AI-Powered Cold Calling Automation with Vapi.ai by Amit MehtaAI-Powered Cold Calling Automation with Vapi.ai by Amit Mehta

AI-Powered Cold Calling Automation with Vapi.ai

Amit Mehta

Completed work

AI Automation

Business Workflow Automation

Google Sheets

N8N

Vapi

Sales

Like this project

Completed work

Posted Jun 23, 2025

Automated cold calling using Vapi.ai, GPT-4o, and Google Sheets for efficient lead management.

Likes

Views

AI-Powered Cold Calling Automation with Vapi.ai

Amit Mehta

Completed work

AI Automation

Business Workflow Automation

Google Sheets

N8N

Vapi

Sales

AI-Powered Cold Calling Automation with Vapi.ai, GPT-4o & Google Sheets

Transform your lead list into an AI-powered calling machine. This workflow automates your entire cold calling process using Vapi's conversational AI to initiate calls, qualify leads, capture detailed insights, and manage intelligent follow-ups - achieving 10x more calls than manual efforts while maintaining personalized, professional conversations.

Built for sales teams, recruiters, and customer success professionals who need to scale outreach without sacrificing quality or adding headcount.

🎯 Use Cases

Sales & Business Development

Lead Qualification: Auto-dial new leads to assess interest and budget

Demo Scheduling: Book meetings with qualified prospects automatically

Re-engagement: Win back cold leads with personalized outreach

Product Launches: Announce new features to your entire customer base

Recruitment & HR

Candidate Screening: Conduct first-round interviews at scale

Interview Scheduling: Coordinate availability without back-and-forth

Reference Checks: Automate reference verification calls

Offer Follow-ups: Ensure candidates received and understood offers

Customer Success

Onboarding Calls: Welcome new customers with consistent messaging

Renewal Reminders: Proactively reach out before contract expiration

Upsell Campaigns: Identify expansion opportunities through conversations

NPS Surveys: Gather voice feedback for authentic insights

Market Research

Customer Interviews: Collect qualitative feedback at scale

Product Validation: Test new concepts with target audiences

Competitive Intelligence: Understand why customers chose competitors

Industry Surveys: Gather market trends through conversational data

⚙️ How it Works

The workflow operates through two parallel processes:

Process 1: Call Initiation (Manual/On-Demand)

Trigger: Manual start or scheduled batch processing

Lead Retrieval: Fetches leads marked "Pending" or "Retry Scheduled" from Google Sheets

Validation: Checks retry count (max 5 attempts) and routes accordingly

API Call: Sends request to Vapi with lead details and AI assistant configuration

Status Update: Marks lead as "Call Initiated" with unique call ID

Batch Processing: Loops through all eligible leads with controlled pacing

Process 2: Result Collection (Every 10 Minutes)

Schedule Trigger: Automatic execution every 10 minutes

Active Call Check: Identifies all "Call Initiated" records

Result Fetching: Retrieves call outcomes from Vapi API

Data Processing: Extracts recordings, transcripts, summaries, and interest scores

Sheet Update: Writes complete results or schedules retry for missed calls

Team Notification: Sends Slack alerts on batch completion

📋 Setup Instructions

Prerequisites

n8n Instance: Version 1.0.0+ (self-hosted or cloud)

Google Account: With Sheets API enabled

Vapi Account: Active subscription with API access

Slack Workspace: Optional, for notifications

Step 1: Prepare Your Lead Database

Create a Google Sheet with these exact columns (case-sensitive):

Customer_id | Name | Phone Number | Email | Status | Recording URL | Transcript | Summary | Interest | Call Duration | Retry count | Last attempt | Call ID

Initial Setup:

Customer_id: Unique identifier (e.g., LEAD001)

Name: Full name for personalization

Phone Number: International format (+14155551234)

Email: For follow-up campaigns

Status: Set to "Pending"

Retry count: Set to 0

Other fields: Leave empty (auto-populated)

Step 2: Configure Vapi AI Assistant

Create Your AI Voice Agent

Log into vapi.ai

Navigate to Assistants → Create New

Design your conversation flow

Configure voice settings (gender, accent, speed)

Set up objection handling

Save and copy the Assistant ID

Set Up Phone Number

Go to Phone Numbers → Purchase/Import

Select local or toll-free number

Configure caller ID settings

Copy the Phone Number ID

Step 3: Import & Configure Workflow

Import to n8n

Download Cold_calling_loop.json

In n8n: Import → From File

Select the JSON file

Connect Credentials

Google Sheets: OAuth2 authentication

Vapi API: HTTP Header Auth

Name: Authorization

Value: Bearer YOUR_API_KEY

Slack: OAuth2 (optional)

Update Configuration

All Google Sheets nodes: Select your spreadsheet

HTTP Request nodes: Update assistantId and phoneNumberId

Slack nodes: Choose notification channels

Step 4: Test & Deploy

Add test lead with your phone number

Execute workflow manually

Answer call and complete conversation

Verify results in Google Sheet

Activate workflow for production

🔄 Workflow Logic Explained

Status Flow Diagram

[New Lead: Pending] → [Call Initiated] → [Completed/Failed]
                                      ↓
                            [Retry Scheduled] ← (if failed & retry &lt; 5)

Key Decision Points

Retry Limit Check (If1 Node)

Condition: Retry count ≤ 5

True: Proceed with call

False: Mark as "Max Retries Reached"

Call Completion Check (If2 Node)

Validates: Recording exists, transcript available, analysis complete

Success: Update with full results

Failure: Schedule retry with incremented counter

Status Routing (If4 Node)

"Pending": Direct to call queue

"Retry Scheduled": Add wait period before calling

📊 Node Reference Guide

Core Processing Nodes

Node Type Purpose Configuration Get Leads from Sheet1 Google Sheets Fetches eligible leads Filter: Status = "Pending" OR "Retry Scheduled" HTTP Request HTTP Initiates Vapi call POST to api.vapi.ai/call with assistant config Loop Over Items Split In Batches Processes leads individually Batch size: 1, ensures sequential processing Get Call Data HTTP Retrieves call results GET from api.vapi.ai/call?id={callId} Edit Fields2 Set Formats result data Maps Vapi response to sheet columns

Status Management Nodes

Node Updates Trigger Update Status - Calling1 "Call Initiated" After successful API call Update Status - Calling "Done" + results When call completed successfully Update Status - for Missed call "Retry Scheduled" When call failed/no answer Update Status - Calling3 "Retry Done" After retry limit reached

Control Flow Nodes

Node Function Logic If1 Retry validation Checks retry count ≤ 5 If2 Result validation Verifies call completion Wait Retry delay Pauses before retry attempt Merge Path combination Unifies success/retry flows

🛠️ Customization Guide

1. Modify Retry Strategy

// Add to Code node for progressive delays
const retryCount = $json["Retry count"];
const delays = {
  1: 30,    // 30 minutes
  2: 120,   // 2 hours
  3: 1440,  // Next day
  4: 2880,  // 2 days
  5: 10080  // 1 week
};
return { waitMinutes: delays[retryCount] || 60 };

2. Add Business Hours Check

// Add before HTTP Request node
const now = new Date();
const hour = now.getHours();
const day = now.getDay();

const isWeekday = day &gt;= 1 && day &lt;= 5;
const isBusinessHours = hour &gt;= 9 && hour &lt;= 17;

if (!isWeekday || !isBusinessHours) {
  throw new Error('Outside calling hours');
}

3. Enhance Lead Context

{
  "assistantId": "your-assistant-id",
  "phoneNumberId": "your-phone-id",
  "customer": {
    "number": "+{{ $json['Phone Number'] }}",
    "name": "{{ $json.Name }}",
    "customData": {
      "company": "{{ $json.Company }}",
      "lastPurchase": "{{ $json['Last Purchase Date'] }}",
      "accountValue": "{{ $json['Account Value'] }}",
      "preferredProduct": "{{ $json['Product Interest'] }}"
    }
  }
}

💡 Sticky Notes Configuration

Note 1: Status Progression

Location: Near Google Sheets nodes

📊 LEAD STATUS FLOW:
Pending → Call Initiated → Done/Retry Scheduled
Retry Scheduled → Call Initiated → Done/Failed

⚠️ Max retries: 5 attempts
❌ Failed = No answer after 5 tries
✅ Done = Call completed with results

Note 2: Phone Format Requirements

Location: Near HTTP Request nodes

📱 PHONE NUMBER FORMAT:
✅ Correct: +14155551234
❌ Wrong: (415) 555-1234
❌ Wrong: 415-555-1234

Must include:
- Plus sign (+)
- Country code
- No spaces or symbols

Note 3: Vapi Setup Checklist

Location: At workflow start

🔧 VAPI CONFIGURATION:
□ Assistant ID copied from Vapi
□ Phone Number ID from Vapi
□ API Key in credentials
□ Credits available
□ Assistant tested in playground

Note 4: Performance Guidelines

Location: Near Loop nodes

⚡ OPTIMIZATION TIPS:
• Batch size: 10-20 leads
• Call hours: 9 AM - 5 PM local
• Delay between calls: 5 seconds
• Monthly archive old records
• Monitor Vapi credit usage

Common Issues & Solutions

🔴 "Authentication Failed"

Cause: Expired or invalid credentials Fix:

Re-authenticate Google Sheets OAuth

Verify Vapi API key is active

Check credential permissions

🔴 "Call Not Initiating"

Cause: Invalid phone format or Vapi configuration Fix:

Ensure phone includes country code

Verify Vapi account has credits

Test assistant in Vapi playground

Check assistant and phone IDs

🔴 "Missing Results"

Cause: Call still processing or webhook failure Fix:

Wait 3-5 minutes for processing

Check Vapi dashboard directly

Verify Get Call Data node query

Review If2 conditions

🔴 "Infinite Loop"

Cause: Status not updating correctly Fix:

Check retry count increment logic

Verify status update mappings

Clear test data and restart

🔴 "No Slack Notifications"

Cause: Bot permissions or channel access Fix:

Invite bot to channel

Verify OAuth scopes

Test Slack node individually

📁 Required Files & Resources

File Description Location Cold_calling_loop.json Complete workflow configuration Main workflow file lead_template.xlsx Google Sheets template with headers Sample data file

🏷️ Tags & Categories

Primary Category

Sales & Marketing Automation

Workflow Tags

cold-calling vapi-ai voice-automation lead-generation ai-sales google-sheets outbound-calling sales-automation conversational-ai crm-automation

Use Case Tags

b2b-sales recruitment customer-success market-research appointment-setting lead-qualification follow-up-automation

Integration Tags

vapi google-sheets slack voice-ai telephony

🚀 Future Enhancements

Planned Features

CRM Integration: Direct sync with Salesforce/HubSpot

Multi-language: Support for 10+ languages

SMS Follow-up: Automated text after calls

Analytics Dashboard: Real-time performance metrics

Sentiment Analysis: Emotional intelligence scoring

Community Roadmap

Webhook support for real-time updates

Custom voice training options

A/B testing for scripts

Predictive best time to call

Integration with calendar systems

📞 Support & Resources

Support email : amitswba@gmail.com

Like this project

Completed work

Posted Jun 23, 2025

Automated cold calling using Vapi.ai, GPT-4o, and Google Sheets for efficient lead management.

Likes

Views

AI-Powered Cold Calling Automation with Vapi.ai, GPT-4o & Google Sheets

Built for sales teams, recruiters, and customer success professionals who need to scale outreach without sacrificing quality or adding headcount.

🎯 Use Cases

Sales & Business Development

Lead Qualification: Auto-dial new leads to assess interest and budget

Demo Scheduling: Book meetings with qualified prospects automatically

Re-engagement: Win back cold leads with personalized outreach

Product Launches: Announce new features to your entire customer base

Recruitment & HR

Candidate Screening: Conduct first-round interviews at scale

Interview Scheduling: Coordinate availability without back-and-forth

Reference Checks: Automate reference verification calls

Offer Follow-ups: Ensure candidates received and understood offers

Customer Success

Onboarding Calls: Welcome new customers with consistent messaging

Renewal Reminders: Proactively reach out before contract expiration

Upsell Campaigns: Identify expansion opportunities through conversations

NPS Surveys: Gather voice feedback for authentic insights

Market Research

Customer Interviews: Collect qualitative feedback at scale

Product Validation: Test new concepts with target audiences

Competitive Intelligence: Understand why customers chose competitors

Industry Surveys: Gather market trends through conversational data

⚙️ How it Works

The workflow operates through two parallel processes:

Process 1: Call Initiation (Manual/On-Demand)

Trigger: Manual start or scheduled batch processing

Lead Retrieval: Fetches leads marked "Pending" or "Retry Scheduled" from Google Sheets

Validation: Checks retry count (max 5 attempts) and routes accordingly

API Call: Sends request to Vapi with lead details and AI assistant configuration

Status Update: Marks lead as "Call Initiated" with unique call ID

Batch Processing: Loops through all eligible leads with controlled pacing

Process 2: Result Collection (Every 10 Minutes)

Schedule Trigger: Automatic execution every 10 minutes

Active Call Check: Identifies all "Call Initiated" records

Result Fetching: Retrieves call outcomes from Vapi API

Data Processing: Extracts recordings, transcripts, summaries, and interest scores

Sheet Update: Writes complete results or schedules retry for missed calls

Team Notification: Sends Slack alerts on batch completion

📋 Setup Instructions

Prerequisites

n8n Instance: Version 1.0.0+ (self-hosted or cloud)

Google Account: With Sheets API enabled

Vapi Account: Active subscription with API access

Slack Workspace: Optional, for notifications

Step 1: Prepare Your Lead Database

Create a Google Sheet with these exact columns (case-sensitive):

Customer_id | Name | Phone Number | Email | Status | Recording URL | Transcript | Summary | Interest | Call Duration | Retry count | Last attempt | Call ID

Initial Setup:

Customer_id: Unique identifier (e.g., LEAD001)

Name: Full name for personalization

Phone Number: International format (+14155551234)

Email: For follow-up campaigns

Status: Set to "Pending"

Retry count: Set to 0

Other fields: Leave empty (auto-populated)

Step 2: Configure Vapi AI Assistant

Create Your AI Voice Agent

Log into vapi.ai

Navigate to Assistants → Create New

Design your conversation flow

Configure voice settings (gender, accent, speed)

Set up objection handling

Save and copy the Assistant ID

Set Up Phone Number

Go to Phone Numbers → Purchase/Import

Select local or toll-free number

Configure caller ID settings

Copy the Phone Number ID

Step 3: Import & Configure Workflow

Import to n8n

Download Cold_calling_loop.json

In n8n: Import → From File

Select the JSON file

Connect Credentials

Google Sheets: OAuth2 authentication

Vapi API: HTTP Header Auth

Name: Authorization

Value: Bearer YOUR_API_KEY

Slack: OAuth2 (optional)

Update Configuration

All Google Sheets nodes: Select your spreadsheet

HTTP Request nodes: Update assistantId and phoneNumberId

Slack nodes: Choose notification channels

Step 4: Test & Deploy

Add test lead with your phone number

Execute workflow manually

Answer call and complete conversation

Verify results in Google Sheet

Activate workflow for production

🔄 Workflow Logic Explained

Status Flow Diagram

[New Lead: Pending] → [Call Initiated] → [Completed/Failed]
                                      ↓
                            [Retry Scheduled] ← (if failed & retry &lt; 5)

Key Decision Points

Retry Limit Check (If1 Node)

Condition: Retry count ≤ 5

True: Proceed with call

False: Mark as "Max Retries Reached"

Call Completion Check (If2 Node)

Validates: Recording exists, transcript available, analysis complete

Success: Update with full results

Failure: Schedule retry with incremented counter

Status Routing (If4 Node)

"Pending": Direct to call queue

"Retry Scheduled": Add wait period before calling

📊 Node Reference Guide

Core Processing Nodes

Status Management Nodes

Control Flow Nodes

🛠️ Customization Guide

1. Modify Retry Strategy

// Add to Code node for progressive delays
const retryCount = $json["Retry count"];
const delays = {
  1: 30,    // 30 minutes
  2: 120,   // 2 hours
  3: 1440,  // Next day
  4: 2880,  // 2 days
  5: 10080  // 1 week
};
return { waitMinutes: delays[retryCount] || 60 };

2. Add Business Hours Check

// Add before HTTP Request node
const now = new Date();
const hour = now.getHours();
const day = now.getDay();

const isWeekday = day &gt;= 1 && day &lt;= 5;
const isBusinessHours = hour &gt;= 9 && hour &lt;= 17;

if (!isWeekday || !isBusinessHours) {
  throw new Error('Outside calling hours');
}

3. Enhance Lead Context

{
  "assistantId": "your-assistant-id",
  "phoneNumberId": "your-phone-id",
  "customer": {
    "number": "+{{ $json['Phone Number'] }}",
    "name": "{{ $json.Name }}",
    "customData": {
      "company": "{{ $json.Company }}",
      "lastPurchase": "{{ $json['Last Purchase Date'] }}",
      "accountValue": "{{ $json['Account Value'] }}",
      "preferredProduct": "{{ $json['Product Interest'] }}"
    }
  }
}

💡 Sticky Notes Configuration

Note 1: Status Progression

Location: Near Google Sheets nodes

📊 LEAD STATUS FLOW:
Pending → Call Initiated → Done/Retry Scheduled
Retry Scheduled → Call Initiated → Done/Failed

⚠️ Max retries: 5 attempts
❌ Failed = No answer after 5 tries
✅ Done = Call completed with results

Note 2: Phone Format Requirements

Location: Near HTTP Request nodes

📱 PHONE NUMBER FORMAT:
✅ Correct: +14155551234
❌ Wrong: (415) 555-1234
❌ Wrong: 415-555-1234

Must include:
- Plus sign (+)
- Country code
- No spaces or symbols

Note 3: Vapi Setup Checklist

Location: At workflow start

🔧 VAPI CONFIGURATION:
□ Assistant ID copied from Vapi
□ Phone Number ID from Vapi
□ API Key in credentials
□ Credits available
□ Assistant tested in playground

Note 4: Performance Guidelines

Location: Near Loop nodes

⚡ OPTIMIZATION TIPS:
• Batch size: 10-20 leads
• Call hours: 9 AM - 5 PM local
• Delay between calls: 5 seconds
• Monthly archive old records
• Monitor Vapi credit usage

Common Issues & Solutions

🔴 "Authentication Failed"

Cause: Expired or invalid credentials Fix:

Re-authenticate Google Sheets OAuth

Verify Vapi API key is active

Check credential permissions

🔴 "Call Not Initiating"

Cause: Invalid phone format or Vapi configuration Fix:

Ensure phone includes country code

Verify Vapi account has credits

Test assistant in Vapi playground

Check assistant and phone IDs

🔴 "Missing Results"

Cause: Call still processing or webhook failure Fix:

Wait 3-5 minutes for processing

Check Vapi dashboard directly

Verify Get Call Data node query

Review If2 conditions

🔴 "Infinite Loop"

Cause: Status not updating correctly Fix:

Check retry count increment logic

Verify status update mappings

Clear test data and restart

🔴 "No Slack Notifications"

Cause: Bot permissions or channel access Fix:

Invite bot to channel

Verify OAuth scopes

Test Slack node individually

📁 Required Files & Resources

File Description Location Cold_calling_loop.json Complete workflow configuration Main workflow file lead_template.xlsx Google Sheets template with headers Sample data file

🏷️ Tags & Categories

Primary Category

Sales & Marketing Automation

Workflow Tags

cold-calling vapi-ai voice-automation lead-generation ai-sales google-sheets outbound-calling sales-automation conversational-ai crm-automation

Use Case Tags

b2b-sales recruitment customer-success market-research appointment-setting lead-qualification follow-up-automation

Integration Tags

vapi google-sheets slack voice-ai telephony

🚀 Future Enhancements

Planned Features

CRM Integration: Direct sync with Salesforce/HubSpot

Multi-language: Support for 10+ languages

SMS Follow-up: Automated text after calls

Analytics Dashboard: Real-time performance metrics

Sentiment Analysis: Emotional intelligence scoring

Community Roadmap

Webhook support for real-time updates

Custom voice training options

A/B testing for scripts

Predictive best time to call

Integration with calendar systems

📞 Support & Resources

Support email : amitswba@gmail.com