Quick start

The browser use tool is available on the Claude API and Google Cloud: add one entry of type browser_toolset_20260801, with no name, to the tools array of a Messages API request.

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": 2048,
    "tools": [
      {
        "type": "browser_toolset_20260801"
      }
    ],
    "messages": [
      {
        "role": "user",
        "content": "Open example.com/docs and tell me how to get started."
      }
    ]
  }'

ant messages create <<'YAML'
model: claude-opus-5
max_tokens: 2048
tools:
  - type: browser_toolset_20260801
messages:
  - role: user
    content: Open example.com/docs and tell me how to get started.
YAML

client = anthropic.Anthropic()

response = client.messages.create(
    model="claude-opus-5",
    max_tokens=2048,
    tools=[{"type": "browser_toolset_20260801"}],
    messages=[
        {
            "role": "user",
            "content": "Open example.com/docs and tell me how to get started.",
        }
    ],
)
print(response)

const client = new Anthropic();

const response = await client.messages.create({
  model: "claude-opus-5",
  max_tokens: 2048,
  tools: [{ type: "browser_toolset_20260801" }],
  messages: [
    {
      role: "user",
      content: "Open example.com/docs and tell me how to get started."
    }
  ]
});

console.log(response);

var client = new AnthropicClient();

var parameters = new MessageCreateParams
{
    Model = Model.ClaudeOpus5,
    MaxTokens = 2048,
    Tools = [new BrowserToolset20260801()],
    Messages =
    [
        new MessageParam
        {
            Role = Role.User,
            Content = "Open example.com/docs and tell me how to get started.",
        },
    ],
};

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: 2048,
	Tools: []anthropic.ToolUnionParam{
		{OfBrowserToolset20260801: &anthropic.BrowserToolset20260801Param{}},
	},
	Messages: []anthropic.MessageParam{
		anthropic.NewUserMessage(anthropic.NewTextBlock("Open example.com/docs and tell me how to get started.")),
	},
})
if err != nil {
	log.Fatal(err)
}
fmt.Println(response.RawJSON())

import com.anthropic.models.messages.BrowserToolset20260801;
// ...

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

    MessageCreateParams params = MessageCreateParams.builder()
        .model(Model.CLAUDE_OPUS_5)
        .maxTokens(2048L)
        .addTool(BrowserToolset20260801.builder().build())
        .addUserMessage("Open example.com/docs and tell me how to get started.")
        .build();

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

$client = new Client();

$response = $client->messages->create(
    maxTokens: 2048,
    messages: [
        ['role' => 'user', 'content' => 'Open example.com/docs and tell me how to get started.'],
    ],
    model: 'claude-opus-5',
    tools: [
        ['type' => 'browser_toolset_20260801'],
    ],
);

echo $response;

client = Anthropic::Client.new

response = client.messages.create(
  model: "claude-opus-5",
  max_tokens: 2048,
  tools: [
    { type: "browser_toolset_20260801" }
  ],
  messages: [
    {
      role: "user",
      content: "Open example.com/docs and tell me how to get started."
    }
  ]
)

puts response

Claude's first response ends with stop_reason: "tool_use" and carries one or more member tool_use blocks, each naming a member tool in name and carrying "toolset_name": "browser":

{
  "id": "msg_01HCDu4XSTLzTAcodEQ58vDo",
  "type": "message",
  "role": "assistant",
  "model": "claude-opus-5",
  "content": [
    {
      "type": "text",
      "text": "I'll open the documentation and read the page to find the getting-started instructions."
    },
    {
      "type": "tool_use",
      "id": "toolu_01NRLabsLyVHZPKxbKvkfSMn",
      "name": "navigate",
      "toolset_name": "browser",
      "input": { "url": "https://example.com/docs" }
    },
    {
      "type": "tool_use",
      "id": "toolu_01UvHU5cDyTZ2vXKf5wCkPqR",
      "name": "read_page",
      "toolset_name": "browser",
      "input": { "filter": "interactive" }
    }
  ],
  "stop_reason": "tool_use",
  "stop_sequence": null
}

Your executor (the part of your application that drives the browser and produces tool results) runs navigate, then read_page. Your application returns one tool_result per block in its next request, echoing toolset_name on each. The navigate result reports the tab it loaded in a browser_state block; the read_page result is text in which every element carries a reference:

{
  "role": "user",
  "content": [
    {
      "type": "tool_result",
      "tool_use_id": "toolu_01NRLabsLyVHZPKxbKvkfSMn",
      "toolset_name": "browser",
      "content": [
        { "type": "text", "text": "Navigated to https://example.com/docs" },
        {
          "type": "browser_state",
          "tabs": [
            {
              "tab_id": "tab-1",
              "title": "Documentation",
              "url": "https://example.com/docs",
              "active": true
            }
          ]
        }
      ]
    },
    {
      "type": "tool_result",
      "tool_use_id": "toolu_01UvHU5cDyTZ2vXKf5wCkPqR",
      "toolset_name": "browser",
      "content": [
        {
          "type": "text",
          "text": "link \"Documentation\" [ref_1]\nlink \"Getting started\" [ref_2]\ntextbox \"Search docs\" [ref_3]\nbutton \"Search\" [ref_4]\nlink \"Pricing\" [ref_5]"
        }
      ]
    }
  ]
}

Claude now holds references it can act on, so its next turn can click ref_2 to open the getting-started page, with no need to locate the link in a screenshot first.