How to use the resource below? – Watch the video below to learn how to use the resources below to get the best results in your work.

These are the code snippets used in our Mini-Course: WordPress Custom API Endpoints: Build, Innovate, and Secure!

• Custom API Prefix: Learn how to change the default wp-json prefix to custom-api To personalize your site’s API URL structure.
• Dummy Endpoint: We start with a simple endpoint that returns a static message, serving as a gentle introduction to WordPress API development.
• Parameter Handling: Explore how to enhance your API’s functionality by accepting parameters and delivering tailored responses.
• Integration with OpenAI: The course features an advanced example where you will create a functional API endpoint that interacts with OpenAI’s API to generate blog titles based on user input. This endpoint handles user authentication, constructs HTTP requests, and processes AI-generated content.

If you don’t have Python installed here is step by step guide. So Python and Visual studio code is required for this project.

add_filter('rest_url_prefix', 'custom_rest_url_prefix');
function custom_rest_url_prefix() {
    return 'custom-api'; // Change this to your desired prefix
}


function return_dummy_text() {
    return 'This is a custom WordPress API Endpoint'; 
}
function generate_dummy_response( WP_REST_Request $request ) {
    
    $parm1 = $request->get_param('parm1');
    
    // Dummy static response
    $dummy_response = array(
        'success' => true,
        'message' => 'done',
        'result' => "Parameter one value: " . $parm1
    );

    // Return the dummy response as an associative array
    return $dummy_response;
}

function generate_blog_titles_openai( WP_REST_Request $request ) {
    $user_topic = $request->get_param('topic');
    
    // OpenAI API URL and key
    $api_url = 'https://api.openai.com/v1/chat/completions';
    $api_key = 'sk-XXX';
    
    
    
    // Headers for the OpenAI API
    $headers = [
        'Content-Type' => 'application/json',
        'Authorization' => 'Bearer ' . $api_key
    ];


    $conversation_history[] = [
        'role' => 'user',
        'content' => 'generate 5 blog post titles about the following topic: ' . $user_topic
    ];

    // Body for the OpenAI API
    $body = [
        'model' => 'gpt-3.5-turbo', // You can change the model if needed
        'messages' => $conversation_history,
        'temperature' => 0.7 // You can adjust this value based on desired creativity
    ];

    // Args for the WordPress HTTP API
    $args = [
        'method' => 'POST',
        'headers' => $headers,
        'body' => json_encode($body),
        'timeout' => 120
    ];

    // Send the request
    $response = wp_remote_request($api_url, $args);
    $response_body = wp_remote_retrieve_body($response);
    $data = json_decode($response_body, true);

    // Handle the response
    $content = $data['choices'][0]['message']['content'];
    return [
            'success' => true,
            'message' => 'Response Generated',
            'result' => $content
        ];
}


// Register a Custom REST API endpoint
add_action('rest_api_init', function () {
    register_rest_route('v1', '/generate-titles/', array(
        'methods' => 'GET',
        'callback' => 'generate_blog_titles_openai',
        'permission_callback' => function () {
           return is_user_logged_in();
           }
        //'permission_callback' => '__return_true', // This makes the endpoint publicly accessible. Adjust the permissions as necessary.
    ));
});

The Code Explanation is Below:

Part 1: Changing the API URL Prefix

add_filter('rest_url_prefix', 'custom_rest_url_prefix');
function custom_rest_url_prefix() {
    return 'custom-api'; // Change this to your desired prefix
}

• Imagine your WordPress website has a special secret passage called “API.”
• But you don’t like its name and want to call it something cooler, like “custom-api.”
• This piece of code tells WordPress, “Hey! From now on, call the secret passage ‘custom-api’ instead of the boring default name.”

---

Part 2: Returning Dummy Text

function return_dummy_text() {
    return 'This is a custom WordPress API Endpoint'; 
}

• This function is like a magic box. When someone says “Show me something!” it will always say, “This is a custom WordPress API Endpoint.”
• It’s like when you ask someone for their favorite phrase, and they always say the same thing!

---

Part 3: Generating a Dummy Response

function generate_dummy_response( WP_REST_Request $request ) {
    
    $parm1 = $request->get_param('parm1');
    
    $dummy_response = array(
        'success' => true,
        'message' => 'done',
        'result' => "Parameter one value: " . $parm1
    );

    return $dummy_response;
}

• Think of this as a game where someone gives you a secret word (called a “parameter”), and you say back, “Here is your word!”
• In this case, if someone gives you parm1 (a secret word), you return something like “Parameter one value: [the secret word they gave].”
• You also add some extra stuff like saying, “Success! Done!”

---

Part 4: Talking to OpenAI and Generating Blog Titles

function generate_blog_titles_openai( WP_REST_Request $request ) {
    $user_topic = $request->get_param('topic');
    
    $api_url = 'https://api.openai.com/v1/chat/completions';
    $api_key = 'sk-XXX';
    
    $headers = [
        'Content-Type' => 'application/json',
        'Authorization' => 'Bearer ' . $api_key
    ];

    $conversation_history[] = [
        'role' => 'user',
        'content' => 'generate 5 blog post titles about the following topic: ' . $user_topic
    ];

    $body = [
        'model' => 'gpt-3.5-turbo',
        'messages' => $conversation_history,
        'temperature' => 0.7
    ];

    $args = [
        'method' => 'POST',
        'headers' => $headers,
        'body' => json_encode($body),
        'timeout' => 120
    ];

    $response = wp_remote_request($api_url, $args);
    $response_body = wp_remote_retrieve_body($response);
    $data = json_decode($response_body, true);

    $content = $data['choices'][0]['message']['content'];
    return [
            'success' => true,
            'message' => 'Response Generated',
            'result' => $content
        ];
}

• Now we want to ask a super-smart robot (OpenAI) to come up with blog title ideas.
• First, we ask the user for a “topic” (like “Dinosaurs”).
• We send this topic to the robot (OpenAI) and say, “Hey robot, can you give me 5 blog titles about Dinosaurs?”
• The robot then sends back some cool titles, and we share those with the user.
• This is done by building a “letter” (an API request) and sending it to the robot using a secret password (API key).

---

Part 5: Creating the Custom API Endpoint

add_action('rest_api_init', function () {
    register_rest_route('v1', '/generate-titles/', array(
        'methods' => 'GET',
        'callback' => 'generate_blog_titles_openai',
        'permission_callback' => function () {
           return is_user_logged_in();
           }
    ));
});

• This part sets up a special door in your website where people can ask the robot for blog titles.
• You decide that only people who are logged in (like when you’re logged into a computer game) can use this door.
• If they are logged in, they can ask for the titles, and the door will let them in.