Expense Tracker API

Problem Statement

The Expense Tracker API is designed to help users manage their personal expenses efficiently. It allows users to perform CRUD operations on their financial data, enabling them to:

1. Track Transactions: Record income and expenses with details such as amount, date, and associated category.
2. Organize by Categories: Classify transactions into predefined or custom categories like "Groceries," "Rent," or "Utilities."
3. User Management: Securely manage user accounts, ensuring each user's financial data is private and protected.

Key Features

• RESTful API with proper request validation and error handling.
• Secure data handling with UUIDs and timestamps for tracking entity creation and updates.
• Scalable architecture using Spring Boot, allowing further enhancements like analytics or reporting in the future.

This API serves as a foundational service for building financial management applications or integrating with larger systems.

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User Endpoints

1. Register User

   • POST /api/users/register
   • Request Body: { "name": "John Doe", "email": "[email protected]", "password": "securepassword" }
   • Response: User details (without password).

2. Login User

   • POST /api/users/login
   • Request Body: { "email": "[email protected]", "password": "securepassword" }
   • Response: Authentication token (JWT).

3. Get User Profile

   • GET /api/users/profile
   • Headers: Authorization: Bearer <token>
   • Response: User profile details.

4. Update User Profile

   • PUT /api/users/profile
   • Headers: Authorization: Bearer <token>
   • Request Body: { "name": "John Updated", "email": "[email protected]" }
   • Response: Updated user profile.

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Transaction Endpoints

1. Create a Transaction

   • POST /api/transactions

   • Headers: Authorization: Bearer <token>

   • Request Body:

     json

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     { "type": "Expense", "categoryId": 1, "amount": 150.0, "date": "2024-11-30", "description": "Groceries" }

   • Response: Created transaction.

2. Get All Transactions

   • GET /api/transactions
   • Headers: Authorization: Bearer <token>
   • Query Parameters (optional):
     • type=Expense
     • categoryId=1
     • startDate=2024-11-01&endDate=2024-11-30
   • Response: List of transactions.

3. Get a Single Transaction

   • GET /api/transactions/{id}
   • Headers: Authorization: Bearer <token>
   • Response: Transaction details.

4. Update a Transaction

   • PUT /api/transactions/{id}

   • Headers: Authorization: Bearer <token>

   • Request Body:

     json

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     { "type": "Expense", "categoryId": 1, "amount": 200.0, "date": "2024-11-30", "description": "Updated groceries" }

   • Response: Updated transaction.

5. Delete a Transaction

   • DELETE /api/transactions/{id}
   • Headers: Authorization: Bearer <token>
   • Response: Success message.

6. Get Monthly Summary

   • GET /api/transactions/summary
   • Headers: Authorization: Bearer <token>
   • Query Parameters: month=2024-11
   • Response: { "totalIncome": 5000.0, "totalExpenses": 3000.0, "balance": 2000.0 }

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Category Endpoints

1. Create a Category

   • POST /api/categories
   • Headers: Authorization: Bearer <token>
   • Request Body: { "name": "Food", "description": "Expenses for food and dining" }
   • Response: Created category.

2. Get All Categories

   • GET /api/categories
   • Headers: Authorization: Bearer <token>
   • Response: List of categories.

3. Update a Category

   • PUT /api/categories/{id}
   • Headers: Authorization: Bearer <token>
   • Request Body: { "name": "Groceries", "description": "Updated description" }
   • Response: Updated category.

4. Delete a Category

   • DELETE /api/categories/{id}
   • Headers: Authorization: Bearer <token>
   • Response: Success message.

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Optional Advanced Endpoints

1. Export Transactions

   • GET /api/transactions/export
   • Headers: Authorization: Bearer <token>
   • Query Parameters: Same as "Get All Transactions".
   • Response: CSV file of transactions.

2. Search Transactions

   • GET /api/transactions/search
   • Headers: Authorization: Bearer <token>
   • Query Parameters: query=groceries
   • Response: List of matching transactions.