPU and Three.js zoom-transitions.md Apple Zoom: fluid zoom transitions with Link.AppleZoom (iOS 18+) ``` #### Imported: Library Preferences - Never use modules removed from React Native such as Picker, WebView, SafeAreaView, or AsyncStorage - Never use legacy expo-permissions - `expo-audio` not `expo-av` - `expo-video` not `expo-av` - `expo-image` with `source="sf:name"` for SF Symbols, not `expo-symbols` or `@expo/vector-icons` - `react-native-safe-area-context` not react-native SafeAreaView - `process.env.EXPO_OS` not `Platform.OS` - `React.use` not `React.useContext` - `expo-image` Image component instead of intrinsic element `img` - `expo-glass-effect` for liquid glass backdrops #### Imported: Code Style - Be cautious of unterminated strings. Ensure nested backticks are escaped; never forget to escape quotes correctly. - Always use import statements at the top of the file. - Always use kebab-case for file names, e.g. `comment-card.tsx` - Always remove old route files when moving or restructuring navigation - Never use special characters in file names - Configure tsconfig.json with path aliases, and prefer aliases over relative imports for refactors. #### Imported: Routes See `./references/route-structure.md` for detailed route conventions. - Routes belong in the `app` directory. - Never co-locate components, types, or utilities in the app directory. This is an anti-pattern. - Ensure the app always has a route that matches "/", it may be inside a group route. #### Imported: Responsiveness - Always wrap root component in a scroll view for responsiveness - Use `` instead of `` for smarter safe area insets - `contentInsetAdjustmentBehavior="automatic"` should be applied to FlatList and SectionList as well - Use flexbox instead of Dimensions API - ALWAYS prefer `useWindowDimensions` over `Dimensions.get()` to measure screen size #### Imported: Behavior - Use expo-haptics conditionally on iOS to make more delightful experiences - Use views with built-in haptics like `` from React Native and `@react-native-community/datetimepicker` - When a route belongs to a Stack, its first child should almost always be a ScrollView with `contentInsetAdjustmentBehavior="automatic"` set - When adding a `ScrollView` to the page it should almost always be the first component inside the route component - Prefer `headerSearchBarOptions` in Stack.Screen options to add a search bar - Use the `` prop on text containing data that could be copied - Consider formatting large numbers like 1.4M or 38k - Never use intrinsic elements like 'img' or 'div' unless in a webview or Expo DOM component # Styling Follow Apple Human Interface Guidelines. #### Imported: Text Styling - Add the `selectable` prop to every `` element displaying important data or error messages - Counters should use `{ fontVariant: 'tabular-nums' }` for alignment #### Imported: Shadows Use CSS `boxShadow` style prop. NEVER use legacy React Native shadow or elevation styles. ```tsx ``` 'inset' shadows are supported. # Navigation #### Imported: Link Use `` from 'expo-router' for navigation between routes. ```tsx import { Link } from 'expo-router'; // Basic link // Wrapping custom components ... ``` Whenever possible, include a `` to follow iOS conventions. Add context menus and previews frequently to enhance navigation. #### Imported: Stack - ALWAYS use `_layout.tsx` files to define stacks - Use Stack from 'expo-router/stack' for native navigation stacks ### Page Title Set the page title in Stack.Screen options: ```tsx ``` #### Imported: Context Menus Add long press context menus to Link components: ```tsx import { Link } from "expo-router"; {}} /> {}} /> ; ``` #### Imported: Link Previews Use link previews frequently to enhance navigation: ```tsx ``` Link preview can be used with context menus. #### Imported: Modal Present a screen as a modal: ```tsx ``` Prefer this to building a custom modal component. #### Imported: Sheet Present a screen as a dynamic form sheet: ```tsx ``` - Using `contentStyle: { backgroundColor: "transparent" }` makes the background liquid glass on iOS 26+. #### Imported: Common route structure A standard app layout with tabs and stacks inside each tab: ``` app/ _layout.tsx — (index,search)/ _layout.tsx — index.tsx — Main list search.tsx — Search view ``` ```tsx // app/_layout.tsx import { NativeTabs, Icon, Label } from "expo-router/unstable-native-tabs"; import { Theme } from "../components/theme"; export default function Layout() { return ( ); } ``` Create a shared group route so both tabs can push common screens: ```tsx // app/(index,search)/_layout.tsx import { Stack } from "expo-router/stack"; import { PlatformColor } from "react-native"; export default function Layout({ segment }) { const screen = segment.match(/\((.*)\)/)?.[1]!; const titles: Record = { index: "Items", search: "Search" }; return ( ); } ``` #### Imported: Limitations - Use this skill only when the task clearly matches the scope described above. - Do not treat the output as a substitute for environment-specific validation, testing, or expert review. - Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.