Configure the toolset

Besides type, the toolset entry accepts configs, cache_control, and allowed_callers; the rules these fields share with the computer use toolset are listed under Client toolsets, and this section covers the browser-specific defaults. configs is an object keyed by member name, and each member's value accepts two fields:

Field	Default	Meaning
enabled	true, except false for the four optional members	Whether the member is offered to Claude.
defer_loading	false	Whether the toolset's definition is deferred for tool search. Must resolve to the same value on every enabled member. With the four optional members left disabled, deferring the toolset means setting it on the other 27; see Client toolsets.

Enable or disable member tools

List only the members you want to change in configs; every member you omit keeps its default. For example, an executor that implements console reads but not low-level pointer or key-hold control turns read_console on and withholds three members:

{
  "type": "browser_toolset_20260801",
  "configs": {
    "read_console": { "enabled": true },
    "left_mouse_down": { "enabled": false },
    "left_mouse_up": { "enabled": false },
    "hold_key": { "enabled": false }
  }
}

A disabled member disappears from the definition Claude sees; that doesn't guarantee Claude never names it, so your executor still answers such a call with an error result.

Combine with other tools

Declare the browser use tool alongside your own tools and other Anthropic-provided tools in the same tools array. A custom tool may share a member's name (your own navigate, for example), because toolset_name distinguishes Claude's calls, but no other entry may be named browser, and a request may contain only one browser toolset entry.

You can also declare it alongside the computer use tool, either the toolset or an earlier computer use tool version. The two work independently, each in its own coordinate frame (viewport pixels here, desktop screenshot pixels there), and Claude's calls to members that share a name, such as screenshot or key, are told apart by toolset_name.