Out of boredom, while I was thinking between moving from RSA to Ed25519 on my GPG key-pair and doing something else, ten days ago
I started writing my own password manager in posix shell, which instead of gpg(1) (there are a lot tbh), it uses age(1) as 
backend for encryption. 
By now it's mostly finished, after some odd struggle with some internal functions of the scripts, which I've already sorted out. 
The script works roughly the same like a similar thing which is an alternative to pass(1), on posix 
shell as well. 
I've documented mine already, and the manual page was written in mdoc(7) format, which I guess it's fairly portable
between Unices, i don't know.
To list all of the entries on the password store, it needs tree(1) to do that. 
Unlike pass(1) or even gopass(1), I probably won't implement VCS integration or generation of passwords built-in into the script.
However, if I do that, they'll be on a separate repository, or something along those lines, as separate scripts.

angou: <https://gt.kalli.st/shokara/angou>
ayu: <https://git.patchysicp.xyz/novaburst/ayu>
gopass: <https://github.com/cortex/gopass>
pass: <https://www.passwordstore.org>