Hi, For outbound calls, I’ve been successfully using

assistantOverrides

to override settings like voice, firstMessage, and variableValues. For inbound calls, can I return something like the following in the

assistant-request

webhook response and have it applied in the same way? { "assistantId": "assistant-id", "assistantOverrides": { "voice": { "provider": "11labs", "voiceId": "voice-id", "language": "ja", }, "firstMessage": "こんにちは、山田です。ご用件を伺ってもよろしいでしょうか？" } } Reference https://docs.vapi.ai/server-url/events#retrieving-assistants Thanks!

Hello, Thanks for reaching out to us. Apologies for the inconvenience this has cause you, let me help you with this. Please do let us know if you need further assistance about this and we will gladly investigate further.

whenever an inbound call comes to my Vapi number, I want my webhook to be triggered immediately (without needing full assistant logic). Could someone clarify: Which server event should I use to intercept incoming calls? There is no

assistant-request

event in the dashboard setting. Basically, I want the webhook to fire as soon as the inbound call is detected, so that I can dynamically pass firstName and email.

Hi, To intercept inbound calls immediately, before any assistant logic runs, you should use the assistant-request webhook event. The

assistant-request

event is triggered as soon as Vapi receives an inbound call and needs to determine which assistant to execute. Your server must respond with: •

assistantId

(or an inline assistant configuration), and • Optionally,

assistantOverrides.variableValues

to dynamically pass values such as

firstName

or

email

. Important: the

assistant-request

event will only fire if the phone number does not have a static

assistantId

or

squadId

assigned. To configure this correctly: 1. Go to your Phone Number settings. 2. Remove the attached

assistantId

or

squadId

. 3. Set the phone number’s Server URL to your webhook endpoint. 4. Ensure the number is configured to send the

assistant-request

event (via

serverMessages

in the API). When Vapi sends the

assistant-request

event to your webhook, your response should look similar to:

{
  "assistantId": "asst_XXXX",
  "assistantOverrides": {
    "variableValues": {
      "firstName": "Andy",
      "email": "andy@example.com"
    }
  }
}

You can then reference

{{firstName}}

and

{{email}}

in your

firstMessage

or system prompt. If you keep a static assistant attached to the phone number, the

assistant-request

event will not trigger. In that case, earlier events such as

call.ringing

or status update webhooks may fire, but they do not allow variable injection before the assistant starts.