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>
?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>