Browser

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Not open yet. Browser is not open to accounts yet. These pages say how it works as it is built, ahead of its opening, and may change before then.

Browser gives each task a Chromium of its own, in a machine of its own, which your code drives from outside over the Chrome DevTools Protocol (CDP): Playwright, Puppeteer or any other CDP client. Each browser is a session. You make one with an API call and get its address; your client connects there, and the address is the credential.

A session is awake while a client is connected to it, whatever its pages are doing, and falls asleep a few seconds after the last one leaves, with its tabs, its pages and their cookies kept. The next connection wakes it where it was.

When to use Browser

• An agent that browses: a model that reads web pages and acts on them, through a CDP client of yours or an MCP server that drives a browser at an address.
• Pages that need a real browser: scraping, testing, filling forms; a session per job or per user, made by name and found again by name.
• A browser that keeps where it was: a session that sleeps between turns keeps its pages and its logins, and wakes where it was; a profile carries a login to new sessions.
• Watching an agent at work: a session’s page, live in any browser, with an address for people who may only look.

How it works

1. Make. POST /v1/browsers makes a session, awake, and answers with its CDP address, cdp_url. A session has a name if you give it one: a create with the name of a session the project has answers that session, woken where it slept.
2. Connect. Your client connects at cdp_url: Playwright’s connectOverCDP, Puppeteer’s connect with browserURL.
3. Sleep. When the last connection closes, the session sleeps sleep_after_seconds later (10 unless you say), its memory and disk kept. A connection wakes it.
4. End. DELETE /v1/browsers/{id} ends it, with its pages.

Three kinds of session:

• chromium-headless, the default: Chromium’s headless shell, a browser with no screen.
• chromium: the full Chromium, on a screen of 1280×800 that a person can watch.
• lightpanda: Lightpanda, a browser made for programs, which runs a page’s scripts and keeps its DOM, and has no layout engine: its screenshots and PDFs hold the page’s text alone.

Every session is a machine of 1 vCPU and 2 GiB. Its id is a sandbox’s, and a session is a sandbox the platform made for it: every call of /v1/sandboxes/{id}/… works on it too, so you can run a command in it or read its files. A plain sandbox never becomes a session, whatever it runs.

Connecting a client

cdp_url is all a CDP client needs, and is a credential: whoever has it drives the browser. Playwright connects with chromium.connectOverCDP(cdp_url) (connect_over_cdp in Python), Puppeteer with puppeteer.connect({ browserURL: cdp_url }). Playwright needs no browser of its own for it.

CDP=$(glac browsers create --name agent-42)       # prints the session's CDP address, and nothing else
npx @playwright/mcp --cdp-endpoint "$CDP"          # an agent's browser tools, driving the session

from glac import Glac

glac = Glac()
with glac.browsers.create(name="agent-42") as session:   # deleted when the block ends
    browser = session.connect()                          # Playwright, connected over CDP
    page = browser.contexts[0].pages[0]
    page.goto("https://example.com")

POST /v1/browsers/{id}/rotate-url gives a session new addresses: the old ones are refused from then on, and the connections they let in are ended at once (new addresses).

The command line has glac browsers; the Python and TypeScript SDKs have glac.browsers, with every call; the Go, Rust and Java SDKs make, find and end sessions; the MCP server opens, lists and closes them (browser_open, browser_list, browser_close). See the command line, the Python SDK and the MCP server.

What it costs

A session is billed as every instance is, by the Cube resources it uses, at the list prices: its CPU time while it computes, its memory while it is awake (in 128 MiB steps, by the millisecond), and its traffic out. It has no price of its own. A session is 1 vCPU and 2 GiB; the calculator on the site’s Browser page takes its vCPU busy half the time it is awake, unless you say otherwise.

• Asleep, a session is billed as any sleeping sandbox: while it is held paused in the machine’s memory, that memory, as if awake; once its memory is saved, what it keeps (its memory and the part of its disk that is its own), at $0.02 a GB-month, and nothing else.
• On Free, its CPU and memory come out of Free’s quotas of the day, with everything else the account runs; on Paid, out of the month’s inclusions, then the balance. See pricing and plans.

Lightpanda

A session of the kind lightpanda runs Lightpanda 1.0.2, a browser made for programs: it fetches pages, runs their scripts and keeps their DOM, and has no layout engine. Use it to read pages and act on them where nothing has to be seen; use chromium-headless where something does. It is made, priced and limited as the other kinds are, and its cdp_url and ws_url work the same way. Lightpanda is open source (AGPL-3.0), and runs in the session as its makers release it.

Connect with a context and a page of your own, as Lightpanda’s makers show: the page a connection finds already open is Lightpanda’s starting point, and does not navigate.

const browser = await chromium.connectOverCDP(session.cdp_url);   // Playwright
const context = await browser.newContext();
const page = await context.newPage();
await page.goto("https://example.com");
console.log(await page.textContent("h1"));

With Puppeteer, puppeteer.connect({ browserURL: session.cdp_url }) (or browserWSEndpoint: session.ws_url), then (await browser.pages())[0] or browser.newPage().

What was tried, through the platform’s edge, with Playwright 1.64 and Puppeteer 24.43:

A screenshot or a PDF holds only the page’s text. Lightpanda has no layout engine: page.screenshot() gives a PNG of the page’s text, set in blocks one under another, and page.pdf() a PDF of that text. Neither is the page as a person would see it: no layout, no images, no colours of the page’s own. chromium-headless gives the rendered page.

Limits

• Awake at once: a session counts as one sandbox of 1 vCPU and 2 GiB against what the account’s plan lets it have awake at once, with its sandboxes and Cubes’ instances (5 on Free: see limits).
• Ports closed for good: a session’s traffic never reaches ports 25, 465 and 587 (mail) or the ports mining pools listen on (3333, 4444, 5555, 7777, 14444, 45700), whatever its network rules say.
• Proxies: on Paid a session’s web traffic can go out through an HTTP proxy of your own (your own proxy); Free has none (403 proxy_not_on_plan).

Next

• Sessions: the calls, what a session has, names, sleep and wake, new addresses, your own proxy.
• Live view and profiles: watching a session’s page, and logins kept in profiles.