Presence

Introduction

A Presence object is a node's business card on the Ixian network. It bundles a node's identity (wallet address and public key) with a list of one or more network endpoints, called PresenceAddresses. This allows other nodes to discover and connect to it. A node broadcasts its Presence to the network, and Master Nodes collect these broadcasts to build a distributed network map known as the Presence List.

This document describes the on-wire serialization formats for the Presence container and its nested PresenceAddress and SignerPowSolution structures.

Core Data Types

• IxiVarInt / IxiVarUInt: See IxiVarInt Encoding.
• IxiBytes: See IxiBytes Encoding.
• string: A standard UTF-8 encoded string, prefixed with its length.
• char: A single byte representing a character.

Top-Level Presence Structure (v1)

This is the main container object.

Field	Data Type	Min	Max	Description
version	IxiVarUInt	1		The Presence structure version.
wallet	IxiBytes	*	*	The wallet address of the node.
pubkey	IxiBytes	*	*	The public key associated with the wallet address.
metadata	IxiBytes	0	*	Optional, application-specific metadata.
addressCount	IxiVarUInt	1	*	The number of PresenceAddress entries that follow.
addresses	PresenceAddress[]	*	*	An array of contact addresses for the node.

PresenceAddress Structure (v2)

Each Presence object contains one or more PresenceAddress entries, each representing a specific client instance or endpoint for the node. Each PresenceAddress is individually signed.

Field	Data Type	Min	Max	Description
version	IxiVarUInt	2		The PresenceAddress structure version.
device	IxiBytes	*	*	A unique identifier for this specific device or client instance.
address	string	*	*	The network contact address (e.g., "123.45.67.89:10234").
type	char	1	1	A character code for the node type: 'M' (Master), 'H' (Full History), 'R' (Relay), 'C' (Client).
nodeVersion	string	*	*	The version string of the Ixian node software.
lastSeenTime	IxiVarInt	*	*	The Unix timestamp when this presence entry was last updated.
signature	IxiBytes	*	*	A signature over the checksum of this PresenceAddress entry, created with the node's private key.
powSolution	IxiBytes	0	*	Optional. A serialized SignerPowSolution object, required for 'M' and 'H' type nodes.

SignerPowSolution Structure

This structure provides a Proof-of-Work solution that is required for Master Nodes to be listed in the Presence List. It proves the node has expended computational effort.

Field	Data Type	Min	Max	Description
blockNum	IxiVarUInt	*	*	The block number this PoW solution is valid for.
solution	IxiBytes	1	64	The nonce or solution that satisfies the PoW challenge.
signingPubKey	IxiBytes	*	*	The public key used in the PoW calculation.

Behavioral Notes

• Individual Signatures: The top-level Presence object is an unsigned container. Security and authenticity are enforced at the PresenceAddress level, where each entry is individually signed. A recipient MUST validate the signature of each PresenceAddress against the pubkey from the parent Presence object.
• PoW Requirement: Master Nodes (type = 'M') and Full History Nodes (type = 'H') MUST include a valid SignerPowSolution in their PresenceAddress entries. Other nodes can omit this field. The PoW difficulty is adjusted dynamically by the network.
• Note: Currently, all Master nodes also function as Full History nodes, as the distinction is not yet implemented in the codebase.