‘Actions on Google’ to open Google Assistant to third-party developers
Tuesday, October 4, 2016 at 11:54PM 
If Google plans to unseat the Amazon Echo in its own category, it’ll need all the help it can get. And that’s what it is planning to do with the Actions on Google program launching in December. This program will allow developers to build “Actions” for Google Assistant (akin to the 3,000+ “skills” of Amazon’s Alexa). There will be two flavors to this: Direct Actions and Conversation Actions. Direct is similar to what you can do with Siri, Alexa, and even Google’s own Google Now voice assistant. You ask it for information, schedule a meeting, etc.
Conversations, on the other hand and as its name suggests, is more of a back and forth. One example given at the Google event is when Scott Huffman tried to get an Uber and had Google Assistant pass the conversation off to Uber to finalize the request. And that’s where developers would need to work with Google. Aside from the Google plans to release an Embedded Google Assistant software development kit to let tinkerers load Google Assistant on things like Raspberry Pi as well as for other hardware manufacturers to have Assistant in other products.
Source: The Verge