Sure @Chowderr ! Here is the workflow. We need to: 1. Collect information from the caller in the first part of the call 2. During the call, we need to pass the info we collect to external API that returns the appropriate transfer number based on that information 3. We then need to forward the call to the transfer number returned to us by the external API 4. We do not have a list of possible numbers prior to the call starting--we just need to transfer blindly to whichever number is returned by the external API To answer your questions: Are these inbound calls? Yes. **Why the weird external API? **The number changes pretty much every time. We are building for a customer who has a list of potential transfer numbers (in the hundreds). The customer has mapping logic that maps the information we collect during the call to the proper number to transfer to. We pass collected info into their API, they return the appropriate transfer number. The customer owns this API that maps the info to the proper transfer number, not us Are they transient? My understanding was that transient calls are only for outbound, not inbound. Is there a transient concept for inbound as well?