how to query a xmpp server from outside to find out what version he is running

Question

There are many xmpps servers around (ejabberd, prosody etc ...). Is there a api call that tells one what brand and what version is running on that server?

Answer 1

API? Probably most servers provide some API to get their name and version number. For example ejabberd provides the status API call:

$ ejabberdctl status
The node ejabberd@localhost is started with status: started
ejabberd 23.01.58 is running in that node

But quite obviously this is not what you want. Each server provides its custom API, and different ways to use them.

Quite probably what you want is to use XEP-0092: Software Version, which is implemented by most if not all XMPP servers, clients and components. Using that XEP, your client can ask any server what is his software name and version.

Of course, the server may reply or may not reply, or may provide false information. For example, ejabberd implements that XEP in mod_version, it's eanbled by default but can be disabled to not reveal this information.