A contact is created from a profile, which represents an invitation link that can be shared to establish the relation. This invitation link consists of a twincode and a public Ed25519 key, and it is signed by the private key to ensure the integrity and trustworthiness of the information. When the invitation link is received by a peer device—or its associated QR code is scanned—a contact relation is established between the device using the invitation link and the device owner.

Once the contact relation is created, each device will then create a new twincode to represent your identity within this new relation. This new twincode is initialized using your profile, including your nickname, avatar, and profile description. Additionally, a new Ed25519 key is generated to sign this new twincode.

The two newly created twincodes are exchanged between the peers, ensuring that each device knows the other’s twincode outbound and the corresponding public key that was generated.