[Divergence] JS Web SDK adds opt-in storageBucket option to keep OPFS databases in a named Storage Bucket (powersync-js #1142) #731

What's changing: @powersync/web database open options gain an optional storageBucket name. When set, the OPFS-based VFS implementations (OPFSCoopSyncVFS, OPFSWriteAheadVFS, AccessHandlePoolVFS) store their database files in that Storage Bucket instead of the default bucket of the origin private file system. This avoids a Chromium defect where, after a user deletes site data, OPFS calls on the default bucket can fail or delete a newly created database. The option requires the Storage Buckets API (Chromium 122 and later), setting it with a non-OPFS VFS is a configuration error, and a database in a bucket is separate from one with the same name in the default bucket, so existing data is not moved. The change is in a pending minor changeset for @powersync/web and has not been released yet.

High priority — existing docs are now inaccurate or incomplete
None identified.

For reviewer consideration — worth documenting

• JavaScript Web SDK (https://docs.powersync.com/client-sdks/reference/javascript-web), VFS section: describes the OPFS VFS options and their per-VFS settings. No page covers storageBucket, its Storage Buckets API requirement, or the fact that switching an existing app starts with an empty local database.

Source PR: powersync-ja/powersync-js#1142 — merged 2026-10-28

Filed automatically by Claude Code (claude-sonnet-5-5). A human must verify the scope, prepare the docs PR, and publish it only once this update has been released.