Browsers for agents

Agents often need the web: a dashboard to read, a form to fill, a page to check after a deploy. SpecWithCode gives them two ways in, and you can watch and take over in both.

	In-app browser	SpecWithCode Browser extension
Where it runs	Inside SpecWithCode, beside the thread	In your own Chrome profile
Signed in as	An in-app profile: imported cookies or a fresh login	You, with that Chrome profile's logins
Agents of	Every provider	Every provider
Turn it on	Settings > Integrations > Agent browser access, per project	Settings > Chrome, per machine

The in-app browser

Every thread has a browser beside it that you and the agent share: you watch and steer, the agent clicks and types. It has tabs, an address bar, DevTools, screenshots and screen recordings, element picking to send part of a page to the chat, a device toolbar for fixed viewports, and a list of the web servers running on the machine.

With agent browser access on, agents get the preview_* tools from SpecWithCode's MCP server (preview_open, preview_navigate, preview_snapshot, preview_click, preview_type and more). The tab an agent opens shows up beside its thread.

One profile per account

Each browser profile keeps its own cookies and storage. Agent tabs use isolated storage unless you pick a profile for them.

1. Settings > Integrations > Browser profiles > Import from, then pick a browser and its profile, for example Chrome, "Work". Only cookies are copied, never saved passwords.
2. In the new profile's menu, choose Use for agents.
3. Repeat for each account, one in-app profile per account, so two logins to the same service never mix.

Cookie import works for Chrome, Edge, Brave, Vivaldi, Opera, Arc, Helium, Firefox and Safari on macOS.

The SpecWithCode Browser extension

The extension lets agents use one of your real Chrome profiles: your tabs, your logins, on this computer only. Agents of every provider can use it. It is the way SpecWithCode recommends for agents to work in Chrome.

1. Open Settings > Chrome and pick the machine; each machine has its own Chrome.
2. Install the extension. While it is in Chrome Web Store review, choose Load unpacked: open chrome://extensions in the profile agents should use, turn on Developer mode, click Load unpacked and pick the folder SpecWithCode shows.
3. Choose Show pairing code and copy it.
4. Click the SpecWithCode icon in Chrome's toolbar, paste the code, name the profile (for example Work or Marketing) and click Pair.

From then on:

• Every tab an agent opens or works in sits in a visible "SpecWithCode" tab group with the profile's name.
• Drag a tab out of the group and it is yours again; the agent lets go of it.
• Pause in the extension stops all agent access at once. Unpair forgets the pairing.
• Chrome's own pages (chrome://, extension pages, DevTools) cannot be controlled.

The extension talks only to SpecWithCode on the same computer, over a loopback connection. A pairing code that points anywhere else is refused, so a pasted code cannot connect your browser to another machine. It has no server of its own, no analytics and no remote code. Details: SpecWithCode Browser privacy policy.

Why agents cannot drive your default Chrome profile directly

Since Chrome 136, Chrome refuses remote debugging on its default user-data folder, where your everyday profiles live, because malware used it to steal cookies. SpecWithCode does not work around that protection. Use the extension for a real profile, or import its cookies into an in-app profile.

For websites only; to work in native apps on the Mac, agents use computer use.