Browser & screen
Give the agent a browser and watch the box's desktop over noVNC
Every box ships a real headed browser and a live VNC desktop. A coding agent can navigate sites, test its own web app, and you can watch it happen — the app it opens is exposed per web-apps-and-tunnels, and the desktop runs alongside the agent from run-an-agent.
Give the agent a browser
Vercel's agent-browser is baked into the box image, so every box (docker, daytona, hetzner, vercel) has a working browser with no setup. The Chromium it drives is provided by Playwright — fetched on first browser use (and reused from the project's own pinned Playwright build when present), so agent-browser and the project's Playwright share a single, current Chromium rather than a stale baked-in one.
The agent calls agent-browser directly from inside the box, and any GUI process renders to the box's VNC display — which is what you see through agentbox screen below.
agent-browser is the default, but it isn't the only stack: the standalone playwright-cli is also available for agents that prefer driving Playwright directly. Add it with --with-playwright (or pin it via the browser.default config key) — see Playwright below.
# inside the box (the agent runs these directly)
$ agent-browser session list
No active sessions
$ agent-browser open --headed https://example.com--headed matters: agent-browser defaults to headless, which renders nothing on the VNC display.
TIP
The agent calls agent-browser itself — you don't have to. Sessions, auth, and cookies persist
under ~/.agent-browser/, surviving pause/unpause and stop/start, and are only wiped on
agentbox destroy.
Playwright
The Playwright runtime ships in the image; the Chromium itself is installed on first browser use (reusing the project's pinned Playwright build when present, so agent-browser and the project's tests share one binary — no version-mismatched, baked-in browser to go stale). Add --with-playwright to also install the standalone Playwright CLI in the box:
agentbox claude --with-playwrightTo make it the default, set the browser.default config key. See configuration for the browser-stack keys and precedence, and CLI commands for all flags.
Live screen
Every box runs a noVNC desktop. agentbox screen <box> opens that viewer in your host browser, auto-unpausing paused boxes and starting stopped ones first. The per-box VNC password is embedded in the URL, so you land straight on the desktop.
agentbox screen myboxThe desktop has a window manager, the AgentBox wallpaper (paper to every edge with the logo centred, whatever size the desktop is), and a small icon dock along the bottom. Everything on it is in the wallpaper's palette: the dock, the window titlebars, and the terminal, which opens light (ink on paper) with an ANSI palette to match. The dock carries: a Terminal button, a Browser button, and one icon per open window. Click an icon to raise that window, drag titlebars to move them, Alt+Tab to cycle; the browser runs undecorated (it is always maximized, and its tab strip already carries the title), so right-click its dock icon for the window menu. Nothing to enable — it's part of the desktop whenever VNC is on. The Browser button opens a browser of your own, separate from the agent's, so clicking it never navigates the page the agent is working on.
Starting a browser is not instant — the first one in a box downloads its Chromium — so a launch puts a small progress window on the desktop (and an entry in the dock) that counts the seconds and closes itself once the browser is up. A launch that fails leaves that window open with the error in it. The same window appears when agentbox screen or the hub opens a box's browser for you, so an empty desktop always tells you whether something is on its way.
screen is distinct from agentbox url: url opens the box's web app; screen opens the desktop viewer. See CLI commands for all flags (--print, --loopback, --ttl).
Opt out at create time with --no-vnc:
agentbox create --no-vncHEADS UP
--no-vnc disables the desktop for the box's whole lifetime — agentbox screen then refuses with
a "VNC is disabled" message. Recreate the box to re-enable it.
This works end-to-end on the cloud providers too (daytona, vercel, hetzner): the same noVNC desktop, reached via the provider's preview URL. The desktop is reachable from every surface — the (VNC) link in agentbox ls, the tray's Open VNC, and the hub UI — not just agentbox screen.
On daytona, vercel and e2b the viewer URL is minted per click rather than stored: those
providers' signed preview URLs expire (an hour by default), so a URL printed into a box listing
would be dead by the time you clicked it. The hub mints a fresh one on demand (GET /api/v1/boxes/ {id}/vnc), which is why the box payload's vncUrl is null for them while vncEnabled is
true. Docker and hetzner boxes have a stable Portless URL and carry it directly.
Screen sharing
agentbox screen does more than open the noVNC viewer. When the box has a web service that declares expose:, it also opens a headed Chromium inside the box pointed at the box's own web app — so you land on the running app rather than an empty desktop.
It's idempotent: if a browser session is already active (the agent is mid-task), screen leaves it untouched and never navigates the agent's page away.
agentbox screen mybox # noVNC viewer + opens the web app inside the box's desktop
agentbox url mybox # open the web app host-sideThe most useful part is one origin from both sides: the in-box Chromium loads the same URL the host uses, so Next.js allowedDevOrigins, OAuth, and CORS behave identically on both sides. This holds across engines and cloud providers (see local-docker for the Portless vs OrbStack details).
From agentbox dashboard, the same two actions are chords on the selected box: Ctrl-a s (screen — noVNC viewer + in-box browser) and Ctrl-a u (url — web app host-side). They shell out to agentbox screen / agentbox url, inheriting the same Portless behavior.
TIP
Run agentbox screen while the agent is working and you'll see exactly what its browser sees.
The expose: service that makes the web app reachable is covered in services-and-tasks.