Since you need to handle an already established call and swap transfer numbers/endpoints dynamically, transient agents let you spin up per-call instances with custom variables, without affecting a static setup. A static agent is better for fixed workflows or long-lived setups, but it’s harder to dynamically swap endpoints on-the-fly for each call. If you want, I can share a quick example of how to structure the transient agent to handle dynamic call routing with Twilio and Vapi.