OpenAI API request with PHP

openai-api-fetch.php

<?php
function openAICompletion(array $messages): string {
    $apiKey = 'OpenAI API key here';
    $url = 'https://api.openai.com/v1/chat/completions';
    $payload = [
        'messages' => $messages,
        'model' => 'gpt-4o',
        'temperature' => 0
    ];
    $options = [
        'http' => [
            'header' => "Content-Type: application/json\r\n".
                        "Authorization: Bearer $apiKey\r\n",
            'method' => 'POST',
            'content' => json_encode($payload),
        ],
    ];
    $context = stream_context_create($options);
    $use_include_path = false;
    $json = @file_get_contents($url, $use_include_path, $context);

    if (!$json) {
        throw new Exception("Error making POST request");
    }

    $data = json_decode($json, true);

    if (isset($data['error'])) {
        throw new Exception('Error from API: ' . $data['error']['message']);
    }

    return $data['choices'][0]['message']['content'];
}

$messages = [['role' => 'user', 'content' => 'ping']];
var_export(openAICompletion($messages));
?>