Automate Lead Calls with RetellAI, Google Sheets & OpenAI

What This Workflow Does

This workflow automates calling and scheduling leads for sales teams.

It solves the problem of manual tracking, late follow-ups, and lost leads.

The system detects new leads, sends reminders, places calls, updates records, and sends summaries automatically.

This saves time and helps close deals faster.

Tools and Services Used

• RetellAI API: Makes and receives phone calls.
• Google Sheets: Stores lead data and updates results.
• Twilio: Sends SMS reminders to sales reps.
• Gmail: Sends call summary emails.
• OpenAI: Analyzes call transcripts to make summaries.
• n8n: Automates and connects all these tools.

Inputs, Processing, and Outputs

Inputs

• New lead data added to Google Sheets (name, phone, UUID).
• Inbound call data captured by webhook.
• Call transcripts and analysis from RetellAI.

Processing Steps

• Trigger watches for new rows in Google Sheets.
• SMS reminder sent to rep via Twilio.
• Wait 5 minutes to allow rep preparation.
• Outbound call placed using RetellAI API call.
• Inbound calls received by webhook and verified against Google Sheets.
• Call results and transcripts received from RetellAI using post-call webhook.
• Filter events to process only analyzed calls.
• Update lead status in Google Sheets with qualification results.
• OpenAI creates call summary from transcript.
• Email summary sent internally via Gmail.
• Optional confirmation email sent to the lead.

Outputs

• Sales reps get SMS reminders on new leads.
• Leads get qualification calls and scheduled appointments.
• Updated Google Sheets with real-time call outcome.
• Sales team receives AI-generated call summaries by email.
• Leads get confirmation emails when applicable.

Beginner Step-by-Step: How to Use This Workflow in n8n

Import and Setup

1. Download the workflow file using the Download button on this page.
2. Open the n8n editor and use “Import from File” to add the workflow.
3. Add required credentials or API Keys for RetellAI, Google Sheets, Twilio, Gmail, and OpenAI.
4. Update Google Sheets IDs, email addresses, phone numbers, or table details as needed.
5. Copy and paste the exact code or prompts for HTTP requests and OpenAI nodes when prompted.

Testing and Activation

1. Run the workflow once to test by adding a sample lead to Google Sheets.
2. Check that the SMS reminder is sent and the RetellAI call is triggered.
3. Verify inbound webhook URLs and updates in Google Sheets.
4. Confirm OpenAI generates a call summary and emails send correctly.
5. When all works, toggle the workflow to active for production use.

Consider hosting n8n yourself for better control and uptime. Visit self-host n8n for help.

Customization Ideas

• Change SMS text in the Twilio node to your own message.
• Adjust the Wait node time to give more or less delay before calling.
• Add extra lead data fields like source or priority in Google Sheets and update post-call.
• Edit the prompt text in the OpenAI node to get different call analysis views.
• Change email recipients in the Gmail nodes to notify different people.

Troubleshooting Common Problems

• Google Sheets trigger not firing: Check sheet ID and event type set to “rowAdded.”
• Twilio SMS not sent: Verify “From” number is SMS-enabled and lead phone format is correct (E.164).
• RetellAI call fails: Confirm API key is valid and HTTP request body is formatted correctly.
• OpenAI summary missing: Check API quota and prompt formatting for errors.

Pre-Production Checklist

• Test adding lead row in Google Sheets triggers SMS.
• Confirm Twilio phone and message settings.
• Send test API call in HTTP request node for RetellAI.
• Check inbound and post-call webhooks receive data correctly.
• Validate Google Sheets lookup and update find the right rows.
• Test OpenAI node with sample transcript inputs.
• Send test emails via Gmail nodes to ensure correct content.
• Backup Google Sheets before going live.

Deployment Guide

After testing, activate the workflow in n8n by toggling the top-right switch.

Watch execution logs to check no errors happen.

Keep API Keys safe and renew when needed.

Consider self-host n8n to run this workflow securely with better uptime.

Summary of Results

→ Saves hours of manual lead calling and tracking.

→ Prevents lead follow-ups from being missed.

→ Updates lead qualification data automatically in sheets.

→ Sends SMS reminders to reps to call fast.

→ Creates AI-generated call summaries for better insights.

→ Sends clear emails to teams and leads summarizing calls.

→ Enables faster, smarter sales qualification and scheduling.