如何通过QT C basd代码将文件上传到OpenAI Assistant API

Question

OpenAI Assistant API 允许客户端在文件中上传额外的“知识”，以便 Assistant 与 ChatGPT 配合提供更多定制/私人 AI 响应。

我的客户端是 QT Creator IDE 中基于 C 的代码。我使用 QT 6.5，它具有 QT 类 QNetWorkManager 和 QNetworkRequest，它提供 REST API GET/POST/PUT 接口（因此我不需要使用curl 库）。我正在尝试编写类似于 OpenAI 的基于 Python 的 OpenAI 库的包装函数（pip install openai）。我确实知道如何通过 Python OpenAI 库实现上传，但 (libai) C 库中的支持是非官方且稀缺的，并且不涵盖 Assistant API 函数。因此我决定自己尝试一下。

OpenAI API 参考的实现非常简单，除了一个（至少对我来说）。那就是文件上传。 OpenAI 参考位于：https://platform.openai.com/docs/api-reference/files/create

OpenAI 特别指出：

上传文件 发布 https://api.openai.com/v1/files

我尝试通过 QNetWorkManager 和 QNetworkRequest 调用 url 没有成功。感谢您的帮助。

以下是QT中代码的关键摘录。我将代码精简为仅解决问题的基本要素。

#define OpenAI_UPLOAD_FILE_URL "https://api.openai.com/v1/files"
/*
 * Supporting function only
 * Pretty Print API response from JSON Object
 */
void AI_Dialog::printJson(QJsonObject json){
    QJsonDocument doc(json);
    QString jsonString = doc.toJson(QJsonDocument::Indented);
    qDebug().noquote() << jsonString.toStdString().c_str();
}

/*
 * Wrapper function to OpenAI to upload a file
 * Note: reply is defined in AI_Dialog class as QNetworkReply *reply.
 *       OpenAI_apiKey is key to OpenAI key (not shown)
 */
bool AI_Dialog::upload_file()
{
    QUrl APIurl(OpenAI_UPLOAD_FILE_URL);

    QNetworkRequest request(APIurl);
    bool status = false;

    //If not API key do not proceed
    if (this->OpenAI_apiKey.isEmpty())
        return false;

    //Setup RestAPI Header
    request.setHeader(QNetworkRequest::ContentTypeHeader, QByteArray("multipart/form-data"));
    request.setRawHeader("Authorization", "Bearer " + this->OpenAI_apiKey.toUtf8());


    QHttpMultiPart *multiPart = new QHttpMultiPart(QHttpMultiPart::FormDataType);

    QHttpPart valuePart;
    valuePart.setRawHeader("purpose", "assistants");
    multiPart->append(valuePart);

    valuePart.setRawHeader("file", "@contents.json");
    valuePart.setBody("bla bla");
    multiPart->append(valuePart);

    // Do REST API Post operation
    reply = this->network_access_manager.post(request, multiPart);

    //Setup REST AI completion callbacks. Mian one is ReadyRead
    status = connect(reply, &QNetworkReply::readyRead, this, &AI_Dialog::readyRead);
    return true;
}

//Rest API callback completion for POST, GET etc to OPenAI
void AI_Dialog::readyRead()
{
    QUrl url;
    QJsonArray array;
    QJsonObject ar1;

    if (reply->error() == QNetworkReply::NoError){

        //Get Data from reply
        QString reply_str = reply->readAll();

        QByteArray byte_array = reply_str.toUtf8();
        QJsonDocument doc = QJsonDocument::fromJson(byte_array);
        QJsonObject obj = doc.object();

        //Debug Only
        printJson(obj);
    }
}

响应结果（通过 printJson） { “错误”： { “代码”：空， "message": "'file' 是必需的属性", “参数”：空， “类型”：“无效请求错误” } }

跟进：这有效（代码摘录）

QHttpMultiPart *multiPart = new 
QHttpMultiPart(QHttpMultiPart::FormDataType);

QHttpPart valuePart;
valuePart.setHeader(QNetworkRequest::ContentTypeHeader, "text/plain");
valuePart.setHeader(QNetworkRequest::ContentDispositionHeader, "form-data; name=\"purpose\"");
valuePart.setBody("assistants");
multiPart->append(valuePart);

QHttpPart filePart;
filePart.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
filePart.setHeader(QNetworkRequest::ContentDispositionHeader, "form-data; name=\"file\"; filename=\"Hello_There.json\"");
filePart.setBody("{bla bla}");

multiPart->append(filePart);

Answer 1

以下代码摘录对我有用：

QHttpMultiPart *multiPart = new 
QHttpMultiPart(QHttpMultiPart::FormDataType);

QHttpPart valuePart;
valuePart.setHeader(QNetworkRequest::ContentTypeHeader, "text/plain");
valuePart.setHeader(QNetworkRequest::ContentDispositionHeader, "form-data; 
name=\"purpose\"");
valuePart.setBody("assistants");
multiPart->append(valuePart);

QHttpPart filePart;
filePart.setHeader(QNetworkRequest::ContentTypeHeader, 
"application/json");
filePart.setHeader(QNetworkRequest::ContentDispositionHeader, "form-data; 
name=\"file\"; filename=\"Hello_There.json\"");
filePart.setBody("{bla bla}");

multiPart->append(filePart);