When does codus use the agent browser instead of the built-in one?
codus uses the built-in browser (the preview) for almost everything, and it needs no setup. It only reaches for the separate agent browser, which is a real Google Chrome, when a website refuses the built-in one. That is mostly sites with a "prove you are human" check, like a Cloudflare gate or a captcha. When your agent hits one of those, it can switch to real Chrome, which those sites accept.
You do not choose between them. The agent picks the right one for the site it is on. If you never work with sites that block automated browsers, the agent browser never comes up, and you can ignore it entirely.
Why a Chrome window opened on its own
When the agent needs the agent browser, codus opens a dedicated Chrome window. This is expected. A few things to know so it does not throw you:
- Let it run. The agent is working inside it. You do not need to click anything, and it is best not to type in it or close it while the agent is using it.
- It is separate from your own browsing. The agent works in its own tabs in that window, so it never touches the tabs and logins in the Chrome you use day to day.
- It may open when you least expect it. It appears the moment the agent meets a site that needs it, not on a schedule.
When the agent is done, you can leave the window where it is. codus reuses it next time rather than opening a fresh one.
The setup happens once
The very first time, the agent browser needs a quick one-time setup: you load a small codus extension into that Chrome profile by hand. After that, it connects itself every time, including after you quit and reopen, so you never do it again.
If the agent tries to use real Chrome before that setup is done, it cannot connect, and it falls back to the built-in browser for anything that is not blocked. The full walkthrough is in How do I set up the agent browser?.
A gentler option first: Native mode
Not every bot check needs real Chrome. The built-in preview has a Native device mode that makes it look more like an ordinary visitor, which clears milder checks on its own. The agent uses this before escalating to real Chrome. You can read about it in How do I preview my site on mobile and tablet?.
Common problems
A Chrome window opened by itself and I do not know why. Your agent hit a site that blocks the built-in browser and switched to the agent browser. Let it run. It is doing its job.
The agent said it could not use real Chrome. The one-time setup has not been done, or the extension is not loaded in that Chrome profile. Follow How do I set up the agent browser?. Until then, everything that is not blocked keeps working in the built-in browser.
I only have Brave or Arc, not Chrome. The agent browser needs Google Chrome itself. Other browsers built on the same technology will not do.