Privacy policy

Draft 0.1, 12 November 2026

Draft, not yet in force. Ostium is being set up and nobody can sign in yet, so it holds no personal data. This text describes how the service is built to work. It has not had its legal review; the final version and its date will replace this notice before sign-in opens.

In short

Ostium signs you in to services with your Google account. It keeps your name and email address to itself and gives each service only an ID that stands for you.
A service gets that ID only after you allow it, and only until you withdraw.
The same ID is used in every service you allow. Services that you connect can therefore tell that you are the same person in each of them.
You can see, download, withdraw and delete everything yourself on your account page.
No advertising, no analytics, no selling or sharing of data for anyone else's purposes.

Who is responsible

Ostium is run by OÜ SOA Trader, registry code 11224441, Estonia, which is the controller of the personal data described here. Contact: info@soatrader.com. Privacy questions are answered within one month.

Each service you sign in to through Ostium is responsible for what it records under your ID, and has its own privacy policy.

What Ostium holds, and why

Data	Why	Legal basis (GDPR)	Kept for
Your name and email address from your Google account, whether Google has verified the address, and the web address of your Google profile picture. Kept in a separate database under a separate ID.	To show you who you are signed in as on your account page, and to answer your requests. Never given to a service.	Providing the account you ask for, Art. 6(1)(b)	Until you delete your account; updated each time you sign in
Your ID: a pseudonym made from your Google account identifier with a keyed one-way function. Ostium does not keep the Google identifier itself.	To be the same person each time you sign in, without a service learning who you are.	Art. 6(1)(b)	It is not stored on its own; it appears in the records below
Your consents: which service you allowed, for what purpose, under which version of the service's text, when, and when you withdrew.	To give a service your ID only while you allow it, and to show you what you allowed.	Your consent, Art. 6(1)(a), for passing your ID to a service; the record of it, Art. 6(1)(c) and (f)	Until you delete your account
Sign-in tokens of the apps you connect, stored only as one-way hashes, with the service each is for.	To keep you signed in to a service through an app.	Art. 6(1)(b)	1 hour (access) and 30 days (refresh), or until you withdraw or disconnect
The name and sign-in registration of the apps you connect (for example Claude).	To run the sign-in and to show you which apps are connected.	Art. 6(1)(b)	As long as the app stays connected
Account-page session: a random key in a cookie, stored on our side only as a one-way hash, linked to your ID.	To keep you signed in on your account page.	Art. 6(1)(b)	7 days, or until you sign out
Organisations you create or are a member of, your role in each, the agents you or they register, and agent tokens (stored only as one-way hashes).	To let an agent act for its owner, and to tell a service which agent is acting and for whom.	Art. 6(1)(b)	Until you delete them or your account. An organisation with other members stays with them.
Deletion requests: when you delete your account, a note for each service you used, with your ID, saying that it must delete what it holds.	To make sure each service is told and to know when it has confirmed.	Legal obligation, Art. 6(1)(c)	With your ID until the service confirms; after that only the dates
Web server logs: IP address, time, requested address, browser or app identifier.	To keep the service secure and working.	Legitimate interest in security, Art. 6(1)(f)	12 months

Ostium does not hold what you do in a service: results, answers, learning records and the like stay with that service.

What a service receives

When you allow a service, and each time it checks that you are still signed in, it receives:

your ID;
whether the sign-in is a person or an AI agent, and for an agent which agent it is and who owns it;
the organisations you are a member of and your role in each;
which app you signed in with, and when the sign-in runs out.

It never receives your name, your email address or your picture, and it cannot contact you through Ostium.

One ID in every service

Your ID is the same in every service you allow. This lets you carry what you did in one service to another without a mapping between accounts. It also means that anyone who can read the records of two services you use can see that they belong to the same person, though not who that person is. If you do not want two services to be linkable in this way, do not allow both with the same Google account.

Withdrawing, and deleting

Withdrawing a service on your account page ends its sign-in for you at once: its tokens are deleted, and the next time it checks, it is told that you are no longer signed in. It ends what the service may do from then on. It does not by itself delete what the service already recorded; ask the service, or delete your account.

Deleting your account deletes your name and email address, ends every consent and sign-in, deletes your own agents and their tokens, and asks every service you used to delete what it holds under your ID. If you sign in again later with the same Google account you get the same ID, are asked for consent again, and start with nothing.

Cookies

These pages (gw.ee) set no cookies. The sign-in service (id.gw.ee) sets two, both strictly necessary, readable only by id.gw.ee and not by scripts:

id_session keeps you signed in on your account page, for 7 days or until you sign out;
id_consent ties the screen that asks for your consent to the browser it was shown in, for at most 10 minutes.

Where your data is and who handles it

Hosting: our server is in a Hetzner Online GmbH data centre in Helsinki, Finland (EU). Hetzner processes the data on our behalf only.
Google: when you sign in, Google confirms who you are and gives us your name, email address and the address of your profile picture, under Google's privacy policy. Google learns that you signed in to Ostium. It does not learn which service you then use.
The services you allow receive what is listed above, each under its own privacy policy.

Ostium does not transfer your data outside the European Economic Area.

Your rights

You can ask us to show you the data we hold about you, give it to you in a file, correct it, delete it, or stop using it for a while, and you can withdraw any consent without affecting what was done before. You can do the most common of these yourself on your account page: download what Ostium holds, withdraw services, disconnect apps and delete your account. For anything else, write to info@soatrader.com from the email address you sign in with, or include your ID, which is shown on your account page. We act on requests within one month.

If you think we handle your data wrongly, you can complain to the Estonian Data Protection Inspectorate (Andmekaitse Inspektsioon, www.aki.ee) or to the data protection authority where you live.

Security

All connections use HTTPS. Sign-in follows OAuth 2.1 with PKCE. Tokens, session keys and agent tokens are stored only as hashes. Your name and email address are in a different database from everything else, under a different ID, and no table links the two. Access to the server is limited to the operator.

Children

Ostium does not knowingly accept accounts of people under 18. If you believe a child has signed in, write to us and we will delete the account.

If the service closes

If we stop running Ostium, we will say so on this site at least 30 days in advance, tell the connected services, and then delete the data.

Changes to this policy

When this policy changes, we update the version and date above and keep earlier versions available on request. We will not start using your data for a new purpose, or let a service change what it does with your ID, without asking you first.