Auto sync an interactive pdf form in embed pdf api to local disk

[Enthusiastic_power5C57]

I'm hosting a website that allows users to use the embed pdf api to open a local interactive pdf from and edit it. However, in order to save user's progress to local disk, the user has to manually download the pdf since the save functionality in the embed api only saves user's progress in the memory. Is there a way to automatically synchronize user's progress to local disk without having to manually download it? (It's kind of like when you use Word to edit documents, you can directly save it to the same file on local disk.)

[Joel Geraci]

It's not possible but this is a browser limitation, not a limitation of Embed API. JavaScript cannot exert any control over the local filesystem.

[Mohamade]

I think your answer is incorrect, i have read this here: 

https://community.adobe.com/t5/document-services-apis-discussions/is-there-any-way-to-save-edited-pd... 

are you sure that it is impossible?

[Test Screen Name]

That reply is also by Joel (same person). It shows how to save the PDF to the server by POSTING it to your own script. This is quite the opposite of what the original question wants - to save to the local disk - which we all hope is and remains impossible (since it would mean security had broken and any web site could attack us that way).