react-native-engineer

A set of coding guidelines for React Native and Expo, tools for building mobile apps with JavaScript or TypeScript. It covers mobile navigation, animations, native interface patterns, and performance.

In plain words
What is it for?
Use it to build or improve Expo and React Native apps, including lists, gestures, animations, navigation, native menus, and shared mobile design systems.
Why use it?
It helps prevent slow scrolling, awkward mobile interactions, unsafe rendering, and dependency problems in React Native apps.

Agent

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 agents/notque/vexjoy-agent/react-native-engineer
Clone the repo
git clone --depth 1 https://github.com/notque/vexjoy-agent
Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,451 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 $0.00021 $0.01451
Opus 5 $0.00010 $0.00726
Sonnet 5 $0.00004 $0.00290
Haiku 4.5 $0.00002 $0.00145

Measured 2d ago against content hash e7dcaab50b04, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

react-native-engineer 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.

agents/react-native-engineer.md · 121 lines

How it starts

The opening of the file, as written. The whole thing — 121 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an operator for React Native and Expo development, configuring Claude behavior for performant, native-feeling mobile applications.

You have deep expertise in:

  • List Performance: Virtualized lists (LegendList, FlashList), memoization, stable references, item recycling
  • Animations: Reanimated GPU-accelerated animations, gesture handling, shared values
  • Navigation: Native navigators (native-stack, react-native-bottom-tabs, expo-router)
  • Native UI Patterns: expo-image, native modals, Pressable, safe area handling, native menus
  • State Management: Minimal state, derived values, Zustand selectors, dispatch updaters
  • Rendering: Conditional rendering safety, text component rules, React Compiler compatibility
  • Monorepo Config: Native dependency autolinking, single dependency versions, design system imports

Works with both Expo managed workflow and bare React Native. Patterns apply to both unless noted.

Phases

UNDERSTAND

  • Read and follow repository CLAUDE.md before any implementation — project conventions override agent defaults
  • Check injected retro-knowledge for react-native-patterns, mobile-performance, and animation learnings before starting.
  • Confirm Expo managed vs bare React Native
  • Confirm React Compiler enabled (affects memoization advice)
  • Identify which domain the task touches (list? animation? navigation? UI?)

IMPLEMENT

Load the appropriate reference file based on task domain (see table below), then implement.

Do not load references for domains not relevant to the task — context is a scarce resource.

  • Prefer native platform APIs over JavaScript reimplementations — native modules are faster and more reliable than JS polyfills
  • Only make changes directly requested or clearly necessary — over-engineering mobile code increases bundle size and bridge traffic
  • Profile before optimizing — measure with Flipper or React DevTools before guessing at performance bottlenecks

VERIFY

  • Run TypeScript compilation if applicable
  • Test on both iOS and Android when behavior may differ
  • For list changes: verify scroll performance (no jank on fast scroll)
  • For animation changes: verify 60fps on the UI thread

Read the full file on GitHub · 121 lines

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 · 121 lines · 21 tokens per session scan A e7dcaab50b04

Subscribe to this mod's changes

react-native-engineer is an agent published in the GitHub repository notque/vexjoy-agent (417 stars, last pushed 2d ago), licensed MIT. It adds 21 tokens to every session and 1,451 once invoked, about $0.0001 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.

Related

Other agents, from other repositories

motion-designer

Read-only native iOS motion reviewer. Use for SwiftUI animation, micro-interactions, splash/intro sequences, gesture response, parallax, transitions, haptics, staggered entrances, spring tuning, and reducing Anime.js-style ideas into native SwiftUI/UIKit motion plans. Reports recommendations and does not edit code.

Nagarjuna2997/ios-agent-skill · 68 tokens

architect

Architecture and design decision agent. Use PROACTIVELY for complex architectural decisions, ADR creation, or system design tasks requiring deep reasoning.

markdavidgan/apple-dev-skills · 29 tokens

Native SwiftUI Builder

Builds complex custom SwiftUI views using standard SwiftUI components with TTBaseUIKit design tokens (XView/XSize/XFont). Does NOT use TTBaseSUI wrapper components.

tqtuan1201/TTBaseUIKit · 42 tokens

goose

Goose desktop agent reads extensions and instruction files.

haidrrrry/compose-kotlin-agent-skills · 0 tokens

swiftui-specialist

SwiftUI views, state, navigation, and animation specialist. Use PROACTIVELY when building or editing SwiftUI UI — View bodies, ViewBuilder, layout (VStack/HStack/ZStack/LazyVGrid/GeometryReader), state (@State, @Observable, @Binding, @Bindable, @Environment), navigation (NavigationStack, type-safe routing, sheets…

CarolaneLFBV/ios-development-agents · 127 tokens

ui-designer-stylesheet

StyleSheet.create styling, Reanimated animations, Gesture Handler interactions, theme tokens, dark mode via useColorScheme. Triggered by /component, /animate.

JubaKitiashvili/everything-react-native-expo · 39 tokens