🌾 VILAI — விலை | Farmer Market Price Intelligence

Empowering Indian Farmers with AI-Powered Price Intelligence
Built with Flutter • Groq AI • Real Government Data

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📌 Problem

In India, 60 crore farmers face a critical challenge:

A farmer sells tomatoes for ₹20/kg → Middlemen sell to restaurants at ₹60/kg → Farmer loses ₹40 profit per kg

Farmers also lack access to:

• Real-time market prices
• Price trend predictions
• Direct buyer connections
• Government scheme information

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💡 Solution — VILAI (விலை = Price)

VILAI is a mobile-first farmer intelligence app that gives farmers:

• ✅ Real mandi prices from Government API
• ✅ ML-powered price predictions (Linear Regression + Groq AI)
• ✅ Direct buyer marketplace — no middleman
• ✅ Tamil voice AI chatbot — speak and get answers
• ✅ Weather-based farming advice
• ✅ Government schemes & loan guidance
• ✅ Multi-language support (Tamil, English, Hindi, Telugu, Kannada)

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📱 Screenshots

Home Screen	Price Prediction	AI Chatbot
Weather + Features	ML Line Chart	Voice Input

Markets	Government Schemes	Loans
Live Prices	12 Schemes	8 Loan Options

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🚀 Features

1. 📈 AI Price Prediction

• Fetches real historical prices from data.gov.in
• Runs Linear Regression (y = mx + b) on real data
• Calculates R² accuracy score
• Groq LLaMA 3.3 70B validates and gives Tamil advice
• Shows: "When to sell for maximum profit?" in selected language

2. 🤖 Tamil Voice AI Chatbot

• Powered by Groq LLaMA 3.3 70B (fastest AI)
• Speech-to-Text input in Tamil (speech_to_text)
• Text-to-Speech output in Tamil (flutter_tts)
• Answers about crop prices, farming tips, market rates

3. 🏪 Live Market Prices

• Real mandi prices from Government of India API (data.gov.in)
• Weather per market from OpenWeatherMap API
• Transport profit calculator — "Which market gives best profit after transport cost?"
• Best market recommendation

4. 🤝 Direct Farmer-Buyer Marketplace

• Farmers post crop listings (crop, quantity, price, grade, location)
• Buyers browse and call/WhatsApp directly
• Zero middleman — 100% profit to farmer

5. 🌦️ Weather-Based Advice

• Real weather from farmer's registered location
• Farming advice: "Safe to go to market?" / "Rain warning!"
• Beautiful blue gradient weather card

6. 🏛️ Government Schemes

• 12 government schemes (Central + Tamil Nadu State)
• PM-KISAN, Crop Insurance, KCC, Solar Pump, Uzhavar Sandhai
• Complete guide: eligibility, documents, how to apply

7. 🏦 Farmer Loan Schemes

• 8 loan options with lowest interest rates
• KCC (4%), Gold Loan (4%), NABARD, SBI, Indian Bank, Canara
• Step-by-step application guide

8. 🌐 Multi-Language Support

• 5 languages: Tamil, English, Hindi, Telugu, Kannada
• Instant switch — entire app changes language in real-time
• No app restart required

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🛠️ Tech Stack

Layer	Technology
Mobile Framework	Flutter 3.24 / Dart 3.0
AI Model	Groq LLaMA 3.3 70B Versatile
Market Data API	data.gov.in (Government of India)
Weather API	OpenWeatherMap
Location	ip-api.com (free, no permissions)
Speech Input	speech_to_text ^6.6.0
Voice Output	flutter_tts ^3.8.5
Charts	fl_chart ^0.65.0
Notifications	flutter_local_notifications ^17.0.0
ML Algorithm	Linear Regression (custom Dart implementation)
State Management	ChangeNotifier + ListenableBuilder

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🧠 ML Algorithm

Price prediction uses a custom Linear Regression implementation in Dart:

// Formula: y = mx + b
slope     = (n·ΣXY - ΣX·ΣY) / (n·ΣX² - (ΣX)²)
intercept = (ΣY - slope·ΣX) / n

// R² accuracy score
R² = 1 - (SS_residual / SS_total)

// Prediction
price(day) = slope × (n - 1 + day) + intercept
           clamped to ±20% of last real price

Data Pipeline:

data.gov.in API → Real Tamil Nadu mandi prices
      ↓
Linear Regression → Trend direction + R² score
      ↓
Groq LLaMA 3.3 → Validate + Tamil advice
      ↓
fl_chart LineChart → Historical + Regression + Predicted lines

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📦 Installation

Prerequisites

• Flutter SDK 3.24+
• Android Studio / VS Code
• Android device or emulator (API 21+)

Setup

# 1. Clone the repository
git clone https://github.com/YOUR_USERNAME/vilai-app.git
cd vilai-app/nilai_app

# 2. Install dependencies
flutter pub get

# 3. Add your API keys in lib/constants.dart
# (See API Keys section below)

# 4. Run the app
flutter run

API Keys

Create or update lib/constants.dart:

const String kGroqApiKey    = 'YOUR_GROQ_API_KEY';
const String kGovApiKey     = 'YOUR_DATA_GOV_IN_API_KEY';
const String kWeatherApiKey = 'YOUR_OPENWEATHERMAP_API_KEY';

Get API Keys (all free):

API	URL	Free Tier
Groq AI	https://console.groq.com	Free — fastest LLM
data.gov.in	https://data.gov.in/user/register	Free government data
OpenWeatherMap	https://openweathermap.org/api	60 calls/minute free

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📁 Project Structure

nilai_app/
├── assets/
│   ├── app_logo.png
│   ├── farmer_hero.png
│   └── register.png
├── android/
│   └── app/src/main/AndroidManifest.xml
├── lib/
│   ├── main.dart                    # App entry, navigation shells
│   ├── constants.dart               # API keys, colors, crop data
│   ├── models/
│   │   ├── chat_message.dart
│   │   └── market_data.dart
│   ├── services/
│   │   ├── auth_service.dart        # Login/Register (in-memory)
│   │   ├── groq_service.dart        # Groq AI API
│   │   ├── weather_service.dart     # OpenWeatherMap
│   │   ├── market_service.dart      # data.gov.in
│   │   ├── notification_service.dart
│   │   └── language_service.dart   # Multi-language translations
│   ├── screens/
│   │   ├── splash_screen.dart
│   │   ├── auth_screen.dart         # Login / Register
│   │   ├── home_screen.dart         # Dashboard + Weather
│   │   ├── prediction_screen.dart   # ML Price Prediction
│   │   ├── chat_screen.dart         # Voice AI Chatbot
│   │   ├── markets_screen.dart      # Live Market Prices
│   │   ├── schemes_screen.dart      # Government Schemes
│   │   ├── loan_screen.dart         # Farmer Loans
│   │   ├── farmer_listing_screen.dart
│   │   ├── buyer_screen.dart
│   │   ├── profile_screen.dart
│   │   └── language_screen.dart    # Language Selector
│   └── widgets/
│       └── bouncing_dots.dart
└── pubspec.yaml

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🏆 Hackathon Build

Built for hackathon to solve real farmer problems in Tamil Nadu, India.

Key Innovations:

1. Real data only — no fake/simulated prices, ever
2. Tamil voice AI — farmers speak, AI answers in Tamil
3. Transport profit calculator — unique feature no other app has
4. ML + AI hybrid — Linear Regression on real data, validated by LLaMA 3.3
5. Zero middleman — direct farmer-to-buyer connection
6. 5-language support — instant switch, no restart

Pitch Summary:

"VILAI gives farmers the right price, right time, and right buyer — using real government data and Tamil AI — so they keep 100% of their profit."

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🔐 Android Permissions

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.RECORD_AUDIO"/>
<uses-permission android:name="android.permission.CALL_PHONE"/>
<uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>

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🌱 Future Roadmap

• Firebase Authentication (persistent login)
• Push notifications for price alerts
• More crops (Banana, Coconut, Sugarcane)
• More languages (Malayalam, Marathi, Bengali)
• Offline mode with cached prices
• FPO (Farmer Producer Organization) features
• Integration with PM-KISAN portal

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🤝 Contributing

Pull requests are welcome! For major changes, please open an issue first.

git checkout -b feature/your-feature
git commit -m "Add your feature"
git push origin feature/your-feature

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📄 License

MIT License — feel free to use and modify for farmer welfare projects.

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👨‍💻 Built With ❤️ for Indian Farmers

"உழைக்கும் கைகளுக்கு சரியான விலை" "The right price for hardworking hands"

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Team members

• Kanishka
• Saranya
• Gopika

Made with Flutter 🐦 • Powered by Groq AI ⚡ • Data from Government of India 🇮🇳