Build a Real-Time Currency Converter

Building a currency converter is a classic project for developers. It's a practical way to learn the fundamentals of working with a third-party API: making an HTTP request, parsing a JSON response, and dynamically updating the UI.

This tutorial will walk you through building a clean, functional currency converter web application from scratch. We will use HTML, CSS, and vanilla JavaScript to call a REST API, fetch a live exchange rate, and perform the conversion instantly. We'll be using the Currency Exchange API for its simple endpoint and straightforward JSON response.

Step 1: Get Your API Key

Before you can make a request, you need an API key to authenticate.

1. Sign up for a free account at hub.juheapi.com.
2. Navigate to your dashboard to find your API keys.
3. Generate a new key for this project and copy it.

Step 2: Understanding the API Request and Response

The API is designed for simplicity.

• The Request: You'll make a GET request with a few key query parameters:

  • key: Your API key.
  • from: The currency you are converting from (e.g., USD).
  • to: The currency you are converting to (e.g., EUR).
  • value: The amount of the base currency to convert.

• The JSON Response: A successful call returns a JSON object. The most important parts are result (the converted amount) and info.rate. For this guide, we'll focus on the primary result. A successful response might look like this:

  {
      "reason": "Success",
      "result": {
          "c_amount": "100",
          "c_from": "USD",
          "c_to": "EUR",
          "camount": "92.54" // The converted amount
      },
      "error_code": 0
  }
  

Step 3: Building the Application

Conclusion & Next Steps

Ready to expand? Dive into the full API Documentation to see the complete list of supported currencies or explore other powerful Fintech APIs on hub.juheapi.com.