Build a Mobile App with AI: React Native + Cursor Guide

Why build a cross-platform mobile app with AI?

AI can transform mobile user experiences—think intelligent chat, personalized suggestions, and on-device inference. In this final episode of our "Build With AI" series, I'll walk you through building a cross-platform mobile app with React Native and Cursor. As we covered in previous episodes (like Episode 2: Build a SaaS Landing Page with Cursor and Episode 4: Build a Full-Stack App with AI), Cursor is great for embedding AI workflows into production apps.

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What you'll need (tools, versions, and costs)

• React Native: use React Native 0.72+ (stable as of recent years).
• Node.js: Node 18+ LTS is recommended for toolchain compatibility.
• React Navigation: v6.x is the mainstream navigation library for React Native.
• Cursor: sign up at cursor.dev; Cursor provides SDKs and API endpoints to integrate AI into apps (they offer a free tier; see cursor.dev/pricing for latest plan details).
• Apple Developer Program: $99/year (required to publish to the App Store).
• Google Play Console: one-time $25 registration fee (required to publish to Google Play).

These are practical, up-to-date components to start a cross-platform app. If you used Episode 1 or Episode 3 of this series, you'll recognize the same approach to rapid bootstrapping and CI/CD we recommended earlier.

Project setup: scaffold a React Native app

1. Install Node 18+ and Yarn or npm.
2. Create a new app with the React Native CLI or Expo (managed workflow):
   • React Native CLI: npx react-native init MyAIApp (good for full native control).
   • Expo: npx create-expo-app MyAIApp (faster iteration, easier builds with EAS).
3. Install React Navigation and essential packages:
   • yarn add @react-navigation/native @react-navigation/native-stack
   • For native CLI: also install react-native-screens and react-native-safe-area-context as documented.
4. Initialize a git repo and create branches: main for production, dev for features.

Tip: Expo is excellent for prototypes and early testing (we used Expo when building landing pages in Episode 2). For production-level AI features, native builds can give you more control over binary size and native modules.

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Build the app structure and navigation

Use a simple stack + tab navigation combination:

• Create a screens folder: Home, Chat, Settings.
• Use React Navigation's Native Stack for modal flows and a Bottom Tab Navigator for core tabs.

Example structure:

• /src
  • /navigation
    • AppNavigator.tsx
  • /screens
    • HomeScreen.tsx
    • ChatScreen.tsx
    • SettingsScreen.tsx
  • /api
    • cursorClient.ts

Why: Separating navigation, screens, and API calls keeps the app maintainable as AI features grow.

Integrate Cursor: authentication and client

Cursor provides APIs and SDKs to call AI models or server-side agents. The exact SDK syntax might change, so check Cursor docs, but the integration pattern is stable:

1. Store your Cursor API key securely. For development, use environment variables via react-native-dotenv or Expo secrets. Never hardcode keys in your repo.
2. Create a small API client wrapper (src/api/cursorClient.ts) that handles:
   • Authentication header injection
   • Request/response normalization
   • Error handling and retry logic

Basic fetch example (pseudocode):

• POST to Cursor's inference endpoint with a prompt or input payload.
• Use streaming responses where available for progressive UI updates.

For heavy AI tasks, do inference server-side (e.g., an Express/Cloud Function) to keep secrets safe and to offload long-running jobs. In Episode 4 we used server-side AI calls to keep client bundles small—same approach applies here.

Build a conversational ChatScreen (AI-powered)

1. UI: show messages in a FlatList, input box, and send button. Use optimistic UI for fast feedback.
2. State: use React Query (or SWR) to manage async status, caching, and background refetches.
3. Sending a message:
   • Append a local optimistic message.
   • Call your Cursor client; if Cursor supports streaming, stream tokens to the UI for a typing effect.
   • On success, replace optimistic message with final content; on error, show retry.

Important UX tips:

• Show model latency and a spinner for transparency.
• Limit consecutive requests to prevent rate-limit errors; queue messages if needed.

Permissions and device capabilities

If your app uses microphone input, device sensors, or photos for multimodal AI: request runtime permissions for iOS and Android and add the correct keys to Info.plist (iOS) and AndroidManifest.xml.

For on-device inference (if you later add TFLite or CoreML models), follow platform-specific packaging best practices to minimize binary size.

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Testing, CI, and building binaries

• Unit / component tests: use Jest + React Native Testing Library.
• End-to-end: Detox or Playwright (for Android/iOS emulators).
• CI: GitHub Actions is a solid choice—set up workflows to run tests and build artifacts.

For building production binaries:

• iOS: use Xcode or EAS Build (if using Expo) to produce an .ipa. Upload via Transporter or App Store Connect.
• Android: generate a signed AAB with Gradle or via EAS Build and upload to the Play Console.

Make sure to configure app icons, launch screens, and localization before final builds. If you used CI in Episode 4, you can reuse the same pipeline patterns here for automated builds.

App Store preparation and compliance

1. Privacy and data handling: document how AI data (prompts, user content) is sent to Cursor and stored. Provide a clear privacy policy in your app and on your website.
2. App Store metadata: title, subtitle, screenshots, privacy details, and age rating.
3. In-app disclosures: if AI-generated content can be incorrect, include a user-facing disclaimer.
4. Accessibility: ensure UI components are accessible—use proper labels and roles.

Costs summary you must budget for:

• Apple Developer: $99/year.
• Google Play Console: $25 one-time.
• Hosting or server costs for backend inference: depends on usage; start small and scale.
• Cursor usage: depends on API usage; check cursor.dev/pricing for the latest plans.

Performance and monitoring

• Monitor API latency and error rates with Sentry or similar APM tools.
• Track model usage and costs so you can optimize prompts and caching.
• Add client-side analytics (Segment, Amplitude, or Firebase Analytics) to understand feature usage and to improve AI prompt behavior.

Launch checklist

1. Finalize UI polish and onboarding.
2. Verify privacy policy and data deletion paths.
3. Build release binaries and test on physical devices.
4. Create app store listings and prepare marketing assets.
5. Submit and respond to reviewer feedback quickly.

Next steps and scaling

• Consider hybrid flows: client-side preprocessing + server-side inference for heavy models.
• Add offline fallbacks and graceful degradation when AI services are unreachable.
• Iterate on prompt engineering and feedback loops—collect user ratings of AI responses to fine-tune experience.

As with earlier episodes in this series, the focus is on iterative delivery: ship a minimal AI feature, learn from users, then expand. Cursor makes it straightforward to add new AI endpoints, and React Native lets you reach both iOS and Android users rapidly.

Summary

Building a cross-platform mobile app with React Native and Cursor involves setting up a modern React Native stack, integrating Cursor securely, crafting good UX around AI latency and errors, and preparing production builds for the App Store and Google Play. Use Expo for fast prototyping and the native CLI for fine-grained control. Follow the app store and privacy rules, and instrument monitoring early.

If you followed our series from Episode 1 through 4, you already have solid patterns for rapid development, deployment, and CI that apply directly here. Good luck—build something people love, and let AI amplify the experience.

Frequently Asked Questions

Do I need Expo or React Native CLI?

Use Expo for fast prototyping and easier builds; choose React Native CLI for full native control and smaller binaries. Both support Cursor integration; pick based on your release needs.

Where should I call Cursor's API from?

For security, call Cursor from a backend server for production to keep API keys secret; for prototypes you can call it from the client with environment-protected keys, but avoid shipping secrets in the app.

How do I handle App Store and Play Store costs?

Apple requires a $99/year developer account; Google Play requires a one-time $25 registration. Additional costs depend on hosting and Cursor usage, so monitor usage to control expenses.

Can I stream AI responses to the UI?

Yes—if the Cursor endpoint supports streaming, implement token-by-token updates in the UI for a responsive typing experience; otherwise use optimistic UI patterns and update when the response completes.