It's truly local first and will work fine in an airgapped situation.
It's also designed to be self-hostable[2], is open source [3] and the API is well documented[4].
[1] https://saveoursecrets.com/ [2] https://saveoursecrets.com/docs/cli/self-hosting/ [3] https://github.com/saveoursecrets/sdk [4] https://docs.rs/sos-sdk/latest/sos_sdk/
Passwords, even ssh keys and passkeys, are little pieces of plain text. If you think needing a specialised sdk or cli to retrieve plain text is a good software architecture, I think we see the world quite differently.
We clearly see things differently but I think using computers to make our lives easier is worthwhile and storing/managing our secrets securely, effectively and conveniently is better managed by software than some ad-hoc setup.
Nitpick, passkeys are not text, they are binary blobs.