Terms of Service#

The terms for using TryFast: plans and limits, workspaces without an account, acceptable use of custom code, AI agents, billing, support and cancellation.

Last updated: 2026-10-24

These terms govern the use of TryFast, an A/B testing service provided by subprocess.eu/company, Osloer Str. 83, 13359 Berlin, Germany ("we", "us"), at tryfast.eu, through its app, REST API, MCP server and tracking script. "You" is the business or person using TryFast; "workspace" is the unit that holds your projects, members, API keys, agent connections and plan.

1. The service#

TryFast lets you show different versions of pages on websites you operate to a share of their visitors, measure which version reaches your goals, and act on the result. It consists of a script you add to your website, the app at tryfast.eu/app, a REST API and an MCP server for AI agents. TryFast is a service for businesses, organizations and website operators; by using it you confirm that you use it for purposes of your trade, business or profession.

2. Accounts and workspaces without an account#

You can start without an account. A workspace created without an account belongs to whoever holds the browser that created it or its recovery link; keep the recovery link private, because anyone with it can take over the workspace. Workspaces without an account are limited as described in section 3 and follow this lifecycle:

• A workspace that never got a project and was never used is deleted 24 hours after it was created.
• After 30 days without use (any action in the app, the API or the MCP server; visitor traffic does not count), the workspace is paused: running experiments are paused, the script on your website does nothing, and API keys and agent connections stop working until you save the workspace.
• After 90 days without use, the workspace and all its data are deleted.

Saving the workspace to an account (signing in) ends this lifecycle; paused experiments stay paused until you resume them. Accounts are created and secured with our sign-in service login0. You keep your sign-in details and recovery links confidential and are responsible for actions taken with them.

3. Plans, limits and tested users#

A tested user is a visitor who saw at least one experiment in a calendar month (UTC), counted once per project however many experiments or pages they saw. Experiments that ship a variation to all visitors count as running experiments. Every plan includes all statistics features, the visual and code editors, the API and the MCP server; in workspaces without an account, custom JavaScript runs in previews only until the workspace is saved to an account.

Limits never break your website. At 80% of your tested users we show a notice in the app. At 100%, visitors already in an experiment keep their variation and keep counting, and new visitors see your original pages until the next month starts or your plan changes. Above the project or running-experiment limit, new projects, launches and ships are refused; nothing running is stopped. A person can own up to 3 Free workspaces.

4. Prices, billing and cancellation#

Prices exclude VAT. Business customers in the EU outside Germany are invoiced under the reverse charge procedure. Paid plans are set up on request (from Plan and usage in the app, or by email to support@tryfast.eu); we confirm within one business day and bill monthly by invoice. Invoices are payable within 14 days. Enterprise terms are agreed individually.

You can cancel a paid plan at any time, effective at the end of the current calendar month, by email to support@tryfast.eu. The workspace then moves back to the Free plan and keeps its data; if it is above the Free limits, nothing running is stopped, but new launches are refused and new visitors are no longer enrolled beyond the Free tested-user limit. We may change prices with at least 30 days notice by email; changes apply from the next month, and you may cancel before they take effect.

5. Support#

• Without an account: documentation.
• Free: documentation and email support at support@tryfast.eu, best effort.
• Pro: email support with an answer within one business day.
• Business: priority email support: your requests are handled before those of other plans, with an answer within one business day.
• Enterprise: a named contact, as agreed.

Business days are Monday to Friday, excluding public holidays in Berlin.

6. Acceptable use#

You may use TryFast only on websites you operate or are authorized to change, and only within the law. TryFast serves your custom JavaScript, CSS and HTML to your visitors from our infrastructure, so in particular you must not use it to:

• deliver malware, cryptocurrency mining, phishing, credential or payment data harvesting, ad injection or deceptive redirects;
• track visitors across websites, fingerprint them, or circumvent their consent or opt-out choices;
• host scripts unrelated to experiments on your own website (TryFast is not a general-purpose script host);
• send special categories of personal data, or names, email addresses, phone numbers or similar direct identifiers, in goal keys, event properties, order ids or URLs;
• attack, overload or probe the service or other customers (security research is welcome under our Vulnerability Disclosure Policy);
• resell TryFast or provide it to third parties as your own service without a written agreement.

Right to switch off. We may switch off a project (its script then does nothing on your pages), pause experiments or block individual code immediately and without prior notice if it serves harmful or abusive code, endangers visitors, third parties or the service, or violates this section. We notify the workspace owners where we can and restore the project once the cause is removed. Experiment data is kept.

7. Your responsibilities#

• Legal basis and consent. You are the controller for your visitors' data. You choose each project's consent mode, connect your consent banner where consent is required, and describe TryFast in your privacy notice. Privacy and consent explains the options; the exempt mode may only be used where its conditions are met under the law that applies to you.
• Your content. You are responsible for the variations, code, goals and targeting you or your agents create, and for checking them, for example with preview links, before launch.
• Credentials. Keep API keys, recovery links and sign-in details confidential, and revoke keys and agent connections you no longer use.
• Domains. Add only domains you operate to your projects.

8. AI agents and API keys#

You can connect AI agents and create API keys for your workspace. An agent or key acts on your behalf within the permission level you granted (read only, build with your approval, or full access) and never beyond the current role of the person who granted it. Actions taken by agents and keys you authorized, and launches approved by you or your team, are your actions. Pausing an experiment is always possible. You choose the AI provider of your agent; what that provider does with the data your agent reads is governed by your agreement with that provider. You can revoke an agent or key at any time in the app; it loses access immediately.

9. Availability and limitations#

We build TryFast for high availability, but Free, Pro and Business plans carry no fixed availability commitment; Enterprise commitments are agreed individually. The script fails safe: if it cannot be loaded, your visitors see your original pages. Changes to running experiments reach every visitor within 2 minutes. Statistical results are decision support: they describe the evidence in the collected data, not a guarantee of future results. Known limits (for example ad blockers, browser storage limits in Safari and anti-flicker trade-offs) are described in Limitations.

10. Data protection#

Our processing of personal data is described in the Privacy Policy. The Data Processing Agreement under Art. 28 GDPR is part of these terms for every workspace and every plan and applies to the visitor data we process on your behalf. In case of conflict on data protection matters, the Data Processing Agreement prevails.

11. Liability#

We are liable without limitation for intent and gross negligence, for injury to life, body or health, and under the German Product Liability Act. For slight negligence we are liable only for breaches of essential contractual obligations (obligations whose fulfilment makes the proper performance of the contract possible and on which you may regularly rely), limited to the foreseeable damage typical for this type of contract. For workspaces without an account and the Free plan, liability for slight negligence is excluded to the extent legally permissible.

12. Term and termination#

Free use, including workspaces without an account, may be ended by either side at any time; you end it by deleting your workspace or account. Paid plans run monthly and can be cancelled as described in section 4. Either side may terminate for good cause; for us, good cause includes in particular serious or repeated violations of section 6. Before your data is deleted you can export it, as described under "Migration and Data Export" on our compliance page. If we ever discontinue TryFast, we give at least 90 days notice.

13. Changes to these terms#

We may amend these terms with at least 30 days notice by email to workspace owners. If you do not object before the changes take effect, they apply from then on; we point this out in the notice. If you object, either side may end the contract when the changes take effect. Changes that affect only workspaces without an account are published on this page.

14. Final provisions#

German law applies, excluding the UN Convention on Contracts for the International Sale of Goods. The place of jurisdiction for merchants and legal entities under public law is Berlin. Should individual provisions be invalid, the remaining provisions stay in effect.

Contact: legal@tryfast.eu

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