Building block
Devices
Pair a new phone or laptop to the same identity and keep an inventory of your devices.
What a person notices
Getting a new phone does not mean starting over. Pairing it to an existing identity brings the same person into the new device, not a fresh copy of them.
There is a plain list of devices attached to an identity, so a person can see what is actually part of their account and notice anything that shouldn't be there.
Removing an old phone or a laptop that was lost or sold takes it out of the identity for good, rather than leaving it quietly able to act on someone's behalf.
A phone is not treated as a weaker or less trusted device than a laptop or desktop. It is encrypted the same way and holds its share of the identity the same way.
What you get as a developer
Devices are the physical holders of an identity's split key, and every change to the set of devices is a real, working operation, not a stub.
Adding a device re-shares the key
Pairing a new device triggers a re-split of the identity's cryptographic key across every current device, including the new one. This is implemented and running, not a placeholder for a future release.
No hard cap on how many
An earlier fixed limit of 16 devices per identity has been removed from the code. The remaining ceiling is just the width of an internal counter, far beyond anything a household or a team would reach, and it is not a number anyone has tuned or recommends aiming for.
Removing a device also re-splits
Taking a device out of an identity runs the same kind of re-split across whatever devices remain, so a removed device is not left holding a usable piece of the key.
Local-first: the device list and the re-split both happen without a server deciding who is allowed to join. Devices agree with each other directly.
How it connects
Identity
Devices exist to hold pieces of one identity's key. Without an identity to attach to, a device pairing has nothing to join.
Vault
Recovery material that can rebuild an identity if every device is lost sits in the vault, separate from any single device.
Signed storage
Every device add or remove becomes a signed record, so the history of what joined and left an identity is not something one device could quietly rewrite.