The customer status page
Every invoice has an unguessable status link, included in reminders. Customers see the amount, outstanding balance, due date and status — no login needed.
Payments: with Stripe configured, customers pay by card and a webhook reconciles the invoice. In demo installations a clearly-labelled simulated test payment demonstrates the flow without moving money.
'Something wrong with this invoice?' lets the customer send a note — the invoice is marked disputed, reminders pause, and you see the note on the invoice page.
Rate limiting protects the public endpoints from abuse.