dsh-chrome — DeepSeek Harness browser companion

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A Chrome side panel that embeds the full dsh web UI (sessions, settings, approvals, tasks, goals, workspaces — everything) and lets the dsh agent perceive and drive your browser:

• Sees the current page automatically. After you switch tabs or navigate (SPA routes included), the "current page" (URL, title, body text, capped at 1,000,000 characters) is injected into your most recently active session, so the agent knows what you are looking at. Only http(s) tabs are injected this way.
• Reads HTTP traffic on request. When you ask it to, the agent starts a capture (browser_start_capture) and records the active tab's request method, URL, status, request body and response body via the Chrome DevTools Protocol; browser_capture_requests reads them back. Secret-shaped values are masked by default — see Security.
• Drives the browser. browser_navigate / browser_click / browser_open_tab.
• Approval-free, with tool-level intent unlock. State-changing actions run only when the current turn was started by a real message from you that contains explicit browser intent. The words that unlock browser_navigate / browser_click / browser_open_tab are open, navigate, click, visit, tab (打开 / 跳转 / 前往 / 点击 / 导航 / 访问 / 浏览一下 / 新标签), plus "go to" when it is followed by a page or URL (go to github.com, go to the page — a bare go to the next step does not unlock anything); the words that unlock browser_start_capture are capture, debug (抓包 / 抓一下 / 抓取请求 / 监听网络 / 网络请求 / 流量). Note that 抓取 on its own does not unlock capture — it reads as ordinary "fetch/scrape" intent; say 抓包 or 抓取请求. If an action is blocked you get a refusal quoting the exact words that would unlock that tool, so you can simply restate. An instruction hidden inside a web page cannot drive the browser (best-effort protection in approval-free mode, not an absolute guarantee).
• While capturing, Chrome shows a "debugging this browser" banner (it disappears when capture stops).

Prerequisites

• dsh web running locally (default http://127.0.0.1:3080; configurable in the extension's settings).
• Chrome 118+ (the extension relies on InjectionResult.error, added in Chrome 118).

Install

Two halves: the host plugins (added to dsh) and the Chrome extension (loaded unpacked).

1. Add the host plugins to your dsh web profile:

dsh plugin --profile web add dsh-chrome

This registers the bridge, the browser tools, and the page injector. dsh hot-applies new plugin rows, so just refresh the browser afterwards — no restart needed unless you later edit an already-loaded plugin file.

2. Install the Chrome extension files and load them:

npx dsh-chrome install

This copies the extension to a stable per-user directory (prints the path) and shows the remaining steps:

1. Open chrome://extensions, turn on Developer mode.
2. Click Load unpacked and select the printed directory.
3. Click the dsh-chrome toolbar icon to open the side panel.

Re-run npx dsh-chrome install after upgrading the package, then reload the extension at chrome://extensions — the installer copies the files, so without both steps Chrome keeps running the previous version against the new host plugins. npx dsh-chrome path prints the directory.

To remove dsh-chrome completely, undo both halves: npx dsh-chrome uninstall deletes the extension directory (then remove it in chrome://extensions), and dsh plugin --profile web remove dsh-chrome unwires the host plugins.

Usage

• The side panel is the full dsh web UI — use it normally.
• Top bar: bridge status (warns if dsh is not running), Stop capture (manual override), Settings (change the dsh address).
• Tell the agent things like "open the xx page", "click the login button", "capture this page's requests".

Security

Trusted, local use only. The bridge and browser tools give a local dsh agent the ability to read pages, capture traffic, and drive your browser.

• Capture is opt-in per tab and only sees requests made after it starts. Two things to be aware of about its scope: stopping a capture stops recording but keeps what was already recorded until the tab closes, and the buffer is not scoped to the dsh session that started it — reading it back (browser_capture_requests) is not intent-gated, so any session talking to the same browser can read it. Only starting a capture requires your explicit instruction. HTTP headers are not captured (so Cookie / Set-Cookie / Authorization headers never reach the model). The remaining credential surface — secret-shaped URL query parameters (?access_token=…), request bodies (form/JSON logins) and tokens embedded in response bodies — is masked as «redacted» by default. To capture raw, unmasked traffic (e.g. for your own debugging), set redactCredentials: false on the dsh-chrome-browser-tools row in your profile's cordis.patch.yml.
  • Redaction is best-effort, not a guarantee: it matches secrets by common key names, so a secret under an unusual key, or in a URL path or an unparseable/truncated body, can still pass through. Treat captured traffic as sensitive, and only enable capture on sites you trust.
  • It does, however, fail closed on shape: if the extension and the host disagree about the reply format (e.g. you upgraded the package but didn't re-run npx dsh-chrome install), unrecognised fields are dropped rather than forwarded unmasked, and an unrecognisable reply raises an error.
• Injected "current page" messages are labelled untrusted data, and the agent is instructed never to execute instructions found inside them. The intent-unlock gate further prevents page content from triggering state-changing browser actions. These are best-effort defenses under an approval-free model, not hard guarantees — do not point the agent at untrusted or sensitive sites while capture is on.

Layout

Notes & limits

• Browser tools that read or manipulate page state (capture included) act on the active tab only; browser_list_tabs and browser_open_tab are the natural exceptions.
• Capture retains a rolling last 500 entries; each request/response body and the automatically injected page body are capped at 1,000,000 characters. browser_get_page — the on-demand read — is a separate, smaller limit: ~40,000 characters of visible text and up to 400 links.
• Page-change detection: tab switch / main-frame navigation / SPA route change (history.pushState and replaceState), ~2 s debounce; scrolling does not trigger it. Only the active tab's navigations count — a background tab churning through SPA routes pushes nothing. The current page is also re-sent whenever the bridge reconnects.
• browser_click never retries. If the click's result is lost — the page navigated away, or the injection/CDP call was cut off — the tool reports that it could not confirm whether the click took effect, rather than clicking again (clicking is not idempotent), and tells the agent to re-read the page with browser_get_page to see what happened.
• Page pushes are deduplicated: a navigation whose URL and body length match the previous push sends nothing. The bridge reconnecting always re-sends, since dsh drops its cached page when the connection closes.
• The extension's own side-panel UI is currently Chinese only (the top-bar labels: bridge status, "stop capture", settings). The embedded dsh web UI follows dsh's own locale; only this thin extension chrome is not yet translated. Planned for a future release.
• Reading and clicking pages Chrome won't let extensions script — chrome-extension:// (another extension's options page), chrome://, file://, and the Chrome Web Store. The worker decides this from the tab's URL before trying, and routes those pages to the browser's remote debugging protocol (http://127.0.0.1:9222) instead. This requires the browser to be launched with --remote-debugging-port=9222 (and --remote-allow-origins=chrome-extension://<this-extension-id> if the remote endpoint enforces the Origin check). If the CDP endpoint is missing or unreachable, reading such a page fails with an explicit error naming the flag — it is not silently empty. Ordinary http(s) pages never take this path, even when injection fails on them, and automatic "current page" injection covers only ordinary http(s) tabs (the Web Store included in the exclusions).

License

MIT © Stuart Hu