construct-retrieval-graph

name	construct-retrieval-graph
description	Design a retrieval-graph (GraphRAG) extract-index-search architecture only after a BM25/no-graph baseline has lost. Hands paradigm III.a to memory-engineering and eval to ai-rag-engineering.

Skill: construct-retrieval-graph

Invoked by: graph-data-modeler (primary). Query patterns after construction go to write-graph-query.

When to invoke: "stand up GraphRAG"; "multi-hop corpus synthesis"; "community summaries over this corpus."

Output: a filled ../../templates/retrieval-graph-design.md.

Procedure

1. STOP if a no-graph baseline and a BM25 / hybrid-vector baseline have not lost on a named eval. Cite ../../best-practices/graphrag-needs-a-humbling-baseline.md.
2. STOP if the real question is “should the agent remember in a graph?” That is paradigm III.a — hand to memory-architect-lead. Read ../../knowledge/graphrag-construction.md.
3. Pick a family as design intent (Microsoft GraphRAG / HippoRAG / LightRAG) — not a bake-off winner. Author-reported metrics stay disclaimed.
4. Extract typed entities and typed relationships. Fill a supernode plan.
5. Index — local / global (communities) / dual-layer. Name the offline bill.
6. Search mode — local / global / DRIFT / PPR. Hand the actual pattern to write-graph-query.
7. Eval — rag-architect-lead / retrieval-eval-analyst (recall@k, faithfulness). Do not invent a graph-only eval and call it done.

Guardrails

• Do not re-decide memory paradigm III.a.
• Do not skip the humbling baseline.
• Do not stand up a graph server from this skill.
• Chunking / embeddings / hybrid lexical stay in ai-rag-engineering.