Integrations
Same idea as VAPI. Custom LLM (full takeover) or function call (during Retell's own conversation).
Custom LLM
Retell → Settings → llm.custom_llm_url = Ambrose's OpenAI-Compatible URL. Use this when you want Ambrose to drive the conversation.
Function
Register a custom function in Retell with URL = /api/{kind}/<slug>/webhook/retell. Retell drives the call; calls Ambrose for specific actions.