Privacy

Who this covers

This policy explains how the Serein app for macOS and the serein.pro website handle information. “Serein”, “we” and “us” mean the Serein team.

What stays on your Mac

• Your library. History, bookmarks, your journal and task records are stored in ~/Library/Application Support/Serein. We don’t run a server that receives them, so we can’t see or restore them.
• Passwords. Saved passwords are kept in the macOS Keychain, and using them needs your device authentication.
• Search and dictation. The index that lets you find a visit by describing it is built and searched on your Mac. Hold-to-talk dictation uses Apple’s on-device speech recognition.
• Imports. When you import bookmarks, history, passwords or cookies from another browser or an export file, Serein reads them locally and leaves the source files unchanged.
• Your agents’ chats. If you allow it, Serein reads the chats that Claude Code, Codex, Cursor Agent, OpenCode, Pi, Oh My Pi, Command Code, Grok and Hermes keep on your Mac, so that you can find them and continue them in Serein. Its index keeps the folder, the first message and the time of each chat, and a chat is read in full only when you open it. Serein also sees which of these apps are running and reads their open chats to show what they are doing. You can turn that off in Settings › Privacy. Serein reads these files without changing them. “Continue in a copy” writes the copy beside the original.

What leaves your Mac, and when

Websites

Like any browser, Serein sends your requests, IP address and browser details to the sites you visit and the services those pages load. Serein’s content blocker is on by default with a short built-in list of common trackers, and you can download fuller lists.

Search

Searches from the address bar go to the search engine you choose: DuckDuckGo by default, or Google or Bing. Search suggestions are off by default. If you turn them on, what you type is sent to that engine’s suggestion service as you type. Suggestions are never requested from private windows, or for addresses, commands or tasks.

Site icons

For regular tabs, Serein fetches each site’s icon from the site itself, without sending cookies. Private windows don’t fetch icons.

Agents

When you give a task to an agent, Serein passes the task and the context you include, such as the current page, a selection or a screenshot, to that agent’s command-line tool on your Mac. The tool sends it to its provider, for example Anthropic or OpenAI, under your own account. The provider’s terms and privacy policy apply to that data. Serein does not receive a copy.

When you continue a chat from Cursor Agent, OpenCode, Pi, Oh My Pi, Command Code, Grok or Hermes in Serein, your message and what you attach go to that app’s own command-line tool on your Mac, as if you typed them there. (Serein runs Claude Code and Codex chats itself, as tasks.) That app sends them to its provider under your account and acts with its own settings, not Serein’s, so Serein asks you before the first reply in each chat. Page text that you attach is marked as untrusted reference material. If you continue a chat with a different agent, Serein passes recent messages of the chat to that agent as context.

If Codex is signed in, Serein runs Codex’s own command to list your Codex Cloud tasks when you open the Codex tab of the Agents card, at most once a minute, and to show a task’s status and changes when you open it. Codex sends these requests to OpenAI under your account. When you choose Apply, Serein writes the task’s changes into the project folder that you confirm, on your Mac, and commits nothing.

Grok and Hermes run web, page, answer and Mac tasks with their own setup. Grok loads your own Grok plugins, hooks and MCP servers, and it reads files and lists folders on your Mac without asking; Serein declines its commands, file edits and other MCP tools. Hermes uses its own web, browser and shell tools, so it can reach websites directly and run most shell commands without asking; Serein declines its file edits and the commands it asks about. Serein runs both in a macOS sandbox that closes the same protected folders as for its other agents, and more: mail, messages, browser data and cookies, SSH and cloud keys, keychains, saved Git and GitHub sign-ins, Serein’s own website data and library, and other agents’ sign-ins. What they read elsewhere goes to their providers under your account.

Agents never see private windows. They never receive what is typed into password, payment or verification-code fields. A page with such fields is read with that cut out of its text and pictured with those fields blanked; when Serein cannot confirm that for the whole page, the page is not read or pictured. A task still hands control back to you to type into those fields.

Background helpers

Some features give your agent a small job, such as naming a group of tabs. For these, Serein passes the data below to an agent on your Mac: the agent you have selected when it can do these jobs, else Claude Code or Codex, else another agent you set up. That tool sends it to its provider under your own account, as it does for a task. Serein does not receive a copy. Helpers run only if such an agent is installed and signed in.

Four helpers run on their own. Each has a switch in Settings › Agents, and all four are on by default:

• Choosing a destination. When you send a request without choosing where it goes, Serein sends the request, the last three messages of that thread, the address of the page in the active tab, and your listed projects: name, folder path, notes, Git branch, recent commit subjects and recent session titles. For a page from a local dev server, it also names the project that serves the page.
• Tab groups. When your open tabs change, Serein sends the title of each tab, its address without the query string, and up to 160 characters of its page text.
• Dictation proofreading. When speech recognition is unsure of a word, Serein sends the dictated text. Dictation longer than 1,500 characters is not sent this way. If you choose “Proofread dictated text” in the message box, Serein sends your whole draft, with no length limit.
• Task results. When a task finishes, or when you press “Summarize how this task went”, Serein sends up to 12,000 characters of the agent’s last message to get a one-line result.

The others run only when you ask:

• Compare tabs. The title, address and text of the two to six tabs you choose: up to 18,000 characters of text for each, and about 3,000 characters of the structured data (JSON-LD) that the page publishes about itself.
• What changed since your last visit. When you press Summarize, up to 8,000 characters of the new text on the page.
• Find a page by description. When you search History by description, your description. The agent then searches a temporary copy of your history, day descriptions and kept passages, and what it reads there goes to the provider.
• Day descriptions. When you ask for one in History, the address, title and up to 500 characters of text for each page you visited that day. This also runs after browsing pauses if you turn on “Organize browsing episodes automatically” in Settings › History, which is off by default.
• Sort projects by purpose. When you press “Sort by purpose” in the Projects map, the name of each listed project, up to 400 characters of its README and up to 200 characters of its manifest file. New projects are sent later only if you turn that on in the map.

Helpers never read private windows. The text of a page that has a password or payment field is sent only without what is typed there, and dictation into such a field is never proofread. The address and title of such a page can still be sent as part of the items above.

Optional features

These stay off until you use them:

• Updates. A release build reads serein.pro/appcast.xml to see whether a newer version exists. Our host, Vercel, sees the request, your IP address and your Serein version. Serein sends nothing else about you. When you install, it downloads the disk image, checks that the signature matches Serein’s update key, replaces the app and reopens it. Your settings and library stay. A build you made yourself does not check.
• Filter lists. When you update the blocker, Serein downloads EasyList and EasyPrivacy from easylist.to.
• Password sync. In builds signed for it, you can sync saved passwords through iCloud Keychain, which Apple provides under its own terms.
• Open on iPhone. Handoff offers the current page to your other Apple devices, and AirDrop sends its address to a device you pick. Both go through Apple’s services.
• Agent setup. Installing an agent from Setup runs that vendor’s own install script, downloaded from the vendor’s website.

This website

serein.pro sets no cookies and uses no advertising or embeds. Fonts are served from serein.pro itself.

To count visits, the home page runs Vercel Web Analytics, a script from our host that is served from serein.pro. When the page opens, the script sends the address of the page and the address of the page that linked to it. From that request, Vercel also records the country, the browser, the operating system and the type of device. The script sets no cookie and stores nothing in your browser. Vercel tells visitors apart with an identifier that it makes from the request.

The site and the download are hosted by Vercel. Like any web host, Vercel processes request data such as your IP address, browser user agent and the page requested, to deliver the site and protect it from abuse. See Vercel’s privacy policy.

Children

Serein is not directed to children under 13, and we don’t knowingly collect information from them.

Your choices

Because your data is on your Mac, you control it directly. You can clear history in Serein, remove saved passwords, or delete the Serein folder in Application Support to remove everything. Depending on where you live, you may have rights to access or delete personal data. We generally hold no personal data about people who use the app. For data held by websites, search engines, agent providers, GitHub, Vercel or Apple, contact them directly.

Changes

If our practices change, we’ll update this page and the date above. Significant changes will also be noted with the release that introduces them.

Contact

A contact address for privacy questions is coming soon and will be listed here.