Before starting…

Slixmpp is a library for using the XMPP protocol, so if you are not very familiar with the core XMPP concepts, here are a few that are essential to understand before diving in:

Entities

XMPP has clients, servers, and components.

  • Clients: user-facing XMPP software (Conversations, Gajim, Poezio…), or bots. They talk to servers.

  • Servers: XMPP servers (Prosody, Ejabberd, Openfire…). Clients connect to them and they connect to servers.

  • Components: Additional software on the server side that provides additional features.

Slixmpp allows you to write clients and components easily, but we do not implement an XMPP server.

JIDs

A JID, for Jabber ID, is the address of an entity over XMPP and can have three primary forms:

  • server, a bare JID without a user part, for components and servers.

  • user@server, a bare JID with a user part.

  • user@server/resource, a full JID including a client resource.

Slixmpp provides a JID class for creating and validating those addresses easily.

XEPs

A XEP (for XMPP Extension Protocol) is a document standardizing XMPP features and interactions. This is the key to XMPP’s extensibility.

Slixmpp implements a hefty number of those documents, and most of those are implemented as plugins, which will only be loaded at the developer’s request.

Some of those plugins may require extra dependencies.

Payloads

There are three main types of payloads in XMPP, called stanzas, those are:

  • <message/>, containing a message to another entity, represented by the Message class.

  • <presence/>, containing presence information, represented by the Presence class.

  • <iq/>, containing a query (of type set or get), which the remote entity must answer with another IQ having the same identifier (either with type error or result). Represented by the Iq class.

The identifier of a stanza is the id attribute of its top-level element, e.g. <message id="some-id" />. An Iq must have an identifier.

Getting Started (with examples)