remix-validity-state is a small React form validation library that aims to embrace HTML input validation and play nicely with Remix and React Router primitives (specifically submitting forms to action handlers). However, it's worth noting that this library doesn't use anything specific from Remix or React Router and could be leveraged in any React application.
Warning
This library is still in a beta stage. It's feeling more stable these days but I can't guarantee there won't be some breaking changes ahead 😀. Please read the release notes for each new version as they'll always be highlighted there.