The Device Fleet

"The file was the truth. Then the truth learned to travel."

Four Days, Eighteen Builds

The same week as the cutover, Rekindle stopped being a Mac-only app. The iPhone and iPad build (RekindleMobile) was born on 2026-09-13 and walked a milestone road in four days: the core packages building for iOS, the Mac's presentation on the device editor, inline images and tables and folding, a Bear-shaped library with snapshots and pin and completion on device, a working share sheet, and the pinned Scratchpad syncing both ways. Eighteen TestFlight builds went up between the 13th and the 17th — each one uploaded through the family's shared pipeline, where 'uploaded' is only fact one of four (processing, internal group, and installed-on-device are the other three, and nobody claims them early). The watch got a memo app too: dictate a thought on your wrist, and it lands pinned to today's daily note.

The Office Sync Engine

The fleet works because office grew a sync engine. The shape is deliberately boring: each device keeps a replica of its slice of the library, and a small engine in office serves protocol v1 over the family's hardened transport — an app-owned loopback listener, a BSD socket beside the Tailscale Serve twin, a LaunchAgent keeping it alive. Peers reach each other's roots through explicit, scoped sync plans with checkpoints; leases lapse after silence so a dead device holds nothing hostage. And the rule that made it all safe is the oldest rule in the quest: the files are still the truth. A replica is a derived mirror with a network in the middle — checkpointed, rebuildable, and never the master. Nothing about the storage doctrine changed; it just got a commute.

Writing Follows the Person

What the fleet is FOR showed up immediately. Phone and watch memos land on the daily note instead of a named scratch, so a thought caught on a walk is already filed where the day's writing lives. The iPhone home shows five recent notes under the pinned ones. The note list on the Mac re-reads itself when another replica's sync lands in the library — one of the seven ruled departures, because Dad's iPhone now writes into office while he sleeps. The market of one grew pockets and a wrist; the editor followed, without growing a second brain or a second master. Same soul, more doors.

Code

The fleet's shape — replicas around one truth·text

office    the sync engine: protocol v1, loopback + BSD socket,
          LaunchAgent, Tailscale Serve twin, leases that lapse
phone     a replica of its slice, checkpointed, synced both ways
watch     memo -> pinned to today's daily note
mac       re-reads the note list when a replica's sync lands

# The .md files remain canonical. A replica is a derived mirror
# with a network in it — never a second master.
# (Track 07's rule, with a commute.)

Exercise

Take something single-device you rely on (a notes folder, a journal, a reading list) and sketch its fleet: which device holds which replica, where the engine lives, what syncs eagerly vs. on demand, and — the hard question — what stays canonical when two devices edit offline at once. If your answer needs a database to be the boss, find the file-shaped answer instead.

Hint

Start from the failure you actually fear: two offline edits to the same note. The answer (one truth, explicit merge at the file layer, replicas that yield) is usually simpler than the sync product you were about to rent.