Terms of service

Runtime Lab is a set of staged programming challenges. You read a stage's instructions and write the code — in the browser, or on your own machine and pushed to the git repo we host for you. When you press Run, we execute the challenge's test suite against your code on our own hardware, in a sandboxed container with no network access, and report the result. We store your code, your progress, your test results and the logs those runs produce.

You need an account to enroll in challenges and run tests, and your account is your GitHub account — we have no separate password. Keep your access token to yourself: it authenticates git pushes as you. You're responsible for what happens under your account. You can rotate your access token at any time from the git access page.

One account is for one person. Sharing an account or a pass with other people is not allowed; using your own account on as many of your own machines as you like is fine.

Paid access is sold as an access pass: a single payment that unlocks a fixed number of months. This is not a subscription.

• ·Nothing renews automatically. We do not store your card, we do not schedule a second payment, and there is nothing to cancel. When the term ends, access simply reverts to the free tier.
• ·Buying another pass while one is active extends it: the new months are added to the end of your current expiry rather than replacing it.
• ·Without a pass you keep full read access to every stage's instructions, the starter code, enrollment, and your progress — and you can run tests for the first couple of stages of every challenge. A pass adds test runs for all remaining stages and access to reference solutions.
• ·Your account, enrollments, and completed stages are unaffected when a pass lapses. Nothing is deleted, and a later pass picks up where you left off.

Prices are shown on the pricing page in US dollars and may change for future purchases; a pass you have already bought is never repriced. Refunds are covered by the refund policy, which forms part of these terms.

You agree not to:

• ·share, resell, or sublicense your account or pass, or pool one pass across several people;
• ·republish challenge instructions, test suites, or reference solutions as your own, or redistribute them as a competing product;
• ·attack the service — scraping at a rate that degrades it, attempting to bypass the free-stage limit or any other access control, probing for vulnerabilities without asking us first, or abusing the git or job endpoints as general-purpose storage or compute;
• ·upload unlawful content, malware, or anything you don't have the rights to, to the git repositories we host for you;
• ·use the service to break the law where you live or where our servers run.

We may suspend or close an account that breaks these rules. If we close an account for a reason other than a breach, we'll refund the unused part of a paid pass.

You own the code you write. Nothing here transfers rights in your work to us. For the snapshot taken when a stage passes, and for code you push to a git repository we host, you grant us the narrow permission needed to store it and show it back to you — nothing more. We do not execute it, and nobody else can read it.

Challenge instructions, test suites, and reference solutions remain the property of their authors and are licensed to you for personal learning use only.

Runtime Lab is provided as is, without warranty of any kind, express or implied. We make no promise that the service will be uninterrupted, error-free, or available at any particular time. There is no uptime guarantee. Challenges may be added, changed, or withdrawn, and a challenge you are part-way through may be revised.

Test runs are rationed, because they cost us machine time: there are limits per hour and per day, and a free account has a small lifetime allowance. The limits are shown in the app and may change. Keep your own backups of your code.

To the fullest extent the law allows, we are not liable for indirect, incidental, or consequential loss, for lost data, or for lost profits arising from your use of Runtime Lab. Where liability cannot be excluded, it is capped at the amount you paid us in the twelve months before the claim. Nothing in these terms limits liability that cannot lawfully be limited — including your statutory consumer rights, which stand alongside this document.

You can stop using Runtime Lab whenever you want and ask us to delete your account by emailing [email protected]; see the privacy notice for what deletion removes. Deleting your account does not by itself refund an active pass — the refund policy governs that.

We may update these terms. The date at the top always reflects the current version, and material changes will be announced in the app. Changes are not retroactive: the terms you agreed to when you bought a pass govern that pass for its term. Continuing to use Runtime Lab after a change means you accept the updated terms.

Questions, complaints, and legal notices: [email protected].