Leo - WhatsApp Chatbot Backend 🤖

Leo is a smart, command-based WhatsApp-style chatbot backend built using Java, Spring Boot, and Firebase Firestore. It’s designed to demonstrate clean architecture, real-time data logging, and human-friendly bot interactions. Ideal for learning backend development, showcasing skills in interviews, or using as a base for advanced chatbot systems.

---

🚀 Features

• ✅ REST API endpoint to receive and respond to messages
• ✅ Command-based smart reply system (like /hi, /help, /about, /time)
• ✅ Stores all messages securely in Firebase Firestore
• ✅ Professional and human-style responses
• ✅ Modular structure: Controller → Service → DTO
• ✅ Deployment-ready (tested on Render.com)

---

🧠 Available Commands

Command	Description
/hi or hi	Greet the user and show available commands
/help or help	List all commands and what they do
/about or about	Information about the bot (Leo)
/time or time	Current server time (human-friendly)

---

📂 Project Structure

src/
 └── main/
     └── java/
         └── com.leo.whatsappbot/
              ├── controller/
              │    └── WebhookController.java
              ├── dto/
              │    └── MessageDTO.java
              ├── service/
              │    └── MessageService.java
              └── config/
                   └── FirebaseConfig.java
     └── resources/
         └── application.properties
         └── firebase-service-account.json (local only)

🛠️ Tech Stack

• Java 17
• Spring Boot 3.x
• Firebase Admin SDK
• Render Deployment
• Postman for testing
• GitHub for Version Control

---

📥 API Usage

POST /webhook

Send a message to this endpoint using Postman or any client:

Sample Request:

{
  "from": "918888888888",
  "message": "hi"
}

Sample Response:

Hey there! 👋 How can I assist you today?

---

🔐 Firebase Setup (for local run)

1. Create a Firebase project in Firebase Console
2. Go to Project Settings > Service Accounts
3. Generate a private key (JSON)
4. Rename the file to:
   firebase-service-account.json
5. Place it inside:
   src/main/resources/

---

🌐 Live Deployment (Render)

🔗 Live URL https://whatsapp-chatbot-b8pf.onrender.com/webhook

📦 GitHub Repository https://github.com/Sidhant2104/whatsapp-chatbot-backend.git

🚀 Render Deployment Instructions

Build Command:        ./mvnw clean install
Start Command:        java -jar target/*.jar
Environment Variable: FIREBASE_CONFIG = <your_base64_encoded_firebase_service_account.json>

✅ Status: Live and tested  
🧪 Tested Via: Postman (POST /webhook)  
📨 Response: Verified replies to commands like /hi, /help, etc.

---

⚠️ Meta API Info

Tried setting up WhatsApp Business Cloud API but account got disabled during Meta business review stage. Backend system remains functional & ready to integrate once account is restored.

---

✨ Developed By

Sidhant Singh (Leo)
Aspiring Backend Developer | Java | Spring Boot
📍 Ranchi, Jharkhand
🌐 GitHub Profile
🔗 LinkedIn