dsh-browser-bridge

A DeepSeek Harness plugin + browser extension pair that lets DSH agents read and control your browser - the equivalent of Kimi's WebBridge extension or Claude's browser extension, but for your own local harness.

+-----------------------------+        WebSocket         +--------------------------+
|  DeepSeek Harness (dsh)    |  ws://127.0.0.1:3080/     |  Your browser            |
|                             |  bridge                  |  (Chrome / Edge / Yandex)|
|  browser_* tools           | <------------------------> |  DSH Browser Bridge      |
|  (this plugin)             |   commands / responses    |  extension (MV3)         |
+-----------------------------+                          +--------------------------+

The DSH side exposes 13 model-facing tools; the extension side executes them in the browser (tabs, DOM, clicks, typing, scrolling, screenshots, eval).

Agent tools

Tool	What it does
browser_status	Is the extension connected? Bridge URL, pending commands.
browser_list_tabs	List open tabs (id, title, url, active).
browser_activate_tab	Bring a tab to the foreground.
browser_navigate	Open a URL, or reload / back / forward; optional new tab.
browser_snapshot	Interactive elements (buttons, links, inputs...) with stable CSS selectors.
browser_read_page	Visible page text (or a subtree), capped in characters.
browser_click	Click an element by CSS selector.
browser_type	Fill an input / textarea / contenteditable (native events).
browser_press	Send a key (Enter, Tab, Escape, arrows...).
browser_scroll	Scroll the page or a scrollable element.
browser_wait	Wait for a selector to appear/disappear, or just let the page settle.
browser_screenshot	Save a PNG/JPEG of the current tab to disk (~/.dsh/browser-bridge/).
browser_eval	Evaluate a JS expression in the page (content-script world).

When the extension is not connected, every tool fails with a clear message telling the model (and the user) how to connect it.

Layout

dsh-browser-bridge/
|-- lib/            # the DSH plugin (node side)
|   |-- index.js    # plugin entry: tools + WS upgrade route + /bridge/info
|   |-- ws.js       # minimal RFC 6455 WebSocket server (no dependencies)
|   |-- bridge.js   # connection registry, request/response correlation, timeouts
|   `-- tools.js    # the 13 browser_* tool definitions
|-- extension/      # the browser extension (Manifest V3)
|   |-- manifest.json
|   |-- background.js   # WebSocket client + chrome.tabs / messaging dispatch
|   |-- content.js      # DOM actions in pages (top frame only)
|   |-- popup.html/js   # connection status, read-this-page preview
|   |-- options.html/js # server URL, auto-connect, "Test connection"
|   `-- icons/
`-- test/run-test.mjs   # standalone protocol test (no harness boot required)

Install

1. The package lives in the web profile's node_modules (~/.dsh/profiles/node_modules/dsh-browser-bridge).
2. Registered in ~/.dsh/profiles/web/cordis.patch.yml as row browser-bridge (name: dsh-browser-bridge).
3. Recorded in ~/.dsh/profiles/web/package.json dependencies.

Verify the composition at any time:

dsh --profile web --dump-config | grep -A 3 browser-bridge

Activate

The plugin is loaded at boot, so restart dsh web once after installing (restarting drops the GUI for a few seconds; it comes back on the same URL). After the restart, the server prints [browser-bridge] bridge ready - point the DSH Browser Bridge extension at ws://127.0.0.1:3080/bridge, and http://127.0.0.1:3080/bridge/info answers JSON. Verify with:

dsh --profile web --dump-config | grep -A 3 browser-bridge
curl http://127.0.0.1:3080/bridge/info   # -> {"name":"dsh-browser-bridge",...}

Load the extension

1. Open your browser: Chrome, Edge, or Yandex (all Chromium).
2. Go to chrome://extensions (Edge: edge://extensions, Yandex: browser://extensions).
3. Enable Developer mode (top-right toggle).
4. Click Load unpacked and select the extension folder of this package.
5. Click the extension icon - the popup should show Connected to DeepSeek Harness.

The default server URL is ws://127.0.0.1:3080/bridge, which matches dsh web running on its default port. If your harness listens on another port, open the extension's Options page, set the URL, and use Test connection.

Then just ask an agent, for example:

Use the browser to open example.com, read the page, and click the first link.

Configuration (cordis.patch.yml)

Key	Default	Meaning
path	/bridge	WebSocket endpoint path on the web server.
commandTimeoutMs	60000	How long a tool waits for the extension to answer.
screenshotDir	~/.dsh/browser-bridge	Where screenshots are saved.
maxMessageBytes	8 MiB	Max WS message size (screenshots travel over WS).

Development

• node test/run-test.mjs - boots a real server + fake extension client and exercises every tool, timeouts, disconnect, and the /bridge/info route (40 assertions, no harness boot required).
• Protocol: JSON text frames. Server -> client request/ping/welcome; client -> server hello/response/pong. Commands are camelCase in the extension protocol (listTabs, snapshot, click, ...) and snake_case in the model-facing tools.

Security notes

• The bridge binds only to the web server's loopback host (127.0.0.1 by default) and has no authentication: any local process could connect to /bridge and drive the browser. Treat it like shell access.
• browser_eval executes JavaScript in pages - powerful by design; only grant it to trusted agents.
• The extension has <all_urls> host permissions (required to read tab URLs and act in any page). It talks only to the configured localhost URL.