Nirvan - AI Life Coach

Minimalist AI Coaching in Your Pocket

Technical Documentation

1. High-Level Architecture

System Overview

Component Architecture

App Structure:

app/
├── (tabs)/              # Main tab navigation
│   ├── index.tsx        # Home/Coach Selection
│   ├── chat.tsx         # Chat Interface
│   └── settings.tsx     # Settings & Account
├── _layout.tsx          # Root layout with providers
├── onboarding.tsx       # First-time user flow
└── paywall.tsx          # Subscription screen

components/
├── CoachCard.tsx        # Coach selection cards
├── ChatBubble.tsx       # Message display
├── PremiumBanner.tsx    # Upgrade prompts
└── LoadingSpinner.tsx   # Loading states

contexts/
├── ChatContext.tsx      # Chat state management
├── PremiumContext.tsx   # Subscription state
└── CoachContext.tsx     # Active coach tracking

utils/
├── ai-service.ts        # OpenAI integration
├── revenuecat.ts        # RevenueCat SDK wrapper
└── storage.ts           # AsyncStorage helpers

2. Technology Stack

Frontend Framework

• React Native: v0.74.5
• Expo SDK: v51
• Expo Router: v3 (file-based routing)
• TypeScript: Type-safe development

UI/UX - Minimalist Design Philosophy

• React Native StyleSheet: Native styling with custom design system
• Expo Vector Icons: Minimal, consistent iconography
• React Native Reanimated: Smooth 60fps animations
• Expo Status Bar: Adaptive status bar styling
• Custom Components: Reusable, composable UI elements

Backend Services

• OpenAI API: GPT-4 for AI conversations
• RevenueCat SDK: Subscription management
• AsyncStorage: Local data persistence

Development Tools

• GitHub Actions: CI/CD automation
• EAS Build: Cloud-based iOS builds
• EAS Submit: Automated TestFlight deployment
• Expo Dev Client: Development builds

3. RevenueCat Integration

Products Configuration

App Store Connect Products

Property	Value
Product ID	monthly_premium
Type	Auto-Renewable Subscription
Duration	1 Month
Price	$9.99 USD
Subscription Group	Premium Subscriptions
Status	Ready to Submit

RevenueCat Offerings

Offering ID: default (Current)
Packages:
  - $rc_monthly → monthly_premium
  - $rc_annual → yearly_premium (future)
  - $rc_lifetime → lifetime_premium (future)

Implementation Details

1. SDK Initialization

// utils/revenuecat.ts
import Purchases from 'react-native-purchases';

const API_KEYS = {
    ios: 'appl_ooxzpzwxHOQNkUCjODAkqnLDbjJ',
    android: 'goog_YOUR_KEY_HERE',
};

export class RevenueCatService {
    static async init() {
        // Safety check for Expo Go
        if (Constants.executionEnvironment === 'storeClient') {
            console.log('[RevenueCat] Running in Expo Go - Mock Mode');
            this.mockPro = true;
            return;
        }

        try {
            if (Platform.OS === 'ios') {
                await Purchases.configure({ apiKey: API_KEYS.ios });
            }
            if (__DEV__) {
                await Purchases.setLogLevel(Purchases.LOG_LEVEL.DEBUG);
            }
            console.log('RevenueCat Initialized');
        } catch (e) {
            console.warn('RevenueCat Init Failed:', e);
        }
    }
}

2. Purchase Flow

static async purchasePackage(pkg: PurchasesPackage) {
    try {
        const { customerInfo } = await Purchases.purchasePackage(pkg);
        return { success: true, customerInfo };
    } catch (e: any) {
        if (!e.userCancelled) {
            console.error('Purchase error', e);
            return { success: false, error: e.message };
        } else {
            return { success: false, userCancelled: true };
        }
    }
}

3. Checking Premium Status

static async isPro(): Promise<boolean> {
    if (this.mockPro) return true; // Mock for testing

    try {
        const customerInfo = await this.getCustomerInfo();
        return customerInfo?.entitlements.active['premium'] !== undefined;
    } catch (e) {
        console.error("Failed to check pro status", e);
        return false;
    }
}

Monetization Flow

4. AI Integration

Implementation

// utils/ai-service.ts
import OpenAI from 'openai';

const OPENAI_API_KEY = process.env.EXPO_PUBLIC_OPENAI_API_KEY || '';

const openai = new OpenAI({
    apiKey: OPENAI_API_KEY,
});

export async function sendMessage(
    coachType: string,
    messages: Message[]
): Promise<string> {
    try {
        const systemPrompt = getCoachSystemPrompt(coachType);
        
        const completion = await openai.chat.completions.create({
            model: 'gpt-4',
            messages: [
                { role: 'system', content: systemPrompt },
                ...messages.map(m => ({
                    role: m.role,
                    content: m.content
                }))
            ],
            max_tokens: 500,
            temperature: 0.7,
        });

        return completion.choices[0].message.content || 'No response';
    } catch (error) {
        console.error('OpenAI API Error:', error);
        throw error;
    }
}

Coach Personas

Each coach has a specialized system prompt:

Coach	Specialization
Fitness Coach	Certified personal trainer and nutritionist providing evidence-based fitness advice, workout plans, and nutrition guidance
Career Coach	Experienced career counselor specializing in tech careers, resume writing, interview prep, and salary negotiation
Mindfulness Coach	Meditation instructor and stress management expert guiding mindfulness practices and mental wellness
Relationship Coach	Licensed relationship therapist providing advice on communication, conflict resolution, and healthy relationships
Finance Coach	Certified financial planner helping with budgeting, saving, investing, and financial goal setting
Productivity Coach	Productivity expert specializing in time management, workflow optimization, and habit building

5. Data Flow

Chat Message Flow

Purchase Flow

6. Security & Privacy

API Key Management

Privacy Principles

• No user data sent to external servers (except OpenAI for chat)
• No analytics tracking
• No data sharing with third parties
• Conversations stored locally only

7. CI/CD Pipeline

GitHub Actions Workflow

Trigger: Manual workflow dispatch

Runner: macOS-latest

Build Time: ~24 minutes

name: Build iOS App

on:
  workflow_dispatch:

jobs:
  build:
    runs-on: macos-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v4

      - name: Setup Node.js 20.x
        uses: actions/setup-node@v4
        with:
          node-version: 20.x
          cache: npm

      - name: Setup EAS
        uses: expo/expo-github-action@v8
        with:
          eas-version: latest
          token: ${{ secrets.EXPO_TOKEN }}

      - name: Install dependencies
        run: npm install

      - name: Build iOS App
        run: eas build --platform ios --profile production
        env:
          EXPO_TOKEN: ${{ secrets.EXPO_TOKEN }}
          EXPO_PUBLIC_OPENAI_API_KEY: ${{ secrets.EXPO_PUBLIC_OPENAI_API_KEY }}

      - name: Submit to TestFlight
        run: eas submit --platform ios --profile production
        env:
          EXPO_APPLE_APP_SPECIFIC_PASSWORD: ${{ secrets.EXPO_APPLE_APP_SPECIFIC_PASSWORD }}

8. Performance Considerations

Optimization Strategies

• Lazy Loading: Components loaded on-demand, images optimized
• Caching: Chat history and API responses cached
• Memory Management: Chat history limited to last 50 messages
• Network Optimization: Debounced API calls, retry logic

Target Metrics

Metric	Target
App launch time	< 2 seconds
Chat response time	< 3 seconds
Purchase flow	< 5 seconds
Memory usage	< 150 MB

Future Enhancements

Phase 1 (Next 30 Days)

• Voice input/output integration
• Goal tracking dashboard
• Daily check-in notifications
• Offline mode support

Phase 2 (60-90 Days)

• Custom coach creation
• Apple Health integration
• Group coaching features
• Multi-language support

Phase 3 (6 Months)

• Multi-modal AI (image analysis)
• Collaborative coaching sessions
• Creator partnerships
• Web app version