I have working to replicate TanStack query experience by writing my own queries wrapped around PowerSync, although actually on Flutter (using Flutter Hooks! which was cool to use coming from React). It’s a very internal design meant for my app tetr[1] right now (and actually being migrated over from Realm). I am hoping to potentially standardize it and publish a package once it’s mature enough but not too wrap to make your own hooks around them for your needs.

[1] https://tetr.app

Not sure if you've looked at PowerSync yet: https://www.powersync.com/ (I'm on the team)

For the read path it hooks into Postgres logical replication or MongoDB change streams (and MySQL binlog soon). It supports partial syncing using declarative rules. For the write path, it allows writing to the local SQLite database and also places writes into an upload queue, and then uses a developer-defined function to upload writes to the backend API.

We did a deep dive on current options for SQLite on the web, and are currently using an IndexedDB-based VFS, and looking to move to OPFS: https://www.powersync.com/blog/sqlite-persistence-on-the-web

We recently released an integration with TanStack Query to allow leveraging some of its features in conjunction with PowerSync: https://docs.powersync.com/client-sdk-references/js-web/java...

> Meanwhile for “local-only” it would be great to use sqlite in the browser + native file system API so that the db could be stored on the user’s file system and we wouldn’t have to worry about browser storage eviction. i think that could really open up a whole world of privacy preserving offline software delivered through the browser

Agreed. This is a limitation of IndexedDB and OPFS as persistent browser storage currently

ElectricSQL and friends seem to be the best option so far, but they all come with a lot of caveats. It feels like local-first is near, and it's so tantalizing, but I haven't seen anything that feels like it's done enough to build on just yet.