Scenario: I want the agent to look up the first and last name of the caller based on their caller number then address the caller immediately by their first name without ever asking for it. What I did: I set up an end point for the Server_URL, and it indeed is called at the beginning of the call. It contains the caller's phone number. I then use that to query my MYSQL database and obtain the first and last name. However, I do not know how to provide that first name, last name and call number back to the agent for use in the phone call. I tried https://api.vapi.ai/assistant/{assistant_id} with this payload: payload = { "metadata": { "caller_number": caller_number, "first_name": first_name, "last_name": last_name, "customer_id": customer_id } } .. but the agent still does not recognize the caller's name. Am I using the wrong API call? Is there a way to feed variables back to the agent during the call?

@Michael P It sounds like you're on the right track by attempting to pass the caller's information back to the agent. However, instead of using the metadata field, you should use the

assistantOverrides

with

variableValues

to pass dynamic variables during the call. Here's how you can do it: 1. When you receive the caller's phone number at your endpoint and look up their information in your database, prepare the data to be passed back to VAPI. 2. Use the

assistantOverrides

field with

variableValues

to set the dynamic variables such as

first_name

,

last_name

, and

caller_number

. 3. Make an API call to VAPI with the correct payload structure to update the call context. The payload should look something like this:

json
{
  "assistantOverrides": {
    "variableValues": {
      "first_name": "John",
      "last_name": "Doe",
      "caller_number": "1234567890"
    }
  }
}

You would send this payload to the appropriate VAPI endpoint that is designed to update the call context with dynamic variables. If you're not sure which endpoint to use or how to structure the request correctly, please ask support for more info on this. They will be able to provide you with the specific details for your VAPI setup.

Am I calling the correct API? I actually tried this first but I always get the following error: "property assistantOverrides should not exist". @User

you need to use a custom server or make to serve an assistant-request type of server call https://docs.vapi.ai/server-url/events Read the section titled "Retrieving Assistants"

Thank you @ErikZ ! So I have a custom server URL, I called it https://my_server_domain/incoming_call and it successfully retrieves all the information I need. It is saving it back that is causing me the headache. Here is an abbreviated version of it: @app.route('/incoming_call', methods=['POST']) def incoming_call(): call_event = request.get_json(force=True) assistant_id = call_event.get('message', {}).get('call', {}).get('assistantId') caller_number = call_event.get('message', {}).get('call', {}).get('customer', {}).get('number') [snipping out part where I look up the first and last name from my DB] update_url = f"https://api.vapi.ai/assistant/{assistant_id}" headers = { "Authorization": f"Bearer {VAPI_API_KEY}", "Content-Type": "application/json" } payload = { "assistantId": assistant_id, "assistantOverrides": { "variableValues": { "first_name": first_name, "last_name": last_name, "customer_id": customer_id, "caller_number": caller_number } } } .. then I call the update_url and that is when it tells me assistantId and assistantOverrides are not valid. Am I calling the wrong API?

your server should be set in the serverUrl of VAPI and it should be able to handle the 'https://api.binarytint.com/api/webhook' endpoint

OK. Not the Server URL in the Assistant?

no, you will not set the override variables in the assistant

yeah would be great to see some sample code

@Michael P You can directly send me your server url. I will add it. Apart from it, just add the server url and wait for couple of minutes

Hi @Sahil - just spoke with support, it looks like I was indeed calling the wrong API. I was trying to call https://api.vapi.ai/assistant/{{assistant_id}} to set the dynamic variable but it looks like it should have been using the https://api.vapi.ai/call - I am going to try this and if it works I will close the ticket and add more information about how I fixed it to the community. Thank you!

Let me explain how I got this working for my assistant, which I figured out just 2 days ago. 1. You need to have your own custom server URL handling requests 2. You need to have a phone number capable of receiving incoming calls 3. You dont want to set an assistant for the number(I.E you want it to say "Select Assistant..." 4. Your server will get a request to the endpoint when a call is made to that number: "https://.com/api/webhook" of type 'assistant-request' 5. You will need to query vapi for the assistant you want to return: api_url = f"https://api.vapi.ai/assistant/{assistant_id}" headers = { 'Authorization': f'Bearer {BEARER_TOKEN}' } response = requests.get(api_url, headers=headers) 6. Once you have the assistant data you will need to unset some of the returned fields: del assistant['id'] del assistant['orgId'] del assistant['createdAt'] del assistant['updatedAt'] del assistant['isServerUrlSecretSet'] 7. You are now able to change the assistant's prompt, effectively setting the variables yourself: payload['model']['messages'][0]['content'] = payload['model']['messages'][0]['content'].replace('{{now}}', now_formatted) payload['model']['messages'][0]['content'] = payload['model']['messages'][0]['content'].replace('{{date}}', date) payload['model']['messages'][0]['content'] = payload['model']['messages'][0]['content'].replace('{{time}}', time) 8. You can replace other variables or parts of your prompt, then you will want to return the assistant like this: assistant_json = {'assistant': assistant} return assistant_json https://cdn.discordapp.com/attachments/1266827885541458065/1267901211772981268/image.png?ex=66aa7885&is=66a92705&hm=58180cd7aeb8db2d9e96cc0a85e1b9dcc2096188ace10c87fbb354fada593a02&

Thanks @ErikZ this is super helpful.

You are not actually changing the system prompt

yes it can be used for inbound calls with dynamic variables.

Question: when I called it, it insisted on the phone number field, but when I send a phone number, it immediately starts calling me

can you share more context please.

I’m on a runaway about to takeoff but I’ll post the code when I land. But I created the assistant, set the server URL, then received the call to the server URL, and tried to set the dynamic variables using assistant override with the /call endpoint. I call the agent, she answers, then immediately (while I’m still on the phone with the agent) I start to receive phone calls from the same agent. And she keeps calling and calling.

you might have added the transfer call function with your number and triggered it in your prompt because of this your getting calls. to verify try chaning the call forwarding number if this is the issue please work on your prompt if not then please share the call id.

This is wrong.

So @Chowderr if this is an inbound agent, she receives a call, it calls the Server URL, from that Server URL we can get the assistant ID and the caller's phone number. This works. I use the caller's number to look up the rest of their information (first name, last name, etc) in the address book. Now, how do I get that new, custom information back to the agent so she can address the caller properly? I assumed this was with dynamic variables, using something like {{first_name}} in the system prompt, but I haven't been able to set the dynamic variables. I tried using assistantOverride with the /call endpoint and a PATCH in the assistant/{assistant_id} endpoint but neither work. How do you suggest that I do it?

I don't use any ID's (all mine are transient) That information would be already mapped with dynamic values in your prompt.

How can I set the values of those dynamic variables?

If you are using Make you do it there in your JSON.

Thank you to @everyonewho has been helping - here is the code : Server URL set to: https://(our server URL)/incoming_call Python code for incoming_call (abbreviated): @app.route('/incoming_call', methods=['POST']) def incoming_call(): call_event = request.get_json(force=True) message_type = call_event.get('message', {}).get('type', 'unknown') call_status = call_event.get('message', {}).get('status', 'unknown') # Extract assistantId and caller's phone number from the event assistant_id = call_event.get('message', {}).get('call', {}).get('assistantId') caller_id = call_event.get('message', {}).get('call', {}).get('id') # Extract the call ID caller_number = call_event.get('message', {}).get('call', {}).get('customer', {}).get('number') if message_type == 'status-update' and call_status == 'in-progress' and caller_number: try: (not showing this code - this connects to the database, and gets the caller’s information) if result: customer_id = result['customer_id'] first_name = result['first_name'] last_name = result['last_name'] caller_context = result['caller_context'] debug_print(f"Caller identified as {first_name} {last_name} for customer ID {customer_id}") # Prepare the payload for the VAPI /call endpoint payload = { "assistantId": assistant_id, "assistantOverrides": { "variableValues": { "first_name": first_name, "last_name": last_name, "customer_id": customer_id, "caller_context": caller_context } }, "customer": { "number": caller_number }, "phoneNumberId": PHONE_NUMBER_ID } # Log the payload debug_print("Payload being sent to VAPI:", json.dumps(payload, indent=4)) # Make the API call to VAPI api_url = "https://api.vapi.ai/call" headers = { "Content-Type": "application/json", "Authorization": f"Bearer {VAPI_API_KEY}" } response = requests.post(api_url, headers=headers, json=payload)

To be fair I dont think it matters - this is curl. You need to have 2 responses and they need to go back to the same webhook. This is an example of if the person exist. You need to create one for if it does not as well. https://cdn.discordapp.com/attachments/1266827885541458065/1268448021524250709/message.txt?ex=66ac75c6&is=66ab2446&hm=f9d2446d7dfb8ad02d250f6a2cb8fdf4b58cbdfef4e091bec0f6a97459f8a00a&

which API are you calling with this JSON here?

call

Great. Can I use assistantOverride here?

This is overide as you don't see an ID ( I also dont use the dashboard at all)

but then it starts calling me 🙂

Where are you getting the phone number ID?

I get it when the agent calls the Server URL at the outset of the call

Dashbaord does not pull any data - plus if its hitting your server you would not have a dashboard assistant. It would be transient. (well you could, but no point)

{ "message": { "type": "status-update", "status": "in-progress", "call": { "id": "9ff2571d-d095-4b62-815d-c75221a8be6e", "orgId": "93919d4a-4ea9-4ee6-976d-2c6447c86e24", "createdAt": "2024-07-30T22:49:14.955Z", "updatedAt": "2024-07-30T22:49:14.955Z", "type": "inboundPhoneCall", "status": "ringing", "phoneCallProvider": "twilio", "phoneCallProviderId": "CAb8d54cccc48735a160ba853eb7585883", "phoneCallTransport": "pstn", "phoneNumberId": "a02b6294-63e4-48aa-81dc-f597d27d5cd4", "assistantId": "4a1ff6bf-757d-4e7b-bac5-b4bb728e48ca", "customer": { "number": "+12393516518" } }, "phoneNumber": { * "id": "a02b6294-63e4-48aa-81dc-f597d27d5cd4", * "orgId": "93919d4a-4ea9-4ee6-976d-2c6447c86e24", "assistantId": "4a1ff6bf-757d-4e7b-bac5-b4bb728e48ca", "number": "+15128818753", "createdAt": "2024-06-03T18:33:37.417Z", "updatedAt": "2024-07-03T18:34:15.773Z", "stripeSubscriptionId": "sub_1PNfhICRkod4mKy31esQ41DW", "stripeSubscriptionStatus": "active", "stripeSubscriptionCurrentPeriodStart": "2024-07-03T18:33:32.000Z" }, "customer": { "number": "+12393516518" }, "artifact": { "messages": [], "messagesOpenAIFormatted": [] }, "timestamp": "2024-07-30T22:49:15.992Z" } }

I was having a slow moment. I was reading customerID for some reason.

np I appreciate any help, I've been stuck on this for weeks 🙇‍♂️

Can I call you really quick?

and none of them have worked

I van only give perspective - I dont use python.

sure, even just the workflow of what to do is helpful

Just sent you a message.

how to set data fetched from server url for inbound calls. can you share the data structure to be used

Dear Shubham, Im sharing the response as suggested but same issue 2d539065-d322-46f3-b5d6-f6cfa4d808b0, 6dfd2dbe-625b-4935-b55b-53f716c263b0 { "results": [ { "toolCallId": " call_9jk1", "result": " customer name is teco and address is 123" } ] }

mostly like it's from our side can you try making more one call and if exisits create a new ticket for this.

Dear Shubam, We tried another call but the same issue remains call id: ddf9952c-e8c8-4964-aa94-9ef58ef47ad5

create a new ticket for this.

to support@vapi.ai mail only right or is there any other option