Hi everyone! I’m building an outbound AI caller using Make.com and Vapi.ai. I’m using the create call API via the HTTP module to trigger calls to a Vapi agent. The issue I’m facing is: • I’m getting a ✅ 201 response • I do receive the call • But the AI assistant doesn’t say anything — no firstMessage, no response I’ve verified that: • The assistant works perfectly when I test it directly from the Vapi Dashboard (“Try Calling Assistant” button) • The customer object is included in the payload • The assistantId is correct Has anyone faced this? Could this be related to the request format or headers from Make? Any help would be appreciated! Let me know if you want to attach your payload too for faster support from the community.

Ensure your API request has the correct assistant ID, valid JSON payload, proper headers Authorization and Content-Type, and that your assistant is configured with a firstMessage, test calls via the dashboard to confirm, and adjust your Make.com request accordingly.

Including both assistantId and an assistant object in a VAPI Create Call request can cause conflicts, use only one to avoid unexpected behavior or errors.

Thanks @Kings_big💫 for the advice I did manage to solve the issue

Glad the issue was resolved. Please reach out to us if you have any other questions regarding this issue

Now the problem I am facing is the vapi.ai assistant is not checking the available slots in my calendar every time I ask AI to set an appointment at tomorrow anytime it says currently not available I have the functions (check availability, bookcalander, checkcalander) added in the tools section of the assistant plz need help

Make sure your Vapi assistant first calls the check availability tool correctly before booking, with proper system prompt instructions, correct time zone settings, and fully tested Make.com scenarios for checking and booking calendar slots; also verify the assistant handles responses properly..

Thank you I made a new scenario with a webhook now it’s working the problem was i was not tell assistant to call check availability function

Glad it's fixed