Structured Output
Also: JSON mode
Configuring Claude to return information in a specific format — like JSON, a table, or a defined list — rather than free-flowing text. Essential when Claude's output needs to be read by another system or fed into a spreadsheet, database, or application. For example: "Return a JSON object with keys: name, email, company, issue_type" rather than "write a paragraph summarizing the contact." Structured output is what makes AI integrations reliable.
In practice
You're building a tool that extracts contract dates and stores them in a database. You need Claude to always return JSON in a specific format, not a sentence like "The contract expires on January 15, 2025." Structured output constrains Claude to return data in a format your code can parse reliably — essential when Claude's output feeds into another system.
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