Force structured JSON output from LLMs — using native JSON mode, function calling schemas, or prompt-based extraction.
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Getting reliable structured data from LLMs is critical for production systems. JSON mode ensures the model outputs valid JSON. Combined with a JSON Schema, you can enforce exact field names, types, enums, and nesting. Techniques range from OpenAI's native JSON mode to Instructor-style schema enforcement to prompt-only approaches with Zod validation.
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