Is there an sftp server with an API?

Question

linux

The previous task of creating an sftp server suddenly became more difficult. We need an sftp-server, to which, first, some users upload their data (if possible, you need to limit the types of uploaded files, at least by extensions, and their size), and then the system automatically uploads this data to itself. It is necessary to create / delete / check the existence of uploading users from the software using api automatically. So far I have found only CerberosFTP with api (we've made the API available so that anyone can use it to programatically control the server).
The platform is not important - it can be Linux, it can be Windows.
What I considered and what I did not find API: ioFTPD , freeFTPd , Serv-U FTP & MFT Server(it's not even clear what ~$3k they are asking for), Xlight ftp server , CoreFTP , CuteFTP , CopSSH .
Scripts in Linux are also an option, but, as far as I understand, you actually have to write this API yourself.

Answer 1

Weird. I wouldn't use ftp/sftp anymore. http/https is well suited for such tasks. You write a simple data download application with authorization and courtesans, and voila! Or take and install something similar to owncloud.org
By the way, by simply setting up nginx or apache, you can limit both downloading and size and authorization and a bunch of everything without writing at all! and on https to drive everything for security.