Automate Lead Qualification with RetellAI Phone Agent, OpenAI GPT & Google Sheet

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Built by Dr. Firas Dr. Firas
Created on June 06, 2026

Description


👉 Build a Phone Agent to qualify outbound leads and schedule inbound calls

Who is this for?

This workflow is designed for sales teams, call centers, and businesses handling both outbound and inbound lead calls who want to automate their qualification, follow-up, and call documentation process without manual intervention. It’s ideal for teams using Google Sheets, RetellAI, OpenAI, and Gmail as part of their tech stack.

Real-World Use Cases

🛍 E-commerce – Instantly handle product FAQs and order status checks, 24/7.
🏬 Retail Stores – Share store hours, directions, and return policies without lifting a finger.
🍽 Restaurants – Take reservations or answer menu questions automatically.
💼 Service Providers – Book appointments or consultations while you focus on your craft.
📞 Any Local Business – Deliver friendly, consistent phone support — no live agent required.

What problem is this workflow solving?

Managing lead calls at scale can be chaotic—between scheduling outbound qualification calls, handling inbound appointment requests, and making sure every call is documented and followed up. This workflow automates the entire process, reducing human error and saving time by:

âś… Sending reminders to reps for outbound calls
âś… Automatically placing calls with RetellAI
âś… Handling inbound calls and checking caller details
âś… Generating and emailing call summaries automatically

What this workflow does

This n8n template connects Google Sheets, RetellAI, OpenAI, and Gmail into a seamless workflow:

Outbound Lead Qualification Workflow
Triggers when a new lead is added to Google Sheets
Sends an SMS notification to remind the rep to call in 5 minutes
(Optional) Waits 5 minutes
Initiates an automated call to the lead via RetellAI

Inbound Call Appointment Scheduler
Receives inbound calls from RetellAI (via webhook)
Checks if the caller’s number exists in Google Sheets
Responds to RetellAI with a success or error message

Post-Call Workflow
Receives post-call data from RetellAI
Filters only analyzed calls
Updates the lead’s record in Google Sheets
Uses OpenAI to generate a call summary
Emails the summary to a team inbox or rep

Setup

âś… You need an active RetellAI API key

Sign up for RetellAI, create an agent, and set the webhook URLs (n8n_call for call events).
Purchase a Twilio phone number and link it to the agent.

âś… Your Google Sheet must have a column for phone numbers (e.g., "Phone")
âś… Gmail account connected and authorized in n8n
âś… OpenAI API key added to your environment variables or credentials

Configure your Google Sheets node with the correct spreadsheet ID and range
Add your RetellAI API key to the HTTP request nodes
Connect your Gmail account in the Gmail node
Add your OpenAI key in the OpenAI node

👉 See full setup guide here: Notion Documentation

How to customize this workflow to your needs

Change SMS content**: Edit the text in the “Send SMS reminder” node to match your team’s tone
Modify call wait time**: Enable and adjust the “Wait 5 minutes” node to any delay you prefer
Add CRM integration**: Replace or extend the Google Sheets node to update your CRM instead of a spreadsheet
Customize call summary prompts**: Edit the prompt sent to OpenAI to change the summary style or add extra insights
Send email to different recipients**: Change the recipient address in the Gmail node or make it dynamic from the lead record

Need help customizing?
Contact me for consulting and support : Linkedin

Nodes Used (5)

Gmail
n8n-nodes-base.gmail
Google Sheets
n8n-nodes-base.googleSheets
HTTP Request
n8n-nodes-base.httpRequest
OpenAI
@n8n/n8n-nodes-langchain.openAi
Twilio
n8n-nodes-base.twilio