SlyOS

SlyOS browser extension — privacy

Last updated 2026-10-16, for version 0.2.1. It replaces the text of 2026-09-11, which described an extension that read LinkedIn and nothing else.

This covers the SlyOS browser extension as it is published in the Chrome Web Store. The SlyOS service has its own privacy policy at slyos.world/privacy; this page describes what the extension in your browser does, and what happens to what it sends.

What the extension is

It puts SlyOS beside the page you are on: a panel that opens from the toolbar button, or with Ctrl+Shift+K (Cmd+Shift+K on a Mac). The panel is the same SlyOS assistant you talk to in the app. It can use two things from your browser, and each only when you ask:

  • the page you are on, when you send a question with that page showing in the panel;
  • a LinkedIn conversation you have open, which it reads so it can write you a reply and put it in LinkedIn's message box.

It needs a SlyOS account, and it does nothing until you connect this browser to that account by approving it in SlyOS.

The page you are on

When it is read

Above the box you type in, the panel shows the page it would use: the word "Using", the page's title, and an ×. That chip is on by default, so if you send a question while it shows, the page goes with the question. Press × and the page stays out, for that page, until you put it back.

It reads the page you are on only when you send a question with that page's chip showing. Not when you open the panel, not when you switch tabs, and not in the background. If the tab has moved to a different page between the chip and your send, nothing is read, and the panel says so.

What is read

  • the page's address and title;
  • the words on the page, as the page shows them, up to 24,000 characters;
  • the text you have selected on it, up to 2,000 characters.

It never reads what you have typed into a page. Text boxes, form fields, drop-down lists and editable areas (a half-written email or comment, say) are skipped, and so is a selection made inside one of them. Hidden text, embedded frames, scripts and images are not read either. If the address carries a username and password, they are taken out before anything is sent.

Pages it will not read

Banks and credit unions, card issuers, payment and money-transfer services, brokers and exchanges; password managers; LinkedIn and X; and the browser's own pages, the Chrome Web Store among them. On those the panel says SlyOS does not read the page, and nothing is sent. SlyOS's server checks the same list again and refuses such a page if one ever reaches it.

The list goes by name, so it cannot be complete: a bank whose name SlyOS does not recognise is read like any other page if you send with its chip showing. Look at the chip before you send.

The access it has, and the one press that widens it

When you open the panel with the toolbar button or the shortcut, Chrome gives the extension access to that one tab (Chrome calls this activeTab). On any other tab the panel offers "Let SlyOS see this page". Pressing it opens Chrome's own prompt asking whether the extension may read web pages. You can say no, and you can take it back at any time in Chrome's settings for the extension.

Be clear about what that access is. Once you grant it, Chrome lets the extension see the address and title of any web page you have open, and read any of them. The extension's code asks Chrome only about the tab you are looking at, in the window the panel is in, and reads it only when you send with its chip showing. That limit is the extension's code, not something Chrome enforces.

What happens to it

The page goes with your question, over HTTPS, to your own SlyOS account, where it is used to answer that one question. To write the answer it goes to Anthropic, SlyOS's model provider, and to no other: not to OpenAI, even when Anthropic is unavailable.

SlyOS treats the page's words as someone else's writing, never as instructions. If a page tells SlyOS to send, buy or remember something, SlyOS does not do it. In a turn that used a page, nothing is sent, booked or remembered without your own press.

Only the page's address, without anything after a ? or #, and its title are kept. They are stored with your question and with SlyOS's answer, in your SlyOS conversation. The words and your selection are not stored anywhere. SlyOS's answer is kept like any other answer in your conversation, and it may quote or summarise the page.

Reading the page is being switched on account by account. Until it is on for yours, SlyOS refuses the page before storing it or showing it to a model, answers your question without it, and the chip goes away.

A LinkedIn conversation you have open

It reads a LinkedIn conversation when you open it: when a page loads with the conversation open, when you move to it, when its tab comes back into view, or when you ask the panel for a reply to it. A new message arriving, LinkedIn redrawing its page, time passing, or a LinkedIn tab sitting in the background reads nothing. It reads the messaging surface only — not your feed, not profiles, not search, not your connections — and it does not open conversations for you.

From a conversation you open it sends to your SlyOS account:

  • the text of each message in it;
  • who sent each one, as an identifier LinkedIn itself uses, and their display name;
  • when each was sent;
  • LinkedIn's own identifier for the conversation.

A reply SlyOS writes is put into LinkedIn's own message box, and the extension stops there. You press Send.

If a different LinkedIn account signs in, the extension stops and asks you. It does not merge two people's conversations, and it does not carry on because time has passed or because the page looked fine. You confirm the new account is yours, or nothing is read.

What else it sends

  • Your questions in the panel, and which SlyOS conversation they belong to. SlyOS's answers come back the same way. Both are kept in your SlyOS account, like any conversation you have with SlyOS.
  • A regular check-in that says the extension is still connected, which sites it can read for you, and why it has stopped if it has. It carries no message and no page.
  • A report, if you send one. "Report a problem" at the foot of the panel sends the kind of report you chose, what you typed, and which screen the panel was on. Never your messages or drafts.

You sign in by approving this browser in SlyOS, which creates a device session for it. No cookie of yours is read — not LinkedIn's, not SlyOS's, not any site's. Requests to SlyOS are made with credentials: 'omit', so the extension could not send a cookie if it tried.

What it stores in your browser

  • the device session for this browser;
  • an opaque identifier for the LinkedIn account that is signed in, so it can notice when a different one signs in;
  • which SlyOS channel it posts LinkedIn messages into;
  • the id of your SlyOS conversation in the panel;
  • until the browser closes, the last 20 things said in the panel — your questions and SlyOS's answers there, and nothing said anywhere else — so the panel opens where you left off. "New chat" in the panel clears them, and so does disconnecting this browser;
  • for a reply currently being placed: its id, which conversation it belongs to, a digest of its text rather than the text, and the times it was claimed and placed;
  • up to 500 ids of LinkedIn messages already sent, so the same message is not sent twice;
  • how many conversations and messages the last LinkedIn read found, and when, for the panel's status line;
  • until the browser closes, whether reading the page is switched off for your account.

Apart from what was said in the panel, until the browser closes, no message text, page text, contact name or conversation title is stored in your browser. Those live in your SlyOS account, under the same encryption and retention as everything else in it. An answer SlyOS gave in the panel can quote a message or a page, and it is kept with the rest of what was said there.

What it never does

  • It never sends, posts, submits or buys anything. It reads, and it puts a LinkedIn reply in LinkedIn's box for you to send. The version in the Chrome Web Store contains no code that presses a button on a page.
  • It never reads what you have typed into a page, or a page you have not sent with its chip showing.
  • It never downloads or runs code from anywhere. Everything that runs is in the package you installed: no CDN, no eval, no code fetched while it runs. The page reader is one function shipped in that package, and an automated check reads the built files for anything that downloads or evaluates code.
  • It never trains a model on your conversations or on the pages you show it. SlyOS trains no model on them, does not sell them, and does not use them for advertising. Who else they reach is a different question, and the next section answers it by name.

Who else sees it

Not nobody. To answer you and to write replies, SlyOS sends what the extension read — including messages the other person wrote, and the words of a page you sent — to the companies it has engaged to run the service:

  • Anthropic (Anthropic PBC) receives the material an answer or a draft is written from: your question and the page you sent with it; for a reply, the recent messages in that conversation, the facts SlyOS has stored about that person and about you, and the description of your writing style.
  • OpenAI (OpenAI, L.L.C.) receives every message and draft that is turned into a search embedding, and, when Anthropic is unavailable, the material a reply is written from. It never receives the page you sent.
  • Neon (Neon Inc.) is the database those messages, your conversation with SlyOS and a page's kept address and title are stored in, and Fly.io (Fly.io, Inc.) runs the service they pass through. Open the same conversation in the SlyOS web app and it passes through Vercel (Vercel Inc.) as well.
  • Apple Push Notification service (Apple Inc.) receives the notification text when SlyOS tells your iPhone a reply is ready, and that text names the person you are talking to. Firebase Cloud Messaging (Google LLC) will receive the same once SlyOS sends notifications to Android phones.

The whole list, and what each one receives, is at slyos.world/legal/subprocessors. Apart from the providers on it, what the extension sends is not sold, not shared, and not transferred except as needed to give you what you asked for.

Those model requests are made from the SlyOS service, not from this extension. What a model provider may do with what SlyOS sends it is governed by that provider's own published terms, which SlyOS has not overridden by a separate agreement — so do not read this as SlyOS having negotiated something stronger, because it has not.

Removing it

Uninstalling the extension stops all reading immediately and removes everything it stored in your browser. Taking back the web-page access in Chrome's settings leaves the panel able to read only a tab you open it on.

What SlyOS already has stays in your SlyOS account until you remove it in the app or delete the account. Disconnecting LinkedIn stops collection from it immediately.

Removing something there takes it out of the live database straight away, and not out of the backups. Our database provider keeps 7 days of history the whole database can be wound back into; we do not edit that history and we do not restore selectively from it, so for 7 days what you deleted is still restorable from a point before you deleted it. After 7 days the provider has nothing left to restore it from.

Contact

support@belto.world