They started with code static analysis metrics, but have now added security analysis too. Ruby only, but same concept applies.
To the OP, please don't take the Code Climate (and so many others') road, consider creating an open source community around your product and then offering enterprise service on top of THAT. If you don't, you're gonna face dire competition sooner or later, even if you are the first to market. If you do, you have the chance to establish yourself an ecosystem that'll keep on giving back, in both code and publicity.
I know, there are plenty of open source projects that make money, and plenty of open source projects that thrive despite not making money. None of those are MVPs, like this project is. I doubt anyone who started on those projects was depending on them to make a living right away.
The solution is to provide the tool and the hosting together. For example, GitHub or Bitbucket could acquire this service and add it to their offerings, and it would fit right in with their existing business model.
If this tool could connect to a remote repo (like the GitHub repo) and operate on the changelog, then you'd be fine. No one would be able to use it privately without publicly exposing their repo.
Perhaps then you could charge a fee to get an ssh key to add to you authorized_keys file, which would allow for private use.