n8n Workflow: Draft Freee Accounting Payment Reminder Emails via Claude & Gmail

Draft Japanese payment reminder emails from freee Accounting using Claude & save them as Gmail drafts

This n8n workflow automatically finds overdue income deals in freee Accounting, uses Anthropic Claude to draft polite Japanese payment reminder emails, and saves each reminder as a Gmail draft—then reports what was created, rejected, and skipped.

What this workflow does

• Runs every weekday at 9:00 (or can be triggered manually) and loads configuration such as your freee company ID, minimum overdue days, and a staff notification email.
• Fetches unsettled income deals and partner details from the freee Accounting API.
• Filters for overdue amounts (past due with an amount still due), groups results by customer, skips customers with no email address, and limits processing to top customers by total overdue amount.
• For each customer, sends invoice facts to Anthropic Claude to generate a JSON-formatted email draft (subject + body) in Japanese.
• Validates the draft to ensure invoice numbers, remaining amounts, and due dates match freee data—rejecting drafts that add extra amounts, include late-fee/legal language, or omit required facts.
• Creates Gmail drafts (no sending) for each passing reminder, and emails staff a single summary: drafts saved, drafts rejected with reasons, and customers that couldn’t be drafted.

Use cases

• Automating overdue payment follow-ups for SaaS operators managing partner invoices in freee.
• Reducing manual work for accounting/admin teams by generating consistent Japanese reminders as drafts.
• Building an auditable workflow where outputs are checked against freee Accounting data before use.

Technical details

• n8n integrations/nodes: if, set, code, http request, gmail, sticky note.
• Credentials: freee OAuth2 (read access to Deals and Partners) + Anthropic credentials for Claude.
• Output behavior: Gmail drafts only, plus a staff email report summarizing results.