HTTAPI allows for FreeSWITCH to ask a webserver what to do to/with a call, and after executing, ask the webserver again. So, is actually a hyper dynamic protocol, where FreeSWITCH sends the webserver all info about a call and the results of last action(s), and webserver reply with what to do as next step. Then the cycle repeat until hangup or the call has been transferred. The obvious use cases are IVRs, but other kind of applications may enjoy this approach.

In this chapter we will discuss:

• The HTTAPI main concepts
• HTTAPI dialplan action
• The structure of the document returned by webserver
• Configuration od mod_httapi
• A sample PHP library that makes HTTAPI applications easier to develop