fix(sync): put the notes-holding device in the approver role so the approval prompt appears

server/src/index.ts

@@ -16,7 +16,7 @@
  *
  * WebSocket protocol (JSON messages):
  *   Client → Server:
- *     { type: 'join',             roomId, token, deviceId, deviceName }
+ *     { type: 'join',             roomId, token, deviceId, deviceName, hasData }
  *     { type: 'push-op',         payload (base64) }
  *     { type: 'ack',             cursor }
  *     { type: 'request-transfer' }
@@ -641,10 +641,18 @@ function handleMessage(client: Client, msg: Record<string, unknown>, ip: string)
     const room = getRoom(roomId)
     room.add(client)
 
-    // Check if this is a new device (cursor = 0 and other devices exist)
+    // A device "needs a transfer" only when it has NO notes of its own yet and
+    // there is another device in the chain to copy from. The client reports
+    // whether it already holds local notes via `hasData` — the server can't
+    // see the (E2E-encrypted) data itself. Relying on `cursor === 0` alone was
+    // wrong: the device that generated the sync code owns all the notes but
+    // hasn't pushed any ops, so its cursor is still 0. That misclassified the
+    // notes-holding device as a transfer requester, so both devices showed
+    // "Choose a source device" and the approval prompt never appeared anywhere.
+    const hasData = msg.hasData === true
     const allDevices = getDevices(roomId)
     const otherDevices = allDevices.filter(d => d.deviceId !== deviceId)
-    const isNewDevice = device.cursor === 0 && otherDevices.length > 0
+    const isNewDevice = !hasData && device.cursor === 0 && otherDevices.length > 0
     const maxSeq = getMaxSeq(roomId)
     const hasPendingOps = device.cursor < maxSeq
 

src/utils/sync.ts

@@ -435,6 +435,25 @@ async function refreshJoinToken(): Promise<{ roomId: string; token: string } | n
   return getJoinToken()
 }
 
+// Build the `join` payload. `hasData` tells the server whether this device
+// already holds notes locally. The server can't inspect our (E2E-encrypted)
+// data, so without this hint it inferred "new device" purely from cursor === 0
+// — which wrongly flagged the device that *generated* the sync code (and owns
+// all the notes, but hasn't pushed any ops yet, so cursor is still 0) as a
+// device needing a transfer. That left both devices stuck on "Choose a source
+// device" with neither ever showing the approval prompt. A device that has
+// local notes is a source/approver, never a transfer requester.
+function buildJoinPayload(roomId: string, token: string): string {
+  return JSON.stringify({
+    type: 'join',
+    roomId,
+    token,
+    deviceId: getDeviceId(),
+    deviceName: getDeviceName(),
+    hasData: (callbacks?.getNotes()?.length ?? 0) > 0,
+  })
+}
+
 async function connect(): Promise<void> {
   if (ws && (ws.readyState === WebSocket.OPEN || ws.readyState === WebSocket.CONNECTING)) return
 
@@ -461,13 +480,7 @@ async function connect(): Promise<void> {
   }
 
   ws.onopen = () => {
-    ws!.send(JSON.stringify({
-      type: 'join',
-      roomId,
-      token,
-      deviceId: getDeviceId(),
-      deviceName: getDeviceName(),
-    }))
+    ws!.send(buildJoinPayload(roomId, token))
   }
 
   ws.onmessage = async (event) => {
@@ -785,13 +798,7 @@ async function handleServerMessage(msg: Record<string, unknown>): Promise<void>
         console.log('[sync] Token expired, refreshing…')
         const newJoin = await refreshJoinToken()
         if (newJoin && ws?.readyState === WebSocket.OPEN) {
-          ws.send(JSON.stringify({
-            type: 'join',
-            roomId: newJoin.roomId,
-            token: newJoin.token,
-            deviceId: getDeviceId(),
-            deviceName: getDeviceName(),
-          }))
+          ws.send(buildJoinPayload(newJoin.roomId, newJoin.token))
         }
       }
       break