Using Keybase as a support platform for proprietary software.

I'm developing software that needs to authenticate documents and people, I'd like to use the Keybase API and I've already started reading it.

My doubts boil down to the following:

* What is the Keybase lifetime, and if it stops being developed, how will I become dependent on it?
* Is it allowed to use Keybase on proprietary software? what is the cost to use the API? and if it's an opensource software that has sponsors, would there be costs?
* Are there restrictions on use in religious institutions?
* What's the best way to start developing a client that uses the Keybase API?

Start with the Keybase API material the author says they have begun reading; no repository file, test, or entry point is identified in the issue. Determine whether the project has documented answers about service lifetime, proprietary use, pricing, religious-institution restrictions, and client development, then consider the work complete only when those questions have authoritative guidance.

Written by the indexing model from the issue text.