Finance Guide – Smart Loan & Repayment Assistant

Finance Guide is an AI-powered mobile-first finance tracker that helps Clients (Borrowers) and Senders (Lenders) manage loans, track installments and get smart, personalized repayment suggestions using LangChain RAG + LLMs (GPT/Gemini).

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📸 Overview

• 📊 Track loan balance, dues, interest
• 💬 AI Chat Assistant for smart finance help
• 🔔 Installment reminders & penalty alerts
• 📱 Mobile-first with Expo + React Native
• 🔙 Scalable backend with Node & Express, MongoDB, Redis

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🧠 System Architecture

➤ High-Level Flow

flowchart TD
  User[User] -->|Mobile UI| Frontend[Frontend]
  Frontend -->|API| Backend[Backend]
  Backend -->|DB Access| DB[(MongoDB & Redis)]
  Backend -->|Query| LangChain[LangChain Engine]
  LangChain -->|Prompt| LLM["LLM (GPT/Gemini)"]
  LLM -->|Response| Backend --> Frontend

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➤ LangChain RAG Flow

User Query ➝ Embed ➝ Semantic Search ➝ Context + Query ➝ GPT ➝ Smart Suggestion

📊 Visual Architectures:

• System Diagram (Draw.io)

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🧑‍💼 User Roles

• Client (Borrower) – Adds loan, views repayments, receives suggestions
• Sender (Lender) – Reviews loan status, receives payments
• Admin – (optional) Platform monitoring and control

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🔧 Tech Stack

Layer	Stack
Mobile Frontend	Expo + React Native, Tailwind (NativeWind), Axios, Recharts
Backend	Node.js + Express.js
Database	MongoDB (relational), Redis (jobs/cache)
AI Layer	LangChain + GPT
Vector Store	ChromaDB / Pinecone
Notifications	node-cron + Twilio/SendGrid
DevOps	Docker, Vercel (frontend), Railway / Render (backend)

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📦 Folder Structure

/finace-guide
├── frontend        # Expo mobile app
├── backend         # Node API + AI engine
├── .env.example    # Secret Keys of project
├── .gitignore
└── CODE_OF_CONDUCT.md
├── CONTRIBUTING.md
└── README.md
├── SUPPORT.md
├── docker-compose.yml  # (Optional)

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📱 Frontend (Expo + React Native)

Features

• 🔐 Login / Register
• 📊 Dashboards (Sender/Client)
• ➕ Add Loan / Track Installments
• 💬 AI Chat Assistant
• 🔔 Notification Center

Tech Stack

• React Native + Expo
• Tailwind CSS (NativeWind)
• Axios for API integration
• File-based Routing via expo-router
• Charts via Victory/Recharts

Run Locally

cd frontend
npm install
npx expo start

• Run on Android/iOS simulator or Expo Go
• Uses .env for base API URL and keys

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🧠 Backend (API + AI + DB)

Core Models

• User: Auth, roles
• Loan: Principal, interest, sender, client
• Installment: Amount, due date, paid status
• Reminder: Notification logs and flags

Key APIs

Method	Endpoint	Description

Backend Setup

cd backend

npm install
npm run dev

✅ Add environment variables in .env ✅ Set up MongoDB & Redis (Docker or local)

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🤖 AI + LangChain Integration

• User uploads PDF or provides context
• LangChain splits, embeds, and stores docs
• Queries are embedded and searched via ChromaDB or Pinecone
• Contextual prompts sent to GPT
• Result returned to frontend via /suggestions/ endpoint

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🔔 Notifications & Reminders

Engine powered by:

• Node + node-cron
• Redis for job queueing
• SendGrid (Email) or Twilio (SMS)

Triggers:

• Due date approaching
• Missed/partial payments
• Full repayment alerts

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🐳 Dockerized Setup (Optional)

docker-compose up --build

• Services: web, db, redis, frontend
• Configure using .env and Docker volumes

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📊 UI/UX Screens (Planned in Figma)

• 📥 Login/Register
• 📋 Add Loan / Installments
• 📈 Repayment Timeline (chart)
• 🤖 AI Chat Assistant
• 🔔 Notification Center

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🛡️ Security

• All auth via JWT
• Sensitive data managed using .env + Docker Secrets
• CORS policies enabled

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📈 Future Enhancements

• Admin Panel
• Offline Mode / Caching
• PDF Upload with Summarized Insights
• Multi-language Support (i18n)

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Thank You!!