UpiPayment

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⚡ UPI MESH - Modern Fintech UPI Payment Ecosystem

Java 17 Spring Boot Spring Cloud React Vite Tailwind CSS Redis MySQL

UPI Mesh is a state-of-the-art, microservices-driven digital wallet and UPI payment network. Built with a robust Spring Boot & Spring Cloud backend and a premium, responsive React + Tailwind frontend, the platform replicates real-world fintech transaction processing pipelines, secure auth workflows, fraud prevention networks, and AI-enabled financial assistants.

🎥 Project Demo Video

https://github.com/user-attachments/assets/d5dd39eb-8468-4f7e-8090-f56d46e560d6

🔮 System Architecture

The ecosystem utilizes a decentralized microservice architecture coordinated via Netflix Eureka for service discovery, and routed through a central Spring Cloud Gateway.

graph TD
    Client[📱 React Client - Port 5173] <--> |REST API / CORS| Gateway[🌐 API Gateway - Port 8080]
    Gateway <--> |Service Discovery| Eureka[🧭 Eureka Registry - Port 8761]

    Gateway --> |Route /auth/**| AuthService[🔐 Auth Service - Port 8081]
    Gateway --> |Route /wallet/**| WalletService[💼 Wallet Service - Port 8082]
    Gateway --> |Route /payment/**| PaymentService[💸 Payment Service - Port 8083]
    Gateway --> |Route /transactions/**| TxnService[📊 Transaction Service - Port 8084]
    Gateway --> |Route /merchant/**| MerchantService[🏪 Merchant Service - Port 8085]
    Gateway --> |Route /fraud/**| FraudService[🛡️ Fraud Service - Port 8086]
    Gateway --> |Route /ai/**| AiService[🤖 AI Service - Port 8087]
    Gateway --> |Route /sync/**| SyncService[🔄 Sync Service - Port 8088]
    Gateway --> |Route /bank-gateway/**| BankGatewayService[🏦 Bank Gateway - Port 8091]
    Gateway --> |Route /settlement/**| SettlementService[💰 Settlement Service - Port 8092]
    Gateway --> |Route /reconciliation/**| RecService[📊 Reconciliation - Port 8093]
    Gateway --> |Route /kyc/**| KycService[🆔 KYC Service - Port 8094]
    Gateway --> |Route /aml/**| AmlService[🕵️ AML Service - Port 8095]
    Gateway --> |Route /risk/**| RiskService[📊 Risk Service - Port 8096]

    AuthService <--> Redis1[(🔴 Redis - OTP & Attempt Cache)]
    AuthService <--> DB_Auth[(🐬 MySQL - Auth DB)]
    WalletService <--> DB_Wallet[(🐬 MySQL - Wallet DB)]
    PaymentService <--> DB_Payment[(🐬 MySQL - Payment DB)]
    TxnService <--> DB_Txn[(🐬 MySQL - Txn DB)]
    KycService <--> Redis2[(🔴 Redis - OTP Cache)]
    AmlService <--> Redis3[(🔴 Redis - Velocity Checks)]
    RiskService <--> Redis4[(🔴 Redis - Scoring Cache)]
    RiskService <--> DB_Risk[(🐬 MySQL - Risk DB)]

    NotificationService[✉️ Notification Service] <-- Async Alerts --> Gateway

🚀 Key Features

🔐 1. Bulletproof Authentication & OTP Pipeline

  • Dual Identifiers: Support for logging in/registering via Email or 10-digit Indian Mobile Numbers.
  • OTP Verification: Multi-factor authentication via secure, 6-digit OTP codes backed by Redis caching.
  • Brute-Force Rate Limiting: Limit of 3 OTP requests per 15 minutes per phone number to prevent spam and credential stuffing.
  • JWT Security & Refresh Rotation: Stateless access token validations with a robust JWT refresh token rotation mechanism.

💼 2. Interactive Wallet & Payments

  • Instantly Assigned UPI ID: Every user receives a standardized <phone>@upimesh handle upon successful sign-up.
  • Wallet-to-Wallet Money Transfers: Instant money transfers utilizing cryptographic transaction flows.
  • Merchant Ecosystem: Support for registering merchant profiles, scanning static/dynamic QR codes, and executing merchant payments.

🆔 3. Multi-Level KYC Verification (RBI Compliance)

  • Level 0 (Initiation): Phone + OTP verification (limit: ₹10,000/month).
  • Level 1 (Basic): PAN verification + Aadhaar OTP via UIDAI integration (limit: ₹1,00,000/month).
  • Level 2 (Full): Face Match (selfie vs document photo) to unlock unlimited transaction limits.
  • Cryptography: Sensitive document numbers (Aadhaar/PAN) are encrypted using secure AES-256-GCM keys.

🕵️ 4. Anti-Money Laundering & Fraud Screening (PMLA 2002)

  • Velocity Rules: Real-time counter checks using Redis to block users exceeding hourly/daily transaction frequencies.
  • Structuring Detection: Scans the last 24h transactions to detect splitting behaviors (e.g. sending multiple ₹9,999 transactions to avoid the ₹10,000 alert threshold).
  • Fuzzy Watchlist Screening: Performs Levenshtein name matching ($\ge$ 80% similarity) against OFAC, UN, and Politically Exposed Persons (PEPs) watchlists.

📊 5. ML-Based Real-Time Risk Scoring

  • Multiple Threat Signals: Evaluates device fingerprint (SHA-256), location anomalies (city checking), timing patterns, and transaction amounts (3x user average) in real-time.
  • Composite Score Calculation: Calculates a dynamic composite risk score (0.0 to 1.0) and blocks transactions exceeding 0.7 risk threshold.
  • Async User Profiling: Updates user risk history and profiles asynchronously (rolling averages, evicting old devices) to maintain sub-second transaction response times.

💰 6. End-of-Day Settlement & Reconciliation Reports

  • Automatic Settlements: Executes daily batch processes using Quartz Schedulers to group successful merchant transactions and initiate mock NEFT/RTGS/IMPS transfers.
  • RBI Audits & Recon Engine: Compares internal transaction logs against bank statements to generate reconciliation reports and flag discrepancies (amount mismatches, duplicate debits, missing entries) exported to Excel formats.

📂 Microservices Portfolio

Service Name Default Port Primary Technologies Core Responsibilities
Eureka 8761 Spring Cloud Netflix Eureka Dynamic service registration and discovery registry.
Gateway 8080 Spring Cloud Gateway, Redis, Resilience4j Central routing, CORS handling, rate limiting, circuit breaker.
Auth 8081 Spring Boot, Security, JWT, JPA, MySQL, Redis Registration, login, JWT issuance/rotation, Redis-backed OTPs.
Wallet 8082 Spring Boot, JPA, MySQL Wallet balance management, deposits, and withdrawal records.
Payment 8083 Spring Boot, JPA, MySQL Core transaction orchestration between wallets/UPI IDs.
Transaction 8084 Spring Boot, JPA, MySQL Immutable transaction logs and history tracking.
Merchant 8085 Spring Boot, JPA, MySQL Merchant onboarding and shop account processing.
Fraud 8086 Spring Boot Real-time transaction screening and compliance enforcement.
AiService 8087 Spring Boot, AI Models Natural Language processing for transaction analysis and tips.
Sync 8088 Spring Boot, Apache Kafka / RabbitMQ Distributed data synchronization across datastores.
Notification 8089 Spring Boot, SMTP / SMS Gateway Dispatching OTP SMS notifications and emails.
BankGateway 8091 Spring Boot, Feign, Resilience4j Strategy Pattern interface connecting with Indian banks (HDFC, SBI, ICICI, etc.).
Settlement 8092 Spring Boot, JPA, Quartz Scheduler Batch settlements for merchants grouped by account configurations.
Reconciliation 8093 Spring Boot, Apache POI, Quartz EOD audit checks matching system ledger values with bank statements.
KycService 8094 Spring Boot, WebFlux, Redis, AES-GCM UIDAI/NSDL identity validations and limit updates.
AmlService 8095 Spring Boot, Redis, MySQL, Levenshtein Money laundering checks: velocity limits, structuring, PEP watchlists.
RiskScoring 8096 Spring Boot, Redis, MySQL, Async Real-time ML-like risk evaluation: device fingerprinting, location, amount, time patterns.
Frontend 5173 Vite, React 18, Tailwind, Zustand, Axios Mobile-first premium user dashboard.

🛠️ Installation & Getting Started

📋 Prerequisites

Ensure you have the following installed on your machine:

  • Java Development Kit (JDK) 17 or higher
  • Node.js (v18+) & npm
  • MySQL Database Server
  • Redis Server (running locally on port 6379)

🏁 Step 1: Run the Backend Microservices

Run the core services in the following recommended order (ensure Eureka and Gateway are running first):

  1. Start Discovery Registry (Eureka): bash cd Eureka/Eureka ./mvnw spring-boot:run
  2. Start API Gateway: bash cd Gateway/Gateway ./mvnw spring-boot:run
  3. Start Authentication Service (Auth): bash cd Auth/Auth ./mvnw spring-boot:run
  4. Start the remaining business services (Wallet, Payment, KycService, AmlService, etc.) in their respective directories using: bash ./mvnw spring-boot:run

💻 Step 2: Run the React Frontend

  1. Navigate to the frontend directory: bash cd frontend
  2. Install the node packages: bash npm install
  3. Start the Vite development server: bash npm run dev
  4. Open the application in your browser at http://localhost:5173.

🍴 How to Fork & Contribute

We welcome enhancements to the UPI Mesh ecosystem! Follow these steps to fork and contribute:

  1. Fork the Repository: Click the Fork button at the top-right of the page to copy the project to your own account.
  2. Clone your Fork: bash git clone https://github.com/YOUR_USERNAME/UpiMesh.git cd UpiMesh
  3. Create a Feature Branch: bash git checkout -b feature/amazing-new-feature
  4. Commit your Changes: bash git commit -m "feat: Add amazing new feature"
  5. Push to your Fork: bash git push origin feature/amazing-new-feature
  6. Open a Pull Request: Submit your pull request to our main branch with a description of the improvements.

📝 License

Distributed under the MIT License. See LICENSE for more details.

Made with ❤️ by the UPI Mesh Development Team.

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