Can there be any appropriate, secure and modular API to get this done?
It will likely be incorporated inside a Wordpress wordpress plugin.

EDIT: More that posts I want send generic data that it's collected via a Wordpress wordpress plugin. These information is not saved within the Wordpress DB, I simply need send them.

You are able to have a look at http://wordbooker.tty.org.uk/.

I'm only a happy user of this wordpress plugin, no affiliation.

After 2 lengthy and sad days I'm able to lead with this particular answer: This API is an extremely, excellent. Which is suggested within the Facebook developer web site to all of your PHP needs:

Facebook PHP SDK