Invoice Generator - AV LABS

Live at invoice.arthurvasconcellos.com - part of AV LABS.

Running   |    Technologies   |    License

Invoice Generator is a local-first, browser-only PWA for contractors who bill foreign companies. It produces deterministic, branded invoice and cancellation PDFs, persists drafts to localStorage, and never talks to a backend you have to run.

App Preview	PDF Preview

🚀 Features

• ✅ Two document types - invoice (INV-YYYY-NNN) and cancellation (CN-YYYY-NNN) with auto-negated totals on cancellation.
• ✅ Distinct issuer and payer parties with full address blocks.
• ✅ Currency-aware - contract currency + payout currency. The FX section appears only when they differ, auto-fetches the latest ECB-sourced rate from frankfurter.dev, and accepts a manual override.
• ✅ Bank details persisted in settings and rendered in the PDF below the parties block.
• ✅ Strong form ergonomics - invalid fields highlight in red and the page jumps to the first invalid input on submit.
• ✅ Internationalised - pt-BR and en across UI and PDF output.
• ✅ Local-first persistence - draft, issuer defaults, bank defaults, and a 6-hour FX cache live in localStorage. No backend, no accounts, no sync.
• ✅ Deterministic PDF filenames - <type>-<number>-<issueDate>.pdf. The hero amount (payout when FX is present, otherwise contractual) reads as the most prominent line.
• ✅ Installable PWA with offline support after first load.
• ✅ Built-in bug report - opens a pre-filled GitHub issue with optional technical context. Maintainer email never enters source.

💻 Running

Requirements

• node >= 22 (Node 24 recommended)
• pnpm

1️⃣ Clone the Repository

git clone https://github.com/arthursvpb/invoice-generator.git
cd invoice-generator

2️⃣ Install dependencies

pnpm install

3️⃣ Start the dev server

pnpm dev

The app runs at http://localhost:3000/invoice (/ redirects).

Other scripts

pnpm typecheck     # tsc --noEmit
pnpm lint          # eslint .
pnpm test          # vitest run (76 unit tests)
pnpm build         # next build (also generates public/sw.js for PWA)
pnpm e2e           # playwright test (68 scenarios, headless Chromium)
pnpm e2e:ui        # Playwright UI mode
pnpm format        # prettier --write .

Regenerating PWA icons from the SVG source:

node scripts/generate-icons.mjs

✍️ Digital signing

The app does not embed cryptographic signatures. The PDF reserves a centered signature placement and populates PDF metadata (Producer, Author, Title, Subject) so external signers attach cleanly.

Recommended external flow:

1. Export the PDF.
2. Upload to a platform signer (D4Sign, Adobe Sign, Assinafy).
3. Sign with your existing ICP-Brasil or eIDAS certificate.
4. Distribute the signed file.

✨ Technologies

• Framework - Next.js 15 (App Router), React 19, TypeScript
• Styling - Tailwind v4, shadcn primitives, Nunito Sans
• Forms & validation - react-hook-form, zod, big.js (decimal math)
• State - zustand (persisted draft + settings stores)
• PDF - @react-pdf/renderer with locally bundled fonts
• FX - frankfurter.dev (ECB-sourced reference rates, browser CORS friendly)
• PWA - Serwist service worker
• Internationalisation - custom dictionary + Intl.NumberFormat/DateTimeFormat
• Testing - Vitest + @testing-library, Playwright (Chromium)

📝 License

This project is under the MIT license. See the LICENSE file for more details.