Skip to main content

Documentation Index

Fetch the complete documentation index at: https://docs.ultravox.ai/llms.txt

Use this file to discover all available pages before exploring further.

Special Tool Response Types

For most tools, the response will include data you want the model to use (e.g. the results of a lookup). However, Ultravox has support for special tool actions that can end the call, change the call stage, or communicate with another thread. These tool actions require setting a special response type.
Response TypeTool Action
hang-upTerminates the call. In addition to having Ultravox end the call after periods of user inactivity, your custom tool can end the call.
new-stageCreates a new call stage. See here for more.
send-to-threadSends a message to another thread. See here for more.
How you set the response type depends on your tool implementation. HTTP tools set the response type via the X-Ultravox-Response-Type header. Client and data connection tools should set the responseType field in their tool result message.