How to Integrate Any Open Third-Party API into WordPress Without a Plugin

Why Use functions.php Instead of a Plugin?

By adding custom code to your functions.php file, you can integrate external open third-party APIs without relying on third-party plugins. This ensures better control over your site’s performance and security.

Step 1: Obtain the API Key and Endpoint

To integrate an API, you need:

The API endpoint (URL) from the provider.
Your API key (if required).
The parameters needed for the API request (check API documentation).

For example, let’s use OpenWeatherMap API to get weather data.

Step 2: Add the Code to functions.php

Open your WordPress theme’s functions.php file (use child theme for best practice) and add the following code:

function get_weather_data() {
    $api_key = 'YOUR_API_KEY_HERE'; // Replace with your OpenWeatherMap API key
    $city = 'Stockholm'; // Change city as needed
    $url = "https://api.openweathermap.org/data/2.5/weather?q={$city}&appid={$api_key}&units=metric";

    $response = wp_remote_get($url);
    
    if (is_wp_error($response)) {
        return 'Error fetching weather data.';
    }

    $body = wp_remote_retrieve_body($response);
    $data = json_decode($body, true);
    
    if (!$data || empty($data['main'])) {
        return 'No weather data available.';
    }

    $temperature = $data['main']['temp'];
    $humidity = $data['main']['humidity'];
    $condition = $data['weather'][0]['description'];

    return "Stockholm Weather: Temperature: {$temperature}°C, Humidity: {$humidity}%, Condition: {$condition}";
}

function display_weather_shortcode() {
    return get_weather_data();
}
add_shortcode('weather_data', 'display_weather_shortcode');

Step 3: Use the Shortcode to Display Data

Now, go to Pages → Add New and insert this shortcode:

[weather_data]

Publish the page and check the weather data displayed on your site!

Adding Exchange Rate API Integration

Another useful API integration is fetching exchange rates. Let’s integrate the ExchangeRate-API to get the conversion rate from USD to EUR.

Step 1: Get API Key

Step 2: Add the Following Code to Your functions.php

function get_exchange_rate() {
    $api_key = 'YOUR_API_KEY_HERE'; // Replace with your ExchangeRate-API key
    $url = "https://v6.exchangerate-api.com/v6/{$api_key}/latest/USD";

    $response = wp_remote_get($url);
    
    if (is_wp_error($response)) {
        return 'Error fetching exchange rate data.';
    }

    $body = wp_remote_retrieve_body($response);
    $data = json_decode($body, true);
    
    if (!$data || empty($data['conversion_rates']['EUR'])) {
        return 'No exchange rate data available.';
    }

    $rate = $data['conversion_rates']['EUR'];
    return "Exchange Rate (USD to EUR): 1 USD = {$rate} EUR";
}

function display_exchange_rate_shortcode() {
    return get_exchange_rate();
}
add_shortcode('exchange_rate', 'display_exchange_rate_shortcode');

Step 3: Use the Shortcode to Display Exchange Rate

Place this shortcode anywhere on your WordPress site:

[exchange_rate]

Now, the latest exchange rate for USD to EUR will be displayed dynamically.

Adapting This Method for Any API

If you want to use a different API:

Replace the API endpoint URL.
Update the parameters in the URL.
Modify the response parsing (extract needed data fields).
You can save this custom code as a snippet using any snippet plugin if you’re not familiar with the functions.php file.
Use a child theme and give this code there for best practice

Conclusion

By following these steps, you can easily integrate any third-party API into your WordPress site without using a plugin. Whether you need live weather data or real-time exchange rates, this approach helps display dynamic data efficiently. Try it out and enhance your WordPress site with useful real-time information!

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