Privacy Policy

Effective 19 September 2026

This Privacy Policy explains what personal information Duende collects when you use the Duende website and app at duende.fm (the “Service”), how that information is used and shared, how long it is kept, and the choices and rights available to you. By using the Service you acknowledge the practices described here.

In short: we collect only what the Service needs to work. We do not sell your personal information, we do not share it for targeted advertising, and we do not use it to build advertising profiles.

1. Who we are

Duende is an independent, invite-only project operated by an individual developer, referred to in this policy as “Duende,” “we,” “us” or “our.” We are responsible for the personal information described in this policy. You can reach us at privacy@duende.fm.

2. Information we collect

We collect the following categories of personal information. Items marked optional are collected only if you choose to use that feature.

Information you provide

Account information: your email address and the invite code you used to join.
Music taste information: the songs you enter, the taste profile (“genome”) generated from them, the songs recommended to you, your reactions to those songs, and any note you type describing what you want to hear.
Invite requests (optional): your email address and any note you include when requesting an invite.
Spotify data export (optional): if you upload files from your Spotify data export, the files are read on your device and we keep only a summary: which songs you already have or play often, your most-played songs, and the artists you play or save most. Nothing else from the files leaves your device.

Information from third parties

Spotify account connection (optional): if you connect Spotify, we receive the songs in your Liked Songs and in playlists you own or collaborate on, plus the access tokens Spotify issues. See section 5.

Information collected automatically

Technical and usage information: when you use the Service, our hosting and infrastructure providers automatically receive standard information such as IP address, browser and device type, pages requested, and the date and time of each request. We use aggregate, cookie-free measurement of page views and visitor counts.

We do not knowingly collect sensitive personal information such as government identifiers, financial account details, precise geolocation, health information, or biometric data, and we ask that you not submit it.

3. How we use it

We use personal information only to:

provide the Service: sign you in, build your taste profile, generate and display recommendations, and keep your data in sync across your devices;
verify that you are permitted to use the Service during its invite-only period;
send sign-in emails you request (we send no marketing email) and respond to invite requests and messages you send us;
maintain, secure and debug the Service, and prevent abuse; and
comply with law and enforce our rights.

Recommendations are generated automatically by an artificial-intelligence model based on the music information described above. They are suggestions only and have no legal or similarly significant effect on you. We do not use your personal information to train artificial-intelligence models.

We do not sell personal information and do not share it for cross-context behavioral (targeted) advertising, as those terms are defined under applicable state laws. We disclose personal information only as follows:

Service providers that process information on our behalf and under our instructions, limited to what they need to perform their services: hosting and content delivery, database and authentication, email delivery, an artificial-intelligence service that generates your taste profile and recommendations (which receives your songs, reactions, any note you type and, if you uploaded a Spotify export, up to 40 artist names; it does not receive your email address, and its terms prohibit it from using this information to train its models), and a music catalogue service that we query with song titles and artist names, not information that identifies you, to show artwork and previews.
Legal and safety: when we believe disclosure is required by law, subpoena or other legal process, or is necessary to protect the rights, property or safety of Duende, our users or others.
Transfers: in connection with a merger, acquisition or sale of all or part of the Service, in which case this policy will continue to apply to information transferred.
With your direction: when you ask us to, for example when you connect a third-party account.

5. Spotify

Connecting Spotify is optional. If you connect, we request read-only access to your saved songs and the playlists you own or collaborate on. We store the songs only as matching keys, together with Spotify’s access tokens, and use them for one purpose: removing songs you already have from your recommendations. Information obtained from your Spotify account is never sent to an artificial-intelligence model. We do not access your listening history, email address or profile through Spotify, and we cannot change anything in your Spotify account.

You can disconnect at any time from the Genome tab, which deletes all information we obtained from Spotify, or revoke access from the Apps page of your Spotify account settings. Your use of Spotify remains subject to Spotify’s own terms and privacy policy.

6. Cookies and browser storage

We use one strictly necessary cookie to keep you signed in, which lasts up to 90 days, and a short-lived cookie while you connect Spotify to protect against forged requests. The Service also saves a working copy of your genome, recommendations and reactions, and recent local backups, in your browser’s storage so it works quickly and offline. We do not use advertising cookies or third-party tracking cookies, and our page-view measurement does not use cookies.

You can clear cookies and site data in your browser settings; doing so signs you out and removes the local copy, but not the copy stored in your account. Because we do not track you across other sites or sell or share your information, we treat a Global Privacy Control signal as a valid opt-out request, and there is no further tracking for a “Do Not Track” signal to switch off.

7. How long we keep it

Account and music taste information: kept while your account exists, and deleted within 30 days after you ask us to delete your account.
Spotify connection data and uploaded export summaries: kept until you disconnect or remove them, which deletes them immediately, or until your account is deleted.
Invite requests: kept until the invite-only period ends or you ask us to delete them, whichever comes first.
Technical logs: kept by our providers for limited periods under their standard retention practices, generally no longer than 30 days.

We may keep information longer where the law requires it or to resolve disputes, and we may keep information that has been de-identified so that it can no longer reasonably be linked to you.

8. Your rights and choices

Depending on where you live, the law may give you some or all of the following rights. We extend them to every user, wherever you live:

Access and portability: to know what personal information we hold about you and receive a copy. The Journal tab’s Backup feature exports your music data at any time.
Correction: to correct inaccurate information. You can edit your songs in the Genome tab.
Deletion: to have your personal information deleted. Start over, Disconnect and Remove in the app delete the related data immediately; to delete your account entirely, contact us.
Opt out: of the sale of personal information, targeted advertising and profiling that produces legal or similarly significant effects. We do none of these.
Non-discrimination: we will not deny you the Service or treat you differently for exercising your rights.

To make a request, email privacy@duende.fm from the address on your account. We may need to confirm that the request comes from you before acting on it. You may use an authorized agent where your state allows it; we may ask for proof of their authority and verify your identity directly. We will respond within 45 days, and if we need more time, as the law permits, we will tell you why.

Appeals. If we decline your request, you may appeal by replying to our decision within a reasonable time. We will respond to your appeal in writing within the period your state’s law requires. If you are not satisfied with the outcome, you may contact your state attorney general.

9. Security

We use reasonable administrative, technical and physical safeguards designed to protect personal information, including encryption in transit, sign-in without passwords, session cookies that page scripts cannot read, and database access controls that limit each account to its own records. No method of transmission or storage is completely secure, and we cannot guarantee absolute security. If a breach affects your personal information, we will notify you as required by law.

10. Children

The Service is intended for people aged 18 and over. We do not knowingly collect personal information from anyone under 18. If you believe a minor has given us personal information, contact us and we will delete it.

11. Where information is processed

The Service is operated from the United States, and information is processed and stored in the United States and in other countries where our service providers operate. If you use the Service from outside the United States, you understand that your information will be transferred to and processed in those places.

12. Changes to this policy

We may update this policy from time to time. We will post the updated policy on this page and change the effective date above. If we make a material change, we will give notice in the Service before the change takes effect and, where the law requires it, ask for your consent.

13. Contact

For questions about this policy or to exercise your rights, email privacy@duende.fm.