with Google's Artificial Intelligence Yourself Kit
The guts lay across my anti-static work mat. The red button, later replaced with a dimmer blue switch, activates the listening. This way I'm not being listened to 24/7.
After installing everything into the included cardboard box I 3D printed a better housing for it.
To be artificially intelligent, it uses Google's Assistant API. Alexa is another option, but less intelligent and more limited. Here's why:
"Amazon has a great head start with about 8 million installed units and 300 hardware partners, but it lacks any serious AI or voice recognition tools. Google came in late in 2016 with maybe a few hundred thousand units sold, but has a serious AI engine that works off Google’s knowledge graph, 20 years of search and mail data, and a great front-end platform with API(dot)AI, which it recently acquired and integrated."
"After discovering the inability to create a true conversational experience with Alexa, we were delighted to find out that Google Assistant does support conversational flows. This was probably the largest factor we have discovered that separates the two voice services, giving Google significantly more potential for true interaction and a much larger variety of potential apps."
So, now I have a powerful smart home speaker that I can easily upgrade, for example, if I want a better speaker, or a large battery.