我正在尝试调用新发布的gpt-3.5-turbo模型的API，并编写了以下代码，该代码应将查询（通过$query变量）发送到API，然后从API的响应消息中提取内容。

但每次调用都得到null响应。有什么想法可以告诉我哪里做错了？

$ch = curl_init();$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;

回答：

你得到NULL响应的原因是JSON主体无法被解析。

你得到了以下错误："我们无法解析您的请求的JSON主体。（提示：这可能意味着您没有正确使用您的HTTP库。OpenAI API期望一个JSON负载，但发送的内容不是有效的JSON。如果您无法弄清楚如何修复这个问题，请发送电子邮件到[email protected]，并附上您需要帮助的相关代码。）"。

将这个…

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

…改成这个。

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

工作示例

如果你在命令行中运行php test.php，OpenAI API将返回以下完成内容：

string(40) “

英格兰的首都是伦敦。”

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);?>