Freepbx, Fusionpbx uses Freeswitch. This is built for Asterisk but there is nothing stopping from setting a SIP trunk from Freeswtich to Asterisk box to make use of Agents like this user did https://github.com/hkjarral/AVA-AI-Voice-Agent-for-Asterisk/...
Freepbxx built on Asterisk primarily for single orgs whereas Fusionpbx is built on freeswitch designed for multi tenant and carrier grade deployments. Is that what you were looking for or something more specific in relation to this project ?