Computer use tool


Claude can interact with computer environments through the computer use tool, which provides screenshot capabilities and mouse/keyboard control for autonomous desktop interaction. On WebArena, a benchmark for autonomous web navigation across real websites, Claude achieves state-of-the-art results among single-agent systems, demonstrating strong ability to complete multi-step browser tasks end to end.

Note

Computer use is in beta and requires a beta header:

  • "computer-use-2025-11-24" for Claude Opus 4.7, Claude Opus 4.6, Claude Sonnet 4.6, and Claude Opus 4.5
  • "computer-use-2025-01-24" for Claude Sonnet 4.5, Claude Haiku 4.5, Claude Opus 4.1, Claude Sonnet 4 (deprecated), and Claude Opus 4 (deprecated)

Reach out through the feedback form to share your feedback on this feature.

Note

This feature is eligible for Zero Data Retention (ZDR). When your organization has a ZDR arrangement, data sent through this feature is not stored after the API response is returned.

Overview

Computer use is a beta feature that enables Claude to interact with desktop environments. This tool provides:

  • Screenshot capture: See what's currently displayed on screen
  • Mouse control: Click, drag, and move the cursor
  • Keyboard input: Type text and use keyboard shortcuts
  • Desktop automation: Interact with any application or interface

While computer use can be augmented with other tools such as bash and text editor for more comprehensive automation workflows, computer use specifically refers to the computer use tool's capability to see and control desktop environments.

For model support, see the Tool reference.

Security considerations

Computer use is a beta feature with unique risks distinct from standard API features. These risks are heightened when interacting with the internet.

Warning

To minimize risks, consider taking precautions such as:

  1. Using a dedicated virtual machine or container with minimal privileges to prevent direct system attacks or accidents.
  2. Avoiding giving the model access to sensitive data, such as account login information, to prevent information theft.
  3. Limiting internet access to an allowlist of domains to reduce exposure to malicious content.
  4. Asking a human to confirm decisions that might result in meaningful real-world consequences and any tasks requiring affirmative consent, such as accepting cookies, completing financial transactions, or agreeing to terms of service.

In some circumstances, Claude will follow commands found in content even if it conflicts with the user's instructions. For example, Claude instructions on webpages or contained in images might override instructions or cause Claude to make mistakes. Take precautions to isolate Claude from sensitive data and actions to avoid risks related to prompt injection.

Anthropic has trained the model to resist these prompt injections and has added an extra layer of defense. If you use the computer use tools, classifiers will automatically run on your prompts to flag potential instances of prompt injections. When these classifiers identify potential prompt injections in screenshots, they will automatically steer the model to ask for user confirmation before proceeding with the next action. This extra protection won't be ideal for every use case (for example, use cases without a human in the loop), so if you'd like to opt out and turn it off, contact support.

These precautions remain important even with the classifier defense layer in place.

Inform end users of relevant risks and obtain their consent prior to enabling computer use in your own products.

Computer use reference implementation

Get started with the computer use reference implementation that includes a web interface, Docker container, example tool implementations, and an agent loop.

Quick start

Here's how to get started with computer use:

curl https://api.anthropic.com/v1/messages \
  -H "content-type: application/json" \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "anthropic-beta: computer-use-2025-11-24" \
  -d '{
    "model": "claude-opus-4-7",
    "max_tokens": 1024,
    "tools": [
      {
        "type": "computer_20251124",
        "name": "computer",
        "display_width_px": 1024,
        "display_height_px": 768,
        "display_number": 1
      },
      {
        "type": "text_editor_20250728",
        "name": "str_replace_based_edit_tool"
      },
      {
        "type": "bash_20250124",
        "name": "bash"
      }
    ],
    "messages": [
      {
        "role": "user",
        "content": "Save a picture of a cat to my desktop."
      }
    ]
  }'
ant beta:messages create --beta computer-use-2025-11-24 <<'YAML'
model: claude-opus-4-7
max_tokens: 1024
tools:
  - type: computer_20251124
    name: computer
    display_width_px: 1024
    display_height_px: 768
    display_number: 1
  - type: text_editor_20250728
    name: str_replace_based_edit_tool
  - type: bash_20250124
    name: bash
messages:
  - role: user
    content: Save a picture of a cat to my desktop.
YAML
import anthropic

client = anthropic.Anthropic()

response = client.beta.messages.create(
    model="claude-opus-4-7",  # or another compatible model
    max_tokens=1024,
    tools=[
        {
            "type": "computer_20251124",
            "name": "computer",
            "display_width_px": 1024,
            "display_height_px": 768,
            "display_number": 1,
        },
        {"type": "text_editor_20250728", "name": "str_replace_based_edit_tool"},
        {"type": "bash_20250124", "name": "bash"},
    ],
    messages=[{"role": "user", "content": "Save a picture of a cat to my desktop."}],
    betas=["computer-use-2025-11-24"],
)
print(response)
import Anthropic from "@anthropic-ai/sdk";

const client = new Anthropic();

const response = await client.beta.messages.create({
  model: "claude-opus-4-7",
  max_tokens: 1024,
  tools: [
    {
      type: "computer_20251124",
      name: "computer",
      display_width_px: 1024,
      display_height_px: 768,
      display_number: 1
    },
    {
      type: "text_editor_20250728",
      name: "str_replace_based_edit_tool"
    },
    {
      type: "bash_20250124",
      name: "bash"
    }
  ],
  messages: [{ role: "user", content: "Save a picture of a cat to my desktop." }],
  betas: ["computer-use-2025-11-24"]
});

console.log(response);
using Anthropic;
using Anthropic.Models.Beta.Messages;
using Messages = Anthropic.Models.Messages;

var client = new AnthropicClient();

var parameters = new MessageCreateParams
{
    Model = Messages::Model.ClaudeOpus4_7,
    MaxTokens = 1024,
    Tools = new BetaToolUnion[]
    {
        new BetaToolComputerUse20251124
        {
            DisplayWidthPx = 1024,
            DisplayHeightPx = 768,
            DisplayNumber = 1
        },
        new BetaToolTextEditor20250728(),
        new BetaToolBash20250124()
    },
    Messages =
    [
        new BetaMessageParam
        {
            Role = Role.User,
            Content = "Save a picture of a cat to my desktop."
        }
    ],
    Betas = ["computer-use-2025-11-24"]
};

var response = await client.Beta.Messages.Create(parameters);
Console.WriteLine(response);
package main

import (
	"context"
	"fmt"
	"log"

	"github.com/anthropics/anthropic-sdk-go"
)

func main() {
	client := anthropic.NewClient()

	response, err := client.Beta.Messages.New(context.TODO(), anthropic.BetaMessageNewParams{
		Model:     anthropic.ModelClaudeOpus4_7,
		MaxTokens: 1024,
		Tools: []anthropic.BetaToolUnionParam{
			{OfComputerUseTool20251124: &anthropic.BetaToolComputerUse20251124Param{
				DisplayWidthPx:  1024,
				DisplayHeightPx: 768,
				DisplayNumber:   anthropic.Int(1),
			}},
			{OfTextEditor20250728: &anthropic.BetaToolTextEditor20250728Param{}},
			{OfBashTool20250124: &anthropic.BetaToolBash20250124Param{}},
		},
		Messages: []anthropic.BetaMessageParam{
			anthropic.NewBetaUserMessage(anthropic.NewBetaTextBlock("Save a picture of a cat to my desktop.")),
		},
		Betas: []anthropic.AnthropicBeta{
			"computer-use-2025-11-24", // typed constant pending in the Go SDK
		},
	})
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(response)
}
import com.anthropic.client.AnthropicClient;
import com.anthropic.client.okhttp.AnthropicOkHttpClient;
import com.anthropic.models.beta.messages.BetaMessage;
import com.anthropic.models.beta.messages.BetaToolBash20250124;
import com.anthropic.models.beta.messages.BetaToolComputerUse20251124;
import com.anthropic.models.beta.messages.BetaToolTextEditor20250728;
import com.anthropic.models.beta.messages.MessageCreateParams;

void main() {
    AnthropicClient client = AnthropicOkHttpClient.fromEnv();

    MessageCreateParams params = MessageCreateParams.builder()
        .model("claude-opus-4-7")
        .maxTokens(1024L)
        .addTool(BetaToolComputerUse20251124.builder()
            .displayWidthPx(1024L)
            .displayHeightPx(768L)
            .displayNumber(1L)
            .build())
        .addTool(BetaToolTextEditor20250728.builder().build())
        .addTool(BetaToolBash20250124.builder().build())
        .addUserMessage("Save a picture of a cat to my desktop.")
        .addBeta("computer-use-2025-11-24")
        .build();

    BetaMessage response = client.beta().messages().create(params);
    IO.println(response);
}
<?php

use Anthropic\Client;

$client = new Client(apiKey: getenv("ANTHROPIC_API_KEY"));

$response = $client->beta->messages->create(
    maxTokens: 1024,
    messages: [
        ['role' => 'user', 'content' => 'Save a picture of a cat to my desktop.'],
    ],
    model: 'claude-opus-4-7',
    tools: [
        [
            'type' => 'computer_20251124',
            'name' => 'computer',
            'display_width_px' => 1024,
            'display_height_px' => 768,
            'display_number' => 1,
        ],
        [
            'type' => 'text_editor_20250728',
            'name' => 'str_replace_based_edit_tool',
        ],
        [
            'type' => 'bash_20250124',
            'name' => 'bash',
        ],
    ],
    betas: ['computer-use-2025-11-24'],
);

echo $response;
require "anthropic"

client = Anthropic::Client.new

response = client.beta.messages.create(
  model: "claude-opus-4-7",
  max_tokens: 1024,
  tools: [
    {
      type: "computer_20251124",
      name: "computer",
      display_width_px: 1024,
      display_height_px: 768,
      display_number: 1
    },
    {
      type: "text_editor_20250728",
      name: "str_replace_based_edit_tool"
    },
    {
      type: "bash_20250124",
      name: "bash"
    }
  ],
  messages: [
    { role: "user", content: "Save a picture of a cat to my desktop." }
  ],
  betas: ["computer-use-2025-11-24"]
)

puts response
Note

A beta header is only required for the computer use tool.

The preceding example shows all three tools being used together, which requires the beta header because it includes the computer use tool.


How computer use works

  1. Provide Claude with the computer use tool and a user prompt

    • Add the computer use tool (and optionally other tools) to your API request.
    • Include a user prompt that requires desktop interaction, for example, "Save a picture of a cat to my desktop."
  2. Claude selects the computer use tool

    • Claude assesses if the computer use tool can help with the user's query.
    • If yes, Claude constructs a properly formatted tool use request.
    • The API response has a stop_reason of tool_use, signaling a tool use request.
  3. Extract tool input, evaluate the tool on a computer, and return results

    • On your end, extract the tool name and input from Claude's request.
    • Use the tool on a container or virtual machine.
    • Continue the conversation with a new user message containing a tool_result content block.
  4. Claude continues calling computer use tools until it's completed the task

    • Claude analyzes the tool results to determine if more tool use is needed or the task has been completed.
    • If Claude determines another tool is needed, it responds with another tool_use stop_reason and you should return to step 3.
    • Otherwise, it crafts a text response to the user.

The repetition of steps 3 and 4 without user input is referred to as the "agent loop" (that is, Claude responding with a tool use request and your application responding to Claude with the results of evaluating that request).

The computing environment

Computer use requires a sandboxed computing environment where Claude can safely interact with applications and the web. This environment includes:

  1. Virtual display: A virtual X11 display server (using Xvfb) that renders the desktop interface Claude will see through screenshots and control with mouse/keyboard actions.

  2. Desktop environment: A lightweight UI with window manager (Mutter) and panel (Tint2) running on Linux, which provides a consistent graphical interface for Claude to interact with.

  3. Applications: Pre-installed Linux applications such as Firefox, LibreOffice, text editors, and file managers that Claude can use to complete tasks.

  4. Tool implementations: Integration code that translates Claude's abstract tool requests (such as "move mouse" or "take screenshot") into actual operations in the virtual environment.

  5. Agent loop: A program that handles communication between Claude and the environment, sending Claude's actions to the environment and returning the results (screenshots, command outputs) back to Claude.

When you use computer use, Claude doesn't directly connect to this environment. Instead, your application:

  1. Receives Claude's tool use requests
  2. Translates them into actions in your computing environment
  3. Captures the results (such as screenshots and command outputs)
  4. Returns these results to Claude

For security and isolation, the reference implementation runs all of this inside a Docker container with appropriate port mappings for viewing and interacting with the environment.


How to implement computer use

Start with the reference implementation

A reference implementation is available that includes everything you need to get started with computer use:

Understanding the agentic loop

The core of computer use is the "agent loop": a cycle where Claude requests tool actions, your application runs them, and returns results to Claude. Here's a simplified example:

Info

The agent loop is a stateful, multi-turn pattern that doesn't translate to a one-off shell command. See the SDK tabs for the implementation.

Info

The agent loop is a stateful, multi-turn pattern that doesn't translate to a one-off shell command. See the SDK tabs for the implementation.

def sampling_loop(model, messages, max_iterations=10):
    """
    Run the computer-use agent loop until Claude stops requesting tools
    or the iteration limit is reached.
    """
    for _ in range(max_iterations):
        response = client.beta.messages.create(
            model=model,
            max_tokens=4096,
            messages=messages,
            tools=TOOLS,
            betas=["computer-use-2025-11-24"],
        )

        # Add Claude's response to the conversation history
        messages.append({"role": "assistant", "content": response.content})

        # Run any tools Claude requested and collect results
        tool_results = process_tool_calls(response)
        if not tool_results:
            return messages  # No more tool use; task complete

        # Send tool results back to Claude for the next iteration
        messages.append({"role": "user", "content": tool_results})

    return messages
async function samplingLoop(
  model: string,
  messages: Anthropic.Beta.BetaMessageParam[],
  maxIterations = 10,
): Promise<Anthropic.Beta.BetaMessageParam[]> {
  // Run the computer-use agent loop until Claude stops requesting tools
  // or the iteration limit is reached.
  for (let i = 0; i < maxIterations; i++) {
    const response = await client.beta.messages.create({
      model,
      max_tokens: 4096,
      messages,
      tools,
      betas: ["computer-use-2025-11-24"],
    });

    // Add Claude's response to the conversation history
    messages.push({ role: "assistant", content: response.content });

    // Run any tools Claude requested and collect results
    const toolResults = processToolCalls(response);
    if (toolResults.length === 0) {
      return messages; // No more tool use; task complete
    }

    // Send tool results back to Claude for the next iteration
    messages.push({ role: "user", content: toolResults });
  }

  return messages;
}
async Task<List<BetaMessageParam>> SamplingLoop(
    Model model,
    List<BetaMessageParam> messages,
    int maxIterations = 10
)
{
    // Run the computer-use agent loop until Claude stops requesting tools
    // or the iteration limit is reached.
    for (var i = 0; i < maxIterations; i++)
    {
        var response = await client.Beta.Messages.Create(
            new MessageCreateParams
            {
                Model = model,
                MaxTokens = 4096,
                Messages = messages,
                Tools = tools,
                Betas = ["computer-use-2025-11-24"],
            }
        );

        // Add Claude's response to the conversation history
        messages.Add(
            new()
            {
                Role = Role.Assistant,
                Content = response
                    .Content.Select(block => new BetaContentBlockParam(block.Json))
                    .ToList(),
            }
        );

        // Run any tools Claude requested and collect results
        var toolResults = ProcessToolCalls(response);
        if (toolResults.Count == 0)
        {
            return messages; // No more tool use; task complete
        }

        // Send tool results back to Claude for the next iteration
        messages.Add(new() { Role = Role.User, Content = toolResults });
    }

    return messages;
}
// samplingLoop runs the computer-use agent loop until Claude stops
// requesting tools or the iteration limit is reached.
func samplingLoop(ctx context.Context, model anthropic.Model, messages []anthropic.BetaMessageParam, maxIterations int) ([]anthropic.BetaMessageParam, error) {
	for range maxIterations {
		response, err := client.Beta.Messages.New(ctx, anthropic.BetaMessageNewParams{
			Model:     model,
			MaxTokens: 4096,
			Messages:  messages,
			Tools:     tools,
			Betas:     []anthropic.AnthropicBeta{"computer-use-2025-11-24"},
		})
		if err != nil {
			return nil, err
		}

		// Add Claude's response to the conversation history
		messages = append(messages, response.ToParam())

		// Run any tools Claude requested and collect results
		toolResults := processToolCalls(response)
		if len(toolResults) == 0 {
			return messages, nil // No more tool use; task complete
		}

		// Send tool results back to Claude for the next iteration
		messages = append(messages, anthropic.BetaMessageParam{
			Role:    anthropic.BetaMessageParamRoleUser,
			Content: toolResults,
		})
	}
	return messages, nil
}

/**
 * Run the computer-use agent loop until Claude stops requesting tools
 * or the iteration limit is reached.
 */
List<BetaMessageParam> samplingLoop(Model model, List<BetaMessageParam> messages, int maxIterations) {
    for (int i = 0; i < maxIterations; i++) {
        BetaMessage response = client.beta().messages().create(MessageCreateParams.builder()
                .model(model)
                .maxTokens(4096)
                .messages(messages)
                .addTool(COMPUTER_TOOL)
                .addBeta("computer-use-2025-11-24")
                .build());

        // Add Claude's response to the conversation history
        messages.add(BetaMessageParam.builder()
                .role(BetaMessageParam.Role.ASSISTANT)
                .contentOfBetaContentBlockParams(
                        response.content().stream().map(BetaContentBlock::toParam).toList())
                .build());

        // Run any tools Claude requested and collect results
        List<BetaContentBlockParam> toolResults = processToolCalls(response);
        if (toolResults.isEmpty()) {
            return messages; // No more tool use; task complete
        }

        // Send tool results back to Claude for the next iteration
        messages.add(BetaMessageParam.builder()
                .role(BetaMessageParam.Role.USER)
                .contentOfBetaContentBlockParams(toolResults)
                .build());
    }
    return messages;
}
/**
 * Run the computer-use agent loop until Claude stops requesting tools
 * or the iteration limit is reached.
 */
function samplingLoop(string $model, array $messages, int $maxIterations = 10): array
{
    global $client, $tools;

    for ($i = 0; $i < $maxIterations; $i++) {
        $response = $client->beta->messages->create(
            model: $model,
            maxTokens: 4096,
            messages: $messages,
            tools: $tools,
            betas: ['computer-use-2025-11-24'],
        );

        // Add Claude's response to the conversation history
        $messages[] = BetaMessageParam::with(role: Role::ASSISTANT, content: $response->content);

        // Run any tools Claude requested and collect results
        $toolResults = processToolCalls($response);
        if ($toolResults === []) {
            return $messages; // No more tool use; task complete
        }

        // Send tool results back to Claude for the next iteration
        $messages[] = BetaMessageParam::with(role: Role::USER, content: $toolResults);
    }

    return $messages;
}
# Run the computer-use agent loop until Claude stops requesting tools
# or the iteration limit is reached.
def sampling_loop(model, messages, max_iterations: 10)
  max_iterations.times do
    response = CLIENT.beta.messages.create(
      model: model,
      max_tokens: 4096,
      messages: messages,
      tools: TOOLS,
      betas: ["computer-use-2025-11-24"]
    )

    # Add Claude's response to the conversation history
    messages << {role: "assistant", content: response.content}

    # Run any tools Claude requested and collect results
    tool_results = process_tool_calls(response)
    return messages if tool_results.empty? # No more tool use; task complete

    # Send tool results back to Claude for the next iteration
    messages << {role: "user", content: tool_results}
  end

  messages
end

The loop continues until either Claude responds without requesting any tools (task completion) or the maximum iteration limit is reached. This safeguard prevents potential infinite loops that could result in unexpected API costs.

Try the reference implementation out before reading the rest of this documentation.

Optimize model performance with prompting

Here are some tips on how to get the best quality outputs:

  1. Specify simple, well-defined tasks and provide explicit instructions for each step.
  2. Claude sometimes assumes outcomes of its actions without explicitly checking their results. To prevent this you can prompt Claude with After each step, take a screenshot and carefully evaluate if you have achieved the right outcome. Explicitly show your thinking: "I have evaluated step X..." If not correct, try again. Only when you confirm a step was executed correctly should you move on to the next one.
  3. Some UI elements (such as dropdowns and scrollbars) might be tricky for Claude to manipulate using mouse movements. If you experience this, try prompting the model to use keyboard shortcuts.
  4. For repeatable tasks or UI interactions, include example screenshots and tool calls of successful outcomes in your prompt.
  5. If you need the model to log in, provide it with the username and password in your prompt inside XML tags such as <robot_credentials>. Using computer use within applications that require login increases the risk of bad outcomes as a result of prompt injection. Review Mitigate jailbreaks and prompt injections before providing the model with login credentials.
  6. When constructing a user turn's content array, place the instruction text before the screenshot image. Providing the target description before the image is processed improves click accuracy.
Tip

If you repeatedly encounter a clear set of issues or know in advance the tasks Claude will need to complete, use the system prompt to provide Claude with explicit tips or instructions on how to do the tasks successfully.

Tip

For agents that span multiple sessions, run end-to-end verification at the start of each session, not only after implementation. Browser-based checks catch regressions from prior sessions that code-level review alone misses. See Effective harnesses for long-running agents for details.

System prompts

When one of the Anthropic-schema tools is requested through the Claude API, a computer use-specific system prompt is generated. It's similar to the tool use system prompt but starts with:

You have access to a set of functions you can use to answer the user's question. This includes access to a sandboxed computing environment. You do NOT currently have the ability to inspect files or interact with external resources, except by invoking the below functions.

As with regular tool use, the user-provided system_prompt field is still respected and used in the construction of the combined system prompt.

Available actions

The computer use tool supports these actions:

Basic actions (all versions)

  • screenshot: Capture the current display
  • left_click: Click at coordinates [x, y]
  • type: Type text string
  • key: Press key or key combination (for example, "ctrl+s")
  • mouse_move: Move cursor to coordinates

Enhanced actions (computer_20250124) Available on all models that support computer use:

  • scroll: Scroll in any direction with amount control
  • left_click_drag: Click and drag between coordinates
  • right_click, middle_click: Additional mouse buttons
  • double_click, triple_click: Multiple clicks
  • left_mouse_down, left_mouse_up: Fine-grained click control
  • hold_key: Hold down a key for a specified duration (in seconds)
  • wait: Pause between actions

Enhanced actions (computer_20251124) Available in Claude Opus 4.7, Claude Opus 4.6, Claude Sonnet 4.6, and Claude Opus 4.5:

  • All actions from computer_20250124
  • zoom: View a specific region of the screen at full resolution. Requires enable_zoom: true in tool definition. Takes a region parameter with coordinates [x1, y1, x2, y2] defining top-left and bottom-right corners of the area to inspect.

Example actions

Take a screenshot:

{
  "action": "screenshot"
}

Click at position:

{
  "action": "left_click",
  "coordinate": [500, 300]
}

Type text:

{
  "action": "type",
  "text": "Hello, world!"
}

Scroll down:

{
  "action": "scroll",
  "coordinate": [500, 400],
  "scroll_direction": "down",
  "scroll_amount": 3
}

Zoom to view region in detail (Opus 4.7, Opus 4.6, Sonnet 4.6, and Opus 4.5):

{
  "action": "zoom",
  "region": [100, 200, 400, 350]
}

Modifier keys with click and scroll actions

To hold modifier keys (such as Shift, Ctrl, or Alt) while performing click or scroll actions, use the text parameter on those actions. This is different from hold_key, which holds a key for a duration without performing other actions.

Shift+click (for example, to select a range of items):

{
  "action": "left_click",
  "coordinate": [500, 300],
  "text": "shift"
}

Ctrl+click (for example, to multi-select on Windows/Linux):

{
  "action": "left_click",
  "coordinate": [500, 300],
  "text": "ctrl"
}

Cmd+click (for example, to multi-select on macOS):

{
  "action": "left_click",
  "coordinate": [500, 300],
  "text": "super"
}

Shift+scroll (for example, to scroll horizontally):

{
  "action": "scroll",
  "coordinate": [500, 400],
  "scroll_direction": "down",
  "scroll_amount": 3,
  "text": "shift"
}

The text parameter in click/scroll actions accepts modifier keys such as shift, ctrl, alt, and super (for the Command/Windows key).

Tool parameters

ParameterRequiredDescription
typeYesTool version (computer_20251124 or computer_20250124)
nameYesMust be "computer"
display_width_pxYesDisplay width in pixels
display_height_pxYesDisplay height in pixels
display_numberNoDisplay number for X11 environments
enable_zoomNoEnable zoom action (computer_20251124 only). Set to true to allow Claude to zoom into specific screen regions. Default: false
Note

Important: Your application must explicitly run the computer use tool; Claude cannot run it directly. You are responsible for implementing the screenshot capture, mouse movements, keyboard inputs, and other actions based on Claude's requests.

Combining with extended thinking

For combining computer use with extended thinking, see Extended thinking.

Tip

For computer use specifically, internal benchmarking suggests these effort settings:

  • Claude Opus 4.7: use high as the default; use low for high-throughput or cost-sensitive workloads.
  • Claude Sonnet 4.6 and Claude Opus 4.6: use medium as the default (best accuracy-to-cost ratio). Avoid max, which adds token cost without improving accuracy on UI tasks. On these models, low uses fewer output tokens than disabling thinking entirely (fewer mistakes mean fewer retries), making it a strong option for cost-sensitive loops.

Augmenting computer use with other tools

To add other tools alongside computer use, include them in the same tools array. The Quick start section shows this pattern with the bash tool and text editor tool. You can add your own custom tool definitions the same way.

Build a custom computer use environment

The reference implementation is meant to help you get started with computer use. It includes all of the components needed to have Claude use a computer. However, you can build your own environment for computer use to suit your needs. You'll need:

  • A virtualized or containerized environment suitable for computer use with Claude
  • An implementation of at least one of the Anthropic-schema computer use tools
  • An agent loop that interacts with the Claude API and runs the tool_use results using your tool implementations
  • An API or UI that allows user input to start the agent loop

Implement the computer use tool

The computer use tool is implemented as a schema-less tool. When using this tool, you don't need to provide an input schema as with other tools; the schema is built into Claude's model and can't be modified.

  1. Set up your computing environment

    Create a virtual display or connect to an existing display that Claude will interact with. This typically involves setting up Xvfb (X Virtual Framebuffer) or similar technology.

  2. Implement action handlers

    Create functions to handle each action type that Claude might request:

    Info

    This is application-side helper code with no API request. See the SDK tabs for the pattern.

    Info

    This is application-side helper code with no API request. See the SDK tabs for the pattern.

    def capture_screenshot():
        return "<screenshot data>"
    
    
    def click_at(x, y):
        return f"clicked at ({x}, {y})"
    
    
    def type_text(text):
        return f"typed: {text}"
    
    
    def handle_computer_action(action_type, params):
        if action_type == "screenshot":
            return capture_screenshot()
        elif action_type == "left_click":
            x, y = params["coordinate"]
            return click_at(x, y)
        elif action_type == "type":
            return type_text(params["text"])
        # Handle other actions as needed
        return f"unhandled action: {action_type}"
    
    function captureScreenshot(): string {
      return "<screenshot data>";
    }
    
    function clickAt(x: number, y: number): string {
      return `clicked at (${x}, ${y})`;
    }
    
    function typeText(text: string): string {
      return `typed: ${text}`;
    }
    
    function handleComputerAction(
      actionType: string,
      params: Record<string, unknown>,
    ): string {
      if (actionType === "screenshot") {
        return captureScreenshot();
      } else if (actionType === "left_click") {
        const [x, y] = params.coordinate as [number, number];
        return clickAt(x, y);
      } else if (actionType === "type") {
        return typeText(params.text as string);
      }
      // Handle other actions as needed
      return `unhandled action: ${actionType}`;
    }
    
    string CaptureScreenshot() => "<screenshot data>";
    
    string ClickAt(int x, int y) => {{CONTENT}}quot;clicked at ({x}, {y})";
    
    string TypeText(string text) => {{CONTENT}}quot;typed: {text}";
    
    string HandleComputerAction(string actionType, IReadOnlyDictionary<string, JsonElement> input) =>
        actionType switch
        {
            "screenshot" => CaptureScreenshot(),
            "left_click" => ClickAt(
                input["coordinate"][0].GetInt32(),
                input["coordinate"][1].GetInt32()
            ),
            "type" => TypeText(input["text"].GetString()!),
            // Handle other actions as needed
            _ => {{CONTENT}}quot;unhandled action: {actionType}",
        };
    
    func captureScreenshot() string {
    	return "<screenshot data>"
    }
    
    func clickAt(x, y int) string {
    	return fmt.Sprintf("clicked at (%d, %d)", x, y)
    }
    
    func typeText(text string) string {
    	return fmt.Sprintf("typed: %s", text)
    }
    
    func handleComputerAction(actionType string, params map[string]any) string {
    	switch actionType {
    	case "screenshot":
    		return captureScreenshot()
    	case "left_click":
    		coord := params["coordinate"].([]any)
    		return clickAt(int(coord[0].(float64)), int(coord[1].(float64)))
    	case "type":
    		return typeText(params["text"].(string))
    	// Handle other actions as needed
    	default:
    		return fmt.Sprintf("unhandled action: %s", actionType)
    	}
    }
    
    
    String captureScreenshot() {
        return "<screenshot data>";
    }
    
    String clickAt(long x, long y) {
        return "clicked at (" + x + ", " + y + ")";
    }
    
    String typeText(String text) {
        return "typed: " + text;
    }
    
    String handleComputerAction(String actionType, Map<String, JsonValue> params) {
        return switch (actionType) {
            case "screenshot" -> captureScreenshot();
            case "left_click" -> {
                List<JsonValue> coordinate = (List<JsonValue>) params.get("coordinate").asArray().get();
                long x = ((Number) coordinate.get(0).asNumber().get()).longValue();
                long y = ((Number) coordinate.get(1).asNumber().get()).longValue();
                yield clickAt(x, y);
            }
            case "type" -> typeText(params.get("text").asStringOrThrow());
            // Handle other actions as needed
            default -> "unhandled action: " + actionType;
        };
    }
    
    function captureScreenshot(): string
    {
        return '<screenshot data>';
    }
    
    function clickAt(int $x, int $y): string
    {
        return "clicked at ({$x}, {$y})";
    }
    
    function typeText(string $text): string
    {
        return "typed: {$text}";
    }
    
    function handleComputerAction(string $actionType, array $params): string
    {
        return match ($actionType) {
            'screenshot' => captureScreenshot(),
            'left_click' => clickAt(...$params['coordinate']),
            'type' => typeText($params['text']),
            // Handle other actions as needed
            default => "unhandled action: {$actionType}",
        };
    }
    
    def capture_screenshot
      "<screenshot data>"
    end
    
    def click_at(x, y)
      "clicked at (#{x}, #{y})"
    end
    
    def type_text(text)
      "typed: #{text}"
    end
    
    def handle_computer_action(action_type, params)
      case action_type
      when "screenshot"
        capture_screenshot
      when "left_click"
        x, y = params[:coordinate]
        click_at(x, y)
      when "type"
        type_text(params[:text])
      # Handle other actions as needed
      else
        "unhandled action: #{action_type}"
      end
    end
    
  3. Process Claude's tool calls

    Extract and run tool calls from Claude's responses:

    Info

    This is application-side helper code with no API request. See the SDK tabs for the pattern.

    Info

    This is application-side helper code with no API request. See the SDK tabs for the pattern.

    def process_tool_calls(response):
        tool_results = []
        for block in response.content:
            if block.type == "tool_use":
                action = block.input["action"]
                result = handle_computer_action(action, block.input)
                tool_results.append(
                    {
                        "type": "tool_result",
                        "tool_use_id": block.id,
                        "content": result,
                    }
                )
        return tool_results
    
    function processToolCalls(
      response: Anthropic.Beta.BetaMessage,
    ): Anthropic.Beta.BetaToolResultBlockParam[] {
      const toolResults: Anthropic.Beta.BetaToolResultBlockParam[] = [];
      for (const block of response.content) {
        if (block.type === "tool_use") {
          const input = block.input as Record<string, unknown>;
          const action = input.action as string;
          const result = handleComputerAction(action, input);
          toolResults.push({
            type: "tool_result",
            tool_use_id: block.id,
            content: result,
          });
        }
      }
      return toolResults;
    }
    
    List<BetaContentBlockParam> ProcessToolCalls(BetaMessage response)
    {
        List<BetaContentBlockParam> toolResults = [];
        foreach (var block in response.Content)
        {
            if (block.TryPickToolUse(out var toolUse))
            {
                var action = toolUse.Input["action"].GetString()!;
                var result = HandleComputerAction(action, toolUse.Input);
                toolResults.Add(new BetaToolResultBlockParam(toolUse.ID) { Content = result });
            }
        }
        return toolResults;
    }
    
    func processToolCalls(response *anthropic.BetaMessage) []anthropic.BetaContentBlockParamUnion {
    	var toolResults []anthropic.BetaContentBlockParamUnion
    	for _, block := range response.Content {
    		switch variant := block.AsAny().(type) {
    		case anthropic.BetaToolUseBlock:
    			input := variant.Input.(map[string]any)
    			action := input["action"].(string)
    			result := handleComputerAction(action, input)
    			toolResults = append(toolResults, anthropic.NewBetaToolResultBlock(variant.ID, result, false))
    		}
    	}
    	return toolResults
    }
    
    
    List<BetaContentBlockParam> processToolCalls(BetaMessage response) {
        List<BetaContentBlockParam> toolResults = new ArrayList<>();
        for (BetaContentBlock block : response.content()) {
            if (block.isToolUse()) {
                BetaToolUseBlock toolUse = block.asToolUse();
                Map<String, JsonValue> input =
                        (Map<String, JsonValue>) toolUse._input().asObject().get();
                String action = input.get("action").asStringOrThrow();
                String result = handleComputerAction(action, input);
                toolResults.add(BetaContentBlockParam.ofToolResult(
                        BetaToolResultBlockParam.builder()
                                .toolUseId(toolUse.id())
                                .content(result)
                                .build()));
            }
        }
        return toolResults;
    }
    
    function processToolCalls(BetaMessage $response): array
    {
        $toolResults = [];
        foreach ($response->content as $block) {
            if ($block instanceof BetaToolUseBlock) {
                $action = $block->input['action'];
                $result = handleComputerAction($action, $block->input);
                $toolResults[] = BetaToolResultBlockParam::with(
                    toolUseID: $block->id,
                    content: $result,
                );
            }
        }
        return $toolResults;
    }
    
    def process_tool_calls(response)
      tool_results = []
      response.content.each do |block|
        next unless block.type == :tool_use
    
        action = block.input[:action]
        result = handle_computer_action(action, block.input)
        tool_results << {
          type: "tool_result",
          tool_use_id: block.id,
          content: result
        }
      end
      tool_results
    end
    
  4. Implement the agent loop

    Create a loop that continues until Claude completes the task:

    Info

    The agent loop is a stateful, multi-turn pattern that doesn't translate to a one-off shell command. See the SDK tabs for the implementation.

    Info

    The agent loop is a stateful, multi-turn pattern that doesn't translate to a one-off shell command. See the SDK tabs for the implementation.

    def sampling_loop(model, messages, max_iterations=10):
        """
        Run the computer-use agent loop until Claude stops requesting tools
        or the iteration limit is reached.
        """
        for _ in range(max_iterations):
            response = client.beta.messages.create(
                model=model,
                max_tokens=4096,
                messages=messages,
                tools=TOOLS,
                betas=["computer-use-2025-11-24"],
            )
    
            # Add Claude's response to the conversation history
            messages.append({"role": "assistant", "content": response.content})
    
            # Run any tools Claude requested and collect results
            tool_results = process_tool_calls(response)
            if not tool_results:
                return messages  # No more tool use; task complete
    
            # Send tool results back to Claude for the next iteration
            messages.append({"role": "user", "content": tool_results})
    
        return messages
    
    async function samplingLoop(
      model: string,
      messages: Anthropic.Beta.BetaMessageParam[],
      maxIterations = 10,
    ): Promise<Anthropic.Beta.BetaMessageParam[]> {
      // Run the computer-use agent loop until Claude stops requesting tools
      // or the iteration limit is reached.
      for (let i = 0; i < maxIterations; i++) {
        const response = await client.beta.messages.create({
          model,
          max_tokens: 4096,
          messages,
          tools,
          betas: ["computer-use-2025-11-24"],
        });
    
        // Add Claude's response to the conversation history
        messages.push({ role: "assistant", content: response.content });
    
        // Run any tools Claude requested and collect results
        const toolResults = processToolCalls(response);
        if (toolResults.length === 0) {
          return messages; // No more tool use; task complete
        }
    
        // Send tool results back to Claude for the next iteration
        messages.push({ role: "user", content: toolResults });
      }
    
      return messages;
    }
    
    async Task<List<BetaMessageParam>> SamplingLoop(
        Model model,
        List<BetaMessageParam> messages,
        int maxIterations = 10
    )
    {
        // Run the computer-use agent loop until Claude stops requesting tools
        // or the iteration limit is reached.
        for (var i = 0; i < maxIterations; i++)
        {
            var response = await client.Beta.Messages.Create(
                new MessageCreateParams
                {
                    Model = model,
                    MaxTokens = 4096,
                    Messages = messages,
                    Tools = tools,
                    Betas = ["computer-use-2025-11-24"],
                }
            );
    
            // Add Claude's response to the conversation history
            messages.Add(
                new()
                {
                    Role = Role.Assistant,
                    Content = response
                        .Content.Select(block => new BetaContentBlockParam(block.Json))
                        .ToList(),
                }
            );
    
            // Run any tools Claude requested and collect results
            var toolResults = ProcessToolCalls(response);
            if (toolResults.Count == 0)
            {
                return messages; // No more tool use; task complete
            }
    
            // Send tool results back to Claude for the next iteration
            messages.Add(new() { Role = Role.User, Content = toolResults });
        }
    
        return messages;
    }
    
    // samplingLoop runs the computer-use agent loop until Claude stops
    // requesting tools or the iteration limit is reached.
    func samplingLoop(ctx context.Context, model anthropic.Model, messages []anthropic.BetaMessageParam, maxIterations int) ([]anthropic.BetaMessageParam, error) {
    	for range maxIterations {
    		response, err := client.Beta.Messages.New(ctx, anthropic.BetaMessageNewParams{
    			Model:     model,
    			MaxTokens: 4096,
    			Messages:  messages,
    			Tools:     tools,
    			Betas:     []anthropic.AnthropicBeta{"computer-use-2025-11-24"},
    		})
    		if err != nil {
    			return nil, err
    		}
    
    		// Add Claude's response to the conversation history
    		messages = append(messages, response.ToParam())
    
    		// Run any tools Claude requested and collect results
    		toolResults := processToolCalls(response)
    		if len(toolResults) == 0 {
    			return messages, nil // No more tool use; task complete
    		}
    
    		// Send tool results back to Claude for the next iteration
    		messages = append(messages, anthropic.BetaMessageParam{
    			Role:    anthropic.BetaMessageParamRoleUser,
    			Content: toolResults,
    		})
    	}
    	return messages, nil
    }
    
    
    /**
     * Run the computer-use agent loop until Claude stops requesting tools
     * or the iteration limit is reached.
     */
    List<BetaMessageParam> samplingLoop(Model model, List<BetaMessageParam> messages, int maxIterations) {
        for (int i = 0; i < maxIterations; i++) {
            BetaMessage response = client.beta().messages().create(MessageCreateParams.builder()
                    .model(model)
                    .maxTokens(4096)
                    .messages(messages)
                    .addTool(COMPUTER_TOOL)
                    .addBeta("computer-use-2025-11-24")
                    .build());
    
            // Add Claude's response to the conversation history
            messages.add(BetaMessageParam.builder()
                    .role(BetaMessageParam.Role.ASSISTANT)
                    .contentOfBetaContentBlockParams(
                            response.content().stream().map(BetaContentBlock::toParam).toList())
                    .build());
    
            // Run any tools Claude requested and collect results
            List<BetaContentBlockParam> toolResults = processToolCalls(response);
            if (toolResults.isEmpty()) {
                return messages; // No more tool use; task complete
            }
    
            // Send tool results back to Claude for the next iteration
            messages.add(BetaMessageParam.builder()
                    .role(BetaMessageParam.Role.USER)
                    .contentOfBetaContentBlockParams(toolResults)
                    .build());
        }
        return messages;
    }
    
    /**
     * Run the computer-use agent loop until Claude stops requesting tools
     * or the iteration limit is reached.
     */
    function samplingLoop(string $model, array $messages, int $maxIterations = 10): array
    {
        global $client, $tools;
    
        for ($i = 0; $i < $maxIterations; $i++) {
            $response = $client->beta->messages->create(
                model: $model,
                maxTokens: 4096,
                messages: $messages,
                tools: $tools,
                betas: ['computer-use-2025-11-24'],
            );
    
            // Add Claude's response to the conversation history
            $messages[] = BetaMessageParam::with(role: Role::ASSISTANT, content: $response->content);
    
            // Run any tools Claude requested and collect results
            $toolResults = processToolCalls($response);
            if ($toolResults === []) {
                return $messages; // No more tool use; task complete
            }
    
            // Send tool results back to Claude for the next iteration
            $messages[] = BetaMessageParam::with(role: Role::USER, content: $toolResults);
        }
    
        return $messages;
    }
    
    # Run the computer-use agent loop until Claude stops requesting tools
    # or the iteration limit is reached.
    def sampling_loop(model, messages, max_iterations: 10)
      max_iterations.times do
        response = CLIENT.beta.messages.create(
          model: model,
          max_tokens: 4096,
          messages: messages,
          tools: TOOLS,
          betas: ["computer-use-2025-11-24"]
        )
    
        # Add Claude's response to the conversation history
        messages << {role: "assistant", content: response.content}
    
        # Run any tools Claude requested and collect results
        tool_results = process_tool_calls(response)
        return messages if tool_results.empty? # No more tool use; task complete
    
        # Send tool results back to Claude for the next iteration
        messages << {role: "user", content: tool_results}
      end
    
      messages
    end
    

Handle errors

When implementing the computer use tool, various errors might occur. Here's how to handle them:

Screenshot capture failure

If screenshot capture fails, return an appropriate error message:

{
  "role": "user",
  "content": [
    {
      "type": "tool_result",
      "tool_use_id": "toolu_01A09q90qw90lq917835lq9",
      "content": "Error: Failed to capture screenshot. Display may be locked or unavailable.",
      "is_error": true
    }
  ]
}

Invalid coordinates

If Claude provides coordinates outside the display bounds:

{
  "role": "user",
  "content": [
    {
      "type": "tool_result",
      "tool_use_id": "toolu_01A09q90qw90lq917835lq9",
      "content": "Error: Coordinates (1200, 900) are outside display bounds (1024x768).",
      "is_error": true
    }
  ]
}

Action execution failure

If an action fails to run:

{
  "role": "user",
  "content": [
    {
      "type": "tool_result",
      "tool_use_id": "toolu_01A09q90qw90lq917835lq9",
      "content": "Error: Failed to perform click action. The application may be unresponsive.",
      "is_error": true
    }
  ]
}

Handle coordinate scaling for higher resolutions

Note

Claude Opus 4.7 supports up to 2576 pixels on the long edge, and its coordinates are 1:1 with image pixels (no scale-factor conversion required). The 1568-pixel guidance that follows applies to earlier models.

The API constrains images to a maximum of 1568 pixels on the longest edge and approximately 1.15 megapixels total (see image resizing for details). For example, a 1512x982 screen gets downsampled to approximately 1330x864. Claude analyzes this smaller image and returns coordinates in that space, but your tool performs clicks in the original screen space.

This can cause Claude's click coordinates to miss their targets unless you handle the coordinate transformation.

To fix this, resize screenshots yourself and scale Claude's coordinates back up:

Info

Coordinate scaling and screenshot resizing happen in your application code, not in the API request. See the SDK tabs for the helper pattern.

Info

Coordinate scaling and screenshot resizing happen in your application code, not in the API request. See the SDK tabs for the helper pattern.

screen_width, screen_height = 1512, 982


def capture_and_resize(w, h): ...
def perform_click(x, y): ...


import math


def get_scale_factor(width, height):
    """Calculate scale factor to meet API constraints."""
    long_edge = max(width, height)
    total_pixels = width * height

    long_edge_scale = 1568 / long_edge
    total_pixels_scale = math.sqrt(1_150_000 / total_pixels)

    return min(1.0, long_edge_scale, total_pixels_scale)


# When capturing screenshot
scale = get_scale_factor(screen_width, screen_height)
scaled_width = int(screen_width * scale)
scaled_height = int(screen_height * scale)

# Resize image to scaled dimensions before sending to Claude
screenshot = capture_and_resize(scaled_width, scaled_height)


# When handling Claude's coordinates, scale them back up
def execute_click(x, y):
    screen_x = x / scale
    screen_y = y / scale
    perform_click(screen_x, screen_y)


print(f"scale={scale:.6f} scaled={scaled_width}x{scaled_height}")
const screenWidth = 1512;
const screenHeight = 982;
function captureAndResize(w: number, h: number): string {
  return "";
}
function performClick(x: number, y: number): void {}
const MAX_LONG_EDGE = 1568;
const MAX_PIXELS = 1_150_000;

function getScaleFactor(width: number, height: number): number {
  const longEdge = Math.max(width, height);
  const totalPixels = width * height;

  const longEdgeScale = MAX_LONG_EDGE / longEdge;
  const totalPixelsScale = Math.sqrt(MAX_PIXELS / totalPixels);

  return Math.min(1.0, longEdgeScale, totalPixelsScale);
}

// When capturing screenshot
const scale = getScaleFactor(screenWidth, screenHeight);
const scaledWidth = Math.floor(screenWidth * scale);
const scaledHeight = Math.floor(screenHeight * scale);

// Resize image to scaled dimensions before sending to Claude
const screenshot = captureAndResize(scaledWidth, scaledHeight);

// When handling Claude's coordinates, scale them back up
function executeClick(x: number, y: number): void {
  const screenX = x / scale;
  const screenY = y / scale;
  performClick(screenX, screenY);
}

console.log(`scale=${scale.toFixed(6)} scaled=${scaledWidth}x${scaledHeight}`);
int screenWidth = 1512, screenHeight = 982;

object? CaptureAndResize(int w, int h) => null;
void PerformClick(double x, double y) { }

double GetScaleFactor(int width, int height)
{
    // Calculate scale factor to meet API constraints.
    int longEdge = Math.Max(width, height);
    int totalPixels = width * height;

    double longEdgeScale = 1568.0 / longEdge;
    double totalPixelsScale = Math.Sqrt(1_150_000.0 / totalPixels);

    return Math.Min(1.0, Math.Min(longEdgeScale, totalPixelsScale));
}

// When capturing screenshot
double scale = GetScaleFactor(screenWidth, screenHeight);
int scaledWidth = (int)(screenWidth * scale);
int scaledHeight = (int)(screenHeight * scale);

// Resize image to scaled dimensions before sending to Claude
var screenshot = CaptureAndResize(scaledWidth, scaledHeight);

// When handling Claude's coordinates, scale them back up
void ExecuteClick(int x, int y)
{
    double screenX = x / scale;
    double screenY = y / scale;
    PerformClick(screenX, screenY);
}

Console.WriteLine({{CONTENT}}quot;scale={scale:F6} scaled={scaledWidth}x{scaledHeight}");
package main

import (
	"fmt"
	"math"
)

func captureAndResize(w, h int) any { return nil }
func performClick(x, y float64)     {}

func getScaleFactor(width, height int) float64 {
	longest := float64(max(width, height))
	area := float64(width * height)
	return min(1.0, 1568/longest, math.Sqrt(1_150_000/area))
}

func main() {
	screenWidth, screenHeight := 1512, 982

	// When capturing screenshot
	scale := getScaleFactor(screenWidth, screenHeight)
	scaledWidth := int(float64(screenWidth) * scale)
	scaledHeight := int(float64(screenHeight) * scale)

	// Resize image to scaled dimensions before sending to Claude
	screenshot := captureAndResize(scaledWidth, scaledHeight)

	// When handling Claude's coordinates, scale them back up
	executeClick := func(x, y int) {
		performClick(float64(x)/scale, float64(y)/scale)
	}

	_, _ = screenshot, executeClick
	fmt.Printf("scale=%.6f scaled=%dx%d\n", scale, scaledWidth, scaledHeight)
}
import java.util.function.BiConsumer;

static Object captureAndResize(int w, int h) { return null; }
static void performClick(double x, double y) {}

static double getScaleFactor(int width, int height) {
    return Math.min(
        1.0,
        Math.min(
            1568.0 / Math.max(width, height),
            Math.sqrt(1_150_000.0 / (width * height))
        )
    );
}

void main() {
    int screenWidth = 1512, screenHeight = 982;

    // When capturing screenshot
    double scale = getScaleFactor(screenWidth, screenHeight);
    int scaledWidth = (int)(screenWidth * scale);
    int scaledHeight = (int)(screenHeight * scale);

    // Resize image to scaled dimensions before sending to Claude
    var screenshot = captureAndResize(scaledWidth, scaledHeight);

    // When handling Claude's coordinates, scale them back up
    BiConsumer<Integer, Integer> executeClick =
        (x, y) -> performClick(x / scale, y / scale);

    IO.println("scale=%.6f scaled=%dx%d".formatted(scale, scaledWidth, scaledHeight));
}
<?php

function captureAndResize(int $w, int $h): mixed { return null; }
function performClick(float $x, float $y): void {}

function getScaleFactor(int $width, int $height): float
{
    return min(
        1.0,
        1568 / max($width, $height),
        sqrt(1_150_000 / ($width * $height)),
    );
}

$screenWidth = 1512;
$screenHeight = 982;

// When capturing screenshot
$scale = getScaleFactor($screenWidth, $screenHeight);
$scaledWidth = (int)($screenWidth * $scale);
$scaledHeight = (int)($screenHeight * $scale);

// Resize image to scaled dimensions before sending to Claude
$screenshot = captureAndResize($scaledWidth, $scaledHeight);

// When handling Claude's coordinates, scale them back up
$executeClick = fn(int $x, int $y) => performClick($x / $scale, $y / $scale);

printf("scale=%.6f scaled=%dx%d\n", $scale, $scaledWidth, $scaledHeight);
def capture_and_resize(w, h) = nil
def perform_click(x, y) = nil

def get_scale_factor(width, height)
  [1.0, 1568.0 / [width, height].max, Math.sqrt(1_150_000.0 / (width * height))].min
end

screen_width, screen_height = 1512, 982

# When capturing screenshot
scale = get_scale_factor(screen_width, screen_height)
scaled_width = (screen_width * scale).to_i
scaled_height = (screen_height * scale).to_i

# Resize image to scaled dimensions before sending to Claude
screenshot = capture_and_resize(scaled_width, scaled_height)

# When handling Claude's coordinates, scale them back up
execute_click = ->(x, y) { perform_click(x / scale, y / scale) }

puts format("scale=%.6f scaled=%dx%d", scale, scaled_width, scaled_height)
Note

macOS Retina displays capture screenshots at a device pixel ratio of 2, so the image is twice the resolution of the logical screen coordinates. Either downscale the screenshot by 2x before sending, or halve the coordinates Claude returns before issuing the click.

Diagnose click issues

If clicks miss their targets, the cause is usually one of the following:

SymptomLikely causeTry
Clicks consistently offset in one directiondisplay_width_px/display_height_px don't match the image dimensions actually sent, or the image exceeds API limits and is silently downscaledEnsure display dimensions exactly match the resized screenshot; pre-downscale to fit within API limits
Clicks land in the right area but miss the targetTarget is very small, detail was lost downscaling a 4K+ source, or aspect ratio was distortedSet enable_zoom: true; capture at lower DPI or crop to the relevant region; preserve aspect ratio when resizing
Claude clicks the wrong element entirelyAmbiguous instruction, or visually similar elements nearbyUse positional prompts ("the blue Submit button in the bottom-right"); break the interaction into smaller steps
Accuracy is consistently poorScreenshots sent above API limits, or resolution too lowPre-downscale to fit within limits; try 1280x720 as a baseline
Tip

Model choice affects click precision. Claude Sonnet 4.6 is more mechanically precise at clicking than Claude Opus 4.6 and is more robust when screenshots require heavy downscaling. Claude Opus 4.7 narrows that gap: its click precision is roughly comparable to Sonnet 4.6, and its higher resolution limit means less downscaling is needed.

Follow implementation best practices

Use appropriate display resolution

Set display dimensions that match your use case while staying within recommended limits:

  • For general desktop tasks: 1024x768 or 1280x720
  • For web applications: 1280x800 or 1366x768
  • Avoid resolutions above 1920x1080 to prevent performance issues

Implement proper screenshot handling

When returning screenshots to Claude:

  • Encode screenshots as base64 PNG or JPEG
  • Consider compressing large screenshots to improve performance
  • Include relevant metadata such as timestamp or display state
  • If using higher resolutions, ensure coordinates are accurately scaled

Manage screenshot history for prompt caching

Long agent loops accumulate screenshots quickly (roughly 1,000–1,800 input tokens each). To keep Prompt caching effective while bounding context:

  • Place one cache_control breakpoint after the system prompt and tool definitions, and up to three more on the most recent tool_result blocks, advancing them each turn.
  • Prune old screenshots in batches, not one each turn. Dropping a screenshot every turn changes the prefix every turn and invalidates the cache. A reasonable default is to keep the last three screenshots and prune every 25 turns, so the prefix stays byte-identical between prune events.

Add action delays

Some applications need time to respond to actions:

Info

This is application-side helper code with no API request. See the SDK tabs for the pattern.

Info

This is application-side helper code with no API request. See the SDK tabs for the pattern.

import time


def click_at(x, y): ...
def click_and_wait(x, y, wait_time=0.5):
    click_at(x, y)
    time.sleep(wait_time)  # Allow UI to update


print("ok")
import { setTimeout } from "node:timers/promises";

function clickAt(x: number, y: number): void {}

async function clickAndWait(x: number, y: number, waitMs = 500): Promise<void> {
  clickAt(x, y);
  await setTimeout(waitMs); // Allow UI to update
}

await clickAndWait(100, 200);
console.log("ok");
ClickAndWait(100, 200);
Console.WriteLine("ok");

static void ClickAt(int x, int y) { }

static void ClickAndWait(int x, int y, double waitSeconds = 0.5)
{
    ClickAt(x, y);
    Thread.Sleep(TimeSpan.FromSeconds(waitSeconds));  // Allow UI to update
}
package main

import (
	"fmt"
	"time"
)

func clickAt(x, y int) {}

func clickAndWaitFor(x, y int, wait time.Duration) {
	clickAt(x, y)
	time.Sleep(wait) // Allow UI to update
}

func clickAndWait(x, y int) {
	clickAndWaitFor(x, y, 500*time.Millisecond)
}

func main() {
	fmt.Println("ok")
}
void clickAt(int x, int y) {}

void clickAndWait(int x, int y) throws InterruptedException {
    clickAndWait(x, y, 500);
}

void clickAndWait(int x, int y, long waitTimeMillis) throws InterruptedException {
    clickAt(x, y);
    Thread.sleep(waitTimeMillis);  // Allow UI to update
}

void main() {
    IO.println("ok");
}
<?php

function clickAt(int $x, int $y): void {}

function clickAndWait(int $x, int $y, float $waitSeconds = 0.5): void
{
    clickAt($x, $y);
    usleep((int) ($waitSeconds * 1_000_000));  // Allow UI to update
}

echo "ok\n";
def click_at(x, y) = nil

def click_and_wait(x, y, wait_time: 0.5)
  click_at(x, y)
  sleep(wait_time) # Allow UI to update
end

puts "ok"

Validate actions before running them

Check that requested actions are safe and valid:

Info

This is application-side helper code with no API request. See the SDK tabs for the pattern.

Info

This is application-side helper code with no API request. See the SDK tabs for the pattern.

display_width, display_height = 1024, 768


def validate_action(action_type, params):
    if action_type == "left_click":
        x, y = params.get("coordinate", (0, 0))
        if not (0 <= x < display_width and 0 <= y < display_height):
            return False, "Coordinates out of bounds"
    return True, None


print(validate_action("left_click", {"coordinate": (2000, 100)}))
const displayWidth = 1024;
const displayHeight = 768;

interface ActionParams {
  coordinate?: [number, number];
}

function validateAction(actionType: string, params: ActionParams): [boolean, string | null] {
  if (actionType === "left_click") {
    const [x, y] = params.coordinate ?? [0, 0];
    if (!(x >= 0 && x < displayWidth && y >= 0 && y < displayHeight)) {
      return [false, "Coordinates out of bounds"];
    }
  }
  return [true, null];
}

console.log(validateAction("left_click", { coordinate: [2000, 100] }));
using System.Text.Json;

const int DisplayWidth = 1024;
const int DisplayHeight = 768;

Console.WriteLine(ValidateAction("left_click", new Dictionary<string, JsonElement> { ["coordinate"] = JsonSerializer.SerializeToElement(new[] { 2000, 100 }) }));

static (bool IsValid, string? Error) ValidateAction(string actionType, IReadOnlyDictionary<string, JsonElement> parameters)
{
    if (actionType == "left_click")
    {
        int x = parameters["coordinate"][0].GetInt32();
        int y = parameters["coordinate"][1].GetInt32();
        if (x is < 0 or >= DisplayWidth || y is < 0 or >= DisplayHeight)
        {
            return (false, "Coordinates out of bounds");
        }
    }
    return (true, null);
}
package main

import "fmt"

const (
	displayWidth  = 1024
	displayHeight = 768
)

func validateAction(actionType string, params map[string]any) (bool, string) {
	if actionType == "left_click" {
		coord, ok := params["coordinate"].([]any)
		if !ok || len(coord) != 2 {
			return false, "Invalid coordinate"
		}
		x, y := int(coord[0].(float64)), int(coord[1].(float64))
		if !(0 <= x && x < displayWidth && 0 <= y && y < displayHeight) {
			return false, "Coordinates out of bounds"
		}
	}
	return true, ""
}

func main() {
	ok, msg := validateAction("left_click", map[string]any{"coordinate": []any{2000.0, 100.0}})
	fmt.Println(ok, msg)
}
import com.anthropic.core.JsonValue;

static final int DISPLAY_WIDTH = 1024;
static final int DISPLAY_HEIGHT = 768;

record Validation(boolean valid, String error) {}

Validation validateAction(String actionType, Map<String, JsonValue> params) {
    if (actionType.equals("left_click")) {
        List<JsonValue> coord = (List<JsonValue>) params.get("coordinate").asArray().get();
        long x = ((Number) coord.get(0).asNumber().get()).longValue();
        long y = ((Number) coord.get(1).asNumber().get()).longValue();
        if (!(0 <= x && x < DISPLAY_WIDTH && 0 <= y && y < DISPLAY_HEIGHT)) {
            return new Validation(false, "Coordinates out of bounds");
        }
    }
    return new Validation(true, null);
}

void main() {
    IO.println(validateAction("left_click", Map.of("coordinate", JsonValue.from(List.of(2000, 100)))));
}
<?php

const DISPLAY_WIDTH = 1024;
const DISPLAY_HEIGHT = 768;

/** @return array{bool, ?string} */
function validateAction(string $actionType, array $params): array
{
    if ($actionType === 'left_click') {
        [$x, $y] = $params['coordinate'] ?? [0, 0];
        if (!(0 <= $x && $x < DISPLAY_WIDTH && 0 <= $y && $y < DISPLAY_HEIGHT)) {
            return [false, 'Coordinates out of bounds'];
        }
    }
    return [true, null];
}

[$valid, $error] = validateAction('left_click', ['coordinate' => [2000, 100]]);
echo ($valid ? 'true' : 'false') . ' ' . $error . "\n";
DISPLAY_WIDTH = 1024
DISPLAY_HEIGHT = 768

def validate_action(action_type, params)
  if action_type == "left_click"
    x, y = params.fetch(:coordinate, [0, 0])
    unless (0...DISPLAY_WIDTH).cover?(x) && (0...DISPLAY_HEIGHT).cover?(y)
      return [false, "Coordinates out of bounds"]
    end
  end
  [true, nil]
end

p validate_action("left_click", {coordinate: [2000, 100]})

Log actions for debugging

Keep a log of all actions for troubleshooting:

Info

This is application-side helper code with no API request. See the SDK tabs for the pattern.

Info

This is application-side helper code with no API request. See the SDK tabs for the pattern.

import logging


def log_action(action_type, params, result):
    logging.info(f"Action: {action_type}, Params: {params}, Result: {result}")


print("ok")
function logAction(actionType: string, params: unknown, result: unknown): void {
  console.error(
    `Action: ${actionType}, Params: ${JSON.stringify(params)}, Result: ${JSON.stringify(
      result
    )}`
  );
}

console.log("ok");
LogAction("screenshot", null, "<image data>");
Console.WriteLine("ok");

static void LogAction(string actionType, object? parameters, object? result)
{
    Console.Error.WriteLine({{CONTENT}}quot;Action: {actionType}, Params: {parameters}, Result: {result}");
}
package main

import (
	"fmt"
	"log"
)

func logAction(actionType string, params map[string]any, result any) {
	log.Printf("Action: %s, Params: %v, Result: %v", actionType, params, result)
}

func main() {
	fmt.Println("ok")
}
import static java.lang.System.Logger.Level.INFO;

static final System.Logger LOGGER = System.getLogger("computer-use");

void logAction(String actionType, Object params, Object result) {
    LOGGER.log(INFO, "Action: {0}, Params: {1}, Result: {2}", actionType, params, result);
}

void main() {
    IO.println("ok");
}
<?php

function logAction(string $actionType, array $params, mixed $result): void
{
    error_log(sprintf(
        'Action: %s, Params: %s, Result: %s',
        $actionType,
        json_encode($params),
        json_encode($result),
    ));
}

echo "ok\n";
require "logger"

LOGGER = Logger.new($stderr)

def log_action(action_type, params, result)
  LOGGER.info("Action: #{action_type}, Params: #{params}, Result: #{result}")
end

puts "ok"

Understand computer use limitations

The computer use functionality is in beta. While Claude's capabilities are state of the art, developers should be aware of its limitations:

  1. Latency: The current computer use latency for human-AI interactions might be too slow compared to regular human-directed computer actions. Focus on use cases where speed isn't critical (for example, background information gathering, automated software testing) in trusted environments.
  2. Computer vision accuracy and reliability: Claude might make mistakes or hallucinate when outputting specific coordinates while generating actions. Extended thinking can help you understand the model's reasoning and identify potential issues.
  3. Tool selection accuracy and reliability: Claude might make mistakes or hallucinate when selecting tools while generating actions or take unexpected actions to solve problems. Additionally, reliability might be lower when interacting with niche applications or multiple applications at once. Prompt the model carefully when requesting complex tasks.
  4. Scrolling reliability: The scroll action supports direction control (up, down, left, right) and a specified amount. In applications where scrolling doesn't take effect, keyboard alternatives such as Page Down can help.
  5. Spreadsheet interaction: Use the fine-grained mouse control actions (left_mouse_down, left_mouse_up) and modifier-key combinations to select individual cells. Complex spreadsheet operations might still require multiple attempts.
  6. Account creation and content generation on social and communications platforms: While Claude will visit websites, Claude's ability to create accounts or generate and share content or otherwise engage in human impersonation across social media websites and platforms is limited. This capability might be updated in the future.
  7. Vulnerabilities: Vulnerabilities such as jailbreaking or prompt injection might persist across frontier AI systems, including the beta computer use API. In some circumstances, Claude will follow commands found in content, sometimes even in conflict with the user's instructions. For example, Claude instructions on webpages or contained in images might override instructions or cause Claude to make mistakes. Consider the following: a. Limiting computer use to trusted environments such as virtual machines or containers with minimal privileges b. Avoiding giving computer use access to sensitive accounts or data without strict oversight c. Informing end users of relevant risks and obtaining their consent before enabling or requesting permissions necessary for computer use features in your applications
  8. Inappropriate or illegal actions: Under Anthropic's Terms of Service, you must not employ computer use to violate any laws or the Acceptable Use Policy.

Always carefully review and verify Claude's computer use actions and logs. Do not use Claude for tasks requiring perfect precision or sensitive user information without human oversight.

Data retention

Computer use is a client-side tool. All screenshots, mouse actions, keyboard inputs, and any files involved in a session are captured and stored in your environment, not by Anthropic. Anthropic processes the screenshot images and action requests in real time as part of the API call but does not retain them after the response is returned.

Because your application controls where and how computer use data is stored, computer use is ZDR eligible. For ZDR eligibility across all features, see API and data retention.

Pricing

Computer use follows the standard tool use pricing. When using the computer use tool:

System prompt overhead: The computer use beta adds 466-499 tokens to the system prompt

Computer use tool token usage:

ModelInput tokens per tool definition
Claude 4.x models735 tokens

Additional token consumption:

  • Screenshot images (see Vision pricing)
  • Tool execution results returned to Claude
Note

If you're also using bash or text editor tools alongside computer use, those tools have their own token costs as documented in their respective pages.

Next steps