Vapi AI #support

Knowledge base result not used by voice assistant

axel@tell-ia

10/31/2025, 1:27 AM

Hey guys, I'm trying the full custom knowledge base, i've a webhook that is called when i ask informations to the assistant. What i'm testing is simple: - "Can you tell me how old i am" And I try to return a static answer: - "You are 30 years old" You can see the knowledge-base is correctly queried in this call log :

019a37d9-f4f2-7ff0-82f0-1c479242798c

You can also see the data i return:

Copy code

attributes.response.data.message.content: you are 30 years old
attributes.response.data.message.role: assistant

You can see on the call log that the AI does not use the answser from the knowledge base, What am I missing ? Thanks !

Custom MCP Doesn't Work When Created via VAPI API

RyGuy

10/30/2025, 11:22 PM

I’m running into a problem when using a custom MCP server with a VAPI assistant created via the API. My MCP defines three tools: 1.

knowledge_base

get_available_appointment_slots

schedule_appointment

However, when I ask the assistant a question that should trigger

get_available_appointment_slots

, it instead calls the generic function name

mcpTools

. Here’s what I’m seeing in the

end-of-call-report

webhook data:

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json
"toolCalls": [
  {
    "id": "call_EdJTABIfAJ3Td03qGiEUioHt",
    "type": "function",
    "function": {
      "name": "mcpTools",
      "arguments": "{}"
    }
  }
]

Even though my MCP server correctly registers the tools using

server.registerTool('get_available_appointment_slots', ...)

, VAPI only sends calls to the MCP under the generic function name (

mcpTools

). Here’s the key part of my assistant’s configuration:

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json
"model": {
  "model": "gpt-4o",
  "tools": [
    {
      "type": "mcp",
      "server": {
        "url": mcpServerUrl,
        "headers": {
          "x-team-id": team_id,
          "x-mcp-tools": enabledTools,
          "x-assistant-id": assistant_id
        },
        "timeoutSeconds": 20
      },
      "function": { "name": "mcpTools" },
      "metadata": { "protocol": "shttp" }
    }
  ]
}

This problem only happens when attaching my MCP via the API. If I create the same MCP through the VAPI dashboard UI, everything works as expected — the assistant correctly calls

get_available_appointment_slots

. So my question is: How do I configure my assistant so that it calls the tool names defined in my MCP server (e.g.,
get_available_appointment_slots
) instead of the wrapper function name (
mcpTools
)?

Transfer only (skip AI) not working

Alex QS

10/30/2025, 11:18 PM

Hi this documented feature doesn't seem to work: https://docs.vapi.ai/server-url/events#transfer-only-skip-ai I've tried it a bunch of times, always an "unknown error". the status update shows the call being forwarded, but the audio always says "unknown error" and doesn't forward the call. I've tried with a few phone numbers, and these numbers are able to transfer during the call when the ai calls transferCall just fine. Call ids: 019a3759-f1c6-7886-839e-e725dec1cbb7 019a3759-85f3-7007-9379-7f4db92d8540 019a3758-5b7d-7007-a283-2d1a759c9529

Campaign Stopped – Call Attempts Failing (Voicerr / Retell Vapi Integration)

Winnie

10/30/2025, 11:11 PM

my client’s outbound campaign stopped running as of yesterday. We’re using Voicerr (which connects through Retell Vapi), and according to their team, calls are not being attempted due to a failure on the Retell/Vapi side. They mentioned that the issue can be seen in the logs, but I’m not sure where to locate the specific call failure reasons within Vapi. Could you please: 1. Confirm where in Vapi I can find detailed call failure logs or reasons for the failed call attempts, 2. Verify whether the issue has already been resolved, and 3. Let me know if any action is needed from my end to restore normal campaign operation? This issue has halted the client’s campaign entirely, so any help or status update would be greatly appreciated. Assistant id: 34e0c19f-929f-4e64-afdc-1c71cf936e25 OrgID: a33e570f-a485-467b-ac40-459b31eca4d0Orgid:

HIPAA Compliance calls recordings

Dove

10/30/2025, 9:07 PM

Quick question - I'd like to use the HIPAA compliance for an healthcare firm, however we need two endpoints from the call but it says on VAPI that once the feature is toggled on, no logs, recordings, or transcriptions will be stored unless custom storage and credentials are configured. How can I get endpoints from the call as we need the recordings / transcription to make a decision?

over concurrency

radium

10/30/2025, 5:45 PM

I'm having the exact same issue as others, no active calls, getting even when testing the agent. Organisation id: 58ca3d2e-e725-47d3-bca6-f2957140fdc7 Getting this with no calls active and using the "talk to assistant" option, not even a real call. Same error being returned when using the API Screen shot https://cdn.discordapp.com/attachments/1433512023920214133/1433512025534890145/image.png?ex=6904f59c&is=6903a41c&hm=d598a369870169287ebdf70dd3be4b7f6d6e6d9f7ed6acb6aac757ccd6ccdd04&

multitenant

novalionn

10/30/2025, 5:39 PM

I’m setting up a multi-tenant architecture in Vapi. I need staging/prod separation and per-tenant assistants cloned from a base template. I’m not seeing how to create/manage multiple workspaces or automate cloning/tagging. Are these features API-only or plan-restricted, and what’s the recommended setup flow? #1211483291191083018 #1228667357849849856 @Vapi Support Bot @Vapiteam @Vapi Incident

Assistant Using mcpTools Instead of Custom MCP Tool Names

RyGuy

10/30/2025, 5:37 PM

I created an assistant via the API with a custom MCP server. My MCP has 3 tools: 1.

knowledge_base

get_available_appointment_slots

schedule_appointment

When I ask for availability (hoping for it to use

get_available_appointment_slots

, it’s calling the function name

mcpTools

instead of

get_available_appointment_slots

despite instructions in the system prompt to use

get_available_appointment_slots

. After reviewing the

end-of-call-report

webhook data, I can see it’s using the wrong function name in the

toolCalls

. See below: 

Copy code

{"toolCalls": [
      {
        "id": "call_EdJTABIfAJ3Td03qGiEUioHt",
        "type": "function",
        "function": {
          "name": "mcpTools",
          "arguments": "{}"
        }
      },
      {
        "id": "call_1bsemJNPsJuWCcNeMHHWOtqv",
        "type": "function",
        "function": {
          "name": "mcpTools",
          "arguments": "{}"
        }
      }
    ],
    "role": "tool_calls",
    "message": "",
    "time": 1761844411824,
    "secondsFromStart": 26.659
},

Here is the assistant’s configuration: 

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"model": {
    "model": "gpt-4o",
    "tools": [
      {
        "type": "mcp",
        "server": {
          "url": mcpServerUrl,
          "headers": {
            "x-team-id": team_id,
            "x-mcp-tools": enabledTools,
            "x-assistant-id": assistant_id
          },
          "timeoutSeconds": 20
        },
        "function": {
          "name": "mcpTools"
        },
        "metadata": {
          "protocol": "shttp"
        }
      }
],

Am I doing something wrong? How do I make sure my assistant is calling the tools listed in my MCP server rather than the function name I gave my MCP server? callId =

019a361b-d3e9-7882-924a-bec9b3eb7544

orgId =

ae6fdc9a-4e2a-4f61-b4f6-e4da9aa7b825

hi wont accept payment for more credits. tried multiple credit cards, nothing is blocked by bank

captjos

10/30/2025, 4:10 PM

I linked a credit card as well, card works fine elsewhere, but when i try to buy credits it says need to add payment details first. going in circles. @Vapi Support Bot

Ham

10/30/2025, 3:28 PM

Can not sign up a new account, generic sign up failed error, tried different emails, different passwords, different browsers.

Couldn't verify payment method

Balint

10/30/2025, 3:16 PM

Hi, when I try to buy credits (regardless with Link or Card), this is returned in error popup. The only 401 request is Cloudflare challenge (I logged out and in again).

Voice Model Mismatch Between API Call and Logged Voice Provider

rmaceissoft

10/30/2025, 3:13 PM

While reviewing the logs for recent calls, I noticed that the voice model referenced in the logs doesn’t match the one specified when triggering the call through the VAPI API. Even though the API request explicitly sets a VAPI voice, the logs show a different provider (for example, 11Labs). Could you please check whether this discrepancy is expected behavior or if there might be an issue with how the voice provider is being recorded or routed? Call ID:

019a2bb6-a9eb-744a-96df-13fc7a6e0acb

https://cdn.discordapp.com/attachments/1433473815714725899/1433473815912124597/Screenshot_2025-10-30_at_10.05.44_AM.png?ex=6904d206&is=69038086&hm=1a07409e5d0e11378dbb1e09ef33710fa6e699033517b292ce5c325b9d27c486& https://cdn.discordapp.com/attachments/1433473815714725899/1433473816394465481/Screenshot_2025-10-30_at_10.07.42_AM.png?ex=6904d206&is=69038086&hm=d2e3998f6a54a7068db1407d735e75b62258925b339f01d121f9ee4f9995965f&

Inconsistent Time Zones Between Call Logs and API Request Logs in Dashboard

rmaceissoft

10/30/2025, 2:46 PM

While reviewing the VAPI dashboard, I noticed an inconsistency in the timestamps displayed between the call logs and the API request logs. I was trying to locate a specific call and match it with the corresponding HTTP request to the API that triggered it. However, the timestamps in both listings appear to use different time zones, which makes it difficult to correlate events accurately. Could you please confirm whether this is a known issue or if there’s a setting that should be adjusted to align the time zones? https://cdn.discordapp.com/attachments/1433467006165975112/1433467006476091453/Screenshot_2025-10-30_at_9.39.18_AM.png?ex=6904cbae&is=69037a2e&hm=312e97c39ead115a3caa4dbd50995e5131d9287ca29fd949496a067ca6d83184& https://cdn.discordapp.com/attachments/1433467006165975112/1433467006861971523/Screenshot_2025-10-30_at_9.40.16_AM.png?ex=6904cbae&is=69037a2e&hm=73bcf0a019e367300bc730cfbc5387a0b18c833a92509d310902eb84cae3b115&

How can I get the call ID injected into an apiRequest type tool call?

dan_quill

10/30/2025, 2:35 PM

Hi - I've got an apiRequest tool (tool ID = c1c55b1e-194a-41af-b4a8-7ec131affc16), and I've attempted to inject the call ID via variables into the tool headers (see screenshot) as was shown in the docs. However, when I log the headers on my side, this is coming through as a static string, not a dynamic variable:

"x-call-id": "{{call.id}}"

Here's a call where I tried this: 019a3588-5dbd-7664-a5b0-6825a1a91fb0, and here's the actual tool call message: { "role": "tool_calls", "time": 1761834733663, "message": "", "toolCalls": [ { "id": "call_Jv4pNjbyt2DmdZF9SUGwQSYq", "type": "function", "function": { "name": "LOCAL-axe-lo-call_axe_server", "arguments": "{\"order_id\": \"4072\"}" } } ], "secondsFromStart": 8.478 } I would have expected my server to log the actual call ID rather than the static string

{{call.id}}

. Is there a more correct way to do this? https://cdn.discordapp.com/attachments/1433464292744757411/1433464293424103544/image.png?ex=6904c928&is=690377a8&hm=166f9d30e39bd246ab770ced31cf461af0681b143d675554e032d76d7ec2b527&

Urgent: transferCall and handoff Tools Failing to Locate Destination Assistant

Fiwa

10/30/2025, 1:45 PM

Hey team, I’ve added the default options available in the dropdown, but I believe there’s a broader issue with the transferCall tool — it’s currently not working. During both test and production runs, I keep getting this error: assistantDestination ‘Not Found’ even though the destination assistant exists. I also tried using the handoff tool instead, but the functionality didn’t work either — the system prompt changed, but the voice settings of the destination assistant were not applied (the destination assistant is in Spanish). Our main goal is simply to transfer calls to a language-based assistant (English or Spanish). We can’t use squad, since there’s no outbound campaign endpoint available — though I’ve tested that setup as well. Problem recap: • Handoff Tool: Switches only the system prompt; does not update the voice settings for the Spanish destination assistant. • TransferCall Tool: Returns this error even though the destination assistant exists: Error: call.start.error-get-assistant Invalid Destination. Assistant "YUB_English" Not Found. {"error":"Bad Request","statusCode":400} Please treat this as urgent — we’re currently blocked on multi-language call transfers. Organization ID: 8fcae760-23cb-4857-a7bc-32a982810e88 Assistants: • YUB_Router • YUB_Spanish • YUB_English

Growth Plan Urgent Question

zurpol

10/30/2025, 1:44 PM

Hi @Vapi, @User , @User ! I'm currently on a "Growth" plan, but having a slow month at the moment, so I probably won't renew the plan next month . Will I lose the option of buying it in December if I want to? Thanks

Error When Creating SIP Trunk Number

Charlie

10/30/2025, 1:05 PM

I'm trying to set up an SIP Trunk from my own phone provider. But after setting it up in VAPI, I get the error ''Failed to create Sip Trunk Credential". Here's the information I was given by my phone provider: In VAPI, I'm going to User - Account Settings - Integrations - SIP Trunk Credentials - Add New SIP Trunk Gateway Configuration Server: sip-mtl-03.voicemeup.com - I'm entering this in the IP Address / Domain box Port: 5060 Netmask: 32 Outbound Protocol: UDP Allow inbound calls - checkmark is in Allow outbound calls - checkmark is on Enable options ping - checkmark is off Authentication (Optional) Username: megtech_vapi Password: I'm entering my regular password Use SIP Registration - checkmark is off Advanced Settings (Optional) Enable leading plus for outbound calls - checkmark is off Use Cluster SIP - checkmark is off Tech Prefix - Left it empty SIP Diversion Header - Left it empty What am I doing wrong? What am I missing? Please help as this is the last step in order to launch the assistant. Thanks! 8:49 But it'S posisble i need to entermore information but i dont know

DPA GDPR documents

Johannes

10/30/2025, 12:46 PM

We use VAPI for a customer but need in EU GDPR compliance. Could you please provide these documents?! They are shown in the trust center and I requested access several times few days ago but nothing happens.

Long response times from nowhere?

korv

10/30/2025, 12:13 PM

Hello, yesterday we did some test calls and it sounded just fine with no audio lags or delays. But today when we ran the same tests with exact same assistant setup there was choppy audio and long response times. What could this be caused by? Good test: 019a2fae-7da2-7bb2-b5db-3a8068e9460f Bad test: 019a3481-e927-7fff-b9e4-2a93174b7840 Using Twilio + GPT Realtime Cluster. We are looking to deploy this on a larger scale (100s of calls each day) once we get it working properly.

chat widget

Usman

10/30/2025, 10:15 AM

Want to send structured data to custom web-hook made on Make.com for chat widget. #1211483291191083018 #chatwidget

Additional credits are not getting updated

Himanshu Bansal

10/30/2025, 8:12 AM

I have purchased additional credits for my organization today (org id: 13ff55cb-5c87-4b13-bf89-cb52f83cde41). Amount is deducted from the card but it still shows in the pending state. My credits are going to exhaust soon, so i need them urgently. https://cdn.discordapp.com/attachments/1433367983132250112/1433367983530573915/Screenshot_2025-10-30_at_13.39.33.png?ex=69046f75&is=69031df5&hm=9df37836b86105bfe9f597a164eae3ff77def607ca1fe32bd6199d539257b2fa&

DTMF tool executing but not navigating

Amit

10/30/2025, 5:34 AM

Call ID: 019a2f5c-96fd-733d-951a-380b38c109ed Assistant ID: 946f4f3a-7490-41c4-bc83-52816850e8a4 Over a month I am facing this issue that dtmf tool is getting executed but it does nothing! I referred all related threads on discord and also set up the system prompt as per the official documentation on IVR guidance of Vapi, but unfortunately it wasn't helpful. I've setup the assistance within Vapi dashboard without any external coding. Can somebody help me with what exactly I need to do to fix this?

VAPI Voice randomly sounds robotic or distorted during some calls

rmaceissoft

10/29/2025, 11:52 PM

Hi team, We’re using Vapi Voices as the TTS for our Voice AI Agent in production, and we’ve noticed a random issue where the voice suddenly sounds robotic or distorted during some calls. It typically returns to normal speech on the next dialogue turn. The issue occurs sporadically, not on every call and we haven’t identified a consistent pattern or trigger. For easier troubleshooting, I’m including the following details: Call ID: 019a2bb6-a9eb-744a-96df-13fc7a6e0acb Timestamp: 00:20 Could you please help us understand what might be causing this? Any suggestions on how to debug it or which logs/metrics to check would be greatly appreciated. Thanks in advance for your help

variable in api tool

aiJeff

10/29/2025, 11:46 PM

I believe I have set this up correctly but the variable in my api request tool url will not populate the dynamic data. I am successfully setting the variable from the HTTP request which initiates the call. I can successfully query the get URL value when I hard code a static value into the URL. But the moment I add the variable to the URL it doesn't recognize it and sends the literal variable text to the GET URL which returns nothing. https://cdn.discordapp.com/attachments/1433240556397658265/1433240557056167972/Screenshot_2025-10-29_at_4.23.11_PM.png?ex=6903f8c9&is=6902a749&hm=6f9baccc49c83265727d291b671d527a5c968170b78a6b621ab36fe3da7c2f07&

google_calendar_check_availability_tool ignores timeZone and treats local timestamps as UTC (America

10/29/2025, 10:54 PM

Hey team — running into a timezone mismatch with the default Google Calendar availability tool. I’m passing Toronto time, but the tool seems to check in UTC and reports the slot as free even though there’s a real event at that local time. Tool config / metadata { "id": "de30655c-1d63-47fb-8c15-7258faa24b50", "type": "google.calendar.availability.check", "function": { "name": "google_calendar_check_availability_tool", "description": "checks for availability on a given date, timezone America/Toronto", "parameters": { "type": "object", "properties": {}, "required": [] } }, "metadata": { "calendarId": "*********************", "timeZone": "America/Toronto" } } Invocation { "startDateTime": "2025-10-30T09:30:00", "endDateTime": "2025-10-30T10:30:00", "timeZone": "America/Toronto" } Actual response { "busy": [], "free": [ { "start": "2025-10-30T09:30:00.000Z", "end": "2025-10-30T10:30:00.000Z" } ] } There is an event on Oct 30, 2025, 9:30–10:30 AM America/Toronto on this calendar. I’d expect busy to include that window (or free to be empty / non-overlapping).

GHL check calendar availability tool and the create appointment tool keep showing 400

Aaron May

10/29/2025, 10:32 PM

Hey there, the GHL check calendar availability tool and the create appointment tool keep showing 400 errors on API error. I've checked, double-checked, triple-checked, reconnected, disconnected every single thing. Check the calendar IDs, everything the tools work, but it's not seeming to connect. What's going on?

Password reset

David Toelle

10/29/2025, 9:55 PM

i need help reseting my password i already tried this Vapi Support Bot APP — 11:34 AM Try clearing your browser cache and cookies for the Vapi domain, then request a new password reset email. Steps: In Chrome, go to Settings > Privacy and security > Cookies and other site data > See all site data and permissions. Search for "vapi" and remove all related cookies. Request a new password reset and use the latest link. If this doesn't work, let me know and I can suggest the next step!

We are getting an increase in errors where it says twilio customer misdialed

Nemnel

10/29/2025, 9:23 PM

This is not an error on our side, everything seems to be working fine and most calls dialed to that number go through fine, however a few calls are dropped. This is somewhat intolerable on our side. Twilio logs show no problem with the numbers themselves, it appears to be an issue solely on the Vapi side. Can someone help us? Here's an example call ID where it happened: 019a31b6-6c4d-7223-84b2-f4f6c906b60a

Absolutely critical Abruptly ended the call in between the conversation.

Saleeq

10/29/2025, 8:58 PM

I am facing this strange issue where agent is abruptly calling the end call tool and ending the call in between the conversation. So when I check the logs, there actually LLM, STT and TTS shows logs on continued conversation but the call was ended abruptly. - The call ID :- 019a3198-9a31-7aa2-9b17-fd4e92cdc677 - When exactly this happened (the timestamp) - Precise time: 01:45:00:371 30/10/2025 - What response you expected to get - The natural conversation should continue smoothly ending the conversation after user talks by calling end call tool. - What response you actually got instead - The call got cut abruptly. This is an absolutely critical issue as it has been re occurring multiple times. So when I go and check the logs under the call detail page continuation of the expected conversation and output is logged. But when I checked the transcript it is not there, even in real call the agent end the call abruptly. This issue is stoping us from using vapi in production and potentially upgrade to the enterprise plan. https://cdn.discordapp.com/attachments/1433198436647309353/1433198437200822313/Screenshot_2025-10-30_at_2.23.17_AM.png?ex=6903d18e&is=6902800e&hm=daa170b9df72393e06236e9342fc467dcc4cd7b8daac3771336d00a5a284377a& https://cdn.discordapp.com/attachments/1433198436647309353/1433198437616324748/Screenshot_2025-10-30_at_2.17.06_AM.png?ex=6903d18f&is=6902800f&hm=1e70b203aa2da1e3bbaaeddf65314d2d2c1f6f7e4fc5c41e37a45d8e3f195499&

TS SDK out of date

liam123

10/29/2025, 8:52 PM

Hey there, is there any information on when a new version of the sdk might be released. It is quite out of date. Thanks