The Google Talk service is built on the following open-source protocols:
- XMPP: Extensible Messaging and Presence Protocol; an IETF standard for instant messaging. XMPP was originally called Jabber, and the XMPP enhancement proposals (XEPs) were previously called Jabber Enhancement Protocols (JEPs).
- Jingle: a family of XMPP extensions that make it possible to initiate and maintain peer-to-peer sessions. Specific Jingle extensions support voice streaming, video streaming, and file-sharing sessions.
http://juberti.blogspot.com/2006/11/gtalk-uri.html" title="Google Talk URIs">Google Talk URIs
gtalk:chat?jid=foo@gmail.com (starts a chat)
gtalk:call?jid=foo@gmail.com (starts a call)
Simply replace "foo@gmail.com" with the XMPP ID of the person you want to chat with/call and you're all set.
If you use multiple accounts, you can also add the "from_jid" parameter to the URL to control which account the message is sent from. Here's an example of a URL using from_jid:
gtalk:chat?jid=foo@gmail.com&from_jid=bar@gmail.com
As mentioned above, "call" and "chat" are the only URL commands currently supported. If you specify any other string, invoking it will simply cause the Talk client to come to the foreground.
Update: previously I had mentioned that you could use these links to put a "contact me with Gtalk" button on a web page. I goofed; the currently released version of Google Talk won't bring up the invitation UI when these URLs are invoked, so you can't do this quite yet.
http://www.quickonlinetips.com/archives/2009/04/google-talk-tricks/
To create a desktop shortcut to quickly chat with your GTalk friend, just right click on your desktop and go to New > Shortcut and type gtalk:chat?jid=username@gmail.com. To initiate a quick call, use the shortcut gtalk:call?jid=username@gmail.com where username should be replaced by your buddy’s GTalk ID. This method doesn’t work on Windows Vista, but only on XP