Web app · documents · DOCX and PDF
Proposal and contract generator
The deal is ready, but the manager assembles documents from old files: copies company details, recalculates amounts, writes them out in words and sometimes gets the tax ID wrong. Here documents are built from a single form using templates: amounts, VAT and amounts in words are calculated automatically, the tax ID is validated by its check digit, and a document with a typo won’t export.
Scenario: Zerno roastery — fictional — sells coffee, gear and barista training to coffee shops and coffee-to-go kiosks.
Open the demo
Best on a computer: the form and the A4 page are side by side. On a phone they’re in tabs.
The app runs in your browser: nothing is sent to a server.
What the demo shows
How to try it
Choose a buyer
A coffee shop (LLC) or a “Coffee to go” kiosk (sole proprietor) — the details are filled in, and the proposal appears on the right.
Build the order
Add items from the catalog, change the quantity, discount and VAT — the amounts and the amount in words are recalculated on the page.
Switch the template
“Contract” — a supply contract with a preamble and an appendix; “Invoice” — an invoice with bank details.
Export the document
Word, PDF or JSON. Try the buyer “With a tax ID typo” — the export won’t go through, and the cursor jumps to the field with the error.
No paid neural networks
Documents are assembled from templates without a neural network — amounts and company details in documents need precision, not guesses. The details of Zerno and the buyers are fictional but pass check digit validation. In a production project a language model can suggest the order contents from the conversation with the customer, and the manager checks and sends it.
The demo runs without OpenAI, YandexGPT or GigaChat API keys. Wherever a production system calls a model, there’s a local stub with the same interface — so the demo is free, always available and never makes things up.
What a production project adds
- The form is filled in by a bot or the CRM: a deal from amoCRM or Bitrix24 becomes documents in one click
- The company’s Word templates with your details, stamp and signature
- Buyer details by tax ID from the tax service or DaData, not by hand
- Numbering, version history and sending documents to the customer in Telegram, Max or by email
Stack
- All demos by stack:
- React
- TypeScript
- React 19
- TypeScript
- React Hook Form
- zod
- docx
- Vite
Developer’s comment
Anton Goncharov
AI systems developer · Python
For business
- The proposal, contract and invoice are built from one form in a couple of minutes, without copying company details from old files.
- Totals, VAT and amounts in words are calculated automatically, and a document with a wrong tax ID simply won’t export.
- All managers’ documents look the same — the company looks more solid.
For developers
- The form uses React Hook Form with a zod schema: tax ID and KPP are checked by check digits, and on error the cursor jumps to the field.
- DOCX is built with the docx library right in the browser, PDF by printing an A4 page.
- Amounts in words and detail checks are a shared package with tests used by other demos too.
Tips
Tip 01
Count money in kopecks as integers: floating-point rounding errors will sooner or later end up in an invoice.
Tip 02
Keep the document template separate from the data: a lawyer edits the text without a developer.
Want the same for your business?
Tell me about your task — I’ll tell you what from the demo fits, how long it will take and what I’ll need from you.
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