Privacy policy

1. Purpose and scope

Browser MCP Companion is the local macOS host for Chrome Control MCP, a browser extension and companion broker that let a Model Context Protocol (MCP) client read, interact with and debug your own browser. This policy describes Browser MCP Companion 0.2.0 for macOS, extension 0.1.13, earlier public installers, and the anonymous, opt-out operational statistics used by companion 0.1.12 and later.

Neither product creates an account with the publisher. There is no advertising service, browser-data sale or unrelated profiling. Browser content is not sent to the publisher. Crash-reporting code is present but delivery is disabled in this build.

2. Data the extension can access

Depending on the tools used by your connected client, Chrome Control MCP can access:

• Open tabs, their URLs and titles, page text and HTML, links, interactive elements, and screenshots.
• Actions and content supplied to browser tools, including clicks, typing, scrolling, JavaScript expressions, and changes to page HTML or CSS.
• Cookies, including authentication cookies accessible through the browser's cookie API, and localStorage and sessionStorage keys and values. When no origin rules are configured, an unfiltered cookie request can return cookies across accessible websites.
• Console messages and network request URLs, methods, request and response headers, status information, and response bodies requested by the client.
• Connection information, including the local broker's port and pairing token, browser name, attached tab IDs, client identifiers, and operational or audit metadata.

These sources may contain passwords or authentication tokens, personal communications, names and contact details, financial or health information, and other sensitive information present in the pages or accounts you use. Cookie values, storage values, headers and returned content are not automatically masked.

Attaching the browser debugger starts console and network recording for that tab, including when attachment is needed for another feature such as a screenshot or trusted input. Chrome may display a debugging indicator; visibility depends on Chrome and its configuration. Disable or remove the extension to stop browser access. Data access is not limited to content visible in a screenshot.

3. How data is used and shared

The extension uses browser data to carry out tools requested by your configured MCP client and return their results. The data flow is:

1. The extension communicates with the local broker at 127.0.0.1 on your computer.
2. The broker passes tool results to the connected MCP client on your computer.
3. Your selected client may retain those results or transmit them to an AI provider, other service, or destination you configure. Review that client's settings and the privacy policies of those services before using it.

The extension and broker do not themselves upload browser results to a publisher-operated server. This does not mean all data stays on your computer: a connected AI client may use a remote service, and browser actions or page scripts can communicate with the websites or destinations they access.

The publisher does not sell browser data or use it for advertising, data brokerage, credit assessment, or unrelated profiling. Chrome Control MCP uses browser data only to provide its disclosed browser-control and debugging purpose. Its use and transfer of information received from Google APIs adhere to the Chrome Web Store User Data Policy, including the Limited Use requirements.

Optional runtime download: self-contained installers include their runtime. Lightweight installers ask before downloading a missing private Node.js runtime from the official nodejs.org source and verify the archive. This download does not upload browser content. Your connection to the download service is subject to that service’s practices.

App Store and public companion updates: Browser MCP Companion delivered through the Mac App Store is sandboxed and updated by the App Store. It contains no public or private update-feed credentials and does not install updates outside the App Store. Earlier public-managed installers use the signed feed at updates.reabow.co/chrome-control-public/. Those update requests send no account credential, pairing token or browser data. Chrome Web Store extension updates are separate and depend on Store delivery.

Anonymous companion statistics (0.1.12 and later): a companion running with statistics enabled sends a small report to the publisher’s own endpoint at updates.reabow.co shortly after start and periodically while it runs. The report contains a random per-install identifier generated on your computer (not derived from hardware, your browser profile or any account), the companion version, operating system and processor architecture, how long the process has run, cumulative counts of tool calls, browser sessions and active days, the connected extension version, and coarse location from Cloudflare’s country and region request headers. The service never receives or stores your IP address, browser content, page data, tool results, cookies, pairing tokens, hostname or user name. The reply carries an operator policy that can require a newer companion, ask you to update the Chrome extension, or, when a companion with statistics enabled has not reached the publisher for 14 days, report that a required security check is needed before browser control continues.

Opt out at any time: create an empty file at ~/.chrome-control-mcp/telemetry-off in the home folder available to the companion and restart it. In the sandboxed App Store build this is the application’s own container, not your account-wide home directory. No statistics are then sent, queued crash fingerprints are discarded and the policy notices are inactive.

This website and its downloads: The public setup and privacy pages and the companion downloads are served from the publisher’s own server, placed behind Cloudflare. Serving a page or a download necessarily involves Cloudflare and that server processing the request metadata needed to deliver and protect the content, such as your IP address, the requested URL and request headers. Downloading a companion installer does not itself upload browser-tool results, page content, or cookies collected by the extension. Ordinary website requests may include applicable site cookies and referrer information under your browser settings. Optional support payments are handled by Stripe and PayPal under their own privacy policies.

4. Storage and retention

• Extension settings: the broker port and pairing token are saved in Chrome's local extension storage until replaced or the extension's stored data is removed.
• In-memory records: the extension buffers up to 500 console entries per tab. Network records, including any response bodies already retrieved, have no fixed entry cap. These buffers are cleared by a top-level tab navigation, closing the tab, an explicit clear request for the relevant buffer, or restarting the extension service worker. Detaching the debugger does not clear existing buffers.
• Companion files: the local broker stores connection/session details and operational logs in its local .chrome-control-mcp directory. In the sandboxed App Store build that directory is inside the application’s container. Its audit log records time, client identifier, tool name, a hash of tool arguments, tab ID, outcome and error code. It does not record raw tool arguments or returned tool data. The broker has no automatic deletion schedule for these files.
• Optional remembered browsers: after explicit opt-in and matching-code approval in both the browser and companion, the extension stores a nonextractable signing key and the pinned companion identity in local IndexedDB. The companion stores its identity key and approved browser public keys, labels, and trust records locally. Approval persists until revoked or forgotten. Forgetting the browser key does not revoke the companion record; revoke it in the companion as well. These records are not sent to a publisher server.
• Connection indicator: the extension can display the names reported by connected MCP clients. These bounded names are connection metadata, not verified identities or evidence that a tool action is in progress. They are sent from the local companion to the authenticated extension for display, not to a publisher service. The red extension icon indicates an authenticated companion connection; the normal icon indicates that connection is not established.
• Client and website records: your MCP or AI client, its service providers, and websites you interact with may keep their own copies. Their retention and deletion practices are separate from the extension's local storage.

5. Your choices and controls

Use the extension only with clients you trust. All broker capabilities are enabled by default; no website allowlist or blocklist is configured by default. You can restrict capabilities and configure origin rules in the companion broker. Browser permissions and supported tools determine the access available.

When origin rules are configured, cookie read and clear requests must supply a URL, and that URL is checked against those rules. The rules do not filter the list of open tabs. They check tool calls rather than providing complete browser or network isolation; debugger access can still reveal network traffic associated with a tab, including requests to other origins.

Use a current extension with a current companion. Installing or updating the Chrome Web Store extension alone does not update the companion. JavaScript evaluation uses the browser debugger; any debugging indicator is controlled by the browser and may not be visible.

To stop extension access, disable or remove the extension. Stopping the broker interrupts its client connection, but does not itself detach an already attached debugger or erase buffered records. Dismissing the debugger banner detaches that tab's debugger; it does not disconnect the broker, clear existing records, or disable tools that do not need the debugger.

You can remove the extension's stored data through browser controls, clear its in-memory console and network buffers through the relevant tools, and delete the companion's local files after stopping the broker. Deleting local files does not delete information previously returned to a client or sent to another service; use that service's controls or contact its provider.

Anonymous statistics are opt-out: create an empty file at ~/.chrome-control-mcp/telemetry-off in the companion’s accessible home folder and restart it. No report is sent while that file exists; removing it and restarting turns reporting back on.

6. Connection security

The broker listens on the computer's loopback address and requires a randomly generated per-run token. The extension and MCP clients present that token to the broker. Their local WebSocket connection and the loopback HTTP MCP endpoint are not encrypted with TLS. Browser MCP Companion uses the macOS App Sandbox for the App Store build and limits individual files with operating-system permissions. These measures do not protect against software with sufficient access to your computer or an untrusted client to which you give access.

Remembered pairing is optional and off by default. When enabled, an approved browser can use a signed challenge to reconnect without entering a new per-run token. It grants the same browser-tool scope, not MCP-client or management authority. Check that both six-digit codes match before approving; never approve a request you did not initiate. Revocation disconnects that browser and denies future authentication, but cannot undo an action already in progress. Native remembered-browser enrollment on Windows is not supported by this release.

7. Publisher and privacy contact

For privacy questions about Chrome Control MCP, contact the publisher at [email protected].

If you contact the publisher for support, share only information needed to describe your question. Do not send passwords, pairing tokens, full cookies, or other secrets.

8. Changes

This policy will be updated when the extension or companion's data practices change. The date and applicable versions appear at the top of this page.