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  "description": "Learn how to use the Claude API in Python to send prompts, control responses with system instructions, and get structured JSON output.",
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        "name": "How do you call the Claude API in Python?",
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          "text": "\u003cp\u003eInstall the \u003ccode\u003eanthropic\u003c/code\u003e package, set your \u003ccode\u003eANTHROPIC_API_KEY\u003c/code\u003e environment variable, and call \u003ccode\u003eclient.messages.create()\u003c/code\u003e with a \u003ccode\u003emodel\u003c/code\u003e name and a list of \u003ccode\u003emessages\u003c/code\u003e. The SDK reads the key automatically, so you don\u0026rsquo;t need to pass it explicitly in your script.\u003c/p\u003e"
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        "name": "Is the Claude API free to use?",
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          "text": "\u003cp\u003eNo, the Claude API is paid and billed by \u003ca href=\"/ref/ai-coding-glossary/token/\" class=\"ref-link\"\u003etoken\u003c/a\u003e for both input and output. New Anthropic accounts can start with a small starter credit, and you can track spending in the \u003ca href=\"https://console.anthropic.com/\"\u003eClaude Console\u003c/a\u003e.\u003c/p\u003e"
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          "text": "\u003cp\u003eSign in to the Claude Console, open the API Keys section, and click \u003cem\u003eCreate Key\u003c/em\u003e. Copy the key right away because you won\u0026rsquo;t see it again, and store it as the \u003ccode\u003eANTHROPIC_API_KEY\u003c/code\u003e environment variable instead of pasting it into your code.\u003c/p\u003e"
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          "text": "\u003cp\u003eA \u003ca href=\"/ref/ai-coding-glossary/system-prompt/\" class=\"ref-link\"\u003esystem prompt\u003c/a\u003e is passed as the top-level \u003ccode\u003esystem\u003c/code\u003e parameter on \u003ccode\u003eclient.messages.create()\u003c/code\u003e and shapes Claude\u0026rsquo;s role, tone, and constraints across the conversation. User messages live inside the \u003ccode\u003emessages\u003c/code\u003e list with the \u003ccode\u003e\"user\"\u003c/code\u003e role and represent the actual back-and-forth dialogue.\u003c/p\u003e"
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          "text": "\u003cp\u003ePass an \u003ccode\u003eoutput_config\u003c/code\u003e with a JSON schema to \u003ccode\u003eclient.messages.create()\u003c/code\u003e, or use \u003ccode\u003eclient.messages.parse()\u003c/code\u003e with a Pydantic \u003ccode\u003eBaseModel\u003c/code\u003e to receive a typed Python object. Both approaches force Claude to return data that matches the shape you specified, which eliminates fragile string parsing.\u003c/p\u003e"
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