Build Gmail contact database with GPT-5 Nano, Brave Search & Google Sheets

Description

Overview

Transform your Gmail sent folder into a comprehensive, enriched contact database automatically. This workflow processes hundreds or thousands of sent emails, extracting and enriching contact information using AI and web search – saving days of manual work.

What This Workflow Does

Loads sent Gmail messages and extracts basic contact information
Deduplicates contacts against your existing Google Sheets database
Searches for email conversation history with each contact
AI-powered extraction from email threads (phone, socials, websites)
Fallback web search via Brave API when no email history exists
Saves enriched data to Google Sheets with all discovered contact details

Perfect For

Musicians & bands** organizing booker/venue contacts
Freelancers & agencies** building client databases
Sales teams** enriching prospect lists from outbound campaigns
Consultants** creating structured contact databases from years of emails

Key Features

Intelligent Two-Path Enrichment
Path A (Email History)**: Analyzes existing email threads to extract contact details from signatures and message content
Path B (Web Search)**: Falls back to Brave API search + HTML scraping when no email history exists

AI-Powered Data Extraction
Uses GPT-5 Nano to intelligently parse:
Phone numbers
Website URLs
LinkedIn profiles
Instagram, Twitter, Facebook, Youtube, TikTok, LinkTree, BandCamp...
Alternative email addresses

Built-in Deduplication
Prevents duplicate entries by checking existing Google Sheets records before processing.

Free-Tier Friendly
Runs entirely on free tiers:
Gmail API (free)
OpenAI GPT-5 Nano (cost-effective)
Brave Search API (2,000 free searches/month)
Google Sheets (free)

Setup Requirements

Required Accounts & Credentials
Gmail Account - OAuth2 credentials for Gmail API access
OpenAI API Key - For GPT-5 Nano model
Brave Search API Key - Free tier (2,000 searches/month)
Google Sheets - OAuth2 credentials

Google Sheets Structure
Create a Google Sheet with these columns (see template link):


Template Sheet: Make a copy here

How to Use

Clone this workflow to your n8n instance
Configure credentials for Gmail, OpenAI, Brave Search, and Google Sheets
Create/connect your Google Sheet using the template structure
Run manually to process all sent emails and build your initial database
Review results in Google Sheets - enriched with discovered contact info

First Run Tips
Start with a smaller Gmail query (e.g., last 6 months) to test
Check Brave API quota before processing large volumes
Manual trigger means you control when processing happens
Processing time varies based on email volume (typically 2-5 seconds per contact)

Customization Ideas

Extend the Enrichment
Include company information parsing
Extract job titles from email signatures

Automate Regular Updates
Convert manual trigger to scheduled trigger
Process only recent sent emails for incremental updates
Add email notification when new contacts are added

Integration Options
Push enriched contacts to CRM (HubSpot, Salesforce)
Send Slack notifications for high-value contacts
Export to Airtable for relational database features

Improve Accuracy
Add human-in-the-loop review for uncertain extractions
Implement confidence scoring for AI-extracted data
Add validation checks for phone numbers and URLs

Use Case Example

Music Promoter Building Venue Database:
Processed 1,835 sent emails to bookers and venues
AI extracted contact details from 60% via email signatures
Brave search found websites for remaining 40%
Final database: 1,835 enriched contacts ready for outreach
Time saved: ~40 hours of manual data entry

Technical Notes

Rate Limiting**: Brave API free tier = 2,000 searches/month
Duplicates**: Handled at workflow start, not during processing
Empty Results**: Stores email + name even when enrichment fails
Model**: Uses GPT-5 Nano for cost-effective parsing
Gmail Scope**: Reads sent emails only (not inbox)

Cost Estimate

For processing 1,000 contacts:
Gmail API**: Free
GPT-5 Nano**: ~$0.50-2 (depending on email length)
Brave Search**: Free (within 2K/month limit)
Google Sheets**: Free
Total**: Under $2 for 1,000 enriched contacts

Template Author:
Questions or need help with setup?
📧 Email:[email protected]
💼 LinkedIn:https://www.linkedin.com/in/vaclavcikl/