metropolitan-bronze•4mo ago
Help understanding how to route Twilio inbound calls via n8n before triggering a Vapi Assistant
Hi guys — I’m working on setting up a smart auto attendant using Twilio and Vapi.
Goal:
When someone calls our Twilio number, I want to:
Run custom logic in n8n (check time of day, detect if caller is a known customer)
Then dynamically start a Vapi Assistant with context variables (e.g. routing options, caller type)
What's unclear to me:
Should the “A call comes in” webhook in Twilio point to:
My own n8n instance, so I can run my logic and then forward the call to Vapi?
OR
Directly to https://api.vapi.ai/twilio/inbound_call, with Vapi handling everything and n8n triggered after via function tools?
Problem I’m hitting now:
When Twilio is set to post directly to my n8n webhook, the call connects but the caller hears an error — likely because Twilio expects a TwiML response, but n8n isn’t providing one.
What I want to know:
Is it possible to intercept and inspect an inbound Twilio call via n8n first, then decide whether or not to start a Vapi call?
Or is the required pattern: Twilio → Vapi webhook → Vapi Assistant (which then uses function tools to call n8n)?
If there’s a recommended pattern for this hybrid logic-based call routing, I’d love to follow it.
i've tried watching videos on youtube but I just cant find the solution
5 Replies
To clarify your goal: Are you able to have your n8n workflow return valid TwiML (XML) to Twilio after running your custom logic, so the call can be routed onward (e.g., to Vapi via SIP or webhook)? This is essential, as Twilio requires a TwiML response at each webhook step to continue the call flow.
If you need, I can provide an example of how to generate TwiML in a custom server or workflow after your logic runs.
See: Call Handling with Vapi and Twilio
Sources:
- Call Handling with Vapi and Twilio
- Personalization with user information
- Twilio SIP Integration
⤵️ Mention @Vapi Support Bot for follow-ups 🐥
metropolitan-bronzeOP•4mo ago
I have have n8n do anything it is required to do. Just would like to read the step by step tutorial on directing people that call the twiliion number to be filtered thru n8n rules before I send that caller to an assistant.
I have already connected twiliio to VAPI and it instantly activates an assistant because I manually set that in the https://dashboard.vapi.ai/phone-numbers section. BUT there is no way that I see to first pass this to n8n for the filtering
Hey Tmove, could you make a loom video? That would help me understand your question better and assist you.
metropolitan-bronzeOP•4mo ago
yes, please accept my apologies for the Video format. https://www.loom.com/share/aefb0264f761419d9a428a2e63be1acc?sid=cac6dbe3-c7a0-4afd-9935-6bd6f387dbd4
To create the payload before the assistant is called: can I sent the Twiliio webhook to n8n to filter things and look up the customer, then send it to vapi for the target assistant.
so far when I try that the caller hears errors only.
Thank you for your time
Loom
Configuring Webhooks with Twilio
In this video, I'm walking through my current setup with Twilio and how I'm sending webhooks. I want to explore the possibility of redirecting these webhooks to a different endpoint instead of the current one. I also discuss extracting caller ID information and routing it to the appropriate assistant based on the time. If you have any insights o...
Hey Tmove, You can personalize your calls right before a call connects with the customer. For this, we give you 7.5 seconds. Basically, you assign a server URL to your phone number, and VAPI makes a request to your server URL asking for the assistant to be used. This time, you can customize it according to your customer details in your CRM or database. Here's the complete documentation to it. https://docs.vapi.ai/assistants/personalization