Ficha Online · Professores

The problem

Preparing a test with questions, answers and marking criteria takes hours, and teachers do it several times a term.

What I built

Teachers describe what they want to assess (subject, year, topic, number of questions) and can paste in what they covered in class. The AI generates the full document, which the teacher reviews and edits before exporting it for printing. It works for tests, worksheets and homework, from primary to secondary school, and real examples are published so the result can be seen before paying.

Decisions

• A single AI call in the whole API. All generation goes through the same place, which makes it easy to measure, limit and switch models.
• A usage ledger that is never deleted. Every generation records its tokens and cost at the time, at the current price. When I compared it with the Anthropic invoice, the recorded amounts matched to the cent, and the gap that existed came entirely from generations made outside that path, which are now recorded too.
• A spending cap per account, so no plan costs more than it earns.
• Launch with 20 founder seats, paid with Stripe, to validate the product with real teachers before opening it to everyone.

Technology

React and Mantine on the frontend, FastAPI on the backend, Claude (Anthropic) for generation, Stripe for payments and print-ready export. It is also a PWA, with automatic updates.