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Chapter 2.4 — Structured outputs and function calling

🎯 Objective

Show that structured output is an integration layer — not a correctness guarantee.

🧠 Concept

  • Structured outputs — the model follows a schema (JSON, Pydantic). Reduces fragile parsing.
  • Function calling — the model proposes a structured call to a function. The application validates, authorizes and executes it.

🛡️ What structured output guarantees

  • The shape of the response.
  • Basic types.
  • Required fields.

⚠️ What it does NOT guarantee

  • That the content is correct.
  • That the proposed action is safe.
  • That the business rule is being respected.
LLM proposes -> schema validates -> policy authorizes -> executor acts -> log audits

📚 References