Sharing & P2P sync

Kalta supports two ways to keep multiple people in sync: cloud-based sharing of a warehouse (invite-link flow through our backend) and peer-to-peer sync between two nearby iPhones over Bluetooth and WiFi (no internet needed).

Most households use cloud sharing as the default. P2P is there for offline scenarios or as a privacy-focused alternative.

Cloud-based sharing (invite links)

A warehouse can be shared with other Kalta users. When you share, everyone who joins has read and write access to that warehouse: they can add and edit items, rename boxes, and mark things as opened. Only the owner can delete a warehouse or remove members.

Generating an invite

1. Open the warehouse → Settings tab.
2. Tap Invite.
3. Kalta generates a link valid for 7 days. You’ll see the iOS share sheet.
4. Send the link however you like — iMessage, email, WhatsApp, AirDrop, Signal, any app on your phone.

Accepting an invite

On the recipient’s side:

1. Open the link on their iPhone.
2. If Kalta is installed → it opens directly. If not → App Store opens to Kalta’s page; after install, the link is remembered and processed on first launch.
3. The recipient signs in with Apple (if they haven’t already).
4. Kalta shows the warehouse preview. Tap Accept.
5. The warehouse appears in their dashboard. It’s now shared.

Member management

Inside the shared warehouse → Settings → Members:

• See all people who have access, with their display name.
• Owners can remove members — swipe left on a member → Remove. Access is revoked immediately.
• A removed member can be re-invited later with a new link.

Safety tips

• Only share invite links with people you trust. There’s no email verification or approval flow — whoever opens the link can accept.
• Invite links expire after 7 days but are active for anyone during that window. If a link goes to the wrong person, the fastest fix is to generate a fresh one (the old one doesn’t auto-revoke, but it only works once). Then remove the wrong person from the Members list if they accepted.
• Removed members can no longer see the warehouse after removal, but any data they viewed or exported while active is theirs to keep — we cannot retroactively revoke what they already saw.

Who sees what

All members see:

• All boxes, items, notes, and photos in the warehouse.
• Other members’ display names.
• Inventory history (who added/changed what, if you had multiple members active at once).

Nobody outside the warehouse membership can see any of this — not other Kalta users, not us (well, we host the data but only you and members can read it via the app).

P2P sync (two nearby iPhones)

P2P sync lets two iPhones running Kalta exchange inventory data directly over Bluetooth and WiFi using Apple’s MultipeerConnectivity framework. No internet is required.

When to use P2P

• Offline locations — cabin without WiFi, remote shelter, underground basement.
• Initial setup — want to clone your inventory to a second device quickly.
• Privacy preference — you don’t want your sync traffic to pass through any server, including ours.

For day-to-day household use, cloud sharing is simpler — changes sync automatically in the background. P2P is a manual, on-demand transfer.

How to start a P2P sync

Both devices must have Kalta open on the P2P Sync screen at the same time.

1. Open Kalta → Settings → P2P Sync (or from a warehouse’s Settings tab).
2. Tap Start searching on both devices.
3. The other device’s name appears in the list.
4. On one device, tap the peer → Connect.
5. The other device shows a connection confirmation → tap Accept.
6. Once connected, tap Sync to exchange data.

What’s exchanged

Both devices send each other a JSON bundle of their local data: warehouses, boxes, items, members, custom products, inventory sessions. The other side merges it using a last-write-wins per field rule: for each field of each item, whichever edit was most recent wins.

Different fields on the same item can come from different devices — for example, if you changed the quantity on device A and the notes on device B, the merged result keeps both changes.

Encryption

The MultipeerConnectivity session is TLS-encrypted end-to-end by Apple’s framework — nobody in between (e.g., a passer-by on the same WiFi) can read the payload.

Conflict resolution

Kalta uses last-write-wins automatically. Most of the time this does the right thing. In rare cases where both devices edited the same field at nearly the same time, the app may flag the conflict in the Settings → Conflicts screen so you can pick the correct version manually.

Troubleshooting P2P

• Make sure Bluetooth is on on both devices (WiFi doesn’t need to be connected to the same network, but the radio must be on).
• Make sure neither device is in Low Power Mode — it aggressively disables Bluetooth scanning.
• The P2P Sync screen has to stay open on both devices for them to see each other. Don’t background the app during sync.
• If they don’t see each other after 30 seconds, force-close Kalta on both devices and retry.
• Verify the device name shown in the peer list matches the device you intend to pair with. P2P is for trusted devices (family, your own second iPhone) — don’t connect to random peers.

Which should you use?

For most households: cloud share with your partner once, forget about it. Use P2P only when you actually need it.

What’s next

• If you haven’t set up notifications yet, read Expiry & reminders.
• For the printing side of boxes (labels, Brother printers), see Printing QR labels.