php - OpenAI ChatGPT (GPT-3.5) API : Why do I get NULL response?

Question

我正在尝试对新发布的 gpt-3.5-turbo 模型执行 API 调用，并具有以下代码，该代码应发送查询(通过 $query 变量)到 API，然后从 API 中提取响应消息的内容。

但是我每次调用都得到空响应。有什么想法我做错了什么吗？

$ch = curl_init();

$query = "What is the capital city of England?";

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

$api_key = 'sk-**************************************';

$post_fields = [
    "model" => "gpt-3.5-turbo",
    "messages" => ["role" => "user","content" => $query],
    "max_tokens" => 500,
    "temperature" => 0.8
];

$header  = [
    'Content-Type: application/json',
    'Authorization: Bearer ' . $api_key
];

curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($post_fields));
curl_setopt($ch, CURLOPT_HTTPHEADER, $header);

$result = curl_exec($ch);
if (curl_errno($ch)) {
    echo 'Error: ' . curl_error($ch);
}
curl_close($ch);

$response = json_decode($result);

$response = $response->choices[0]->message[0]->content;

Answer 1

您收到 NULL 响应的原因是无法解析 JSON 正文。

您收到以下错误:“我们无法解析您请求的 JSON 正文。(提示:这可能意味着您没有正确使用 HTTP 库。OpenAI API 需要 JSON 负载，但是什么发送的 JSON 无效。如果您无法弄清楚如何解决此问题，请发送电子邮件至 support@openai.com，并附上您需要帮助的任何相关代码。)”。

改变这个...

$post_fields = [
    "model" => "gpt-3.5-turbo",
    "messages" => ["role" => "user","content" => $query],
    "max_tokens" => 12,
    "temperature" => 0
];

...对此。

$post_fields = array(
    "model" => "gpt-3.5-turbo",
    "messages" => array(
        array(
            "role" => "user",
            "content" => $query
        )
    ),
    "max_tokens" => 12,
    "temperature" => 0
);

工作示例

如果您在 CMD 中运行 php test.php，OpenAI API 将返回以下完成信息:

string(40) "

The capital city of England is London."

test.php

<?php
    $ch = curl_init();

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

    $api_key = 'sk-xxxxxxxxxxxxxxxxxxxx';

    $query = 'What is the capital city of England?';

    $post_fields = array(
        "model" => "gpt-3.5-turbo",
        "messages" => array(
            array(
                "role" => "user",
                "content" => $query
            )
        ),
        "max_tokens" => 12,
        "temperature" => 0
    );

    $header  = [
        'Content-Type: application/json',
        'Authorization: Bearer ' . $api_key
    ];

    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($post_fields));
    curl_setopt($ch, CURLOPT_HTTPHEADER, $header);

    $result = curl_exec($ch);
    if (curl_errno($ch)) {
        echo 'Error: ' . curl_error($ch);
    }
    curl_close($ch);

    $response = json_decode($result);
    var_dump($response->choices[0]->message->content);
?>