<?php

$rapidApiKey = getenv("RAPIDAPI_KEY");
$rapidApiHost = getenv("RAPIDAPI_HOST") ?: "YOUR_RAPIDAPI_HOST";

if (!$rapidApiKey) {
    throw new RuntimeException("Set RAPIDAPI_KEY before running this example.");
}

$curl = curl_init("https://" . $rapidApiHost . "/v1/chat/completions");
$payload = json_encode([
    "model" => "gpt-5.6",
    "messages" => [
        ["role" => "user", "content" => "Give me one concise API reliability tip."]
    ]
]);

curl_setopt_array($curl, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HEADER => true,
    CURLOPT_HTTPHEADER => [
        "Content-Type: application/json",
        "X-RapidAPI-Key: " . $rapidApiKey,
        "X-RapidAPI-Host: " . $rapidApiHost
    ],
    CURLOPT_POSTFIELDS => $payload,
    CURLOPT_TIMEOUT => 180
]);

$result = curl_exec($curl);
if ($result === false) {
    throw new RuntimeException(curl_error($curl));
}

$headerSize = curl_getinfo($curl, CURLINFO_HEADER_SIZE);
$status = curl_getinfo($curl, CURLINFO_HTTP_CODE);
echo "HTTP " . $status . PHP_EOL;
echo substr($result, $headerSize) . PHP_EOL;
curl_close($curl);