The POST request is an alternative to a PUT request. A POST object upload is the process of accepting objects from an HTTP form sent by a web browser. When a user submits the form, the browser uploads its contents, which can include data such as a text field or a file, to HCP. Any parameters are passed, not within the header as in a PUT request, but as form fields within the body of the request. The web page can be hosted on the same domain as HCP or a different domain. A user must have write access to a bucket to add an object to it. The POST request can upload a security policy with the request using form fields in the multipart/form-data encoded message body, so a bucket administrator can create preset conditions under which the upload is allowed.
Because the request is authenticated without passing data through a secure intermediary node that protects credentials, POST object uploads can reduce latency. Because an object is uploaded in a single operation, an HTTP success response indicates that the entire object has been stored.