Overdue Invoice Chaser

After this module you can chase every unpaid invoice politely and on time, without ever double-sending, and get a weekly accounts-receivable summary.

What it does

Entry	What happens
Weekdays 9 AM (Stripe) or POST /webhook/ar/run (invoices in the body)	Load open invoices (Stripe REST API via HTTP Request with the Stripe credential), work out days past due in your timezone, pick the one reminder that's due (3 days before → due today → +3 → +10 → final at +21 with the owner in cc → escalate to the owner at +30), send it with Gmail, record it, and build an aging summary (emailed on Mondays)
POST /webhook/ar/pause	Pause an invoice until a date (promise to pay) or indefinitely (dispute); resume: true undoes it
GET /webhook/ar/status?invoice_id=…	Reminder history for one invoice

Rules: skip paid/void, balances under $5, invoices with no due date, and customers on the do-not-chase list; at least 3 days between emails; if runs were missed, send only the latest stage (no burst); escalate only 7 days after the final notice. Body options: now (inject the clock), dry_run, record_only (mark as sent without emailing, for importing existing invoices), summary, source: "stripe".

Flow

Weekdays 9 AM / Chase Run API ─┐
Pause API ─────────────────────┼→ Settings → Route ─run→ Invoices from API? ─no→ Get Stripe Invoices ─┐
Status API ────────────────────┘                  │                         └yes──────────────────────┴→ Normalize Invoices → Plan Reminders
                                                  │     → Send Now? → Send Reminder (Gmail) → Record and Summarize → respond (API) / Email A/R Summary (Mondays)
                                                  ├pause→ Pause Invoice → respond
                                                  └status→ Invoice Status → respond

Verification status (n8n 2.43.6)

• 30 behavior checks (60 assertions) without credentials: stage selection and catch-up, skip rules, email content (amount, date, pay link), aging buckets and summary, Monday summary, a full 30-day timeline (via record_only + injected clock), 3-day gap, final → escalate after 7 days, pause/dispute/resume, Stripe-format mapping (cents, unix dates, hosted link), Gmail and Stripe failures reported, failed sends retried next run.
• Not run with Gmail or Stripe credentials (WITH_CREDS=1 TEST_EMAIL=… [STRIPE=1] ./test/test.sh). The Stripe request has not been made against a real account.

Files

File	Tier	Purpose
lesson.md	Free	Step-by-step build, tone guidance
workflow/starter.json	Free	Triggers, Stripe fetch, normalization
workflow/learner.json	Learner	Finished workflow
workflow/code/	Learner	Readable copies of the Code nodes
exercises.md	Learner	Practice tasks
solutions.md	Learner	Exercise solutions
notes.md	Private	Learning log
sell/	Private	Offer, video script, blog post