Knowledge Graph Construction Turning unstructured documents into a queryable graph has four stages: extract, link, validate, load. Skip any one and you get a graph that's either empty, hallucinated, inconsistent, or unusable. Pipeline Overview Schema First Define the ontology up front. Free-form extraction produces noise ("rel": "is related to") that kills downstream querying. Every relation type should have a clear, narrow intent; prefer many specific types over a few broad ones. LLM-Based Extraction (Structured Output) Anthropic tools API OpenAI structured outputs Costs - Use a cheaper mode…