Automating Google Slides production

It's 2018, and great news (and answers!) to this older question:

• The Google Slides REST API launched in Nov 2016... here is its launch post and 1st developer video I made to get you started. A shorter code sample than the video's is the Quickstart in the docs (available in a variety of languages). If you're new to Google APIs, I recommend you watch this video, then this one, and finally this one first to get an idea of how to use them. The code samples are in Python, but if you're not a Python developer, just pretend it's pseudocode because many languages are supported by Google APIs Client Libraries. :-)
• If you code in JS and want to have Google host+run your app, the Slides service in Google Apps Script launched in Sep 2017... here is its launch post and 1st developer video I made to get you started. This is also the same technology behind Slides Add-ons. If you're new to Apps Script, I recommend you watch this video to get an idea of what it is and how to use it. Then check out its video library for more examples of using Apps Script. (Admittedly, it's easier to code w/Apps Script vs. the REST APIs, making it more "addictive" for developers... you were warned!) :-)
• Additional videos on programmatically accessing Google Slides can be found via its developer video library. Videos on this and other G Suite developer technologies can be found in the G Suite Dev Show series which I produce.
• There's no video for this, but there's an open source Markdown-to-Google Slides generator (written in Node.js) my colleague created that you may be interested in, representing one of the "reference apps" using the Slides API. You can find more about this app as well as others on the Samples page of the documentation.
• No video for this either, but Node.js developers who want to get up-to-speed quickly learning how to use this API should try the Slides API codelab where you build an app that uses Google BigQuery to analyze open source licenses and generate a report presentation... letting you learn TWO Google Cloud technologies with one tutorial! :-)

The Google Slides API was launched on 11/9/2016. It provides the ability to read, create, and edit Google Slides presentations.

At the moment there still isn't an equivalent service in Apps Script, but you can use the Apps Script OAuth2 library and UrlFetchApp to make calls to the API within a script.

Requested feature, follow https://code.google.com/p/google-apps-script-issues/issues/detail?id=1573&q=presentation&colspec=Stars%20Opened%20ID%20Type%20Status%20Summary%20Component%20Owner for updates.