Get Started ↗

Make your first API call to Claude and build a simple web search assistant.

Prerequisites#

• An Anthropic Console account
• An API key

Call the API#

Get your API key from the Claude Console and set it as an environment variable:

```bash
    export ANTHROPIC_API_KEY='your-api-key-here'
    ```

Run this command to create a simple web search assistant:

```bash
    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-4-6",
        "max_tokens": 1000,
        "messages": [
          {
            "role": "user",
            "content": "What should I search for to find the latest developments in renewable energy?"
          }
        ]
      }'
    ```

**Example output:**
```json
    {
      "id": "msg_01HCDu5LRGeP2o7s2xGmxyx8",
      "type": "message",
      "role": "assistant",
      "content": [
        {
          "type": "text",
          "text": "Here are some effective search strategies to find the latest renewable energy developments:\n\n## Search Terms to Use:\n- \"renewable energy news 2024\"\n- \"clean energy breakthrough\"\n- \"solar/wind/battery technology advances\"\n- \"green energy innovations\"\n- \"climate tech developments\"\n- \"energy storage solutions\"\n\n## Best Sources to Check:\n\n**News & Industry Sites:**\n- Renewable Energy World\n- GreenTech Media (now Wood Mackenzie)\n- Energy Storage News\n- CleanTechnica\n- PV Magazine (for solar)\n- WindPower Engineering & Development..."
        }
      ],
      "model": "claude-opus-4-6",
      "stop_reason": "end_turn",
      "usage": {
        "input_tokens": 21,
        "output_tokens": 305
      }
    }
    ```

Get your API key from the Claude Console and set it as an environment variable:

```bash
    export ANTHROPIC_API_KEY='your-api-key-here'
    ```

Install the Anthropic Python SDK:

```bash
    pip install anthropic
    ```

Save this as quickstart.py:

```python
    import anthropic

    client = anthropic.Anthropic()

    message = client.messages.create(
        model="claude-opus-4-6",
        max_tokens=1000,
        messages=[
            {
                "role": "user",
                "content": "What should I search for to find the latest developments in renewable energy?",
            }
        ],
    )
    print(message.content)
    ```

bash python quickstart.py

**Example output:**
```python
    [
        TextBlock(
            text='Here are some effective search strategies for finding the latest renewable energy developments:\n\n**Search Terms to Use:**\n- "renewable energy news 2024"\n- "clean energy breakthroughs"\n- "solar/wind/battery technology advances"\n- "energy storage innovations"\n- "green hydrogen developments"\n- "renewable energy policy updates"\n\n**Reliable Sources to Check:**\n- **News & Analysis:** Reuters Energy, Bloomberg New Energy Finance, Greentech Media, Energy Storage News\n- **Industry Publications:** Renewable Energy World, PV Magazine, Wind Power Engineering\n- **Research Organizations:** International Energy Agency (IEA), National Renewable Energy Laboratory (NREL)\n- **Government Sources:** Department of Energy websites, EPA clean energy updates\n\n**Specific Topics to Explore:**\n- Perovskite and next-gen solar cells\n- Offshore wind expansion\n- Grid-scale battery storage\n- Green hydrogen production\n- Carbon capture technologies\n- Smart grid innovations\n- Energy policy changes and incentives...',
            type="text",
        )
    ]
    ```

Get your API key from the Claude Console and set it as an environment variable:

```bash
    export ANTHROPIC_API_KEY='your-api-key-here'
    ```

Install the Anthropic TypeScript SDK:

```bash
    npm install @anthropic-ai/sdk
    ```

Save this as quickstart.ts:

```typescript
    import Anthropic from "@anthropic-ai/sdk";

    async function main() {
      const anthropic = new Anthropic();

      const msg = await anthropic.messages.create({
        model: "claude-opus-4-6",
        max_tokens: 1000,
        messages: [
          {
            role: "user",
            content:
              "What should I search for to find the latest developments in renewable energy?"
          }
        ]
      });
      console.log(msg);
    }

    main().catch(console.error);
    ```

bash npx tsx quickstart.ts

**Example output:**
```javascript
    const _ =
      // output
      {
        id: "msg_01ThFHzad6Bh4TpQ6cHux9t8",
        type: "message",
        role: "assistant",
        model: "claude-opus-4-6",
        content: [
          {
            type: "text",
            text:
              "Here are some effective search strategies to find the latest renewable energy developments:\n\n" +
              "## Search Terms to Use:\n" +
              '- "renewable energy news 2024"\n' +
              '- "clean energy breakthroughs"\n' +
              '- "solar wind technology advances"\n' +
              '- "energy storage innovations"\n' +
              '- "green hydrogen developments"\n' +
              '- "offshore wind projects"\n' +
              '- "battery technology renewable"\n\n' +
              "## Best Sources to Check:\n\n" +
              "**News & Industry Sites:**\n" +
              "- Renewable Energy World\n" +
              "- CleanTechnica\n" +
              "- GreenTech Media (now Wood Mackenzie)\n" +
              "- Energy Storage News\n" +
              "- PV Magazine (for solar)..."
          }
        ],
        stop_reason: "end_turn",
        usage: {
          input_tokens: 21,
          output_tokens: 302
        }
      }
    ```

Get your API key from the Claude Console and set it as an environment variable:

```bash
    export ANTHROPIC_API_KEY='your-api-key-here'
    ```

Add the Anthropic Java SDK to your project. First find the current version on Maven Central.

**Gradle:**
```groovy
    implementation("com.anthropic:anthropic-java:1.0.0")
    ```

**Maven:**
```xml
    <dependency>
      <groupId>com.anthropic</groupId>
      <artifactId>anthropic-java</artifactId>
      <version>1.0.0</version>
    </dependency>
    ```

Save this as QuickStart.java:

```java
    import com.anthropic.client.AnthropicClient;
    import com.anthropic.client.okhttp.AnthropicOkHttpClient;
    import com.anthropic.models.messages.Message;
    import com.anthropic.models.messages.MessageCreateParams;

    public class QuickStart {

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

        MessageCreateParams params = MessageCreateParams.builder()
          .model("claude-opus-4-6")
          .maxTokens(1000)
          .addUserMessage(
            "What should I search for to find the latest developments in renewable energy?"
          )
          .build();

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

bash javac QuickStart.java java QuickStart

**Example output:**
```java
    [ContentBlock{text=TextBlock{text=Here are some effective search strategies to find the latest renewable energy developments:

    ## Search Terms to Use:
    - "renewable energy news 2024"
    - "clean energy breakthroughs"
    - "solar/wind/battery technology advances"
    - "energy storage innovations"
    - "green hydrogen developments"
    - "renewable energy policy updates"

    ## Best Sources to Check:
    - **News & Analysis:** Reuters Energy, Bloomberg New Energy Finance, Greentech Media
    - **Industry Publications:** Renewable Energy World, PV Magazine, Wind Power Engineering
    - **Research Organizations:** International Energy Agency (IEA), National Renewable Energy Laboratory (NREL)
    - **Government Sources:** Department of Energy websites, EPA clean energy updates

    ## Specific Topics to Explore:
    - Perovskite and next-gen solar cells
    - Offshore wind expansion
    - Grid-scale battery storage
    - Green hydrogen production..., type=text}}]
    ```

Next steps#

You made your first API call. Next, learn the Messages API patterns you’ll use in every Claude integration.

Learn multi-turn conversations, system prompts, stop reasons, and other core patterns.

Once you’re comfortable with the basics, explore further:

Compare Claude models by capability and cost. Browse all Claude capabilities: tools, context management, structured outputs, and more. Reference documentation for Python, TypeScript, Java, and other client libraries.