Build Your Own Currency Converter API

The "Currency Converter" project involves developing a simple, user-friendly API that allows users to convert one currency into another using real-time exchange rates. The API will support conversion for a wide range of currencies and provide users with historical conversion data. Users can create accounts, save their favorite currency pairs, and track the latest exchange rates. This API will be available via a web interface and mobile application, offering a seamless experience for quick and accurate currency conversion.

Detailed Description

Currency conversion is essential for international travel, commerce, and business operations. This project aims to create a currency converter that offers real-time and accurate exchange rate information. The API will allow users to convert currencies easily, view historical rates, and even track their favorite currency pairs. Here’s a detailed look at how users will interact with the app:

1. User Registration and Preferences:

   • Sign Up: Users can create accounts by providing a username, email, and password. Registered users can save currency pairs for future reference and set their preferred base currency.

   • Login: Users can log in to access their saved currency pairs, conversion history, and profile settings.

   • Currency Preferences: Users can set preferred currencies for quicker conversions.

2. Real-Time Currency Conversion:

   • Convert Currencies: Users can input an amount and select the currencies they want to convert from and to. The system will display the equivalent amount based on the real-time exchange rate.

   • Reverse Conversion: Users can quickly switch between the "from" and "to" currencies for reverse conversions.

3. Historical Data:

   • Historical Exchange Rates: Users can view historical exchange rate data for selected currencies over a specified date range (e.g., last week, last month, last year).

   • Graphical Representation: Users can view exchange rate trends in a graphical format, allowing them to see how currency values have changed over time.

4. Favorite Currency Pairs:

   • Save Favorite Pairs: Users can save frequently used currency pairs for easy access.

   • View Saved Pairs: Users can access and convert their saved pairs quickly without re-entering currency details.

5. Notifications and Alerts:

   • Rate Alerts: Users can set custom alerts for when a currency pair reaches a certain exchange rate. The app will notify the user via push notifications, email, or SMS.

   • Daily Exchange Rate Updates: Users can opt-in to receive daily updates on exchange rates for their favorite currency pairs.

Real-World Example

Imagine Sam, a frequent traveler who often moves between Europe and the United States. Sam signs up for an account on the currency converter app and sets USD and EUR as his favorite currency pair. Before his trip, he checks the real-time conversion rate between USD and EUR, converts $1,000 into EUR, and saves the rate.

While traveling, Sam monitors the exchange rate daily through notifications. The app also provides him with historical data showing how the exchange rate has fluctuated over the past few weeks, helping him decide when to make further currency exchanges.

Table of Contents

1. Introduction

2. Objectives

3. Functional Requirements

4. Non-Functional Requirements

5. Use Cases

6. User Stories

7. Technical Requirements

8. API Endpoints

9. Security

10. Performance

11. Documentation

12. Glossary

13. Appendix

1. Introduction

The "Currency Converter" project aims to develop a web and mobile application that allows users to convert currencies using real-time exchange rates. Users will be able to track historical rates, save favorite currency pairs, and set notifications for specific rate changes.

2. Objectives

• Allow users to create accounts, save currency pairs, and set notifications.

• Provide accurate real-time exchange rates for a wide range of currencies.

• Enable users to track historical exchange rate data.

• Support users in setting rate alerts and receiving updates via notifications.

3. Functional Requirements

User Management

• Sign Up: Users can create an account to save preferences and currency pairs.

• Login: Users can log in to access saved currency pairs and historical data.

• Profile Management: Users can set their preferred base currency and notification settings.

Currency Conversion

• Convert Currencies: Users can input an amount and convert it from one currency to another using real-time exchange rates.

• Reverse Conversion: Users can quickly reverse the conversion currencies.

Historical Data

• View Historical Rates: Users can view exchange rate history for specific currency pairs over a selected period.

• Graphical Trends: Display historical data in graphical formats for easy analysis.

Favorite Currency Pairs

• Save Favorite Pairs: Users can save frequently used currency pairs.

• View Saved Pairs: Quickly access saved pairs for conversion.

Notifications and Alerts

• Rate Alerts: Users can set alerts for specific rate changes and receive notifications.

• Daily Updates: Users can opt-in to receive daily updates on exchange rates.

4. Non-Functional Requirements

• Scalability: The app should handle a growing number of users and real-time data requests.

• Performance: The app should have low latency for real-time exchange rate retrieval.

• Security: Implement authentication and encryption for user data.

• Reliability: The app should be highly available with minimal downtime.

• Usability: The interface should be simple, clean, and intuitive, optimized for both desktop and mobile devices.

5. Use Cases

• User Sign Up and Login: New users sign up, and existing users log in.

• Real-Time Currency Conversion: Users convert amounts between currencies using real-time rates.

• View Historical Data: Users check historical exchange rates and trends.

• Save Favorite Currency Pairs: Users save and view their favorite currency pairs for quick access.

• Set Rate Alerts: Users receive notifications when a currency pair reaches a specified rate.

6. User Stories

1. As a user, I want to sign up for an account so that I can save my favorite currency pairs.

2. As a user, I want to convert one currency to another using real-time exchange rates.

3. As a user, I want to reverse the currency pair for quick conversion.

4. As a user, I want to see historical exchange rate trends to analyze the performance of currencies over time.

5. As a user, I want to save my most frequently used currency pairs for fast access.

6. As a user, I want to receive alerts when a currency reaches a specific rate.

7. As a user, I want to receive daily updates on exchange rates to stay informed.

7. Technical Requirements

• Programming Language: Choose an appropriate backend language (e.g., Node.js, Python).

• Database: Use a database to store user data, saved currency pairs, and historical conversion data (e.g., PostgreSQL, MongoDB).

• Currency Data Source: Integrate with a reliable currency exchange rate provider (e.g., Open Exchange Rates, Fixer.io).

• Real-Time Communication: Use WebSockets or similar technologies for real-time currency updates.

• API Documentation: Use Swagger or similar tools for API documentation.

8. API Endpoints

User Management

• POST /signup: Register a new user.

• POST /login: Authenticate a user.

• GET /profile: Get user profile details.

• PUT /profile: Update user profile and preferences.

Currency Conversion

• GET /convert: Convert an amount from one currency to another using real-time rates.

• GET /reverse: Reverse the currency pair for a new conversion.

Historical Data

• GET /historical: Get historical exchange rate data for a specified date range.

Favorite Currency Pairs

• POST /favorites: Save a favorite currency pair.

• GET /favorites: Retrieve saved currency pairs.

Notifications and Alerts

• POST /alerts: Set a rate alert for a currency pair.

• GET /alerts: Retrieve active rate alerts.

9. Security

• Use HTTPS for data encryption during transfer.

• Implement secure password storage using hashing algorithms such as bcrypt.

• Implement two-factor authentication (2FA) for added security.

10. Performance

• Implement caching strategies for real-time exchange rates to improve response times.

• Use load balancing to handle high traffic and API requests efficiently.

11. Documentation

• Provide comprehensive API documentation using tools like Swagger.

• Create a user manual explaining how to perform currency conversions, save pairs, and set rate alerts.

12. Glossary

• API: Application Programming Interface.

• 2FA: Two-Factor Authentication.

• Exchange Rate: The value of one currency for the purpose of conversion to another.

13. Appendix

• Include relevant diagrams or flowcharts to describe data flow and app architecture.

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