LMOS Beta Update: Local Runtime Keeps Heavy Creative Files on Your Device
Update 31 adds one shared LM Local Runtime beneath LMFS and the media apps: device file references, local browser storage, lightweight fingerprints, relinking, capability detection and explicit Managed Cloud choices instead of automatically uploading source media.
What changed
Added a shared LM Local Runtime service with capability detection for persistent file handles, directory handles, browser storage, WebCodecs, WebGPU/WebGL2, AudioWorklet, local CPU availability and online state.
Extended the existing LM local-media IndexedDB database instead of creating another LMFS. It now keeps file-handle references, lightweight local manifests and explicit local-cache assets.
Added partial file fingerprints based on metadata plus small head/tail samples so LMOS can recognize or warn about a relink without hashing multi-gigabyte originals end to end.
LMFS / My Stuff now offers Local Reference or Managed Copy. Local Reference registers only the small server manifest while the source remains on the user device.
Local LMFS items remain visible in the synced library manifest on another device and provide a Relink path when the bytes are unavailable there.
LM Video local sources now use the shared runtime descriptor while preserving legacy localKey projects and existing Drive/managed-media support.
LM Podcast new microphone recordings default to Local Mode; Managed Cloud is available when the user intentionally wants an uploaded copy.
LM Photo new projects default to Local Mode. Original photos and local thumbnails stay on-device while edit decisions remain in the project manifest; intentionally shared watermarked client proofs can still upload.
LM Draw imported images now default to Local Mode with an explicit Managed Cloud choice. Existing cloud-hosted graphics assets continue to load.
Added an LMOS Local Runtime system page showing the device capabilities, browser-storage estimate and the local/server responsibility split.
Added Local Runtime to the shared-engine map only for apps that benefit from device media or compute instead of forcing every LMOS app through it.
The storage rule
Source media should not be uploaded merely because the user opened an editor. Local Mode keeps heavy originals where they already live. Managed Cloud is a user choice for cases where hosted bytes, sharing or cross-device availability are worth the storage cost.
What still requires the server
Accounts, subscriptions, permissions, collaboration metadata, project manifests, publishing, public sharing, hosted proofs and server-only services still use Floot. Local Runtime is not an attempt to make LMOS an offline-only island; it is a way to stop treating the server as an unnecessary hard drive and render farm.
Browser boundaries
Persistent file and directory handles depend on browser support and user permission. LMOS falls back to browser-managed local storage or explicit relinking when needed.
Browser storage can be subject to platform eviction rules unless persistence is granted; LMOS exposes the current storage policy and can request persistent storage without repeatedly nagging.
A synced manifest cannot make a device-only file magically available on a second computer. The second device sees the reference and must relink the source or use a deliberately managed/cloud copy.
Client proofs, publishing outputs and other intentionally shared artifacts may still upload because sharing is the purpose of those actions.
What testers should try
Open My Stuff and add a large source file as a Local Reference. Confirm LMOS registers it without showing an upload transfer.
Open the same account in another browser/device and confirm the manifest remains visible but the source asks to be relinked instead of pretending the bytes are present.
Record a podcast in Local Mode, reopen the project and verify the recording remains available from the same browser storage.
Add photos in LM Photo Local Mode, edit them, export locally and confirm only a watermarked proof is uploaded when you explicitly add it to a client gallery.
Import an image into LM Draw in Local Mode, save/reopen the project and verify the design still points to the local source.
Open Local Runtime from the LMOS menu and review file-handle, storage, CPU/GPU/media-codec and online capabilities reported for the current device.
Use the beta on real work.
The most useful feedback is not “I like it.” Tell us where you hesitated, what took too many clicks, what did not save the way you expected, and what would make this useful enough to return to next week.
