n8n Teacher Substitute Matching: Google Sheets + GPT-4o + Gmail/Telegram

Automatically match teacher leave requests to the right substitute—and notify everyone in minutes

This n8n workflow captures teacher leave requests, pulls timetable and substitute availability from Google Sheets, uses OpenAI (gpt-4o-mini) to choose the best substitute, then sends updates via Gmail and Telegram—while logging coverage and payroll back to Google Sheets.

What this workflow does

• Receives a leave request from an n8n form (teacher name, email, leave date, reason).
• Loads data from Google Sheets: retrieves the full timetable and the substitute availability pool.
• Finds affected classes by filtering the timetable to the absent teacher’s classes on the requested leave date and creating one item per affected class.
• Builds a structured prompt per class (subject fit, availability, and weekly hours).
• Uses OpenAI to select the best substitute with gpt-4o-mini, then parses the returned JSON to extract the selected substitute, match reason, and confidence.
• Notifies stakeholders: emails the assigned substitute via Gmail, notifies affected students via Gmail, and sends an assignment summary to an admin via Telegram.
• Updates operations records in Google Sheets: marks coverage and appends a payroll log entry for the substitute.

Use cases

• A school admin wants automatic substitute assignment when teachers request leave.
• An operations team needs consistent coverage tracking and payroll logging in Google Sheets.
• Automation engineers building an n8n workflow for education scheduling with AI-assisted matching.

Technical details

• n8n Form Trigger to collect leave requests.
• Google Sheets integration (Timetable, Substitutes, SubstitutePayroll sheets; replace YOUR_SPREADSHEET_ID and timetable IDs).
• OpenAI using gpt-4o-mini for substitute selection and JSON parsing.
• Gmail for emailing substitutes and notifying students (OAuth2 credential required).
• Telegram for admin assignment summaries.
• Nodes used: code, gmail, telegram, sticky note (and related helper logic).