Is it possible to access local files via remote SSH connection (local files of the connecting client of course, not other clients)?
To be specific, I'm wondering if the app I'm making (which is designed to be used over SSH, i.e. user connects to a remote SSH server and the script (written in Python) is automatically executed) can access local (client's) files. I want to implement an upload system, where user(s) (connected to SSH server, running the script) may be able to upload images, from their local computers, over to other hosting sites (not the SSH server itself, but other sites, like imgur or pomf (the API is irrelevant)). So the remote server would require access to local files to send the file to another remote hosting server and return the link.
You're asking if you can write a program on the server which can access files from the client when someone runs this program through SSH from the client?
If the only program running on the client is SSH, then no.  If it was possible, that would be a security bug in SSH.
Remote SSH server accessing local files