----------------------------- **While I generate an answer, here are some sources that might be helpful**: * [Create Phone Call]() * [List Calls]() * [Get Call]() * [Dynamic Variables]() -----------------------------

### Answer Currently, Vapi does not support dynamically updating the agent model, voice, or prompts during an existing call. There is no built-in functionality for daisy chaining agents or employing sub-agents in the middle of a call. Once a call has started with a specific configuration in Vapi, the settings for the assistant, including the model and voice, remain static throughout the duration of that call. Adjusting these elements dynamically during a call is not supported at this time. For modifying an assistant's behavior or settings, changes need to be made before initiating the call or after the call has ended. This includes any updates or configurations related to the assistant used for the call [(1)]() .