Arcos Drop — Save to Arcos: Privacy Policy
Last updated: October 11, 2026
Arcos Drop (formerly Marc) is a browser extension that saves web pages, highlights,
and notes into your Arcos account. This policy
describes what data the extension handles and where it goes.
What Arcos Drop collects, and when
Arcos Drop sends data when you take an action: saving a page or your tabs, creating
a highlight or note, searching your library, or chatting about a saved page. The one
exception is checking whether the page you are on is already saved, described below.
- Account session — when you sign in, your Arcos session token is
stored locally in the extension's storage. It is sent only to Arcos's backend to
authenticate your requests.
- Pages you save — the page's address, title, and a copy of its
content are sent to Arcos to create the item and its reader view in your account.
Arcos's servers may send that content to Anthropic's Claude, as a processor, to fill
in the item's details, such as its description.
- Tabs — when you use "Save all tabs", Arcos Drop reads the address
and title of each tab in the window and saves the ones you keep to your Arcos account.
To date a saved link by when you first opened it, Arcos Drop notes when each open
tab's address first appeared. Those times are kept only in your browser, are forgotten
a week after the tab closes, and leave your browser only with a link you save.
- Whether a page is already saved — Arcos Drop keeps a local index
of the addresses already in your Arcos library, read from your account, so it can
show whether the page you are on is saved without asking the server. Until that index
has been built, the page's address is checked against your Arcos account instead.
You can turn off the corner button that makes this check in Settings.
- Highlights, notes, and chats — text you highlight or write is
stored in your Arcos account, governed by the privacy settings you choose there.
Chat replies are generated by Arcos's servers using Anthropic's Claude as a
processor; your chat messages and the saved page's text are sent for that purpose.
- Search queries — text you type into Arcos Drop's search (including
the
arc address-bar keyword) is sent to Arcos to search your own library.
- Settings — preferences (sidebar width, hidden sites, toggles) are
stored locally in your browser and sync nowhere.
What Arcos Drop does not do
- No analytics, tracking, or advertising of any kind.
- No record of the pages you visit. The only addresses that leave your browser are
pages and tabs you save, and the page you are on when Arcos Drop checks whether it is
saved before its local index is built. Page content leaves your browser only when you
save, highlight, or chat about a page.
- No sale or sharing of your data with third parties. The only processors are
Arcos's own infrastructure (Supabase) and Anthropic (chat replies, and filling in
the details of items you save).
Retention and deletion
Everything you save lives in your Arcos account and can be deleted there at any time
(deleting an item removes it from search and chat context). Signing out of the extension
deletes the locally stored session token and the local index of your saved addresses.
Tab first-opened times are forgotten a week after each tab closes. Local settings are
removed when you uninstall the extension.
Contact
Questions or deletion requests: vincent@catalist.org.