n8n Leave Request Triage: Google Sheets, Groq AI & Gmail

Automate leave request triage end-to-end with n8n—validation, AI flagging, and manager approvals

This n8n workflow receives employee leave requests via a webhook, validates them against Google Sheets records, uses Groq AI to flag abusive or inconsistent reasons, and then routes approvals through Gmail—updating statuses in Google Sheets as it goes.

What this workflow does

• Receives leave requests via a webhook endpoint (path: leave-request, method: POST).
• Extracts request fields—email, start date, end date, and reason.
• Reads employee and historical leave data from Google Sheets to ensure the requester exists and to review prior requests.
• Calculates working days, enforces same-year leave dates, checks remaining balance, and detects overlapping team leave.
• If any validation fails, it returns an immediate JSON error response to the webhook caller; otherwise it returns a JSON success response.
• Runs Groq AI (chat completions) to produce a short AI note that flags empty/abusive/inconsistent reasons.
• Creates a “Pending” approval entry in the Google Sheets Requests sheet and emails the manager (including balance, teammates off, and the AI note) with an approval link.
• On manager decision, updates Google Sheets to Approved or Rejected and emails the employee the result.

Use cases

• Reduce manual HR admin by automatically validating leave requests before they reach managers.
• Catch policy violations early using AI reason checks with Groq while keeping a paper trail in Google Sheets.
• Prevent scheduling conflicts by checking overlapping team leave and remaining balance.

Technical details

• Webhook for POST submissions to /leave-request
• Google Sheets (employee records + existing leave requests + Requests sheet)
• Groq API via chat completions for AI triage of the leave reason
• Gmail for manager approval emails and employee confirmation/rejection emails
• n8n logic nodes such as if, set, code, and sticky note