LangChain Structured Output & HITL

1. Structured Output: Transform unstructured model responses into validated, typed data
2. Human-in-the-Loop: Add human oversight to agent tool calls, pausing for approval

Key Concepts:

• response_format: Define expected output schema
• with_structured_output(): Model method for direct structured output
• human_in_the_loop_middleware: Pauses execution for human decisions