Sequoia consists of a number of components. There is the low-level crate. We released version 1.0 of that in Dec. 2020. There is sq, the CLI tool. We released that a few weeks ago. We've barely started work on the high-level interface.
Just because we plan to write a high-level tool, doesn't mean the low-level crate is hard to use. On the contrary, our experience is that it is pretty easy to use and actually does a good job hiding a lot of the low level details that don't need to be tweaked. For instance, I ported the pep engine from gpgme (GnuPG's high-level interface) to Sequoia's low-level interface. The initial port required about half as many lines of code.
Just because we plan to write a high-level tool, doesn't mean the low-level crate is hard to use. On the contrary, our experience is that it is pretty easy to use and actually does a good job hiding a lot of the low level details that don't need to be tweaked. For instance, I ported the pep engine from gpgme (GnuPG's high-level interface) to Sequoia's low-level interface. The initial port required about half as many lines of code.