调用OpenAI API遇400错误，排查后通过正确传递payload解决

问题背景 #

我尝试用XMLHttpRequest向OpenAI API的completions接口发送请求，测试接口是否能正常工作。

初始代码 #

var openairequest = new XMLHttpRequest();
const payload = ({
    "model": "text-davinci-003",
    "prompt": "say this is a test"
});

console.log(payload)
openairequest.open("POST",`https://api.openai.com/v1/completions?data=${encodeURIComponent(JSON.stringify(payload))}`)
openairequest.setRequestHeader("Content-Type", "application/json");
openairequest.setRequestHeader("Authorization",`Bearer ${open_ai_key}`)

收到的错误响应 #

{
    "error": {
        "message": "You didn't provide an API key. You need to provide your API key in an Authorization header using Bearer auth (i.e. Authorization: Bearer YOUR_KEY), or as the password field (with blank username) if you're accessing the API from your browser and are prompted for a username and password. You can obtain an API key from https://platform.openai.com/account/api-keys.",
        "type": "invalid_request_error",
        "param": null,
        "code": null
    }
}

我很困惑，明明已经传入了JSON对象，却还是收到未提供API密钥的错误。

第一次修改 #

后来发现自己漏写了发送请求的send()方法，补上后代码如下，但还是搞不懂为什么Authorization请求头里的API密钥不生效：

var open_ai_key = "MY KEY"

var openairequest = new XMLHttpRequest();
const payload = ({
    "model": "text-davinci-003",
    "prompt": "say this is a test"
});

openairequest.open("POST",`https://api.openai.com/v1/completions?data=${encodeURIComponent(JSON.stringify(payload))}`)
openairequest.setRequestHeader("Content-Type", "application/json");
openairequest.setRequestHeader("Authorization",`Bearer ${open_ai_key}`)
openairequest.send()
console.log(openairequest)

最终解决 #

最后我通过将字符串化后的payload传入send()方法解决了问题，关键修改是：

openairequest.send(JSON.stringify(payload))

内容的提问来源于stack exchange，提问作者elijah