Kairo Invoice — Next.js 16 Invoicing App with Stripe Payment Links

Create, send and get paid. Kairo Invoice is a complete invoicing application built with Next.js 16, React 19, Tailwind CSS 4 and shadcn/ui. Not a UI kit: authentication, database, Stripe payments, PDF generation, emails and a scheduled job are wired together and tested.

LIVE DEMO: https://kairo-invoice-demo.vercel.app — create an account and click “Load sample data”.

What it does

• Invoices with line items from a price catalog, discounts, tax, notes and payment details
• Statuses draft → sent → viewed → paid, overdue and void, with the right guards (paid invoices can't be edited or deleted)
• PDF rendered on the server, identical in the download and in the email attachment
• Pay-by-link: every invoice has a secure page where the client downloads the PDF and pays by card through Stripe Checkout; a signed, idempotent webhook records the payment and emails a receipt
• Send and resend invoices with a personal message; see when the client opened it
• Recurring invoices (weekly, monthly, quarterly, yearly) with optional auto-send and “run now”
• Automatic weekly reminders for overdue invoices from the daily job
• Clients with billing details, items catalog, expenses with billable flag
• Dashboard: cash received, outstanding, overdue, profit, six-month cash flow, invoices that need attention
• Reports by period: revenue, expenses, profit margin, tax collected, top clients, expenses by category
• Business settings: 10 currencies (zero-decimal aware), tax label and rate, invoice numbering, payment terms, bank details

Tech stack

Next.js 16 (App Router), React 19, TypeScript, Tailwind CSS 4, shadcn/ui, Better Auth (email + password, Google, GitHub), Drizzle ORM with SQLite locally and Turso in production, Stripe Checkout + webhooks, @react-pdf/renderer, React Email + Resend, Vercel Cron.

Developer experience

• Demo mode: runs right after npm install with no API keys. Payments are simulated and emails are printed to the console
• Sample data loader fills a new workspace with clients, invoices in every status, a schedule and expenses
• One function computes every total (form, server, PDF, email); amounts stored as integers
• 100% TypeScript, zero lint errors, detailed README (setup, Stripe, cron, deployment, customization)
• Standard shadcn/ui setup: add any component with npx shadcn add

What you get

Full source code (.zip), README, LICENSE.md, CHANGELOG.md. Free updates: re-download the latest version from your Payhip library.

License

Personal: one end product (personal or commercial). Commercial: unlimited end products. You can't resell or redistribute the template itself.

Support

Questions or a bug? Reply to your purchase email with your order number.