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.
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.
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.
To minimize risks, consider taking precautions such as:
- Using a dedicated virtual machine or container with minimal privileges to prevent direct system attacks or accidents.
- Avoiding giving the model access to sensitive data, such as account login information, to prevent information theft.
- Limiting internet access to an allowlist of domains to reduce exposure to malicious content.
- 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.
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
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
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."
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_reasonoftool_use, signaling a tool use request.
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
usermessage containing atool_resultcontent block.
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_usestop_reasonand 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:
-
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.
-
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.
-
Applications: Pre-installed Linux applications such as Firefox, LibreOffice, text editors, and file managers that Claude can use to complete tasks.
-
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.
-
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:
- Receives Claude's tool use requests
- Translates them into actions in your computing environment
- Captures the results (such as screenshots and command outputs)
- 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:
- A containerized environment suitable for computer use with Claude
- Implementations of the computer use tools
- An agent loop that interacts with the Claude API and runs the computer use tools
- A web interface to interact with the container, agent loop, and tools.
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:
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.
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:
- Specify simple, well-defined tasks and provide explicit instructions for each step.
- 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. - 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.
- For repeatable tasks or UI interactions, include example screenshots and tool calls of successful outcomes in your prompt.
- 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. - When constructing a user turn's
contentarray, place the instruction text before the screenshot image. Providing the target description before the image is processed improves click accuracy.
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.
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: truein tool definition. Takes aregionparameter 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
| Parameter | Required | Description |
|---|---|---|
type | Yes | Tool version (computer_20251124 or computer_20250124) |
name | Yes | Must be "computer" |
display_width_px | Yes | Display width in pixels |
display_height_px | Yes | Display height in pixels |
display_number | No | Display number for X11 environments |
enable_zoom | No | Enable zoom action (computer_20251124 only). Set to true to allow Claude to zoom into specific screen regions. Default: false |
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.
For computer use specifically, internal benchmarking suggests these effort settings:
- Claude Opus 4.7: use
highas the default; uselowfor high-throughput or cost-sensitive workloads. - Claude Sonnet 4.6 and Claude Opus 4.6: use
mediumas the default (best accuracy-to-cost ratio). Avoidmax, which adds token cost without improving accuracy on UI tasks. On these models,lowuses 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_useresults 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.
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.
Implement action handlers
Create functions to handle each action type that Claude might request:
InfoThis is application-side helper code with no API request. See the SDK tabs for the pattern.
InfoThis 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 endProcess Claude's tool calls
Extract and run tool calls from Claude's responses:
InfoThis is application-side helper code with no API request. See the SDK tabs for the pattern.
InfoThis 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_resultsfunction 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 endImplement the agent loop
Create a loop that continues until Claude completes the task:
InfoThe 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.
InfoThe 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 messagesasync 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
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:
Coordinate scaling and screenshot resizing happen in your application code, not in the API request. See the SDK tabs for the helper pattern.
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)
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:
| Symptom | Likely cause | Try |
|---|---|---|
| Clicks consistently offset in one direction | display_width_px/display_height_px don't match the image dimensions actually sent, or the image exceeds API limits and is silently downscaled | Ensure display dimensions exactly match the resized screenshot; pre-downscale to fit within API limits |
| Clicks land in the right area but miss the target | Target is very small, detail was lost downscaling a 4K+ source, or aspect ratio was distorted | Set enable_zoom: true; capture at lower DPI or crop to the relevant region; preserve aspect ratio when resizing |
| Claude clicks the wrong element entirely | Ambiguous instruction, or visually similar elements nearby | Use positional prompts ("the blue Submit button in the bottom-right"); break the interaction into smaller steps |
| Accuracy is consistently poor | Screenshots sent above API limits, or resolution too low | Pre-downscale to fit within limits; try 1280x720 as a baseline |
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_controlbreakpoint after the system prompt and tool definitions, and up to three more on the most recenttool_resultblocks, 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:
This is application-side helper code with no API request. See the SDK tabs for the pattern.
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:
This is application-side helper code with no API request. See the SDK tabs for the pattern.
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:
This is application-side helper code with no API request. See the SDK tabs for the pattern.
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:
- 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.
- 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.
- 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.
- 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.
- 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. - 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.
- 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
- 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:
| Model | Input tokens per tool definition |
|---|---|
| Claude 4.x models | 735 tokens |
Additional token consumption:
- Screenshot images (see Vision pricing)
- Tool execution results returned to Claude
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.