n8n Lead Capture Workflow: GPT-4o-mini + Sheets + Slack

Instant lead scoring + Slack alerts from an n8n webhook

This n8n Lead Capture Workflow accepts new lead submissions via a webhook, validates and normalizes the data, uses OpenAI (gpt-4o-mini) to qualify the lead with a score, logs the result (as a placeholder for Google Sheets/CRM), and immediately posts a formatted update to Slack—then returns a JSON response to the requester.

What this workflow does

• Receives leads via webhook: Handles a POST request at the /lead-capture endpoint, expecting lead details in the request body.
• Validates & normalizes payload: Checks required fields (email and name), verifies email format, and adds default values plus a timestamp.
• Qualifies the lead with OpenAI: Sends the lead details to the OpenAI Chat Completions API using gpt-4o-mini to generate a JSON qualification result (including `score`, `reasoning`, and a suggested action).
• Flags qualified leads: Merges the AI result back into the lead record and marks the lead as qualified when the score is 7 or higher.
• Logs for Sheets/CRM (simulated): Creates a placeholder “write to Google Sheets/CRM” outcome and returns a success payload with a placeholder row number.
• Notifies your team on Slack: Posts a formatted message via a Slack incoming webhook including lead details and the qualification score.

Use cases

• Capture leads from a landing page form/app and auto-qualify them in near real time.
• Route higher-intent submissions to sales by alerting a Slack channel with the AI score.
• Provide an API-style response so your frontend or form service can confirm submission status.

Technical details

• Webhook (lead capture endpoint: /lead-capture)
• Code node for validation, normalization, and response shaping
• HTTP Request to OpenAI Chat Completions API (gpt-4o-mini)
• HTTP Request to Slack incoming webhook
• Respond to Webhook to return final JSON to the caller

Setup tip: Add your OpenAI API key in the OpenAI HTTP request authorization header, and replace the Slack incoming webhook URL in the Slack HTTP request node.