Customers bring their own Anchor key. Anchor bills browser use directly.
Chromium runs as a managed Anchor cloud session, so the sandbox stays light.
agentTask() takes a plain-language instruction and returns the result.
A link per session lets a person watch the agent browse.
The Half a Sandbox Doesn't Cover
A sandbox gives an agent somewhere safe to run code. Much of the work agents are asked to do still happens on websites: signing in to an account, clicking through a flow, holding a session open long enough to finish.
The web was built for people at keyboards. A headless browser started inside a sandbox gets flagged as a bot, stalls at multi-factor sign-in, and adds weight to every machine that runs it.
Code Here, Browser There
CreateOS Sandbox
Runs the agent's code in an isolated machine: install packages, run scripts, call a model. No browser runs here.
Anchor Browser
Runs the browser as a managed cloud session, with stealth, proxies, managed sign-in, live view and the session's lifecycle.
- Add your Anchor key as a sandbox secret. Store it as ANCHOR_API_KEY, and alias ANCHORBROWSER_API_KEY to it, which is the name the Anchor SDK reads by default.
- Install the Anchor SDK in your image. anchorbrowser from pip or npm, in the image's app directory. Playwright is only needed for direct browser control.
- Give the agent a browser tool. agentTask() in Node or agent.task() in Python takes an instruction such as 'go to this page and return its title' and returns the result. For full control, connect Playwright to the session over CDP.
Anchor recommends one browser session per agent run, a time limit on every session so an abandoned sandbox does not hold a browser open, and deleting the session when the sandbox shuts down.
CreateOS runs the agent. Anchor runs the browser.
Each side does the part it is built for, and the customer's Anchor key connects them.
A Working Example
Example 53 in the CreateOS Sandbox SDK runs an OpenAI tool-calling agent whose browser tool lives in a sandbox. It creates a sandbox from devbox:1, passes in the Anchor key, installs the Anchor SDK, and has agentTask() scrape a public page through an Anchor cloud browser. With no key set, it fetches a small trial key through Anchor's Agent Access instead.
CreateOS and Anchor announced the partnership on September 29, 2026.
Highlights
- CreateOS runs the agent, Anchor runs the browser. Chromium is a managed Anchor cloud session; the sandbox holds the Anchor SDK and talks to it over HTTPS and CDP.
- Bring your own key: the customer adds an Anchor API key as a sandbox secret, and Anchor bills browser use directly. CreateOS does not meter it.
- One call, agentTask(), turns a plain-language instruction into a finished web task. Playwright over CDP is there for full control.
- Every session has a live view link, so a person can watch what the agent is doing in the browser.
About Anchor Browser
Anchor Browser is cloud browser infrastructure for AI agents and automation: browser sessions controlled over CDP or REST, natural-language web tasks, managed authentication into third-party web apps, persistent profiles, recordings, live view, and network options including residential proxies, extra stealth and captcha solving.
Anchor's docs list CreateOS among the sandboxes it integrates with.
