Cookie Policy

Last updated: 29 September 2026

English translation; the Spanish version prevails. The original is Política de Cookies.

1. What are cookies?

Cookies are small text files stored on your device (computer, tablet or mobile) when you visit a website. Cookies allow the website to recognise your device and remember information about your visit, such as your preferences and settings.

At Matemática del Alma, we use cookies to improve your experience, provide essential features and analyse the use of the platform.

This cookie policy complies with the General Data Protection Regulation (GDPR) and Spain’s Organic Law on Data Protection and Guarantee of Digital Rights (LOPD-GDD).

2. Types of cookies we use

We use different types of cookies according to their purpose and duration:

Essential (Technical) Cookies

These cookies are strictly necessary for the platform to work. Without them, you could not use basic features such as signing in or keeping your session active.

Purpose:

Authentication and session management (Supabase Auth)
Security and fraud prevention
Remembering your sign-in preferences

Duration:Session / 1 year

Origin:First party (Supabase)

Legal basis: these cookies do not require prior consent under the GDPR, as they are strictly necessary to provide the service requested.

Preference (Functional) Cookies

These cookies remember your preferences and personalise your experience on the platform.

Purpose:

Remembering your theme preference (light/dark mode)
Saving interface settings
Remembering your preferred language

Duration:1 year

Origin:First party

Visit measurement (first-party analytics)

We measure visits with our own tool. The data is kept in our database (Supabase, in its London region, United Kingdom, a country covered by a European Commission adequacy decision) and is not shared with third parties or used for advertising. We do not use Google Analytics, Vercel Analytics or any other external analytics service.

Without your permission (anonymous measurement):

We only count which pages are visited, with no identifier at all
We do not store cookies or identifiers on your device for this measurement
We record approximate data: device type, browser, operating system, country and the site you arrived from

With your permission (detailed measurement):

A random visitor identifier (mda_vid) stored in your browser’s local storage
A session identifier (mda_sid) that is renewed after 30 minutes of inactivity
Clicks on links and buttons, reading time and how far you scroll on each page
If you are signed in, the visit is linked to your account
We never record what you type into forms or the content of your dreams

Retention:13 months

Origin:First party

Note: if your browser sends the “Do Not Track” or “Global Privacy Control” signal, we treat it as a refusal and only anonymous measurement takes place.

Third-Party Cookies

Some external services may set their own cookies when you interact with content embedded in our platform.

Providers:

Supabase: authentication and session management
Stripe: payment processing (only when you use payment features)
Vercel: hosting of the platform (we do not use its analytics services)

Each of these providers has its own cookie policy. We recommend that you review them:

3. How to manage cookies

You have full control over the cookies you accept. You can manage your preferences in several ways:

On this site

You can change your choice about detailed measurement whenever you like. When you press the button, we clear your choice and the measurement identifiers from this browser, and we will ask you again.

Browser settings

All modern browsers let you configure cookies. You can:

Block all cookies
Accept cookies only from specific sites
Delete existing cookies
Set them to be deleted when you close the browser

Important note on essential cookies

Please note that if you block essential (authentication) cookies, you will not be able to use key features of the platform such as signing in or keeping your session active.

Instructions by browser

See your browser’s instructions for managing cookies:

4. Specific cookies

Below are the specific cookies Matemática del Alma uses:

Name	Type	Purpose	Duration
sb-*-auth-token	Essential	Supabase authentication token	1 hour
sb-*-auth-token-code-verifier	Essential	PKCE verification for secure authentication	Session
theme	Preference	Save theme (light/dark)	1 year
mda_consent	Essential	Remember whether you accepted or declined detailed measurement	12 months
mda_vid	Analytics (only with permission)	Random visitor identifier, in the browser's local storage	Until you withdraw permission or clear the site's data
mda_sid	Analytics (only with permission)	Session identifier, in the browser's session storage	Session (renewed after 30 minutes of inactivity)
__stripe_mid	Third party	Fraud prevention in payments	1 year
__stripe_sid	Third party	Stripe session identifier	30 minutes

Note: the asterisk (*) in the names of the Supabase cookies stands for your project’s unique ID. Stripe cookies are only set when you use payment features.

5. Updates to this policy

We may update this Cookie Policy from time to time to reflect changes in our practices or for other operational, legal or regulatory reasons.

We recommend that you review this page regularly to stay informed about how we use cookies.

The “Last updated” date at the top of this page shows when this policy was last reviewed.

6. Contact

If you have questions about this Cookie Policy or about how we manage cookies, you can contact us:

Email: privacidad@matematicadelalma.com

Form: matematicadelalma.com/contacto (in Spanish)

Related documents: Privacy Policy • Terms and Conditions