requestAdd2 (40)

The requestAdd2 message is the standard, version-aware method for initiating a new contact connection. The sender includes their public key and the maximum protocol version they support. The entire message is signed to prove ownership of the sending address.

Core Data Types

• IxiVarUInt: See IxiVarInt Encoding.
• IxiBytes: See IxiBytes Encoding.

Payload Structure

Field	Data Type	Min	Max	Description
maxVersion	IxiVarUInt	1		The maximum S2 protocol version the sender supports.
publicKey	IxiBytes	*	*	The sender's public key. The address derived from this key must match the sender's address in the StreamMessage envelope.

Behavioral Notes

• Sending: A user sends this message to a new contact's address. The StreamMessage containing it MUST be signed using the private key corresponding to the publicKey in the payload.
• Receiving: Upon receipt, the recipient's client verifies the signature of the StreamMessage. If valid, it adds the sender to its contact list with a "Request Received" status and stores their public key and protocol version.
• User Action: The recipient's client should then display a notification to the user, allowing them to accept or decline the contact request. Accepting the request triggers sending an acceptAdd2 message.
• Version Negotiation: The maxVersion field allows for future protocol upgrades. The recipient will use this information to decide which protocol version to use when replying with acceptAdd2.