Invoicing that feels like typing a document

A free, open-source invoice editor. Click any line and write, then download a print-ready PDF.
No account, no server, and your invoice never leaves your browser.

Try it at trybilly.tech · Features · Run it locally · Contributing

Why billy

• You edit the invoice itself. There are no forms or dialogs. Click the company name, a line item or the due date and type.
• The PDF matches the screen. The editor, the preview and the export all render the same page, so what you see is what you download.
• Nothing to sign up for, nothing uploaded. There are no accounts, no backend and no database. Your draft is saved in your browser's local storage.

Features

Editing

• Click-to-edit fields right on the document, with autosave to your browser
• Undo and redo, a ⌘K command palette and keyboard shortcuts
• Multi-page invoices
• An editor that works on a phone

Look

• Ten templates: Clean, Modern Green, Minimal Teal, Corporate Blue, Mono Classic, Mono Elegant, Studio, Ledger, Receipt and Letterhead
• An extra Early Bird template for the people who joined the waitlist
• Logo and digital stamp upload

Money

• Ten currencies: INR, USD, EUR, GBP, JPY, AUD, CAD, SGD, AED and SAR
• Tax and discount, payment terms (on receipt, Net 7, 15 or 30), bank details, PO numbers, notes and terms

Made for India as well

• GSTIN, HSN and SAC codes, CGST, SGST and IGST lines, and reverse charge
• Quick presets for freelancers, GST vendors, agencies and consultants that switch on the fields each one needs

Export

• A print-ready PDF generated in the browser

How it works

browser: /  (landing)   and   /editor  →  InvoicePage  →  localStorage
                                              │
                          canvas, preview and PDF all render this one page

• apps/web/components/invoice/invoice-page.tsx is the single layout used for the canvas, the preview and the PDF, so the three cannot drift apart.
• The PDF is made in the browser from that same page (html-to-image and jsPDF).
• packages/invoice-core holds the pure TypeScript domain: types, totals, templates, themes, currencies and presets. It has no React in it and it is the only part with unit tests.
• The site is a Next.js static export. There are no route handlers, server actions or middleware.

Run it locally

You need Bun (the version is pinned in packageManager in package.json).

bun install        # install every workspace
bun run dev        # start the app on http://localhost:3000
bun run build      # static production build into apps/web/out
bun run lint       # lint

Checks for the domain package:

cd packages/invoice-core
bun test           # unit tests
bunx tsc --noEmit  # typecheck

Project layout

A Turborepo on Bun workspaces:

billy/
├─ apps/
│  └─ web/                 # the Next.js app: landing page, editor and early birds wall
│     ├─ app/              #   routes: /, /editor, /early-birds
│     ├─ components/       #   invoice/ (editor), landing/, founders/, ui/, icons/
│     └─ lib/              #   PDF export, storage, early bird helpers
├─ packages/
│  ├─ invoice-core/        # @billy/invoice-core: types, totals, templates, currencies, presets
│  ├─ design/              # @billy/design: design tokens
│  └─ typescript-config/   # shared tsconfig base
├─ scripts/founders/       # launch-day CLIs for early bird numbers and unlock links
├─ docs/                   # project documentation
├─ DESIGN.md               # the design spec of record
├─ wrangler.jsonc          # Cloudflare Worker config: serves the site on trybilly.tech
└─ vercel.json              # Vercel build settings and security headers

Deployment

The app is a static export (output: 'export' in apps/web/next.config.ts), deployed on Cloudflare Workers from main. wrangler.jsonc routes trybilly.tech and www.trybilly.tech to the billy Worker, which serves apps/web/out; Cloudflare Workers Builds builds and deploys every push to main. Vercel still builds preview deployments for pull requests, with vercel.json holding those settings. DNS is on Cloudflare.

• Install command: bun install
• Build command: bun run build
• Output directory: apps/web/out
• Environment: NEXT_PUBLIC_POSTHOG_PROJECT_TOKEN for analytics. It is read at build time, and analytics stay off without it.

Production security headers come from apps/web/public/_headers, which Cloudflare reads when serving the export; vercel.json keeps the same set on previews. Deploy steps, the apex redirect and rollback live in docs/deploy.md.

Contributing

Contributions are welcome. billy is small, so the process is light. The short version is below, and CONTRIBUTING.md has the rest.

• Open an issue first for anything bigger than a small fix, so we can agree on the approach before you write code. Typos and obvious bugs can go straight to a pull request.
• Branch from main and keep each pull request to one change.
• Before you push, check that bun run build passes and that bun run lint reports nothing new.
• For anything visible, include before and after screenshots at desktop and phone widths.
• Match the code around your change. The UI follows DESIGN.md, and user-facing copy uses plain punctuation, so no em-dashes.
• Using an AI coding agent? Read AGENTS.md first.

By contributing, you agree that your work is licensed under the MIT license.

If billy saves you time, a star on GitHub helps other people find it.

License

MIT. Bundled third-party files keep their own licenses, listed in THIRD_PARTY_NOTICES.md.