foreign-sapphire•4mo ago

Tools are not called

My prompt ask to call the tool at 2 moments. But the tools is never called and so my webhook is not working. Can you please help me?

27 Replies

foreign-sapphireOP•4mo ago

I'm using this in my prompt : 1. [TASK] Demandez le type de service souhaité : coupe, coloration, ou soin capillaire. 2. [TASK] Demandez le jour et l'heure souhaités pour le rendez-vous. 3. [TASK] THIS IS MANDATORY. After collecting the appointment date, trigger the Reservation tool with these values

Vapi•4mo ago

To help you further, could you please share the section of your assistant configuration where you define the tools array and the serverUrl (webhook) settings? This will help me check if the tools are properly set up for function calling and webhook triggering. Sources: - Vapi Tools documentation - Default Tools documentation - Prompting Guide - Outbound Sales Example

⤵️ Mention @Vapi Support Bot for follow-ups 🐥

foreign-sapphireOP•4mo ago

Vapi•4mo ago

To ensure your Reservation tool is called, you must define it in your assistant's configuration—not just in the prompt.
Add your tool to the tools array with its function name, parameters, and webhook URL, like this:

{
  "type": "function",
  "function": {
    "name": "Reservation",
    "parameters": {
      "type": "object",
      "properties": {
        "date": { "type": "string" },
        "service": { "type": "string" }
      }
    }
  },
  "server": { "url": "https://your-server.com/reservation" }
}

{
  "type": "function",
  "function": {
    "name": "Reservation",
    "parameters": {
      "type": "object",
      "properties": {
        "date": { "type": "string" },
        "service": { "type": "string" }
      }
    }
  },
  "server": { "url": "https://your-server.com/reservation" }
}

Update your assistant config, then test again—this should trigger your webhook when the tool is called.
Just updating the prompt is not enough; the tool must be registered in the assistant's model. Sources: - Custom Tools – Vapi Documentation - Custom LLM Tool Calling Integration

foreign-sapphireOP•4mo ago

how can I see the code of my assistant? ?? the tools is registered in the assistant model as you can see in the screenshot

Vapi•4mo ago

To help you further, could you please confirm if you are able to access the Vapi Dashboard and see your assistant's configuration details (such as the tools and server URL) there, or do you need instructions on how to retrieve the configuration using the API?
This will help me guide you to the exact steps for viewing or editing your assistant's "code". Sources: - Vapi Dashboard – Assistants - Vapi API Reference – Get Assistant - Custom Tools – Vapi Documentation To view your assistant's configuration as code, use the Vapi API to fetch it in JSON format. Here’s a sample cURL command:

curl https://api.vapi.ai/assistant/{your-assistant-id} \
  -H "Authorization: Bearer <your-token>"

curl https://api.vapi.ai/assistant/{your-assistant-id} \
  -H "Authorization: Bearer <your-token>"

This will return your assistant's full configuration, including tools and prompts, as code.
Note: Replace {your-assistant-id} and <your-token> with your actual values.
See API reference Source: - Get Assistant – Vapi API Reference Thank you for confirming the tool is registered. To help further, could you please copy and paste the exact JSON configuration of your assistant's tools array (including the Reservation tool definition)? This will help me check for any parameter or structure mismatches that might prevent the tool from being called. Sources: - Custom Tools – Vapi Documentation - Custom LLM Tool Calling Integration

foreign-sapphireOP•4mo ago

{ "id": "c10dc9f9-bd78-4abc-9be6-68fdf77dd530", "createdAt": "2025-05-15T17:49:37.013Z", "updatedAt": "2025-05-23T08:42:26.031Z", "type": "function", "function": { "name": "Reservation", "strict": false, "description": "Cette information est utilisée pour prendre des rendez-vous pour nos services", "parameters": { "type": "object", "properties": { "Email": { "description": "", "type": "string" }, "NomClient": { "description": "", "type": "string" }, "Reservation": { "description": "", "type": "string" }, "TypeService": { "description": "", "type": "string" } }, "required": [] } }, "orgId": "e45085fc-efaf-4efd-842d-f6a87f3d3729", "server": { "url": "https://hook.eu2.make.com/wt77twb3m24dsmbs55eugxfzuvjkhkgn", "timeoutSeconds": 1, "headers": {} }, "async": true }

Vapi•4mo ago

Your "Reservation" tool is correctly registered in your assistant's configuration. To ensure it is called, make sure your prompt and user instructions clearly direct the assistant to use the Reservation tool by name, and that the function name matches exactly (including case). If the tool still isn't triggered, try adding an explicit instruction in your prompt, such as:

When the user wants to book an appointment, call the Reservation tool with the required parameters.

When the user wants to book an appointment, call the Reservation tool with the required parameters.

This helps the model know when to invoke your webhook.
See Vapi Custom Tools Guide Source: - Custom Tools – Vapi Documentation Your Reservation tool is registered correctly.
If the tool is not being triggered, try explicitly prompting the assistant with a phrase that matches the tool's function and parameters. For example:

Please create a reservation with the following details: 
Email: test@example.com, NomClient: John Doe, Reservation: 25 May, TypeService: Consultation.

Please create a reservation with the following details: 
Email: test@example.com, NomClient: John Doe, Reservation: 25 May, TypeService: Consultation.

If this still doesn't trigger the tool, check the assistant logs for errors or mismatches in parameter names and ensure your prompt uses the exact parameter keys as defined.
See Custom Tools Guide Source: - Custom Tools – Vapi Documentation

foreign-sapphireOP•4mo ago

still not working

Vapi•4mo ago

To view your assistant's configuration as code, use the Vapi API to fetch it in JSON format:

curl https://api.vapi.ai/assistant/{your-assistant-id} \
  -H "Authorization: Bearer <your-token>"

curl https://api.vapi.ai/assistant/{your-assistant-id} \
  -H "Authorization: Bearer <your-token>"

This will return your assistant's full configuration—including tools and prompts—in a code-like JSON structure.
Note: Replace {your-assistant-id} and <your-token> with your actual values.
See API reference Source: - Get Assistant – Vapi API Reference

foreign-sapphireOP•4mo ago

yes I've seen but the tools is still not called

Vapi•4mo ago

Thank you for confirming the tool setup and prompt adjustments. To help narrow down the issue, could you please check your assistant's logs for any tool call attempts or related errors when you try to trigger the Reservation tool? This will help determine if the call is being attempted but failing, or not being invoked at all. If you need guidance on accessing the logs, let me know! Sources: - Custom Tools – Vapi Documentation - Prompting Guide – Vapi Documentation Thanks for confirming your tool setup. To help pinpoint the issue, could you please check your assistant's logs and let me know if there are any entries related to the "Reservation" tool being called or any error messages when you try to trigger it? This will help determine if the tool call is being attempted at all. If you need instructions on how to access the logs, let me know! Source: - Custom Tools – Vapi Documentation

Shubham Bajaj•4mo ago

Hey Max, can you send me the call_id? So, that I can take a look into it.

foreign-sapphireOP•4mo ago

here is the call ID : 5cb97f29-45b9-4408-9990-34df9bbddb65 it should work when we are doing it via Chat too ? I'm not always testing via Voice, also via Chat to keep credit

Vapi•4mo ago

Yes, your "Reservation" tool should work in chat interactions as well as voice, provided your prompts and user inputs are structured to trigger it. The Vapi documentation confirms that tool calls can be tested and evaluated in chat scenarios (see Chat Testing). To help pinpoint the issue:
When you test via chat, do you see any tool call attempts or related errors in your assistant's logs? Checking the logs for chat sessions can reveal if the tool is being invoked or if there are parameter/prompt mismatches. Let me know what you find in the logs, and I can help further! Sources: - Chat Testing – Vapi Documentation - Custom Tools – Vapi Documentation Yes, your Reservation tool should work when testing via Chat as well as Voice.
Chat testing in Vapi is designed to trigger tool calls just like voice calls, so if your tool is not being called in chat, double-check your prompt and parameter names for exact matches.
See the Chat Testing Guide for more details. Sources: - Chat Testing – Vapi Documentation - Custom Tools – Vapi Documentation Next step:
Check your assistant's logs for any entries related to the "Reservation" tool call or error messages during your test. This will help determine if the tool is being invoked or if there is a deeper issue. If you need help accessing the logs, let me know. Since you've provided the call ID, support staff can also review it for more detailed troubleshooting. Sources: - Custom Tools – Vapi Documentation - Prompting Guide – Vapi Documentation Yes, your custom tools should work in Chat testing as well as Voice. To verify, try running a chat test with a prompt that exactly matches your tool's function name and parameters. For example:

Please create a reservation with: Email: test@example.com, NomClient: John Doe, Reservation: 25 May, TypeService: Consultation.

Please create a reservation with: Email: test@example.com, NomClient: John Doe, Reservation: 25 May, TypeService: Consultation.

If the tool still isn't triggered in chat, double-check your parameter names and review the assistant logs for any errors or missed tool call attempts.
See Chat Testing Guide Sources: - Chat Testing – Vapi Documentation - Custom Tools – Vapi Documentation Yes, your custom "Reservation" tool should work in chat interactions as well as voice. Vapi supports tool invocation during chat testing, allowing you to simulate and verify tool calls like appointment booking in a text-based environment. If the tool isn't triggered in chat, double-check your prompt phrasing and parameter names for exact matches.
See Chat Testing Guide Source: - Chat Testing – Vapi Documentation

foreign-sapphireOP•4mo ago

Can you check please? It's working when I'm calling the voice Agent, but not via Chat Agent

Vapi•4mo ago

Thank you for providing the call ID. To help pinpoint the issue, could you please check your assistant's logs for the chat session and let me know if there are any entries showing a tool call attempt or related error messages when you try to trigger the "Reservation" tool via chat? This will help determine if the tool is being invoked at all or if there is a prompt/parameter mismatch. Once you share what you see in the logs, I can assist you further! Sources: - Chat Testing – Vapi Documentation - Custom Tools – Vapi Documentation

multiple-amethyst•4mo ago

Make sure the tool is correctly configured and named, the prompt gives clear invocation instructions, the webhook is accessible and properly formatted..

Vapi•4mo ago

To help troubleshoot further:
When you run a chat test and try to trigger the "Reservation" tool, do you see any tool call attempts or error messages in your assistant's logs for that chat session?
Please share what you find in the logs—this will help pinpoint whether the tool is being invoked or if there is a prompt/parameter mismatch. Chat Testing Guide | Custom Tools Guide Sources: - Chat Testing – Vapi Documentation - Custom Tools – Vapi Documentation

foreign-sapphireOP•4mo ago

It’s not working when chatting. Is that normal?

Vapi•4mo ago

No, it is not normal for your Reservation tool to work in voice but not in chat—both modes should trigger tool calls if configured correctly (Chat Testing Guide). To help pinpoint the issue, could you please check your assistant's logs for the chat session and let me know if you see any tool call attempts or error messages when you try to trigger the Reservation tool via chat? This will help determine if the tool is being invoked or if there is a prompt/parameter mismatch. Sources: - Chat Testing – Vapi Documentation - Custom Tools – Vapi Documentation No, it is not normal for your custom tool to work in voice but not in chat—both should trigger tool calls if configured correctly (Chat Testing Guide). Could you please check your assistant's logs for the chat session and let me know if there are any tool call attempts or error messages when you try to trigger the "Reservation" tool via chat? Sources: - Chat Testing – Vapi Documentation - Custom Tools – Vapi Documentation

multiple-amethyst•4mo ago

Can you share more call id

foreign-sapphireOP•4mo ago

5cb97f29-45b9-4408-9990-34df9bbddb65 08e6b227-68fe-4fe0-ae53-fbdcf228b201 I can"t see the chat history to give you call

Vapi•4mo ago

It's definitely not expected for your "Reservation" tool to work in voice but not in chat—both should trigger tool calls if everything is set up correctly. Since you can't access the chat history or logs right now, it's tricky to pinpoint exactly what's happening, but the tool should function in both modes when configured properly. If you get access to the logs later, checking for tool call attempts or errors during chat sessions would help narrow things down. To help resolve this:
Could you please check your assistant's logs for one of the provided chat session call IDs and let me know if you see any tool call attempts or error messages when you try to trigger the "Reservation" tool via chat? This will help pinpoint whether the tool is being invoked or if there is a prompt/parameter mismatch. Chat Testing Guide | Custom Tools Guide Sources: - Chat Testing – Vapi Documentation - Custom Tools – Vapi Documentation To help diagnose the issue, could you please check your assistant's logs for the chat session (using the provided call IDs) and let me know if you see any tool call attempts or error messages when you try to trigger the "Reservation" tool via chat? This will help determine if the tool is being invoked or if there is a prompt/parameter mismatch. Chat Testing Guide | Custom Tools Guide Sources: - Chat Testing – Vapi Documentation - Custom Tools – Vapi Documentation

multiple-amethyst•4mo ago

Looking into it

Vapi•4mo ago

It's definitely not normal for your "Reservation" tool to work in voice but not in chat—both modes should trigger tool calls if everything is set up correctly. Since you can't access the chat logs right now, it's tricky to pinpoint the exact cause, but the tool is expected to function in both voice and chat when configured properly. If you get access to the logs later, checking for tool call attempts or errors during chat sessions will help narrow things down.

Shubham Bajaj•4mo ago

The chat API is currently experiencing an outage and undergoing a comprehensive overhaul. This endeavor is expected to conclude within two weeks, after which the API will be fully functional and accessible for testing of your tools. We apologize for any inconvenience this may cause. The rework is necessary to enhance the API's functionality and speed, ensuring optimal performance for our users.

Tools are not called

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