API Calling for Freeswitch/Asterisk

We need a skilled freeswitch or asterisk developer to help develop an API interface capable of initiating phone calls on freeswitch (similar to Twilio APIs for voice calls). Sample use cases are to embed the API in a CRM or webservice to enable to user click a button on an external web application, and initiate a call on the freeswitch machine and the call is then connected to a softphone or webrtc endpoint for audio.