Update Assistant

Update an assistant’s configuration. If published, changes auto-sync to the voice engine.

Endpoint

assistant_id
string
required
Assistant ID or UUID

Request Body

All fields are optional — only include what you want to change.
name
string
Updated name
system_prompt
string
Updated system prompt
model
object
Updated LLM configuration
voice
object
Updated voice configuration
transcriber
object
Updated transcriber configuration
credential_ids
array
Update Vapi credential UUIDs for provider authentication
server
object
Update server webhook configuration (url, timeout, secret)
first_message
string
Updated greeting

Example Request

Switch to Custom Provider (Spitch)

Add Credential Reference

Set Custom Webhook URL

Response

If the assistant is published, the update is automatically synced to the voice engine. No need to re-publish.