The docs are definitely copyrighted. Same as if you wrote a blog post and they copied it, it would be copyright infringement.

Otonomo sounds like a deeply unethical and shady company. If I was doing any kind of business with them I would not continue to do so. While it would be hard to sue them, hopefully when you Google them in the future the fact they ripped of Smartcar will be one of the first results.

In the US, whether APIs are copyrightable is a question being currently litigated. https://en.wikipedia.org/wiki/Oracle_America,_Inc._v._Google....

The latest decision in that saga is that yes, they can be. Whether that holds up in the Supreme Court is an open question. Most of us hope it doesn't, I suspect.

Copying documentation is definitely a copyright violation. Similar situation exists with recipes - a list of ingredients can't be copyrighted, but the wording of the steps can be. You have to at least put it in your own words.

As it turns out, probably nothing. Their API docs are apparently open source.