Księgowy AI — an operating system for entrepreneurs
Overview
Księgowy AI is an independent, non-commercial SaaS project — a 24/7 digital accountant for sole traders and small businesses in Poland. Rather than yet another click-through invoicing app, it is an operating system for entrepreneurs: accounting is the first module, and the whole company is managed by talking to an AI agent.
Problem
Running a business in Poland means taxes, social security (ZUS), VAT, e-invoicing (KSeF) and deadlines scattered across tools. Księgowy AI brings them together and proactively tracks obligations — computing advances, reminding about deadlines and explaining "what to pay and when" in plain language.
How it works
- Tool-using AI agent — answers questions grounded in the company's real data (taxes, invoices, contractors, deadlines) and proposes confirm-first actions (e.g. issuing an invoice), with streamed responses (SSE).
- Tax engine — lump-sum/progressive/flat PIT, VAT, ZUS and health contribution computed per activity, with a payments ledger and per-month liability estimates.
- Invoices & KSeF — issuing, PDF and KSeF integration (mock/sandbox), contractors with VAT-ID autofill, and payments and operational cases generated automatically.
- Import & analytics — CSV/JSON import from any program, data-quality checks, cash-flow and liquidity forecasting, plus a tax blog (25 MDX articles with SEO and "Ask AI").
Architecture
The frontend is Next.js 15 / React 19 (TypeScript, Tailwind CSS, PWA); the backend is written in Rust — Axum + Tokio, SQLx, backed by PostgreSQL with RLS (the app connects as a non-superuser role, so multi-tenancy is enforced at the database level) and Redis for rate limiting. Model integration goes through a custom AI Gateway (OpenAI or a mock mode, BYOK). Principles: AI First · API First · Mobile Ready · Multi-Tenant · Event Driven. Everything runs on Docker from day one, with CI (fmt/clippy/tests + build and content validation).
An independent project — architecture and security (RLS, magic-link auth, rate limiting) are first-class from the start.
Tech
Screenshots
