In this post, I am going to quickly share how you can add Facebook Messenger to your OS X’s built-in iMessages Application.
Follow these steps to setup the Facebook Chat Messenger on your iMessages app.
1) Start iMessages Application and open it’s Preferences
2) Goto Accounts Tab and Click on “+” icon to add a new account.
3) In the Account Setup window, input the following details as –
Account Type: Jabber
Account Name : firstname.lastname@example.org
You can view these settings in the image below, to ensure that you input correct values.
Hope this helps you.