Privacy Policy — McFiddles Browser Relay

Extension: McFiddles Browser Relay (Chrome extension, id oklbkdfgjgjajfpdpbkdgnnoebndcfgf)
Last updated: 2026-10-16

What this extension is

McFiddles Browser Relay connects your Chrome browser to your McFiddles platform so that one of your own McFiddles agents can operate the browser on your behalf — but only when you explicitly grant control, only for the duration you choose, only on the sites you allow, and only until you stop it. The extension runs on your machine and acts as the authoritative local enforcer of what an agent is allowed to do: the remote platform is advisory, and this extension has the final say on every action.

This extension is intended for McFiddles operators and their teams. Using it requires a McFiddles platform account with the browser-relay capability enabled for your tenant.

What data the extension accesses

When — and only when — you grant an agent control of a tab, the extension may access the following, scoped to that tab and that grant:

• Visible page content. The extension reads the visible text of the controlled tab through a fixed, vetted extraction routine that runs in an isolated execution context. It reads what a person can see (via innerText / computed style), so the agent can act on the page. It does not capture screenshots, serialize the full DOM, or read hidden markup.
• Tab information. The URL/origin and basic state of the controlled tab, used to enforce which sites an agent may touch and to detect navigation.
• DevTools-protocol events for the controlled tab, used to carry out the individual, policy-checked actions an agent performs.

Microphone — only while you turn voice on

The side panel can let you talk to the agent (voice). Chrome microphone permission is required; if Chrome cannot show its prompt in the panel, Allow microphone in a tab opens a permission page. You can refuse, and typing keeps working.

• Audio is captured only while voice is on in the side panel, and stops when you press End voice, change conversations or close the panel. The extension never listens in the background.
• Where the audio goes depends on the agent's voice runtime, which your workspace configures (the panel shows the sentence that applies while a call is on):
  • Standard voice: your microphone audio goes to your McFiddles platform, which sends it to your workspace's speech-to-text provider and plays back the agent's reply that its text-to-speech provider renders.
  • Conversational voice (OpenAI): your microphone audio and the agent's voice go directly between your browser and OpenAI, in a session your McFiddles platform sets up; McFiddles receives the conversation's text and events, not the audio.
• The extension itself stores no audio and no transcript.
• Voice is off unless your workspace turns it on, and voice is refused for agents your workspace marks private.

The extension does not access, and the agent can never reach through it:

• your cookies, localStorage, or sessionStorage;
• network request or response bodies;
• arbitrary script execution or network interception (unless your specific grant's domain policy explicitly permits a gated capability);
• any sensitive site — identity providers, single-sign-on, banking, and password managers are hard-blocked and never driveable, regardless of your settings.

Secrets are scrubbed before they leave your browser

Before any extracted visible text is sent anywhere, the extension redacts true secrets in-page — authentication tokens, API keys, JWTs, auth headers, and credit-card / SSN-shaped values are replaced with [REDACTED] so they never leave your browser.

Authentication data

• You sign in to your own McFiddles platform through Chrome's standard web sign-in flow (chrome.identity.launchWebAuthFlow).
• The extension generates a non-extractable device key inside your browser to identify this device. The private key never leaves your browser.
• A device token and a short-lived relay token are stored locally in the browser so the extension can reconnect without re-pairing.

What is stored locally vs. sent to the platform

Stored locally in your browser (chrome.storage, IndexedDB), never sold or shared with third parties:

• your configured platform URL, paired-device state, and tokens;
• the non-extractable device key (private half stays local);
• the current control-grant state (allowlisted domains, expiry) and a recent activity feed shown in the popup and side panel.

Sent to your McFiddles platform (the platform you signed in to, under your account) to provide the single advertised function:

• the individual agent actions you authorized, as they are relayed;
• a metadata-only audit record of each action (see next section).

The extension does not send your data to any party other than the McFiddles platform you connect it to.

Audit logging — metadata only

Your McFiddles platform keeps an immutable, per-tenant audit trail of relay activity. By design it records metadata only — never payloads:

This boundary is enforced structurally: the audit writer rejects any field that looks like a raw payload. The log records that an action happened and where (which host) — it is not a place where your content or secrets accumulate.

Retention

• Local browser data (tokens, device key, grant state, activity feed) remains in your browser until you stop control, sign out, or remove the extension. Removing the extension clears its local storage.
• Platform-side audit metadata is retained by your McFiddles platform under your tenant's data-retention and garbage-collection policy (audit, pairing, and grant records are GC'd per platform configuration). Because it is metadata only, it contains no page content, typed text, full URLs, or credentials.

How we use the data

Solely to provide the extension's single function — letting your agent operate your browser under your control, and giving you an auditable record of what it did. We do not:

• sell your data;
• use your data for advertising;
• use your data for any purpose unrelated to the extension's function;
• transfer your data to third parties other than the McFiddles platform you connect to.

Your control

• Control is opt-in per grant — nothing happens until you approve it.
• Every grant is time-boxed to the duration you choose and expires on its own.
• You can stop control instantly from the toolbar; Stop acts locally first, so it works even if the network is unavailable.
• A visible banner and toolbar badge mark every controlled tab; if the banner is tampered with, the extension fails closed and detaches.
• You can remove the extension at any time from chrome://extensions.

Children

This extension is a professional tool for McFiddles operators and is not directed to children.

Changes to this policy

If this policy changes, we will update the version date above and the hosted copy. Material changes will be reflected in the extension's listing.

Contact

Questions about this policy or your data: gcp-developers@mcfiddles.ai (mcfiddles inc.). The McFiddles platform's own privacy policy is at mcfiddles.ai/privacy.