PromptInvoice

Free invoice and payment voucher generator. Live at https://invoice.flowsxr.com

I run a small company and didn't want to pay for invoicing software just to send a few invoices and pay a few contractors, so I built this for myself. A few friends use it now too. Feel free to use it.

What it does

• Invoices, quotes, estimates, receipts and payment vouchers, with a live preview and a clean PDF.
• Describe the job in plain words and AI drafts it for you.
• Several businesses, a client book, saved documents, 150+ currencies, tax and discounts.
• Free, no sign-up. Everything stays in your browser unless you sign in to share with your team.

For AI agents

Your agent sends the document as JSON and gets the finished PDF back. No account, no key, nothing stored, and no AI on the server, so it barely uses any tokens.

curl -sS https://invoice.flowsxr.com/api/pdf -H 'Content-Type: application/json' -o voucher.pdf -d '{
  "docType": "voucher", "number": "PV-2026-014",
  "from": { "name": "Studio Nova Ltd" }, "to": { "name": "Jane Contractor" },
  "items": [ { "description": "Design services, September 2026", "rate": 350 } ],
  "currency": "SGD"
}'

Point your agent at https://invoice.flowsxr.com/agents. It explains every field, with examples.

For developers

Static site, no build step. Two small Vercel functions: api/draft.js (AI drafting via DeepSeek) and api/pdf.js (PDFs for agents).

npm install
npm start       # http://localhost:8080
npm test

To host your own copy, deploy to Vercel and set DEEPSEEK_API_KEY for AI drafting. Team sign-in is optional: run supabase/schema.sql in a Supabase project and add its URL and anon key to js/config.js.

Privacy

Your documents stay in your browser unless you sign in. The PDF API renders and discards each document. Anonymous usage stats (Google Analytics: pages, document type, approximate location) never include names, amounts or document text.

Feedback

Email [email protected] or open an issue. Pull requests welcome.

License

MIT