Invoice Ninja

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Build invoicing you own, and take the numbering rules seriously.

STACK
- Astro with a Node adapter, SQLite, Stripe for payment links, a PDF renderer

THE PARTS
- Clients, invoices, line items, payments
- An invoice is immutable once issued: a correction is a credit note, never an edit

NUMBERING, WHICH IS A LEGAL MATTER
- Sequential with no gaps, per year, allocated inside a transaction
- Never derive a number from a row id, and never reuse one after a deletion
- Store the issue date separately from the created date

THE PDF
- Rendered from HTML; store the generated file, do not re-render on every view
- A re-render after a template change would silently alter an issued document

GETTING PAID
- A Stripe payment link per invoice; payment recorded by webhook, idempotent by event id
- Partial payments allowed, with a running balance

CHASING
- Reminders at 7, 14 and 30 days past due, cancelled by any payment

Include the schema, the numbering transaction and the reminder job.