Claude gets a separate toolset for driving a browser

On August 19, Anthropic split two jobs that had been going through the same tool. Driving the whole desktop stayed in computer_toolset_20260801, which left beta the same day, while working inside a page got its own browser_toolset_20260801. The difference is not cosmetic: the new set sees the structure of a page, not just a picture of it.

Thirty-one tools, sorted by the job

The set ships with 27 tools enabled from the start and four more you turn on yourself. The split follows what people actually do in a browser.

• Navigation and capture: navigate, screenshot, and zoom.
• Pointer: clicks with every button, double and triple click, hover, drag, separate press and release, movement, and scrolling.
• Keyboard and timing: type, key, hold_key, and wait.
• Reading the page: read_page returns the accessibility tree with references, find locates an element from a plain-language description, and get_page_text extracts visible text, favoring the main content.
• Forms and tabs: form_input sets a field value directly, while new_tab, list_tabs, switch_tab, and close_tab manage tabs.

An element reference instead of a point in pixels

Actions take a target in one of two forms. The first is a viewport coordinate, x and y, the same shape the computer use tool understands. The second is an element reference such as ref_2, returned by read_page and find.

The second form is what makes this set usable on real sites. A reference survives a layout shift and requires no pixel guessing, so a button that moved after an image loaded is still hit. References hold until the tab navigates to a new address or the page structure changes substantially, and they belong to a single tab.

Browser state comes back with the result

Results can carry a browser_state block, in which the executor reports what actually happened in the browser: which tabs are open, with title and address, which one is active, whether any opened or closed, and whether a download started, finished, or failed.

• A single block holds at most 100 tabs, and exactly one carries the active marker.
• A tab reference is a stable string of at most 4,096 characters, with no control characters.
• Several actions in one turn run in order, but after the first failure the rest do not run and a message says so.

What stays off until you turn it on

Four tools ship disabled, and for good reason. Running JavaScript in the page and uploading files give the most power, while reading the console and network traffic serve diagnostics. You enable them individually through the configs array, and only once your executor actually supports them and the task calls for them.

Where it runs and where it does not

• Supported models are Claude Fable 5, Claude Mythos 5, Claude Opus 5, Claude Sonnet 5, and Claude Opus 4.8.
• The set is available only on the Claude API. It is not on Amazon Bedrock, Google Cloud, or Microsoft Foundry, and not within Managed Agents.
• There is no separate billing. Usage counts as ordinary token consumption, with the caveat that page reads and screenshots consume input context.
• The browser runs in your environment, not on Anthropic's servers.

Security is a condition here, not a recommendation

The documentation is explicit on this point, because executing someone else's content and taking real actions meet here. The browser should run in an isolated environment without credentials, the allowed-domain list belongs on the network, and navigate should accept only http and https addresses. Actions with consequences, such as a purchase or an account change, require a human to confirm.