LiveStore FileSync

File sync for LiveStore apps. The missing piece for local-first apps that need to sync files.

Key Features

Local-first Files are written to local storage first, ensuring best UX and offline support
Background sync Files are synced in the background by reacting to LiveStore events
Cross-platform Web, desktop and mobile support through pluggable filesystem adapters
R2 and S3 storage Built-in support for Cloudflare R2 and any S3-compatible remote storage
File preprocessing Resize, convert and transform files before saving with pluggable preprocessors
Image thumbnails Optional client-side thumbnail generation in a dedicated web worker
Multi-tab support Automatic leader election ensures only one tab runs the sync loop

The library is split into focused packages:

@livestore-filesync/core Framework-agnostic API and schema helpers
@livestore-filesync/opfs OPFS filesystem adapter for browsers
@livestore-filesync/expo Expo/React Native filesystem adapter
@livestore-filesync/r2 Cloudflare R2 storage handler (Worker-proxied)
@livestore-filesync/s3-signer S3-compatible presigned URL signer (direct-to-storage)
@livestore-filesync/image Image preprocessing and thumbnail generation

TypeScript, Effect, LiveStore, Cloudflare Workers

Pluggable filesystem Adapters built on the @effect/platform FileSystem interface
Signer-based auth Backend mints short-lived signed URLs for uploads and downloads
Content-hash tracking Correct file versions are displayed after edits across clients
Leader election Web Locks API ensures only one tab handles sync in multi-tab scenarios