In the meantime, you can still achieve your goal of booking appointments to your GHL calendar by using a custom tool with a server URL (webhook):

Create a custom tool in your Vapi assistant for "check availability" and "book appointment" Set up a webhook endpoint on your side (or use GHL Workflows) that receives the tool call from Vapi

Your webhook handles the API call to GHL's calendar endpoints using your API key Return the result back to Vapi, and the assistant will use it in the conversation

This gives you full control over the booking logic and works reliably. Our docs on custom tools can help you get started: https://docs.vapi.ai/tools/custom-tool

Let us know if you need help setting this up.

Hi Shaunak, Thanks for getting back to me and I apologize for the late response. I tried using the custom tool and asked Vapi's AI Composer to help me troubleshoot the custom tools I made to check availability and book a meeting. But to no avail. Composer identified a few problems with the custom tools. And when I tried to ask it to fix it, it just keeps on detecting more and more errors that it seems that even Composer can't solve. I maybe missing something here. Like an important detail hidden right under my nose. Or the GoHighLevel integration with VAPI is the root cause of all the errors I'm having in having the Assistant book appointments through calls and have those appointments booked into our GoHighLevel calendar. If memory serves, 've read somewhere in some other Support Ticket I found here in the Discord server about resetting the GoHighLevel MCP connection to VAPI. And that I can ask you guys to reset it on your end. But I'm not sure if this is even possible. But in the slight chance that it is, how do I request for a reset? I've tried everything to do the reset on my end but nothing seems to work.

By the way, I tried using Make.com. I'm having trouble with that too. Which is that I can't make the Scenario in Make.com get the proper dates. The webhook I set up Make.com is only sending VAPI the "traceId" instead of like the date and time.

Regarding the GHL integration reset - unfortunately that won't help here since the native GHL integration itself is what's currently not working on our end. Resetting it won't resolve the underlying issue.

For the custom tool / Make.com approach, it sounds like the tool configuration may need some adjustments. Could you share the following so we can help troubleshoot: Your assistant ID The custom tool configuration (a screenshot or the JSON) A call ID from a recent test where the tool failed

The issue you're describing with Make.com only receiving the traceId instead of the date/time usually means the tool's parameters aren't configured correctly - the tool needs to define the specific input fields (like date, time, calendarId) so Vapi knows to extract and pass those values from the conversation to your webhook.

The workaround is to use custom tools with webhooks to connect to GHL's API. You'd set up a custom tool in your assistant that sends the relevant data (date, time, contact info, etc.) to a webhook endpoint (Make.com, n8n, or your own server), which then calls GHL's API to book appointments, look up contacts, etc.

If you share your use case (e.g., booking appointments, CRM lookups), we can help point you in the right direction for the tool setup.

That said, the custom tool approach is actually pretty straightforward for appointment booking.

You'd just need one tool that passes the date, time, and contact info to a webhook, and a simple Make/n8n scenario (or even a lightweight serverless function) that calls GHL's calendar API.

Once it's set up, it's stable and doesn't need much maintenance.

Feel free to open a new ticket at support@vapi.ai if anything else comes up. Happy building!