Cookie Policy

Last updated October 15, 2026

The Short Version

You can start a session without an account, and then this site uses no cookies and stores nothing about you on our servers. If a clinician creates an account for a custom link or saved trays, we store their email address and any trays they save, and use one cookie to keep them signed in. We never collect or store anything about clients.

Cookies

We set one cookie, saderra_auth, and only if you sign in. It's shared by the Saderra tools (BLS, Sand and Canvas), since one account works on all of them, so signing in or out on one does the same on the others. It keeps you signed in for 6 months, renewed each time you visit, so you don't have to sign in every time. It holds a signed reference to your account, not your email address, and can't be read by scripts on the page. Signing out removes it.

This cookie is needed for signing in to work, and we don't use advertising or tracking cookies from anyone. That's why you won't see a cookie banner here.

Accounts

Accounts are for clinicians who want a custom link or saved trays. Accounts here are separate from Saderra BLS accounts. When you create one, we store:

• Your email address, so we can send you sign-in emails
• Your custom link
• The date you created the account
• Whether you've asked for update emails, and when you chose
• Any trays you save: the name you give each one, the figures and where they are, the shape of the sand, a small picture of the tray, and when you saved it

There are no passwords. Each time you sign in, we email you a 6-digit code that works once, for 15 minutes. These emails are sent by Postmark.

We use your email address to send sign-in emails. We'll only send you other emails, such as occasional updates about Saderra Sand, if you tick Send me occasional updates when you sign in or in your account. You can untick it there at any time, and every update email has an unsubscribe link.

Tray names must not include client names, initials or any other information that could identify a client. If we find any, we'll delete the account immediately. You can delete a saved tray at any time from Saved Trays in your tray.

You can delete your account at any time with the Delete Account button on the home page. This deletes your email address and saved trays, and releases your custom link, straight away.

Storage in Your Browser

While a session is open, the therapist's tray keeps a copy of itself in your browser's local storage, so reloading the page doesn't lose it. It stays on your device, is never sent to us, is removed when you end the session, and is ignored after 12 hours.

The client's tray stores nothing in the browser.

Sessions

Session links are random letters and numbers, or a clinician's custom link. We don't keep a list of sessions or a record of when they happen. Changes to the tray pass through our realtime provider, Ably, only while a session is running. A tray is kept on our servers only if a signed-in clinician saves it.

Analytics

We use Fathom Analytics to count page visits. Fathom doesn't use cookies and doesn't collect personal information, so we can't identify or follow individual visitors.

Other Services

Like any website, loading these pages means your browser connects to the services that deliver them: Netlify (hosting), Google Fonts (fonts), jsDelivr (code library), Ably (live connection) and, for accounts, Postmark (email). These providers see your IP address in order to respond, as described in their own privacy policies. We don't receive or keep it.

Changes

If this changes, we'll update this page and the date at the top.

Contact

Questions about this policy? Email hello@saderra.com.