I have a client that wants something I'm not sure how to do. It's a restaurant, and they want to automatically post the daily specials to facebook whenever they're updated.

To make things even more fun, the specials are split into various categories, so it would need to be several fields merged into one before being posted.

Is this possible using CouchCMS?

[KK]

Not possible out-of-the-box, I'm afraid. Will require custom development.

[trendoman]

If you are inclined to use CouchCMS then there are people here who can help with CMS part, but are you into php to use something like PHP SDK? https://developers.facebook.com/docs/reference/php
For the CMS part - your client can indicate today's specialties by setting checkboxes in backend. These meals from different categories can be combined with a basic filter. Filter can be based on 'custom_field' parameter of cms:pages tag, so get familiar with it in docs. Of course, complete solution is more than just getting together data from database. Making it really comfortable for the client would take some effort.

The straightforward way to do this is to create an RSS feed for the daily specials. There are a number of services that will monitor your feed and auto-post it to any number of platforms.
http://docs.couchcms.com/concepts/rss-feeds.html

Here's an example of someone posting to Twitter with IFTTT.
viewtopic.php?f=8&t=9735&p=21944

I've used dlvr.it for auto-posting, but there are many others.