Triage inbound leads with Claude, Gmail, Google Sheets, and Slack

Quick overview This workflow collects inbound leads via an n8n Form, uses Anthropic Claude to classify the lead and draft a reply, requests human approval in Gmail, and logs approved leads (with the draft) to Google Sheets while sending Slack alerts if the Claude step fails.

How it works Receives a new lead submission through an n8n Form. Normalizes the form fields into consistent lead properties and adds a submission timestamp. Sends the lead details to the Anthropic Messages API (Claude) to classify the lead (hot/warm/cold/spam) and generate a draft reply email. Parses and validates Claude’s JSON response, and routes failures to a Slack alert. Emails the classification and draft reply to a reviewer in Gmail and waits for an approve/reject decision. If approved, appends the lead details, classification, and draft reply to a Google Sheets “Leads” tab; if rejected, the workflow ends without taking further action.

Setup Add an Anthropic API key as an HTTP Header Auth credential and ensure the request headers include your Anthropic version. Connect a Gmail OAuth2 account and replace reviewer@example.com with the reviewer’s email address. Connect a Google Sheets OAuth2 account, set your spreadsheet ID, and ensure a “Leads” sheet exists with columns matching the appended fields. Connect a Slack account and set the target channel (for example, #alerts) for failure notifications. Publish the n8n Form and share its URL where you collect lead submissions.

Requirements Anthropic API key (any Claude model works; the workflow defaults to claude-sonnet-5)

Customization Change the lead categories (hot/warm/cold/spam) or the reply tone by editing one system prompt; swap Gmail approval for Slack buttons; log to a CRM instead of Sheets

Additional info The AI drafts but never sends: human approval gates every outbound email, failures alert loudly in Slack, and lead text is treated as data, never as instructions. Full docs: github.com/kelsonworks/n8n-claude-lead-pipeline