Quick start

Add the computer use toolset to the tools array of a Messages API request as \{"type": "computer_toolset_20260801"\}. The request needs no beta header. This example also declares the text editor tool and bash tool, which Claude typically uses alongside 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" \
  -d '{
    "model": "claude-opus-5",
    "max_tokens": 1024,
    "tools": [
      {
        "type": "computer_toolset_20260801"
      },
      {
        "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 messages create <<'YAML'
model: claude-opus-5
max_tokens: 1024
tools:
  - type: computer_toolset_20260801
  - 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

client = anthropic.Anthropic()

response = client.messages.create(
    model="claude-opus-5",
    max_tokens=1024,
    tools=[
        {"type": "computer_toolset_20260801"},
        {"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."}],
)
print(response)

const client = new Anthropic();

const response = await client.messages.create({
  model: "claude-opus-5",
  max_tokens: 1024,
  tools: [
    {
      type: "computer_toolset_20260801"
    },
    {
      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." }]
});

console.log(response);

var client = new AnthropicClient();

var parameters = new MessageCreateParams
{
    Model = Model.ClaudeOpus5,
    MaxTokens = 1024,
    Tools =
    [
        new ComputerToolset20260801(),
        new ToolTextEditor20250728(),
        new ToolBash20250124(),
    ],
    Messages =
    [
        new MessageParam
        {
            Role = Role.User,
            Content = "Save a picture of a cat to my desktop.",
        },
    ],
};

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

client := anthropic.NewClient()

response, err := client.Messages.New(context.TODO(), anthropic.MessageNewParams{
	Model:     anthropic.ModelClaudeOpus5,
	MaxTokens: 1024,
	Tools: []anthropic.ToolUnionParam{
		{OfComputerToolset20260801: &anthropic.ComputerToolset20260801Param{}},
		{OfTextEditor20250728: &anthropic.ToolTextEditor20250728Param{}},
		{OfBashTool20250124: &anthropic.ToolBash20250124Param{}},
	},
	Messages: []anthropic.MessageParam{
		anthropic.NewUserMessage(anthropic.NewTextBlock("Save a picture of a cat to my desktop.")),
	},
})
if err != nil {
	log.Fatal(err)
}
fmt.Println(response.RawJSON())

import com.anthropic.models.messages.ComputerToolset20260801;
// ...
import com.anthropic.models.messages.ToolBash20250124;
import com.anthropic.models.messages.ToolTextEditor20250728;

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

    MessageCreateParams params = MessageCreateParams.builder()
        .model(Model.CLAUDE_OPUS_5)
        .maxTokens(1024L)
        .addTool(ComputerToolset20260801.builder().build())
        .addTool(ToolTextEditor20250728.builder().build())
        .addTool(ToolBash20250124.builder().build())
        .addUserMessage("Save a picture of a cat to my desktop.")
        .build();

    Message response = client.messages().create(params);
    IO.println(response);
}

$client = new Client();

$response = $client->messages->create(
    maxTokens: 1024,
    messages: [
        ['role' => 'user', 'content' => 'Save a picture of a cat to my desktop.'],
    ],
    model: 'claude-opus-5',
    tools: [
        ['type' => 'computer_toolset_20260801'],
        [
            'type' => 'text_editor_20250728',
            'name' => 'str_replace_based_edit_tool',
        ],
        [
            'type' => 'bash_20250124',
            'name' => 'bash',
        ],
    ],
);

echo $response;

client = Anthropic::Client.new

response = client.messages.create(
  model: "claude-opus-5",
  max_tokens: 1024,
  tools: [
    { type: "computer_toolset_20260801" },
    {
      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." }
  ]
)

puts response

When Claude acts on the desktop, the response has a stop_reason of tool_use and contains one or more member tool_use blocks, each naming a member tool and carrying "toolset_name": "computer". Partway through this task, after Claude has seen a screenshot of the desktop, a response might look like this:

{
  "id": "msg_01UZ3bXcQH8mTqNhVfL9eK2p",
  "type": "message",
  "role": "assistant",
  "model": "claude-opus-5",
  "content": [
    {
      "type": "text",
      "text": "I'll open the web browser to find a picture of a cat."
    },
    {
      "type": "tool_use",
      "id": "toolu_01WkoTUvSHDzTBu2xnGk8Ep8",
      "name": "left_click",
      "toolset_name": "computer",
      "input": { "coordinate": [512, 742] }
    },
    {
      "type": "tool_use",
      "id": "toolu_017nJn3RgSCkTMwuZDb4uUov",
      "name": "screenshot",
      "toolset_name": "computer",
      "input": {}
    }
  ],
  "stop_reason": "tool_use",
  "stop_sequence": null
}

Your application runs each call in order in your own environment, returns one tool_result block per tool_use block, and calls the API again; How computer use works describes that loop, and the rest of this page shows how to implement it.

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