Privacy · Updated 29 September 2026

How Duncan handles your data.

Duncan is a desktop library for your documents and notes. This page describes the current preview for Mac and Windows.

Local library

Imported files, extracted text, notes, conversations, and related metadata are stored on your computer. Duncan does not encrypt the local library. You can export it and clear local data from Settings. Keep your own backups.

Account and optional cloud sync

You can use the local library without signing in. Google or GitHub sign-in is available for an account. During setup, cloud sync is offered as a separate, unchecked choice. If you enable sync, Duncan transfers the library, including original files and recordings, to its Supabase cloud service. A signed-in session may resume automatic sync outside setup when sync is not paused. Pause sync in Settings to stop further automatic transfers.

Clearing local data and signing out do not delete cloud data. To delete your account and synced cloud library, choose Delete account in Duncan’s Cloud sync settings. The local library on this device stays in place and automatic sync stops. If you cannot access the app, email sppreus@gmail.com from the address used for sign-in; do not email your documents or provider keys.

AI connections

When you connect an AI tool through MCP, that tool can request the library content you allow. The tool may send that content to its own AI provider under that provider’s terms. If you configure an AI provider in Duncan, questions, selected source passages, images, or recordings may be sent to that provider for answering, analysis, or transcription. Provider keys are stored in the operating system credential store. Review the provider and connection permissions before sharing sensitive material.

Website and support

Visiting this website makes a normal request to its hosting provider, which may process network information such as your IP address and browser details. We use Vercel Web Analytics to count page views and see aggregate traffic information, including visited pages, referrers, device type, and approximate location. It does not use third-party cookies or identify individual visitors. The website has no account form. If you contact support by email, we use your message and address to respond.

Contact

For privacy questions or cloud data deletion, contact sppreus@gmail.com.