Tool use with Claude

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-sonnet-4-5",
    "max_tokens": 1024,
    "tools": [
      {
        "name": "get_weather",
        "description": "Get the current weather in a given location",
        "input_schema": {
          "type": "object",
          "properties": {
            "location": {
              "type": "string",
              "description": "The city and state, e.g. San Francisco, CA"
            }
          },
          "required": ["location"]
        }
      }
    ],
    "messages": [
      {
        "role": "user",
        "content": "What is the weather like in San Francisco?"
      }
    ]
  }'

import anthropic

client = anthropic.Anthropic()

response = client.messages.create(
    model="claude-sonnet-4-5",
    max_tokens=1024,
    tools=[
        {
            "name": "get_weather",
            "description": "Get the current weather in a given location",
            "input_schema": {
                "type": "object",
                "properties": {
                    "location": {
                        "type": "string",
                        "description": "The city and state, e.g. San Francisco, CA",
                    }
                },
                "required": ["location"],
            },
        }
    ],
    messages=[{"role": "user", "content": "What's the weather like in San Francisco?"}],
)
print(response)

import { Anthropic } from '@anthropic-ai/sdk';

const anthropic = new Anthropic({
  apiKey: process.env.ANTHROPIC_API_KEY
});

async function main() {
  const response = await anthropic.messages.create({
    model: "claude-sonnet-4-5",
    max_tokens: 1024,
    tools: [{
      name: "get_weather",
      description: "Get the current weather in a given location",
      input_schema: {
        type: "object",
        properties: {
          location: {
            type: "string",
            description: "The city and state, e.g. San Francisco, CA"
          }
        },
        required: ["location"]
      }
    }],
    messages: [{ 
      role: "user", 
      content: "Tell me the weather in San Francisco." 
    }]
  });

  console.log(response);
}

main().catch(console.error);

import java.util.List;
import java.util.Map;

import com.anthropic.client.AnthropicClient;
import com.anthropic.client.okhttp.AnthropicOkHttpClient;
import com.anthropic.core.JsonValue;
import com.anthropic.models.messages.Message;
import com.anthropic.models.messages.MessageCreateParams;
import com.anthropic.models.messages.Model;
import com.anthropic.models.messages.Tool;
import com.anthropic.models.messages.Tool.InputSchema;

public class GetWeatherExample {

    public static void main(String[] args) {
        AnthropicClient client = AnthropicOkHttpClient.fromEnv();

        InputSchema schema = InputSchema.builder()
                .properties(JsonValue.from(Map.of(
                        "location",
                        Map.of(
                                "type", "string",
                                "description", "The city and state, e.g. San Francisco, CA"))))
                .putAdditionalProperty("required", JsonValue.from(List.of("location")))
                .build();

        MessageCreateParams params = MessageCreateParams.builder()
                .model(Model.CLAUDE_OPUS_4_0)
                .maxTokens(1024)
                .addTool(Tool.builder()
                        .name("get_weather")
                        .description("Get the current weather in a given location")
                        .inputSchema(schema)
                        .build())
                .addUserMessage("What's the weather like in San Francisco?")
                .build();

        Message message = client.messages().create(params);
        System.out.println(message);
    }
}