SEVASTOPOL
Stray 0 XP

A coding tutor for your own computer

A tutor that stays with you
when you're stuck.

Sevastopol puts an editor, a terminal and a tutor side by side. It gives hints before answers, checks your code with tests, and remembers what you already know.

One payment. No subscription. Windows launcher included.

The app, as it looks

Tutor, editor and terminal in one window

Screenshots from Sevastopol itself, in its dark purple theme, working on a small C++ program that adds up four numbers.

The Sevastopol window in its dark purple theme: the tutor chat on the left explaining why a C++ program printed nothing, the code editor on the right, and the terminal below it.
Left, the tutor explains in plain words and gives a small separate example instead of rewriting your code. Right, your own code. Below, a real terminal.
The tutor chat: after a run that printed nothing, the tutor explains that the program never prints the sum, shows a small example with cout, and says what the terminal should show.
The tutor can write in the language you chat in; here it answers in Hinglish.

What you are looking at

  1. You run your code and nothing prints.
  2. The tutor explains why, in plain words, and gives a small separate example.
  3. You add the line yourself and run again. The terminal should show 20.

Which AI model answers depends on the provider you choose, so wording differs from run to run.

Optional

Your first quests

Little things to do while you look around. XP is just for fun: it never changes the price and nothing expires.

    A real taste of the tutor

    Predict the output

    Sevastopol asks you to guess what code does before it runs. Get one wrong and you'll see how it helps: a nudge first, then a bigger one, then the answer with no judgement.

    Round 1 of 3Python
    
          

    What does it print?

    What you get

    Made so you actually learn it

    Hints, then answers

    The full solution stays locked until you've tried twice, and you explain it back before it counts. In a 2025 study of high-school maths (PNAS), students who practised with unrestricted GPT scored 17% lower once it was taken away; a tutor version with safeguards largely avoided that. It was maths, not coding, and not Sevastopol.

    Tests that check your code

    Practice problems come with tests, plus a timing check on big inputs. The tests are cross-checked before you see them, so a wrong test doesn't send you hunting for a bug that isn't there.

    It knows what you know

    A learner model tracks each skill and brings old ones back just before you'd forget them. The tutor notices when you're looping or stuck and changes how it helps.

    23 languages

    C++, Python, JavaScript, Go and 19 more. Missing ones show the command to install them.

    Your computer, your keys

    The app and your files stay on your machine. The tutor sends your chat and code to the AI you choose: a free provider, your own key, or a local model with Ollama or LM Studio, which keeps everything offline.

    Pixel skies

    The whole app lives in the same hand-painted skies you see here, from a 6 am meadow to a midnight shop, with themes to match.

    Price

    One price, one time

    A guided coding workspace built around your own reasoning, your code and real test results. You pay for the app once. What the AI provider charges, if anything, is separate and your choice.

    Sevastopol

    ₹76one-time, India

    Regional prices: ₹76 in India, $3.42 everywhere else. They are two set prices, not a currency conversion. The server picks the price from your connection's country, and you can always choose the higher one.

    What you are buying

    • The app with a Windows launcher (also Linux and macOS, Node.js 18+)
    • A personal licence key, kept on your account
    • A tutor that gives hints before answers, with editor, terminal and tests
    • Learner tracking with spaced review
    • 23 languages and all the themes

    What it does not include

    • The AI that answers you: free providers (your own free key, their limits), a local model with Ollama or LM Studio (needs capable hardware), or a paid key billed by that provider
    • Taxes: the amount shown in the payment window is the amount charged. Tax rules for your country have not been confirmed by the seller yet

    What happens when you click

    1. Sign in with Google, Discord, phone or email, so the licence is attached to you.
    2. Pay with Razorpay: UPI, cards and netbanking in India; cards elsewhere.
    3. Your key and download link appear on your account page.

    One payment, no subscription. A refund within 7 days if it doesn't run on your machine or isn't what you expected: read the refund policy and the licence terms first.

    · Try a round first

    Join the crew

    One account for your licence and your progress. New here? Choose any option and you're registered.

    or with your phone

    or with email

    By continuing you accept the terms and privacy policy.