What I would like it is to run a script that automatically checks for new assets (files that aren't code) that have been submitted to a specific directory, and then every so often automatically commit those files and push them.
I could make a script that does this through the command line, but I was mostly curious if mercurial offered any special functionality for this, specifically I'd really like some kind of return error code so that my script will know if the process breaks at any point so I can send an email with the error to specific developers. For example if for some reason the push fails because a pull is necessary first, I'd like the script to get a code so that it knows this and can handle it properly.
I've tried researching this and can only find things like automatically doing a push after a commit, which isn't exactly what I'm looking for.
You can always check exit-code of used commands

hg add (if new, unversioned files appeared in WC) "Returns 0 if all files are successfully added": non-zero means "some troubles here, not all files added"
hg commit "Returns 0 on success, 1 if nothing changed": 1 means "no commit, nothing to push"
hg push "Returns 0 if push was successful, 1 if nothing to push"
Automating commit and push through mercurial from script