@try-works/dsh-browser-agent

A DeepSeek Harness (DSH) bundle that gives agents a real Chrome browser, and gives you a live window onto it. One shared page, three agent tools, and a collapsible browser pane docked inside the DSH Web GUI that streams that page and takes real mouse/keyboard input.

It is a fork of zenbu-labs/terminal-browser with the terminal UI replaced by a DSH tool surface and a web pane — the same idea (pixels out, synthetic input in), built on the harness's own plugin, module, and slot systems.

What this plugin is and does

• Three tools for agents — browser_goto, browser_evaluate, browser_screenshot — all driving one shared Chrome page that persists across calls, so an agent can navigate, read, interact, and capture.
• A live pane for humans — a right-docked, collapsible, resizable panel in the DSH Web GUI showing that same page in real time. You can watch the agent browse and take over yourself: click, drag, scroll, type, or use the address bar. Everything lands in the page through the Chrome DevTools Protocol.
• Five packaged skills — bundled guidance (plus a search runbook) that teaches agents how to find web sources, navigate, automate pages, verify renders, and manage tabs through the tools.
• URL normalization — tools and address bar accept URLs, hostnames, localhost:port, existing local file paths, or plain search text.

Chrome runs as a separate OS process launched by the plugin (puppeteer-core), so a browser crash can never take the harness down — the next call simply relaunches.

Install

Prerequisites: a DSH deployment with a profile (the Web surface is needed for the pane; the tools work on any surface).

# install from the npm registry into a profile (the DSH CLI forwards to pnpm
# in the profile directory, then reconciles the profile's plugin bundles)
dsh plugin --profile web add @try-works/dsh-browser-agent

The plugin's own bundle patch mounts the row automatically — no manual composition edit is needed. Then restart dsh web and hard-refresh the GUI tab (Ctrl+F5) so the client pane bundle is fetched. The three browser_* tools appear in the agent's tool set, and the pane docks on the right edge of the GUI.

Fresh releases and the supply-chain policy — DSH profiles enable pnpm's minimumReleaseAge check. A version published less than 24 hours ago is rejected unless it is listed in the profile's pnpm-workspace.yaml:

minimumReleaseAgeExclude:
  - '@try-works/dsh-browser-agent@0.2.0||0.2.1'

One rule per package name — multiple versions go in a single || union on the same line; separate lines for the same package shadow each other and only the first applies.

Local development

dsh plugin --profile web add link:D:/path/to/dsh-browser-agent

Configuration

All fields are optional (schemastery defaults fill them). Override via the profile's cordis.patch.yml:

- id: dsh-browser-agent
  config:
    chromePath: 'C:\Program Files\Google\Chrome\Application\chrome.exe'
    viewport: { width: 1920, height: 1080 }
    navTimeoutMs: 45000
    scriptTimeoutMs: 20000
    timeoutMs: 60000
    headed: false
    pane: true

Field	Default	Purpose
chromePath	system Chrome on Windows	Absolute path to a Chrome/Chromium executable.
viewport	1920 × 1080	Default viewport for new pages (and the headed window size).
navTimeoutMs	45000	page.goto navigation timeout.
scriptTimeoutMs	20000	page.setDefaultTimeout (script/evaluate timeout).
timeoutMs	60000	Per-tool execution timeout.
headed	false	Launch a visible Chrome window instead of headless. The window is the same shared page the pane shows — two views of one browser. Needs a desktop session.
pane	true	Serve the browser pane in the Web GUI. Headless/TUI compositions have no web server, so the pane never mounts there regardless.
userDataDir	'' (temp profile)	Chrome profile directory. Empty = a fresh temporary profile per launch. Set an absolute path to persist cookies, logins, and storage across launches (note: session cookies without an expiry are still session-only).

The browser tools

Tool	What it does
browser_goto	Navigate the shared page and return {url, finalUrl, status, title, text, links} — up to 6000 chars of extracted heading/paragraph/list text and 25 links.
browser_evaluate	Run a JavaScript expression in page context (document, window, DOM available) and return the JSON-serializable result.
browser_screenshot	Capture the current page as a PNG/JPEG data URL ({dataUrl, mime, bytes}); fullPage for the whole page height.
browser_click	Click the first element matching a CSS selector; returns the clicked tag/text or ok: false with a message.
browser_type	Type text into an input/textarea/select with real key events (React-safe); returns the field value.
browser_read	Inner text of a selector (default: whole body), up to 6000 chars, with the match count.
browser_wait	Wait until a selector appears (async content done), then return its text.
browser_back / browser_forward / browser_reload	History navigation of the active tab.
browser_a11y	Compact accessibility tree (role/name/value, up to 400 nodes) — what screen readers consume.
browser_tabs	List tabs (index, url, title, active); the other tools act on the active tab.
browser_tab_open / browser_tab_switch / browser_tab_close	Manage tabs; popups and target=_blank links open as new tabs.

The page is shared and persistent: browser_goto to a site, browser_evaluate to interact with its DOM, browser_screenshot to see it — all the same tab.

URL handling

browser_goto and the pane's address bar accept (matching the terminal-browser reference semantics):

• full URLs (https://…, data:, mailto:, about:, view-source:, …)
• host-like input (example.com/docs, localhost:5173 — http:// for localhost/127.0.0.1, https:// otherwise)
• existing absolute or ~-expanded local paths (opened as file://)
• anything else → a Google search

The browser pane

Expanded, the pane docks full-height on the right edge (like a mirrored sidebar); collapsed, it shrinks to a thin vertical rail with a toggle. Its left edge is a drag handle — drag to resize (320 px to 85 % of the window), the width persists across reloads, and the whole GUI reflows around it. The header carries back / forward / reload buttons next to the address bar.

The pane is a real two-way remote:

• Frames out — the pane subscribes to GET /browser-pane/stream (SSE). The host half drives Chrome's Page.startScreencast (JPEG frames on visual change only — no screenshot polling) and pushes each frame with the page URL. The screencast follows its subscribers: the first client starts it, the last one stops it, and late subscribers get the current state and last frame replayed immediately.
• Input in — pointer and keyboard events post to /browser-pane/input and land in the page through the CDP Input domain (Input.dispatchMouseEvent / Input.dispatchKeyEvent). Fidelity matches the terminal-browser reference: double/triple-click counting, modifier bitmasks (Shift/Ctrl/Cmd/Alt on mouse and keys), fractional wheel accumulation with line-mode detent scaling, held-key release on focus loss, and focus emulation while the pane owns the page.
• Address bar — POST /browser-pane/goto navigates the shared page.

Route	Purpose
GET /browser-pane/stream	SSE frame + state feed (frame / state events).
POST /browser-pane/input	Synthetic input: {type: mouse-move | mouse-down | mouse-up | wheel | key-down | key-up, …}.
POST /browser-pane/goto	Navigate: {url}.

How it works

One package, two halves, both mounted from a single composition row:

Host half (Node process) — runs the browser, the tools, the skill, and the pane server:

• A BrowserRuntime owns one lazily launched Chrome and a tab session: any number of tabs, one active. On a crash or disconnect the cached handles are cleared and the next call relaunches.
• All fifteen tools register on the host tools registry; the five packaged skills register on skills, each with its bundled skills/<name>/ directory as its resource base.
• The pane server registers the three routes above on the shared web server (ctx.webServer), only when one exists. Request bodies are parsed by schemastery schemas at the route boundary.
• Tabs: popups and target=_blank links open as new tabs (the terminal-browser tabs-as-popups model) and the pane's tab strip mirrors the session, so the pane, the tools, and any headed window never disagree about which page is live. Blank targets are never closed (a page under creation is blank too); foreign targets are adopted once they carry a real URL.
• Background throttling is disabled so frames keep flowing when Chrome is occluded.

Client half (browser bundle) — the pane UI:

• package.json declares dsh.client (platform: "web"), and the built bundle is exported at exports["./client"]. The DSH client-modules host scans enabled entries for dsh.client packages, serves the bundle at /plugins/@try-works/dsh-browser-agent/client.js, and the client kernel adopts it as a cordis plugin — no extra composition row required.
• The pane registers into the frame-wide shell.overlay slot declared by the GUI layout, docked to the right edge. The bundle is written with React.createElement (no JSX); react itself is a shell-seeded platform module, so the bundle carries no framework bytes.

Lifecycle — registration is wrapped in a ctx.effect generator (the dsh-recursive-mode pattern): unloading the plugin unregisters the tools and skill, tears down the pane routes and the screencast, releases held keys, and closes Chrome.

The bundled skills

The bundle registers four packaged skills on ctx.skills (the dsh-plugin packaged-skill standard: each skills/<name>/SKILL.md ships in the package and registers with a directory resourceBase, so relative references resolve against the bundle's copy):

Skill	Teaches the agent
browser-search	Finding and reading web sources through the tools and web_search, with route triage and a full runbook (references/search-engine-access-guide.md — search-engine captchas/403s, SearXNG fallback, Wayback Machine, site search, and API routes).
browser-navigation	Moving around the shared page: URL forms (URLs, hostnames, localhost ports, file paths, search text), reading the browser_goto summary, redirects/statuses/timeouts, and the single shared-page model.
browser-interaction	DOM automation through browser_evaluate: reading state, clicking, typing, form filling, scrolling, waiting for async content, JSON-safe results, and batching reads into one evaluate.
browser-visual-check	Verifying renders with browser_screenshot (viewport/full page, PNG/JPEG) and keeping the shared page presentable for the human watching the live pane.
browser-multitab	Working with several pages at once: tab tools, which tab the other tools act on, popups-as-tabs, and tab discipline.

Development

pnpm install     # links the type-only harness devDependencies
pnpm build       # tsc declarations + tsdown: lib/index.js (host) and lib/client.js (client)
pnpm typecheck   # tsc --noEmit

prepublishOnly runs pnpm build, so npm publish always ships fresh artifacts.

License

ISC — see LICENSE. This package derives from zenbu-labs/terminal-browser (ISC); see NOTICE.