Use objects to talk to various Google APIs (G Suite & beyond) without knowledge of HTTP, REST, nor OAuth2. It's a custom server-side JavaScript runtime supporting apps that are hosted+executed in Google's cloud. OTOH, Apps Script is a simpler, higher-level alternative. (It's not a full-fledged G Suite Dev Show episode but does link to a working sample.) Check out the various guides on using the API, including Quickstart examples in a variety of programming languages. I produced a high-level video overview of what a mail merge application using the API would look like. The Docs API was officially launched in Feb 2019.
#HOW TO CREATE A APPLICATION IN GOOGLE DOCS PLUS#
Alex's link now redirects to the more generic document that shows mostly. (I wasn't able to find the Python-specific developer's guide referenced by Alex's doc link - possibly it's been lost or buried in Google's move of documentation assets from to. discovering (as the OP's followup to the Google Group post mentions) that the unit tests are a great source of examples.
(Creation through POST requests is similar to what's normally described as a REST API, though in real REST you'd typically use a PUT request instead of course). While the docs call it "uploading", everything boils down to sending an appropriately formatted HTTP POST request, so of course it can actually be a new creation rather than an actual "upload" of an otherwise existing file.