Runs ONE action exactly as a computer-use model's tool gives it, in Anthropic's shape ({action: "left_click", coordinate: [x, y]}) or OpenAI's ({type: "click", x, y, button}), on the session's browser page. Then it returns what happened and a screenshot.

Inputs

Name	Type	Default	Allowed values	Description
`sessionId`required	`string`	–	–	The session's id, from `session_create`.
`action`required	`object`	–	–	The provider's action object, as the model wrote it.
`maxWidth`	`integer`	–	–	Scale the screenshot down to at most this width (100 to 3840). The action's coordinates are then read in that screenshot's pixels.
`screenshot`	`boolean`	true	–	false skips the screenshot.

This tool works in a session with a browser. On a shell-only session (created with browser: false) it answers browser_disabled. See the three kinds of session.

sessionId is the id that session_create returned. The server keeps no default session. If that session is stopped, this tool resumes it first, as it was (a resume starts a machine again, and billing with it).

Example call

This is what an MCP client sends. You do not write it yourself: ask the model in plain words and it calls the tool.

tools/call

{  "name": "browser_computer",  "arguments": {    "sessionId": "6c1f3c9e-1d2a-4f67-9b0e-1b2c3d4e5f60",    "action": {      "action": "left_click",      "coordinate": [        320,        240      ]    },    "maxWidth": 1024  }}

What it returns

A line saying what happened, the pointer, the scale, the page's title and URL, and the screenshot as an image.

Result

Clicked at (400, 300)Pointer: (320, 240) · scale 0.8 · Example Domain — https://example.com/

When a call fails, the result is marked as an error. Its text starts with the API’s error code, such as unauthorized or session_not_running, followed by its message.

Annotations

The server tells every client what this tool does to the world, so a client can decide what to ask you about before it runs.

Annotation	Value
`title`	Run a computer-use action
`readOnlyHint`	`false`
`destructiveHint`	`false`
`openWorldHint`	`true`

Good to know

It acts on the browser page only, never on the machine's desktop.
It is limited to 300 calls a minute per session, and screenshots share that limit with browser_screenshot.

The same thing with the API

Endpoint	Reference
`POST /v1/sessions/{id}/browser/computer`	Run a computer-use action

These docs describe a beta API. Endpoints, fields and SDK methods may change before general availability; breaking changes will be listed in the changelog.