# Browser extension

> Review risky prompts and commands before supported AI websites submit them.

Source: https://docs.agentbeam.com/agent-cli/extension/overview

Beam Sentinel is a Chrome Manifest V3 extension for supported AI assistant pages. It checks recognizable prompt surfaces at send time, pauses high-risk matches, and keeps a short redacted history locally. It works independently of the CLI, dashboard, and MDM.

## Supported websites

The current manifest injects the content script into these top-level HTTPS sites:

| Assistant         | Domain                  |
| ----------------- | ----------------------- |
| ChatGPT           | `chatgpt.com`           |
| Claude            | `claude.ai`             |
| Gemini            | `gemini.google.com`     |
| Perplexity        | `www.perplexity.ai`     |
| Microsoft Copilot | `copilot.microsoft.com` |
| Grok              | `grok.com`              |

The extension checks form submission, send/submit-style buttons, and Enter from editable prompt surfaces. Shift+Enter remains available for new lines. It does not run in every iframe or on arbitrary websites.

## How a check behaves

High and critical heuristic matches pause submission and present a review action. Medium findings are allowed with a warning. Ordinary actions continue. Recognized secrets can be removed from supported editable content while the send is held so you can review the result.

These are browser-level heuristics, not comprehensive control over every network request a website can make. Changes to a site's composer or submission behavior can affect coverage.

![Beam Sentinel toolbar popup showing protection status, action counts, and recent decisions.](https://docs.agentbeam.com/images/toolbar-popup.png)

## Local history and privacy

The extension requires Chrome's storage permission and checks content locally. There is no extension authentication or remote collection request. The latest 100 redacted decisions are kept in `chrome.storage.local`, with redacted preview text rather than a stored full editor buffer.

The AI website still receives content you choose to submit. The extension does not make the destination provider local, erase a message already sent, or guarantee recognition of every secret.

## Start using it

Follow the [installation guide](https://docs.agentbeam.com/agent-cli/extension/install), reload an existing assistant tab, and verify the toolbar says protection is on. Use a harmless test input to verify that ordinary messages still work before relying on the review flow. Keep the extension enabled on the supported site's extension-access settings.


For team policy, audit logs and redaction, use **Agentbeam**, our main extension with every feature, from the [Chrome Web Store](https://chromewebstore.google.com/detail/agentbeam/cfnfncghihajlmpjafimebnafkhibipg). See [workspace browser data](https://docs.agentbeam.com/agent-cli/extension/workspace-data) for what it records. Its enrollment and collection settings are independent of free Sentinel.