Hi, due to the latest update in VAPI, we are unable to create tool calls for checking and booking appointments. Previously, we could create tool calls to fetch parameters, but now we are confused about how to use this feature. We are not able to see any tool calls with parameters. Kindly guide us on what to do.

Hi there! 👋 I understand you're having trouble with tool calls after the latest VAPI update. Let me help clarify the changes and guide you on creating tool calls for appointments. ### What Changed in the Latest Update VAPI has migrated from the

ToolCallFunction

to the new

ToolCall

schema. This means you'll need to update your code to use the new structure:

json
{
    "function": {
        "id": "your_tool_id",
        "function": { "name": "yourFunctionName", "parameters": { "param1": "string" } }
    }
}

Instead of the previous

tool

and

toolBody

properties, you now need to use the

function

property with

id

and

function

details [(source)](https://docs.vapi.ai/changelog/2025/1/29). ### Creating Tool Calls for Appointments For appointment booking functionality: 1. Set up your server URLs to receive tool call requests for appointment interactions [(source)](https://docs.vapi.ai/examples/outbound-sales) 2. Define your function calls - For example, create a

bookAppointment

function with the necessary parameters like date, time, and user info 3. Format your responses correctly - When your server responds to VAPI's tool calls, use this JSON structure:

json
   {
       "results": [
           {
               "toolCallId": "call_VaJOd8ZeZgWCEHDYomyCPfwN",
               "result": "Appointment booked successfully for March 10th at 2 PM."
           }
       ]
   }

4. Handle errors properly - Make sure your

toolCallId

dynamically matches VAPI's initial request to avoid errors ### Tool Call Integration in Workflows You can now incorporate

ToolCall

nodes directly into workflow block steps, making it easier to automate appointment booking processes [(source)](https://docs.vapi.ai/changelog/2025/1/22). I hope this helps! Let me know if you need any clarification on implementing these changes for your appointment booking system. Sources:

There doesn't seem to be an option for creating parameters with the new tool set up. @User

I'm experiencing the same issue here.

Same

same here

yeah it is really weird, it kinda seems like something is missing!

Me too ,are they fixing this or something?

@User @User its not correct to keep on updating your tools. we are doing certain development on this and suddenly you are changing the tools. now through vapi interface we cannot create a custom tool. ok i tried with api call on creating custom tool on check availability and book availability but the result is no correct. sometimes its giving the paremeters and sometime its not. please help us to solve this issues .we need the tool to be run everytime. please respond to the queries https://cdn.discordapp.com/attachments/1347623841869861006/1348547956319453245/image.png?ex=67cfdca7&is=67ce8b27&hm=f1f01e2a09fa43c74ca2ad1b9fe41a7641f40fc132e06c903740bf5aac5a3a84&

@Ayush @Will Monteiro @PauliesBoutique @Loler2006 @Luminous @Brave @tk25 @kishan We will add the support for adding headers and parameters within tools calling UI within a day.

i created custom tool.by issue is on few calls only iam getting parameters as output.