Terms of service

1Who these terms are for

Cestra is operated by [Cestra legal entity], registered at [address], ("Cestra", "we", "us"). "You" means the person holding a Cestra account, or the person reading this website.

You must be at least 16 years old to hold an account. If you use Cestra on behalf of a company, you confirm that you are allowed to accept these terms for it.

By creating an account, joining the waitlist or opening an app published on Cestra, you accept these terms and our privacy policy.

2Private beta

Cestra is in private beta. Invites go out a few hundred people at a time. Being on the waitlist does not create an account or any obligation on either side.

During the beta, features can change, be renamed or be removed. We may limit how much you can build or how many people can use an app. We will announce changes that affect published apps by email before they happen, except where a change is needed for security.

The beta is free. If we introduce paid plans, we will tell you in advance, and nothing you have already built will stop working because of it.

3Your account

One Cestra account signs you in to the studio and to every app published on Cestra, whether it is yours, shared with you, or public. There are no separate passwords and no separate subscriptions per app.

You are responsible for what happens under your account. Keep your password and sign-in codes private, and tell us at once if you think someone else has used your account.

You can close your account at any time from your account settings. See the section on ending the agreement for what happens to your apps and data.

4What you own

Everything Cestra produces for you belongs to you: the descriptions you write, the screens, the code, the database and its contents, the docs, and every version. Cestra claims no ownership of your apps and no licence to use their contents beyond what is needed to run them.

So that Cestra can do its job, you allow us to store, run, back up and serve your apps and their data, and to send your descriptions and app content to the AI models we use to build and change them. This permission ends when you delete an app or close your account, apart from backups, which are removed on the schedule in the privacy policy.

Cestra keeps the rights to the studio itself, the runtime that serves apps, the design system and the tooling. Those are licensed to you, not sold, for as long as you have an account.

You can export your app at any time. Export gives you the code, the database contents and the docs in standard formats.

5Listing and cloning on Explore

Listing an app on Explore is optional and off by default. When you list an app, you let other Cestra users clone it. A clone copies the design, the code and the docs of the version you listed. It never copies your data: every clone starts with an empty database owned by the person who cloned it.

By listing, you confirm that you have the right to share what is in the app, and you give other users a permanent, free licence to use and change their clones. You can unlist an app at any time, which stops new clones but does not take back clones already made.

Cestra may remove a listed app from Explore if it breaks these terms or if someone reports it and the report is upheld.

6Publishing apps for other people

Every app you publish gets one link that never changes. You decide who can open it: anyone with a Cestra account, only people you invite, or only you. You can give invited people roles, set when access expires, and limit what each role can read or change.

If other people use your app, you are the one responsible for it. In data protection terms, you are the controller of the data they enter, and Cestra is your processor. That means you must:

• collect only the data the app needs, and tell people what it is for
• have a lawful reason to process it, and honour requests to see, correct or delete it
• not use the app to collect sensitive data, such as health or financial records, unless you are allowed to and the app is set up for it
• remove people’s access and data when they ask, which they can also do themselves from their account

Visitors see, before they join an app, that it runs in your database, what the app can reach outside Cestra, and that you will see usage insights. Do not describe your app in a way that contradicts that.

Apps can only call the outside hosts you list in the app’s allowed domains. An empty list means the app reaches nothing outside Cestra. You are responsible for the hosts you allow.

7AI, tokens and allowances

Cestra builds and changes apps with AI models. The result can be wrong, incomplete or different from what you asked for. Check what has been built before you publish it, and treat anything an app says as information, not advice.

Your subscription includes a token allowance. Building in the studio, and AI actions people run inside your apps, draw on it. Usage is shown in your account, by app and by person.

For each app you choose who pays for AI actions inside it: you, the person using it, or a split. Tokens are never moved from you to a person automatically. When an allowance you pay for is used up, the app shows a warning, and AI continues only if the person has turned on “Use my own tokens” for that app. You can also set a monthly cap on what the whole app can spend.

Do not try to get around caps, allowances or access rules, and do not use the AI to produce content that is illegal, harmful or that you have no right to make.

8Acceptable use

Use Cestra for things that are legal where you are and where the people using your app are. In particular, do not:

• build or publish apps that harass, threaten, defraud or discriminate against people
• publish malware, phishing pages, or anything designed to collect credentials or payment details under false pretences
• impersonate a person or an organisation, or present an app as something it is not
• scrape, overload or probe Cestra or other people’s apps, or try to reach data you have not been given access to
• upload or process content you do not have the rights to, including other people’s personal data without a lawful basis
• send unsolicited messages from an app, or use an app to track people across other websites

Anyone can report an app from inside it. We look at every report. If an app breaks these terms, we may unpublish it, remove it from Explore, or suspend the account behind it. Where we can, we tell the owner why and give them a chance to fix it first.

9Availability and support

We try to keep Cestra and every published app running all the time, but we do not promise it, especially during the beta. We may take the service down for maintenance, and we will give notice when we can.

Support is by email at hello@cestra.ai. We answer as quickly as we can, and faster for anything about security or lost access.

10Ending the agreement

You can stop using Cestra at any time by closing your account. Before you do, export the apps you want to keep. When you close your account, your published apps go offline, people you invited lose access, and your data is deleted on the schedule in the privacy policy.

We can end the agreement by giving you 30 days’ notice by email, or at once if you have seriously broken these terms. If we end the beta or stop offering Cestra, we will give you at least 60 days to export your apps.

Sections on ownership, liability and governing law continue to apply after the agreement ends.

11Liability

Cestra is provided as it is, and during the beta without any warranty that it will be error-free, uninterrupted, or fit for a particular purpose.

To the extent the law allows, Cestra is not liable for indirect loss, lost profits, lost data that you could have exported, or loss caused by apps that other users built. Where liability cannot be excluded, it is limited to the amount you paid Cestra in the 12 months before the claim, or €100 if you paid nothing.

Nothing in these terms limits liability for death, personal injury, fraud, or anything else that cannot be limited by law. If you are a consumer in the European Union, your statutory rights are not affected by these terms.

12Governing law and disputes

These terms are governed by the law of [country], and disputes go to the courts of [city, country]. If you are a consumer in the EU, you can also bring a claim in the courts of the country where you live, and you may use the European Commission’s online dispute resolution platform.

If part of these terms turns out to be invalid, the rest still applies.

13Changes to these terms

We will update these terms as Cestra grows. For changes that matter, we email account holders at least 14 days before they take effect. The date at the top of this page tells you when the current version started. If you keep using Cestra after a change takes effect, the new terms apply.

Questions about these terms: hello@cestra.ai.