From 16 KB a picture's or binary file's entry names its bytes by their
SHA-256 instead of holding them; the bytes are on F, content-addressed
(GET/POST /blobs with the session's grant, from the editor's origin, at
most 16 MiB). A document's blob side says where they are: the editor's
fetches and uploads, the room thread's asks F's main thread, and a start
waits for the ones asked for; without a side everything stays in the
document. Text stays Y.Text. A blob whose bytes are not there is never
written back empty. A blob F has not got yet is asked for again a few
times, and a running room reads late bytes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Over Yjs awareness each editor tells who it is (F names the person in
the access message), the device it has chosen and the windows it has
open, and nothing else: no pointer, nothing that changes without a
cause, sent only when it changed. Others' states are read with care.
A frame in their colour round a device they chose, a dot on a window
they have open too, a circle with initials each beside the mode
buttons; the bridge tells the dashboard who is there.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
?project=<uuid> opens the shared document over /sync and the room over
/sim (RemoteSimHost: messages wait for the socket, a lost socket comes
back with what it watched, F's refusal or parting ends it); instead of
the editor, a word why when F refuses or lets go. F tells each
connection its access at once. Who only reads sees everything and
changes nothing: no palette or undo, a locked surface, the sheet's
fields disabled (tabs stay), no starting or stopping; thawed, the
document comes anew. The toolbar names who started the simulation.
Refusals carry no message, so Hocuspocus writes nothing outside F's
JSON log. A browser test runs three people against a real F.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
julian.kiedaischandClaude Opus 5.5