When does codus use the agent browser instead of the built-in one?
Codus uses the built-in browser for previews and ordinary browser work, without extra setup. An agent can use Agent Browser, which is real Google Chrome, when a site refuses the built-in browser or the task needs Chrome. A site may still require sign-in or human verification.
The agent chooses the browser for its task. In Codus 0.2.183 or later, you can also choose where Agent Browser opens Chrome: a separate profile or a window in your normal Chrome profile. This preference does not change the built-in preview.
Codus 0.2.184 or later adds Automatic: separate first. New pages start separately. With both extensions connected, the agent can open a page in your normal Chrome for an existing login or a persistent verification challenge. Choosing this mode grants that permission without asking each time. The agent explains the switch and keeps the original tab open; ordinary connection errors, rate limits and access restrictions do not trigger fallback.
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.
- Its logins depend on your mode. The default Separate browser has separate cookies and logins and can show a second Chrome icon on macOS. Window in your Chrome, available from 0.2.183, shares your chosen normal profile's logins. Agents can control only their own tabs.
- 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
Install the Codus extension once in each mode and profile you use. Settings shows the correct folder. The extension reconnects when that browser is running; updates can require Reload on its extension card. Codus reports when that is needed. Finish active browser work before reloading the extension.
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.
Links from other apps open in the wrong Chrome or stop opening. After saving browser work and letting agent browser tasks finish, fully quit every Chrome instance and reopen your usual browser first. Then retry an external link. See Why do links open in the wrong Chrome window or stop opening? for the steps and what to check if the problem continues. A separate agent profile does not rule out an external-link problem.