> ## Documentation Index
> Fetch the complete documentation index at: https://docs.browspark.krishm.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Privacy and security

> What leaves your machine (nothing), what the agent can reach, and how access is bounded.

## Local only

* The companion binds to `127.0.0.1`. There is no cloud component, no telemetry and no account.
* The extension talks only to that port and only after presenting the pairing token.
* Messages from the extension to the companion are validated; malformed frames are rejected and the socket closed.

## Access is opt-in per tab

The agent reaches exactly the tabs you share, plus tabs it opened itself in your window. `chrome://` pages, extension pages and the Web Store are never automatable. Emergency stop revokes everything at once.

## What the agent can see in a shared tab

Everything the page can: DOM, cookies for the page origin, local and session storage, network requests and their bodies while a `devtools_session` is running, and JavaScript evaluation in the page. Treat a shared tab as fully visible to the agent. Do not share tabs you would not paste into the chat.

## Restricting what the agent does

* [Disable tools](/concepts/tool-policy) you do not want used.
* [Domain policies](/tools/browser/browser_policy) limit where a tab, or every tab the agent opens, may navigate and load resources from.
* Set the developer browser to **Never** if the agent should not get a second browser.
* The activity log is off by default and keeps nothing; on, it holds the last 200 commands in memory only, never on disk. See [Activity](/dashboard/activity).

## Secrets

* The pairing token is in `~/.browspark/token` with mode `0600` and in the extension's local storage. It appears in the HTTP endpoint URL and live-view URLs; treat those like passwords.
* Recorder exports and HAR files can contain form values, cookies and headers. They are written to `~/.browspark/artifacts` or the path you give.
* Developer-context profiles under `~/.browspark/` hold logins like any Chrome profile.

## The debugger permission

Chrome grants the extension the `debugger` permission at install time. The extension attaches only to shared tabs, only when a command arrives, and detaches after 30 seconds of inactivity. The yellow bar Chrome shows is the honest signal that a tab is attached.