n8n Lead Qualification Workflow: GPT-5 + Google Sheets + Gmail/Slack

Turn form leads into qualified opportunities—automatically

This n8n lead qualification workflow captures new submissions from an n8n hosted form, enriches and de-duplicates them in Google Sheets, qualifies them with OpenAI (GPT-5-mini via LangChain), and then routes follow-ups through Gmail and Slack based on Hot/Warm/Cold scoring.

What this workflow does

• Receives new lead submissions from an n8n Form Trigger lead-capture form.
• Cleans and validates input: formats fields, validates email format, and flags free/personal email domains.
• Prevents duplicates by looking up the email in Google Sheets and stopping re-processing when the lead already exists.
• Enriches company details using Clearbit autocomplete to guess the company domain and merge enrichment into the lead record.
• Qualifies with AI: sends enriched details to OpenAI (GPT-5-mini via LangChain) to generate structured outputs—lead score, category, summary, owner, and follow-up timing.
• Tracks results in Google Sheets by appending both the lead and the AI qualification output.
• Routes follow-ups by category:
  • Hot: sends Slack and Gmail alerts plus an auto-reply.
  • Warm: sends an auto-reply, then waits 1 day before a nurture email.
  • Cold: logs only (no outreach).

Use cases

• SaaS teams qualifying inbound leads from an n8n form before sales outreach.
• Automation engineers building an end-to-end lead scoring pipeline with Sheets tracking and routing.
• Ops workflows that enrich leads with Clearbit and send Gmail/Slack follow-ups by priority.

Technical details

• n8n Form Trigger for lead capture
• OpenAI (GPT-5-mini by default) qualification via LangChain
• Google Sheets for duplicate lookup and appending qualified results
• Clearbit autocomplete for company domain enrichment
• Gmail for alerts and auto-replies/nurture timing
• Slack for Hot lead notifications
• Workflow nodes include: if, set, code, no op, wait, gmail