Programming Jabber

jabber:iq:agent

The jabber:iq:agent namespace is used to request and return information on an agent. An agent is a service running on a Jabber server, and it has a JID. To find out what features the particular agent offers, an IQ-get can be made using this namespace:

SEND: <iq type='get' to='yak/groups'>
        <query xmlns='jabber:iq:agent'/>
      </iq>

Here, a request for features is being made of the agent with the JID yak/groups, which is the standard name for the Shared Groups service. The JID here is composed of a hostname (yak) and a resource (groups).

The response looks like this:

RECV: <iq type='result' to='dj@yak/Work' from='yak/groups'>
        <query xmlns='jabber:iq:agent'>
          <name>Jabber Server at yak</name>
          <url>http://yak</url>
          <service>jabber</service>
          <register/>
        </query>
      </iq>

In reality, although the agent or service itself is specified as the recipient of the query, it is often a centralized mechanism that responds on behalf of the agent if the agent itself doesn’t or can’t respond. (This is the mod_agents module within the JSM.) This means that the results of the query might not be as helpful as you might expect. The only detail in the response shown here that might be of some use is the <register/> tag, but that’s actually misleading as it’s picked up from the general registration capabilities configuration and not anything particular to what was queried.

The main reason for this is actually also the answer to a question you might have right now: “How do I know which ...