Terms of service

Plain language, same as the privacy page. Last updated August 2026. DevMargin is operated by Peter Buchlak, a sole operator based in the Czech Republic. Using DevMargin means you accept these terms.

What DevMargin does

DevMargin reads revenue figures from billing providers you connect, subtracts running costs you enter, and shows the result — per project and across your portfolio. It can also expose that data read-only to an AI agent you authorise. That is the whole service.

Your account and your credentials

• Keep your login and any API tokens you create private. Anything done with them counts as done by you.
• Connect only credentials you are entitled to use, and only read-only ones. If a provider offers a restricted key, use it.
• You can revoke DevMargin’s access at any time from the provider’s side, and delete your account from the Account page.

The numbers are not accounting

This matters more than anything else here. DevMargin reports what your providers report, plus the costs you type in. Figures may be incomplete, delayed, converted at a snapshot’s FX rate, or missing where a provider reports nothing — which is why unknown values are shown as “—” rather than as zero. DevMargin is not accounting, tax or audit software, and net margin here is not a legal or fiscal profit figure. Do not use it to file taxes, prepare statutory accounts, or make investment decisions. Check anything that matters against the provider and your accountant.

Plans and payment

• The free plan is unmetered except for one thing: it shows the last 30 days of history. Pro shows all of it. Nothing is deleted on either plan — snapshots keep being recorded whatever you pay, and upgrading makes the earlier ones readable again straight away.
• Pro is billed monthly or yearly in advance. Prices are shown excluding VAT, which is added at checkout where applicable.
• Payments are processed by Stripe as merchant of record — Stripe handles the transaction, invoices, VAT and any statutory cooling-off rights. Your card details never reach DevMargin.
• Cancel any time, from the Account page or from Stripe. Access continues to the end of the period you already paid for, and nothing is charged after that.
• If a price changes, existing subscriptions keep their price until the following renewal, and you will be told before it applies.

Fair use

Don’t try to break, overload or probe the service, don’t resell access, and don’t use it to process data you have no right to. The push API and MCP endpoint are rate-limited; automate against them sensibly.

Availability, changes and liability

DevMargin is run by one person. There is no uptime guarantee: providers go down, APIs change, and pulls can fail — the dashboard tells you when data is stale rather than hiding it. Features may change, and the service could be discontinued; if that happens you will get reasonable notice and time to export or delete your data. To the extent the law allows, DevMargin is provided as-is, and liability for any claim is limited to the fees you paid in the twelve months before it arose. Nothing here limits liability that cannot legally be limited.

Ending it

You can delete your account whenever you like — Account → Delete account, immediate and irreversible, as described in the privacy page. Accounts that abuse the service or break these terms may be suspended or closed, with a refund of any unused prepaid period.

Changes and law

If these terms change materially, the date above changes and you will be told before it affects you. Czech law governs this agreement. Questions: hello@devmargin.app.