Qualify inbound leads with Vapi voice AI and log results to Google Sheets

Description

Who is this for

Agencies, sales teams, and service businesses who want to instantly qualify inbound leads with an AI-powered phone call — no manual follow-up needed.

What it does

This workflow captures leads via a web form, validates their phone number, and immediately triggers an AI voice call through Vapi. The AI assistant qualifies the lead through a natural conversation, extracting structured data about service interest, motivation, urgency, budget, and intent. Everything gets logged to Google Sheets.

Captures lead info via a web form (name, phone, email, company, role, request, company size)
Validates the phone number format (US 10-digit) and logs invalid numbers separately
Calls the lead instantly via Vapi AI voice assistant
Polls until the call completes, handling voicemails and completed calls differently
Logs results to Google Sheets with AI-extracted qualification insights

How to set up

Create a Vapi account and configure a voice assistant with structured outputs for: Service Interest, Motivation, Urgency, Past Experience, Budget, Intent
Create a Google Sheet with these headers: Date · Name · Phone · Email · Company · Role · Request · Company Size · Service Interest · Motivation · Urgency · Past Experience · Budget · Intent? · Status
Replace YOUR_VAPI_ASSISTANT_ID and YOUR_VAPI_PHONE_NUMBER_ID in the Call Lead node's JSON body
Replace the YOUR__UUID placeholders in the *Log Complete** node with your Vapi structured output UUIDs
Paste your Google Sheet URL into all three Google Sheets nodes
Connect Bearer Auth (Vapi API key) and Google Sheets credentials
Activate the workflow and share the form URL

Requirements

n8n account (cloud or self-hosted)
Vapi account with a configured voice assistant and phone number
Google Sheets (one sheet with the column headers above)

How to customize

Edit the form fields to match your intake needs
Adjust the Vapi assistant prompt for your industry and qualification criteria
Change the initial wait time (default 60s) based on your typical call length
Add email or Slack notifications when high-intent leads are detected