Buddycloud is a collection of servers, running as XMPP components that enable rich, federated communications for groups and individual users. users uses and groups. Buddycloud builds on XMPP's native federation and pub-sub principles to connect to and synchronise updates with other Buddycloud servers.

Channels are a bundle of pub-sub nodes that have the same owner, folllowers and access permissions. There are two types of channel: user channels (named after the user's JID), for example romeo@montagu.lit) and topic channels, for example balcony-speeches@topics.montague.lit) which are owned by the channel creator. Content posted into channels is automatically synchronised to the correct followers on other Buddycloud servers.

Service discovery happens per domain, and is a multi step process.

To discover the channels component for a domain, the entity first sends an items discovery request to the domain to discover all the available components.

The server replies with the list of available components, along with their associated JIDs.

The entity then iterates through the <item/> elements, sending an info discovery request to each jid.

Each component replies with its identity. The channels component has an identity of category 'pubsub' and type 'channels'.

A domain MUST only host one component with an identity of category 'pubsub' and type 'channels'.

Upon connection to the buddycloud server a user should send a register stanza.

The register request creates the user's personal channels on first use and has the additional benefit of creating additional new channel nodes as they become available on the server (e.g. 'status' node, 'geoloc' nodes).