An app with no backend

KayD Invoice Studio lets you create, save and export invoices without an account. There is no login and no backend: everything stays in the browser's storage.

Storage needs a schema too

Without a server, the browser is the database, so it gets treated like one. Local storage is versioned, with migration, and conflicts between open tabs are detected.

Because the data never leaves the browser, there are JSON backups to move it elsewhere, and a restore that validates the file before it is used.

PDFs in the browser

PDFs are generated in the browser, as A4 pages with pagination and repeated headers. Sinhala and other non-Latin scripts get a print fallback, so an invoice in any language can still be saved.