Source: https://docs.claude.com/en/docs/initial-setup

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Get started with Claude

Home Developer Guide API Reference Model Context Protocol (MCP) Resources Release Notes

On this page

• Prerequisites

• Call the API

• Next steps

​

Prerequisites

• An Anthropic Console account

• An API key

​

Call the API

• cURL
• Python
• TypeScript
• Java

1

Set your API key

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

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

2

Make your first API call

Run this command to create a simple web search assistant:

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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": 1000,
    "messages": [\
      {\
        "role": "user", \
        "content": "What should I search for to find the latest developments in renewable energy?"\
      }\
    ]
  }'

Example output:

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{
  "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-sonnet-4-5",
  "stop_reason": "end_turn",
  "usage": {
    "input_tokens": 21,
    "output_tokens": 305
  }
}

​

Next steps

Now that you have made your first Claude API request, it’s time to explore what else is possible:

Working with Messages
---------------------

Learn common patterns for the Messages API. Features Overview
-----------------

Explore Claude’s advanced features and capabilities. Client SDKs
-----------

Discover Anthropic client libraries. Claude Cookbook
---------------

Learn with interactive Jupyter notebooks.

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