# Micro-Investing App MVP Implementation I'll help you implement the micro-investing app MVP step by step. Let's start with the core infrastructure and initial setup. ## Project Structure ``` micro-investing-app/ ├── backend/ │ ├── src/ │ │ ├── controllers/ │ │ ├── models/ │ │ ├── routes/ │ │ ├── services/ │ │ ├── utils/ │ │ └── app.ts │ ├── package.json │ └── tsconfig.json ├── frontend/ │ ├── public/ │ ├── src/ │ │ ├── components/ │ │ ├── pages/ │ │ ├── services/ │ │ ├── App.tsx │ │ └── index.tsx │ ├── package.json │ └── tsconfig.json ├── docker-compose.yml └── README.md ``` ## Backend Implementation First, let's set up the backend with TypeScript and Express: ```typescript // backend/src/app.ts import express from 'express'; import bodyParser from 'body-parser'; import cors from 'cors'; import dotenv from 'dotenv'; import authRoutes from './routes/auth'; import transactionRoutes from './routes/transactions'; import portfolioRoutes from './routes/portfolio'; dotenv.config(); const app = express(); const PORT = process.env.PORT || 5000; app.use(cors()); app.use(bodyParser.json()); // Routes app.use('/api/auth', authRoutes); app.use('/api/transactions', transactionRoutes); app.use('/api/portfolio', portfolioRoutes); app.listen(PORT, () => { console.log(`Server running on port ${PORT}`); }); ``` ## Database Models Here are the core database models for our application: ```typescript // backend/src/models/User.ts import { Entity, PrimaryGeneratedColumn, Column, OneToMany } from 'typeorm'; import { Transaction } from './Transaction'; import { Portfolio } from './Portfolio'; @Entity() export class User { @PrimaryGeneratedColumn('uuid') id: string; @Column({ unique: true }) email: string; @Column() passwordHash: string; @Column() firstName: string; @Column() lastName: string; @Column() dob: Date; @Column() address: string; @Column({ default: 'pending' }) kycStatus: 'pending' | 'approved' | 'rejected'; @OneToMany(() => Transaction, transaction => transaction.user) transactions: Transaction[]; @OneToMany(() => Portfolio, portfolio => portfolio.user) portfolios: Portfolio[]; } ``` ```typescript // backend/src/models/Transaction.ts import { Entity, PrimaryGeneratedColumn, Column, ManyToOne } from 'typeorm'; import { User } from './User'; @Entity() export class Transaction { @PrimaryGeneratedColumn('uuid') id: string; @Column() plaidTransactionId: string; @Column('decimal', { precision: 10, scale: 2 }) amount: number; @Column() date: Date; @Column() merchantName: string; @Column({ default: false }) processedRoundup: boolean; @ManyToOne(() => User, user => user.transactions) user: User; } ``` ```typescript // backend/src/models/Portfolio.ts import { Entity, PrimaryGeneratedColumn, Column, ManyToOne } from 'typeorm'; import { User } from './User'; @Entity() export class Portfolio { @PrimaryGeneratedColumn('uuid') id: string; @Column() ticker: string; @Column('decimal', { precision: 10, scale: 6 }) weight: number; @Column('decimal', { precision: 10, scale: 2 }) shares: number; @Column('decimal', { precision: 10, scale: 2 }) avgCost: number; @ManyToOne(() => User, user => user.portfolios) user: User; } ``` ## Round-up Calculation Service ```typescript // backend/src/services/RoundupService.ts import { Transaction } from '../models/Transaction'; import { getRepository } from 'typeorm'; class RoundupService { async calculateRoundup(transaction: Transaction): Promise { const amount = transaction.amount; const roundup = Math.ceil(amount) - amount; return roundup > 0.01 ? roundup : 0; } async processTransactionRoundups(userId: string): Promise { const transactionRepo = getRepository(Transaction); const transactions = await transactionRepo.find({ where: { user: { id: userId }, processedRoundup: false } }); let totalRoundup = 0; for (const transaction of transactions) { const roundup = await this.calculateRoundup(transaction); if (roundup > 0) { totalRoundup += roundup; transaction.processedRoundup = true; await transactionRepo.save(transaction); } } return totalRoundup; } } export default new RoundupService(); ``` ## Portfolio Service ```typescript // backend/src/services/PortfolioService.ts import { Portfolio } from '../models/Portfolio'; import { getRepository } from 'typeorm'; class PortfolioService { private defaultPortfolio = { 'VTI': 0.6, 'BND': 0.4 }; async initializeUserPortfolio(userId: string): Promise { const portfolioRepo = getRepository(Portfolio); for (const [ticker, weight] of Object.entries(this.defaultPortfolio)) { const portfolioItem = portfolioRepo.create({ ticker, weight, shares: 0, avgCost: 0, user: { id: userId } }); await portfolioRepo.save(portfolioItem); } } async investRoundup(userId: string, amount: number): Promise { const portfolioRepo = getRepository(Portfolio); const portfolioItems = await portfolioRepo.find({ where: { user: { id: userId } } }); for (const item of portfolioItems) { const investmentAmount = amount * item.weight; // In a real app, we'd call the brokerage API here // For now, we'll just update the portfolio const currentPrice = await this.getCurrentPrice(item.ticker); // Mock function const sharesToAdd = investmentAmount / currentPrice; const newTotalShares = item.shares + sharesToAdd; const newAvgCost = ((item.avgCost * item.shares) + investmentAmount) / newTotalShares; item.shares = newTotalShares; item.avgCost = newAvgCost; await portfolioRepo.save(item); } } private async getCurrentPrice(ticker: string): Promise { // Mock function - in a real app, you'd call a market data API const mockPrices: Record = { 'VTI': 220.50, 'BND': 80.25 }; return mockPrices[ticker] || 100; } } export default new PortfolioService(); ``` ## Frontend Implementation Now let's set up the React frontend with TypeScript: ```typescript // frontend/src/App.tsx import React from 'react'; import { BrowserRouter as Router, Route, Routes } from 'react-router-dom'; import AuthPage from './pages/AuthPage'; import DashboardPage from './pages/DashboardPage'; import PortfolioPage from './pages/PortfolioPage'; import SettingsPage from './pages/SettingsPage'; import Navbar from './components/Navbar'; import { AuthProvider } from './context/AuthContext'; const App: React.FC = () => { return ( } /> } /> } /> } /> ); }; export default App; ``` ## Dashboard Page ```typescript // frontend/src/pages/DashboardPage.tsx import React, { useContext, useEffect, useState } from 'react'; import { AuthContext } from '../context/AuthContext'; import { getPortfolioValue, getRoundupAmount } from '../services/api'; import { Box, Button, Card, Typography } from '@mui/material'; const DashboardPage: React.FC = () => { const { user } = useContext(AuthContext); const [portfolioValue, setPortfolioValue] = useState(0); const [roundupAmount, setRoundupAmount] = useState(0); useEffect(() => { const fetchData = async () => { if (user) { const portfolio = await getPortfolioValue(user.id); setPortfolioValue(portfolio); const roundup = await getRoundupAmount(user.id); setRoundupAmount(roundup); } }; fetchData(); }, [user]); const handleInvest = async () => { // Call API to invest the roundup amount // await investRoundup(user.id); setRoundupAmount(0); }; return ( Dashboard Portfolio Value ${portfolioValue.toFixed(2)} Available to Invest ${roundupAmount.toFixed(2)} ); }; export default DashboardPage; ``` ## Docker Setup ```yaml # docker-compose.yml version: '3.8' services: db: image: postgres:13 environment: POSTGRES_USER: postgres POSTGRES_PASSWORD: postgres POSTGRES_DB: microinvest ports: - "5432:5432" volumes: - postgres_data:/var/lib/postgresql/data backend: build: ./backend ports: - "5000:5000" environment: DB_HOST: db DB_PORT: 5432 DB_USER: postgres DB_PASSWORD: postgres DB_NAME: microinvest JWT_SECRET: your_jwt_secret depends_on: - db frontend: build: ./frontend ports: - "3000:3000" depends_on: - backend volumes: postgres_data: ``` ## CI/CD Pipeline ```yaml # .github/workflows/main.yml name: CI/CD Pipeline on: push: branches: [ main ] pull_request: branches: [ main ] jobs: test: runs-on: ubuntu-latest steps: - uses: actions/checkout@v2 - uses: actions/setup-node@v2 with: node-version: '16' - run: npm install working-directory: ./backend - run: npm test working-directory: ./backend build: needs: test runs-on: ubuntu-latest steps: - uses: actions/checkout@v2 - uses: docker/setup-buildx-action@v1 - uses: docker/login-action@v1 with: username: ${{ secrets.DOCKER_HUB_USERNAME }} password: ${{ secrets.DOCKER_HUB_TOKEN }} - run: docker-compose -f docker-compose.yml build - run: docker-compose -f docker-compose.yml push ``` ## Next Steps 1. Set up the database by running migrations 2. Configure the Plaid API integration 3. Implement the brokerage API integration 4. Complete the frontend components 5. Set up authentication flows 6. Deploy to your cloud provider Would you like me to elaborate on any of these components or provide additional implementation details?