📸 ImageGram Backend API

A robust, scalable social media backend service designed to handle user authentication, post management, and secure media uploads.

🚀 Key Features

• Secure Media Storage: Direct integration with AWS S3 buckets for highly available and scalable image hosting.
• RESTful Architecture: Clean, modular API design following industry best practices for routing and controller logic.
• Database Management: Efficient data modeling and querying using MongoDB and Mongoose.
• Authentication: Secure user session management and password hashing (Custom auth flow, no third-party OAuth providers).
• Caching & Performance: Integration with Redis to optimize data retrieval and API response times.

🛠️ Tech Stack

• Runtime: Node.js
• Framework: Express.js
• Database: MongoDB
• Cloud Storage: AWS S3
• Caching: Redis

📡 Core API Endpoints

Here is a high-level overview of the primary RESTful routes:

Method	Endpoint	Description	Auth Required
POST	/api/users/register	Register a new user	No
POST	/api/users/login	Authenticate and start session	No
POST	/api/posts/upload	Upload image to AWS S3 & create post	Yes
GET	/api/posts/feed	Retrieve paginated user feed	Yes
DELETE	/api/posts/:id	Remove post and associated S3 media	Yes

🏗️ System Architecture & Database

Here is a high-level overview of how the backend services interact and the structure of our data.

Architecture

graph TD
    Client[📱 Client / Frontend] -->|API Request| API[🚀 Express API Server]
    
    subgraph "Backend Services (Node.js)"
    API -->|1. Auth Middleware| Auth[🔒 JWT Auth]
    Auth -->|2. Route Handler| API
    end
    
    subgraph "Data & Storage Layers"
    API <-->|Cache Lookup/Write| Redis[(🧠 Redis Cache)]
    API <-->|CRUD Operations| DB[(🍃 MongoDB Database)]
    API <-->|Image Upload/Delete| S3[(☁️ AWS S3 Bucket)]
    end

    classDef client fill:#f9f,stroke:#333,stroke-width:2px;
    classDef server fill:#bbf,stroke:#333,stroke-width:2px;
    classDef storage fill:#dfd,stroke:#333,stroke-width:1px,stroke-dasharray: 5 5;
    class Client client;
    class API server;
    class Auth,Redis,DB,S3 storage;

Loading

Database Schema (ERD)

erDiagram
    USER ||--o{ POST : creates
    
    USER {
        ObjectId _id PK
        string username
        string email
        string passwordHash
        date createdAt
    }
    
    POST {
        ObjectId _id PK
        ObjectId userId FK
        string s3ImageUrl
        string s3Key
        string caption
        date createdAt
    }

Loading

⚙️ Environment Variables

To run this project, you will need to add the following environment variables to your .env file:

PORT MONGO_URI AWS_ACCESS_KEY_ID AWS_SECRET_ACCESS_KEY AWS_REGION AWS_BUCKET_NAME REDIS_URL

💻 Local Setup

1. Clone the repository:

   git clone https://github.com/Hexacoder5678/ImageGram.git