Digital_Banking

💳 Digital Banking API (.NET 6)

A simple banking API built with ASP.NET Core 6 and Entity Framework Core. It supports operations like deposits, withdrawals, transfers, balance history tracking, daily transaction limits, and transaction fee calculations.

---

🚀 How to Run the API

✅ Prerequisites

• .NET 6 SDK
• SQL Server or SQL Server Express
• Postman or curl for testing

💠 Setup Steps

1. Clone the repository

   git clone https://github.com/your-repo/digital-banking-api.git
   cd digital-banking-api

2. Configure the Database Connection Edit appsettings.json:

   "ConnectionStrings": {
     "DefaultConnection": "Server=localhost;Database=BankingDb;Trusted_Connection=True;"
   }

3. Apply EF Core Migrations

   dotnet ef migrations add InitialCreate
   dotnet ef database update

4. Run the API

   dotnet run

5. Visit Swagger UI at:

   https://localhost:7044/swagger
   

---

🖁 Sample API Calls

👤 Customer Endpoints

➕ Create Customer

curl -X POST https://localhost:7044/api/Customers \
  -H "Content-Type: application/json" \
  -d '{"firstName":"Juan","lastName":"Dela Cruz","email":"juan@example.com","phone":"09123456789"}'

📋 Get All Customers

curl https://localhost:7044/api/Customers

📄 Get Customer by ID

curl https://localhost:7044/api/Customers/1

💼 Account Endpoints

➕ Create Account

curl -X POST https://localhost:7044/api/Accounts \
  -H "Content-Type: application/json" \
  -d '{"customerId":1,"accountType":"Savings"}'

📋 Get All Accounts

curl https://localhost:7044/api/Accounts

📄 Get Account by ID

curl https://localhost:7044/api/Accounts/1

✅ Update Account Status

curl -X PUT https://localhost:7044/api/Accounts/status \
  -H "Content-Type: application/json" \
  -d '{"accountNumber":"10000001", "isActive": false}'

💳 Transaction Endpoints

📅 Deposit

curl -X POST https://localhost:7044/api/Transactions/deposit \
  -H "Content-Type: application/json" \
  -d '{"accountNumber":"10000001","amount":1000,"description":"Initial deposit"}'

📄 Withdraw

curl -X POST https://localhost:7044/api/Transactions/withdraw \
  -H "Content-Type: application/json" \
  -d '{"accountNumber":"10000001","amount":500,"description":"ATM withdraw"}'

🔄 Transfer

curl -X POST https://localhost:7044/api/Transactions/transfer \
  -H "Content-Type: application/json" \
  -d '{"fromAccount":"10000001","toAccount":"10000002","amount":200,"description":"Send money"}'

📜 Transaction History

curl https://localhost:7044/api/Transactions/history/10000001

🔍 Search Transactions (by amount or description)

curl "https://localhost:7044/api/Transactions/search?accountNumber=10000001&amount=500"
curl "https://localhost:7044/api/Transactions/search?accountNumber=10000001&description=deposit"

📈 Balance History Endpoints

📊 Get Balance History

curl https://localhost:7044/api/Transactions/balance-history/10000001

📤 Export Balance History (CSV / PDF)

curl https://localhost:7044/api/Transactions/balance-history/export/10000001?format=csv
curl https://localhost:7044/api/Transactions/balance-history/export/10000001?format=pdf

---

📃 Database Schema Overview

🧝 Customer

Field	Type
Id	int (PK)
FirstName	string
LastName	string
Email	string
Phone	string
CreatedDate	datetime

💼 Account

Field	Type
Id	int (PK)
AccountNumber	string (unique)
CustomerId	int (FK)
AccountType	string
Balance	decimal(18,2)
DailyLimit	decimal(18,2)
IsActive	bool
CreatedDate	datetime

💸 Transaction

Field	Type
Id	int (PK)
FromAccountId	int (FK)
ToAccountId	int? (FK)
Amount	decimal(18,2)
TransactionType	string
Description	string
Timestamp	datetime
Status	string

📈 BalanceHistory

Field	Type
Id	int (PK)
AccountId	int (FK)
Balance	decimal(18,2)
Timestamp	datetime
TransactionId	int? (FK)

---

📌 Business Assumptions

1. Daily Transaction Limit

   • Each account has a DailyLimit to restrict total outgoing transactions per day.
   • Transactions exceeding this amount return a 400 error.

2. Transaction Fees

   • A flat or tiered transaction fee is applied (e.g., transfer fees).

3. Balance History Tracking

   • Balance snapshots are recorded after every transaction and can be exported.

4. Inactive Accounts

   • Accounts marked as IsActive = false are blocked from transactions.

5. Unique Account Numbers

   • AccountNumber field is unique and indexed.

6. Currency

   • All currency is represented in Philippine Peso (₱) using decimal(18,2) format.

---

⚠️ Error Response Samples

🚫 400 Bad Request – Daily Transaction Limit Exceeded

{
  "message": "Daily transaction limit exceeded. You can still transact ₱2000.00 today."
}

🔒 403 Forbidden – Inactive Account

{
  "message": "Account 10000001 is inactive and cannot perform transactions."
}

🧾 404 Not Found – Account Not Found

{
  "message": "Account with ID 99999 not found."
}

📉 400 Bad Request – Insufficient Balance

{
  "message": "Insufficient balance to complete the transaction."
}

📄 500 Internal Server Error – Unexpected Exception

{
  "message": "An unexpected error occurred. Please contact support."
}

---

📂 Postman Collection

You can import the DigitalBankingAPI.postman_collection.json file into Postman for easy testing.

---

✅ License

This project is open-source and free to use for educational or non-commercial projects.