OpenAI Chat Completions API: Why am I not getting a response if the stream parameter is set to false?

You can see the $prompt value in my application below. When I type this promp value, chatGPT does not give results. But this is because "stream" => false in the params. If "stream" => true, chatGPT gives results.

My question here is why chatGPT does not give results when "stream" => false. And what to do for it to give results.

$API_KEY = "API_KEY_HERE";

$model = 'gpt-3.5-turbo';
$header = [
    "Authorization: Bearer " . $API_KEY,
    "Content-type: application/json",
];

$temperature = 0.6;
$frequency_penalty = 0;
$presence_penalty= 0;
$prompt = 'What can you help me with? For example: What do you suggest to keep me motivated?';
 

$messages = array(
    array(
        "role" => "system",
        "content" => "Your name is 'JOHN DOE'. I want you to act as a motivational coach. I will provide you with some information about someone's goals and challenges, and it will be your job to come up with strategies that can help this person achieve their goals. This could involve providing positive affirmations, giving helpful advice or suggesting activities they can do to reach their end goal. if you don't understand the question, don't think too much, tell the user to be more specific with more details"
        ),
    array(
        "role" => "assistant",
        "content" => "Hello, I'm JOHN DOE, and I'm a motivational coach who loves helping people find their drive and achieve their goals. With years of experience in coaching and personal development, I've developed a unique approach to motivation that combines mindset, energy, and action."
    ),
    array(
        "role" => "user",
        "content" => $prompt
    )
);
//Turbo model
$isTurbo = true;
$url = "https://api.openai.com/v1/chat/completions";
$params = json_encode([
    "messages" => $messages,
    "model" => $model,
    "temperature" => $temperature,
    "max_tokens" => 1024,
    "frequency_penalty" => $frequency_penalty,
    "presence_penalty" => $presence_penalty,
    "stream" => false
]);

$curl = curl_init($url);
$options = [
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => $header,
    CURLOPT_POSTFIELDS => $params,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_SSL_VERIFYPEER => false,
    CURLOPT_SSL_VERIFYHOST => 0,
    CURLOPT_WRITEFUNCTION => function($curl, $data) {
        //echo $curl;
        $httpCode = curl_getinfo($curl, CURLINFO_HTTP_CODE);

        if ($httpCode != 200) {
            $r = json_decode($data);
            echo 'data: {"error": "[ERROR]","message":"'.$r->error->message.'"}' . PHP_EOL;
        } else {
            $trimmed_data = trim($data); 
            if ($trimmed_data != '') {
                $response_array = json_decode($trimmed_data, true);
                $content = $response_array['choices'][0]['message']['content'];
                echo $content;
                ob_flush();
                flush();
            }
        }
        return strlen($data);
    },
];

curl_setopt_array($curl, $options);
$response = curl_exec($curl);

if ($response === false) {
    echo 'data: {"error": "[ERROR]","message":"'.curl_error($curl).'"}' . PHP_EOL;
}else{

}

The reason why you don't get a response back if you set "stream" => false is that the whole code is designed to return a response in a streaming fashion when the stream parameter is set to true.

With the following modification, the response will be processed as a whole, regardless of the value of the stream parameter.

Try this:

$API_KEY = "API_KEY_HERE";

$model = 'gpt-3.5-turbo';
$header = [
    "Authorization: Bearer " . $API_KEY,
    "Content-type: application/json",
];

$temperature = 0.6;
$frequency_penalty = 0;
$presence_penalty= 0;
$prompt = 'What can you help me with? For example: What do you suggest to keep me motivated?';

$messages = array(
    array(
        "role" => "system",
        "content" => "Your name is 'JOHN DOE'. I want you to act as a motivational coach. I will provide you with some information about someone's goals and challenges, and it will be your job to come up with strategies that can help this person achieve their goals. This could involve providing positive affirmations, giving helpful advice or suggesting activities they can do to reach their end goal. if you don't understand the question, don't think too much, tell the user to be more specific with more details"
        ),
    array(
        "role" => "assistant",
        "content" => "Hello, I'm JOHN DOE, and I'm a motivational coach who loves helping people find their drive and achieve their goals. With years of experience in coaching and personal development, I've developed a unique approach to motivation that combines mindset, energy, and action."
    ),
    array(
        "role" => "user",
        "content" => $prompt
    )
);

$url = "https://api.openai.com/v1/chat/completions";

$params = json_encode([
    "messages" => $messages,
    "model" => $model,
    "temperature" => $temperature,
    "max_tokens" => 1024,
    "frequency_penalty" => $frequency_penalty,
    "presence_penalty" => $presence_penalty,
    "stream" => false
]);

$curl = curl_init($url);
$options = [
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => $header,
    CURLOPT_POSTFIELDS => $params,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_SSL_VERIFYPEER => false,
    CURLOPT_SSL_VERIFYHOST => 0,
];

curl_setopt_array($curl, $options);
$response = curl_exec($curl);

if ($response === false) {
    echo 'data: {"error": "[ERROR]","message":"'.curl_error($curl).'"}' . PHP_EOL;
}else{
    $response_array = json_decode($response, true);
    $content = $response_array['choices'][0]['message']['content'];
    echo $content;
}