LLM Structured Output Validation in Python That Holds Up

Most LLM "structured output" tutorials are unserious. They teach you to ask for JSON politely and then hope the model behaves. That is not validation. That is optimism with braces. OpenAI's own docs make the distinction explicit. JSON mode gives you valid JSON, while Structured Outputs enforces schema adherence, and OpenAI recommends using Structured Outputs instead of JSON mode when possible. That still does not make the payload trustworthy. JSON Schema defines structure and allowed values,...