🧩Extended Thinking

Let Claude reason step-by-step for complex problems

Extended Thinking

Extended thinking lets Claude show its reasoning process before giving an answer. It's like asking someone to "think out loud."

When to Use Extended Thinking

Complex math or logic problems
Code debugging with multiple potential causes
Analysis requiring multiple steps
Decision-making with trade-offs
Any task where you want to verify the reasoning

Basic Usage

JavaScript
const response = await client.messages.create({
  model: "claude-sonnet-4-6",
  max_tokens: 16000,
  thinking: {
    type: "enabled",
    budget_tokens: 10000   // Max tokens for thinking
  },
  messages: [{
    role: "user",
    content: "Is there a pattern in the sequence: 2, 6, 14, 30, 62?"
  }]
});

// Process the response
for (const block of response.content) {
  if (block.type === "thinking") {
    console.log("Claude's reasoning:", block.thinking);
  } else if (block.type === "text") {
    console.log("Final answer:", block.text);
  }
}

Response Structure

JSON
{
  "content": [
    {
      "type": "thinking",
      "thinking": "Let me analyze this sequence step by step...\n2, 6, 14, 30, 62\nDifferences: 4, 8, 16, 32\nThese are powers of 2! So the pattern is 2^(n+1) - 2..."
    },
    {
      "type": "text",
      "text": "The pattern is 2^(n+1) - 2. The next number would be 126."
    }
  ]
}

Adaptive Thinking (Claude Opus 4.7)

For the latest models, use adaptive thinking instead — Claude dynamically decides how much to think:

JavaScript
const response = await client.messages.create({
  model: "claude-opus-4-7",
  max_tokens: 16000,
  // Claude automatically decides thinking depth
  messages: [{
    role: "user",
    content: "Analyze the time complexity of this algorithm..."
  }]
});

Key Parameters

Parameter	Description
`budget_tokens`	Max tokens Claude can use for thinking
`display: "summarized"`	Get a summary instead of full thinking (default on Claude 4)
`display: "omitted"`	Skip thinking output — faster first response

Cost Note

You're billed for all thinking tokens, even when display is "summarized" or "omitted". Use budget_tokens to control cost.

Next up: Tools and web search — extending Claude's capabilities.

Module 6

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👁️ Vision — Claude Can See

Tools & Web Search 🔧

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