agentmods.dev

building-native-ui

A guide to building app interfaces with Expo Router, including styling, reusable components, navigation, animations, forms, storage, media, and native tabs. Expo Router is a way to organize screens and navigation in Expo apps.

In plain words
What is it for?
Use it to build screens, navigation, forms, search, tabs, animations, camera or media features, local storage, visual effects, and some 3D graphics.
Why use it?
It gives developers patterns for common interface features and explains platform-specific controls and route organization in one place.

Skill for Claude CodeCodex

438 +4 1mo ago A scan 31 tokens original Apache-2.0
View the source file zai-org/Synapse
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/zai-org/synapse/building-native-ui
Any agent
npx skills add zai-org/Synapse --skill building-native-ui
Clone the repo
git clone --depth 1 https://github.com/zai-org/Synapse

Made for: Claude Code, Codex.

Per session 31 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,478 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00031 $0.02478
Opus 5 $0.00015 $0.01239
Sonnet 5 $0.00006 $0.00496
Haiku 4.5 $0.00003 $0.00248

Measured 2d ago against content hash dc9c08d2601e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

building-native-ui scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

5 near-identical copies found in the catalogue:

.agents/skills/building-native-ui/SKILL.md · 322 lines

How it starts

The opening of the file, as written. The whole thing — 322 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Expo UI Guidelines

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+)

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

Read the full file on GitHub · 322 lines

Files

What ships with it

14 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 322 lines · 31 tokens per session scan A dc9c08d2601e

Subscribe to this mod's changes

building-native-ui is a skill published in the GitHub repository zai-org/Synapse (438 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 31 tokens to every session and 2,478 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

FrontendMobile
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