To facilitate discovery of information of individual domains in an XMPP-based network, this specification defines a data format to define basic information for individual XMPP domains. By leveraging &xep0060; this information can efficiently be shared with applications that compose an overview of the larger XMPP network.

• Describe links between nodes in an XMPP-based network, by enumerating connections used for federation between XMPP domains.
• An extensible data format, allowing additional data (such as that defined in &xep0092;) to be retrievable without requiring additional round-trips.

Support is advertised by publishing a first-level leaf node using the name 'serverinfo' on a pub-sub service. An entity trying to discover support will, for a given domain name, use &xep0030; to identify a Publish-Subscribe service for the domain, and subsequently use service discovery to discover the node with name 'serverinfo' as defined in section 5.3 of &xep0060;.

The data format uses an element named 'serverinfo' in the namespace 'urn:xmpp:serverinfo:0'. In its minimal form, it only defines the XMPP domain name in a child-element named 'domain'.

The optional 'federation' child element is used to denote remote XMPP domains with which the local domain is federating. Each federated domain is added as a 'connection' child-element to the 'federation' element, that has an optional 'type' attribute, defining the directionality of the connection (one of 'incoming', 'outgoing' and 'both'). The domain name of the remote XMPP domain is added in a 'domain' child element.

Additional data MAY be included in child-elements of the 'server-info' element. Such data MUST be namespaced appropriately. The example below uses the 'query' element defined in &xep0092; to include information about the software application associated with the local domain.

The data is to be published using a pub-sub node named 'serverinfo' that MUST be a first-level leaf node of a pub-sub service for the domain. It is RECOMMENDED that the leaf-node is configured to have an open access model and contain a maximum of 1 item.

As certain information can be expected to be updated continuously and frequently, the server MAY choose to reduce the frequency of updates of the 'serverinfo' pub-sub node.

This document requires no interaction with the &IANA;

Inspiration was taken from the (now defunct) 'server info' crawler by Thomas Leister. Many thanks to Dave Cridland, as well as 'zoidberg' from the Ignite Realtime community for helping to test the initial implementation of a graphing implementation based on this XEP.