Connecting and Sync

Phone connects to computer over your local Wi-Fi. Encrypted, peer-to-peer, no internet required.

The sync concept

Sync is on demand and entirely user-driven. The phone connects to the computer, then nothing happens until you click SYNC NOW on the computer. Each sync is a complete state exchange resolved by an automatic three-way merge. Both sides' edits survive without you picking a winner. The computer compares its own state, the phone's state, and a saved snapshot of the last successful sync, then produces a result that includes everyone's adds, edits, deletions, and reorders.

Been out adding things to your phone? Been at your computer crossing things off? Sync. The result has both. No dialog, no choice, no lost edits.

Two safety dialogs can interrupt a sync, both rare:

Sync conflict. Opens when both devices changed the same value at the exact same moment. You pick which version to keep, one row per conflict. In normal use you will not see it.
Large change detected. Opens when eighty percent or more of the items the computer remembered from the last sync are missing on one side with no deletion records. Almost always this means one side was reinstalled or wiped. Three buttons: USE COMPUTER DATA, USE PHONE DATA, CANCEL SYNC. The picked side's data is sent to the other device.

Both dialogs auto-cancel after sixty seconds with no changes on either device.

Connection flow

You tap Sync on the phone. The phone never connects on its own.
The phone opens a WebSocket to the computer's IP and port (set during pairing).
Both sides exchange ephemeral keys and derive a shared secret. Every later message is encrypted.
The phone sends a handshake with its device name, pairing secret, and last sync timestamp.
The computer validates the pairing secret and accepts the connection. Both sides are now connected, but no state exchange happens until you click SYNC NOW.

State sync

When you click SYNC NOW on the computer:

The computer asks the phone for its current state.
The phone sends its lists, locked lists, scratchpad, and categories.
The computer reads its own state and the saved ancestor snapshot from the last successful sync.
The computer runs a three-way merge.
The merged result is applied on the computer.
The computer sends the merged snapshot to the phone, which applies it directly.
Both sides save a fresh ancestor snapshot for next time.

If the merge produces a true tie (same value changed on both sides at the exact same instant), the sync conflict dialog appears. If you cancel or wait sixty seconds, the sync aborts with no changes on either device.

If both sides are identical, the sync runs silently and just updates the timestamp.

What the merge does in plain language

Situation	Result
Phone added a new item, computer did not touch it	Item appears on the computer
Computer added a new item, phone did not touch it	Item appears on the phone
Both sides added different new items	Both new items survive
Phone edited item A's text, computer toggled item A's checkbox	Both changes apply to the same item
Both sides edited the same field of the same item	Most recent change wins; if exactly tied, the sync conflict dialog opens
Phone deleted an item, computer did not touch it	Item is gone on both sides
Phone deleted an item, computer edited the same item	Delete wins
Both sides reordered the same list	Both reorderings combine into one stable order
Both sides added an item at the same position	Both items survive; order is consistent across devices

Button states during transfers and saves

To prevent overlapping operations from stepping on each other, the computer briefly disables certain buttons while a transfer or save is in progress:

While phone-to-computer media is still arriving (after expanding a jot or starting a download): Sync Now, Download All, the big save button on every jot, and the per-row save buttons for items whose data has not arrived yet are all disabled.
While the computer is writing a jot to disk (Download All in progress, or a per-jot save with media): Sync Now, Download All, and every jot's big save button are disabled.

Buttons re-enable the moment the operation finishes. The system messages panel shows what is happening in plain text.

What syncs

Data	Direction	Method
Lists (items and categories)	Both ways	Three-way merge
Locked Lists	Both ways	Three-way merge
Scratchpads (text and categories)	Both ways	Three-way merge (most recent change wins on text bodies)
Jot media (images, files, audio, drawings)	Phone to computer	Manifest plus binary download
Settings	Not synced	Local to each device

See also: Pairing | Sync Protocol | Security | Debug Logging