An agent can use a browser with Action in three ways. They differ in which tools reach the page, which identity the page has, and whether the user sees it.

Choose a surface

Surface	Served by	Control	Identity
Your regular Chrome	Action MCP native tools	Screen capture and accessibility only (`observe_snapshot`, `resolve_target`, `act_execute`)	Your real Chrome profiles
An Action browser	Lattices MCP `browser_*` tools	DOM control over the Chrome DevTools Protocol (CDP)	An Action-owned Chrome profile, blank or seeded
A private-layer browser	Action MCP `layer_*` tools	CDP only, on a prepared virtual display	An Action-owned profile per workspace

Use regular Chrome when the task needs your live session and visible tabs. Use an Action browser for DOM-level work in a window you can watch. Use a private-layer browser when the work must stay off your screens.

Regular Chrome

browser_open {mode:"regular"} opens a URL in your own Chrome as a visible handoff. Nothing attaches DevTools to it. To act in that window, use the Action MCP native loop: observe_snapshot, then resolve_target, then act_execute.

Action browsers

The browser_* tools are part of the Lattices MCP server, not Action.app. Register it once:

claude mcp add lattices -s user -- lattices mcp

The tools launch a real, non-headless Chrome on an Action-owned user data directory and drive it over CDP. The debug port defaults to 9334 and can be set with ACTION_BROWSER_DEBUG_PORT.

Tool	Purpose
`browser_open`	Open a URL in an Action browser, or hand it to regular Chrome
`browser_snapshot`	Read the page as an element list with refs
`browser_click`, `browser_fill`	Act on an element ref
`browser_screenshot`, `browser_resize`	Capture or size the viewport
`browser_tabs`, `browser_close`	List or close tabs
`browser_console`	Read console output
`browser_profiles`, `browser_profile_info`, `browser_use_profile`	List and select browser identities
`browser_import_cookies`	Seed an identity with cookies from one of your Chrome profiles
`browser_companion_status`	Check the optional Chrome companion bridge on `ws://127.0.0.1:4321`

Identities, cookie seeding, and the companion bridge are covered in Browser profiles. The full tool reference is in the Lattices MCP page.

Private-layer browsers

A private-layer browser runs on a prepared virtual display in an agent-layer workspace. Prepare the display once with the CLI, then use the Action MCP:

layer_open     {workspace, browser:true, url, task}
layer_snapshot {workspace}
layer_click / layer_type / layer_press / layer_js / layer_go
layer_close    {workspace}

layer_open begins a drive lease unless you pass an existing leaseId. layer_close releases it.
Coordinates come from the last layer_snapshot.
The path is CDP only. There is no native fallback, so do not mix in desktop observe_* or drive_aim calls.
Browser flags, navigation, input, and JavaScript need MCP. The CLI layer commands cover lifecycle, snapshot, picture-in-picture, and recording.

Read capabilities first and confirm that the host and build accept private layers. See Agent layer.