Hi @Kipling - welcome to the farmOS forum!
Thanks for asking about this! And excited to hear about the potential integration!
Take a look at the farmOS Trademark Guidelines, specifically the section titled “Statements about compatibility, interoperability or derivation”: farmOS Trademark Guidelines | farmOS
You may use the Word Marks, but not the Logos, to truthfully describe the relationship between your software and ours. Our Mark should be used after a verb or preposition that describes the relationship between your software and ours. So you may say, for example, “Bob’s software for the farmOS platform” but may not say “Bob’s farmOS software.” Some other examples that may work for you are:
- [Your software] works with farmOS software
- [Your software] uses farmOS software
- [Your software] is compatible with farmOS software
- [Your software] is powered by farmOS software
- [Your software] runs on farmOS software
- [Your software] for use with farmOS software
- [Your software] for farmOS software
One of the main goals of the trademark is to prevent confusion. Specifically you just want to make sure it doesn’t appear to be an “official” library supported by the farmOS maintainers, and obviously it shouldn’t confuse anyone into thinking that it is “farmOS” itself. So be sure to make that clear in your README or other project documentation.
As for the package name itself, I think it’s fine to use the name “farmos”, as long as the docs/description make it clear that it’s “unofficial”.
It does make me wonder… should farmOS have an “official” Dart library? 
We have Python and JavaScript libs: