hackathon: Mobile App

.npmrc

@@ -1 +1,2 @@
-node-linker=hoisted
+node-linker=hoisted
+shamefully-hoist=true

README.md

@@ -4,11 +4,12 @@
 
 # PostHog Array Monorepo
 
-This is the monorepo for PostHog's Array desktop task manager and the agent framework that powers it.
+This is the monorepo for PostHog's Array apps and the agent framework that powers them.
 
 ## Projects
 
-- **[apps/array](./apps/array)** - The Array desktop application
+- **[apps/array](./apps/array)** - Array desktop application (Electron)
+- **[apps/mobile](./apps/mobile)** - PostHog mobile app (React Native / Expo)
 - **[packages/agent](./packages/agent)** - The TypeScript agent framework
 
 ## Development
@@ -42,6 +43,24 @@ pnpm dev:agent   # Run agent in watch mode
 pnpm dev:array   # Run array app
 ```
 
+### Mobile App
+
+```bash
+# Install mobile dependencies
+pnpm mobile:install
+
+# Build and run on iOS simulator
+pnpm mobile:run:ios
+
+# Start development server (without rebuilding again)
+pnpm mobile:start
+
+# Submit to TestFlight
+pnpm mobile:testflight
+```
+
+See [apps/mobile/README.md](./apps/mobile/README.md) for more details on developing the mobile app. 
+
 ### Other Commands
 
 ```bash
@@ -63,7 +82,8 @@ pnpm test
 ```
 array-monorepo/
 ├── apps/
-│   └── array/          # Electron desktop app
+│   ├── array/          # Electron desktop app
+│   └── mobile/         # React Native mobile app (Expo)
 ├── packages/
 │   └── agent/          # Agent framework
 ├── pnpm-workspace.yaml # Workspace configuration

apps/array/package.json

@@ -45,8 +45,8 @@
     "@testing-library/react": "^16.3.0",
     "@testing-library/user-event": "^14.6.1",
     "@types/node": "^20.19.21",
-    "@types/react": "^18.2.48",
-    "@types/react-dom": "^18.2.18",
+    "@types/react": "^19.1.0",
+    "@types/react-dom": "^19.1.0",
     "@types/uuid": "^9.0.7",
     "@vitejs/plugin-react": "^4.2.1",
     "@vitest/ui": "^4.0.10",
@@ -57,11 +57,11 @@
     "jsdom": "^26.0.0",
     "lint-staged": "^15.5.2",
     "postcss": "^8.4.33",
-    "tailwindcss": "^3.4.1",
+    "tailwindcss": "^3.4.18",
     "tsx": "^4.20.6",
     "typed-openapi": "^2.2.2",
     "typescript": "^5.9.3",
-    "vite": "^5.0.12",
+    "vite": "^6.0.7",
     "vite-tsconfig-paths": "^5.1.4",
     "vitest": "^4.0.10",
     "yaml": "^2.8.1"
@@ -138,8 +138,8 @@
     "posthog-js": "^1.283.0",
     "posthog-node": "^4.18.0",
     "radix-themes-tw": "0.2.3",
-    "react": "^18.2.0",
-    "react-dom": "^18.2.0",
+    "react": "19.1.0",
+    "react-dom": "19.1.0",
     "react-hook-form": "^7.64.0",
     "react-hotkeys-hook": "^4.4.4",
     "react-markdown": "^10.1.0",

apps/array/src/renderer/features/sessions/components/raw-logs/RawLogsHeader.tsx

@@ -10,7 +10,7 @@ interface RawLogsHeaderProps {
   onToggleSearch: () => void;
   onCopyAll: () => void;
   onSearchChange: (query: string) => void;
-  searchInputRef: RefObject<HTMLInputElement>;
+  searchInputRef: RefObject<HTMLInputElement | null>;
 }
 
 export function RawLogsHeader({

apps/array/src/renderer/hooks/useAutoScroll.ts

@@ -10,7 +10,7 @@ interface UseAutoScrollOptions<T extends string> {
 }
 
 interface UseAutoScrollReturn {
-  scrollRef: React.RefObject<HTMLDivElement>;
+  scrollRef: React.RefObject<HTMLDivElement | null>;
   autoScroll: boolean;
   setAutoScroll: (value: boolean) => void;
 }

apps/mobile/.gitignore

@@ -0,0 +1,41 @@
+# Learn more https://docs.github.com/en/get-started/getting-started-with-git/ignoring-files
+
+# dependencies
+node_modules/
+
+# Expo
+.expo/
+dist/
+web-build/
+expo-env.d.ts
+
+# Native
+.kotlin/
+*.orig.*
+*.jks
+*.p8
+*.p12
+*.key
+*.mobileprovision
+
+# Metro
+.metro-health-check*
+
+# debug
+npm-debug.*
+yarn-debug.*
+yarn-error.*
+
+# macOS
+.DS_Store
+*.pem
+
+# local env files
+.env*.local
+
+# typescript
+*.tsbuildinfo
+
+# generated native folders
+/ios
+/android

apps/mobile/README.md

@@ -0,0 +1,218 @@
+# PostHog Mobile App
+
+React Native mobile app built with Expo and expo-router.
+
+## Quick Start
+
+From the **repository root**:
+
+```bash
+# Install dependencies
+pnpm mobile:install
+
+# Build and run on iOS simulator
+pnpm mobile:run:ios
+
+# Start the development server (after initial build)
+pnpm mobile:start
+```
+
+## Tech Stack
+
+- [Expo](https://expo.dev) - Build tooling, native APIs, OTA updates
+- [expo-router](https://docs.expo.dev/router/introduction/) - File-based routing
+- [NativeWind](https://www.nativewind.dev/) - Tailwind CSS for React Native
+- [React Query](https://tanstack.com/query) - Async data fetching and caching
+- [Zustand](https://zustand-demo.pmnd.rs/) - Client state management (UI state, selections, local flags)
+- [Phosphor Icons](https://phosphoricons.com/) - Icon library
+
+## Architecture
+
+### Feature Folders
+
+Code is organized by feature in `src/features/`. Each feature is self-contained with its own components, hooks, stores, and API logic.
+
+```
+src/features/
+├── auth/           # Authentication & user session
+│   ├── hooks/
+│   ├── lib/
+│   ├── stores/
+│   └── types.ts
+├── chat/           # PostHog AI chat interface
+│   ├── components/
+│   ├── hooks/
+│   ├── stores/
+│   └── types.ts
+├── conversations/  # PostHog AI conversation list & management
+│   ├── api.ts
+│   ├── components/
+│   ├── hooks/
+│   └── stores/
+└── tasks/          # Task management
+    ├── api.ts
+    ├── components/
+    ├── hooks/
+    └── stores/
+```
+
+### File-Based Routing
+
+Routes for the screens are defined by the file structure in `src/app/` using expo-router. 
+
+- `(tabs)/` - Parentheses create a layout group (tab navigator)
+- `_layout.tsx` - Configures the navigator for that directory
+- `[id].tsx` - Square brackets define dynamic route parameters
+- Stacks and modals live outside tab group, configured in `_layout.tsx`
+
+```
+src/app/
+├── _layout.tsx        # Root layout
+├── index.tsx          # Entry redirect
+├── auth.tsx           # Auth screen (unauthenticated)
+├── (tabs)/            # Tabs group
+│   ├── _layout.tsx    # Layout for all tabs
+│   ├── index.tsx      # Home tab (Conversations)
+│   ├── tasks.tsx      # Tasks tab
+│   └── settings.tsx   # Settings tab
+├── chat/              # Chat stack
+│   ├── index.tsx      # New chat
+│   └── [id].tsx       # Chat by ID (dynamic route)
+└── task/              # Task stack
+    ├── index.tsx      # New task
+    └── [id].tsx       # Task by ID (dynamic route)
+```
+
+### Shared Code
+
+```
+src/
+├── components/     # Reusable UI components (Text, etc.)
+└── lib/
+    ├── posthog.ts  # Analytics setup
+    ├── queryClient.ts  # React Query client
+    ├── theme.ts    # Design tokens
+    └── logger.ts   # Logger setup
+```
+
+## Prerequisites
+
+- Node.js 22+
+- pnpm 10.23.0
+- Xcode (for iOS development)
+- Android Studio (for Android development)
+- EAS CLI: `npm install -g eas-cli`
+
+## Commands
+
+### From Repository Root
+
+**Development server:**
+```bash
+pnpm mobile:start              # Start Expo dev server
+pnpm mobile:start:clear        # Start with cleared Metro cache
+```
+
+**Build and run:**
+```bash
+pnpm mobile:run:ios            # iOS simulator
+pnpm mobile:run:ios:device     # iOS device (requires Apple Developer account)
+pnpm mobile:run:android        # Android emulator/device
+```
+
+**Native code generation:**
+```bash
+pnpm mobile:prebuild           # Generate ios/ and android/ folders
+pnpm mobile:prebuild:clean     # Delete and regenerate (when adding native deps)
+```
+
+**EAS builds:**
+```bash
+pnpm mobile:build:dev          # Development build (iOS, cloud)
+pnpm mobile:build:dev:local    # Development build (iOS, local)
+pnpm mobile:build:preview      # Preview build (iOS)
+pnpm mobile:build:production   # Production build (iOS)
+```
+
+**TestFlight:**
+```bash
+pnpm mobile:testflight         # Submit to TestFlight
+```
+
+**Utilities:**
+```bash
+pnpm mobile:install            # Install mobile dependencies
+pnpm mobile:lint               # Run Biome check
+pnpm mobile:format             # Run Biome format
+```
+
+### From apps/mobile/ Directory
+
+```bash
+cd apps/mobile
+
+# Development server
+npx expo start
+npx expo start --clear
+
+# Build and run
+npx expo run:ios
+npx expo run:ios --device
+npx expo run:android
+npx expo run:android --device
+
+# Generate native code
+npx expo prebuild
+npx expo prebuild --clean
+
+# EAS builds (iOS)
+npx eas build --profile development --platform ios
+npx eas build --profile development --platform ios --local
+npx eas build --profile preview --platform ios
+npx eas build --profile production --platform ios
+
+# EAS builds (Android)
+npx eas build --profile development --platform android
+npx eas build --profile preview --platform android
+npx eas build --profile production --platform android
+
+# TestFlight
+npx testflight
+npx eas submit --platform ios
+
+# Linting
+pnpm lint
+pnpm lint:fix
+pnpm format
+```
+
+## Prebuild Explained
+
+`expo prebuild` generates the native `ios/` and `android/` folders from your Expo configuration.
+
+**When to run `prebuild`:**
+- First time setting up the project
+- After adding/removing native dependencies (e.g., `expo-camera`, `react-native-maps`)
+- After changing `app.json` iOS/Android configuration
+- After updating Expo SDK version
+
+**When to use `--clean`:**
+- Switching between Expo SDK versions
+- Native build is failing and you want a fresh start
+- You've made manual changes to native files that you want to discard
+
+The `--clean` flag removes existing `ios/` and `android/` directories before regenerating.
+
+## Build Profiles
+
+Defined in `eas.json`:
+
+| Profile | Purpose | Distribution |
+|---------|---------|--------------|
+| `development` | Dev client with debugging | Internal only |
+| `preview` | Production-like for testing | Internal only |
+| `production` | App Store / Play Store release | Public |
+
+**Local vs Cloud builds:**
+- Cloud (default): Runs on Expo's servers, no local Xcode needed
+- Local (`--local`): Runs on your machine, faster iteration, requires Xcode/Android SDK