GraphRAG is a modular graph-based retrieval-augmented generation system from Microsoft Research, with 36,000+ stars on GitHub, designed to answer questions that ordinary RAG cannot over private data.
Standard RAG retrieves a handful of similar chunks, which fails on global questions like “what are the main themes across these thousand documents?” GraphRAG takes a structural approach: it uses an LLM to extract entities and relationships from your corpus, builds a knowledge graph, detects communities within it and pre-generates summaries of each community. At query time, global search reasons over those community summaries for corpus-wide sense-making, while local search drills into specific entities and their neighborhoods. The result is a pipeline and transformation suite aimed at narrative, private datasets — investigative documents, research collections, internal reports. Microsoft notes the project is now largely in maintenance mode, receiving bug fixes rather than new features, and warns that indexing is an LLM-driven operation that can be expensive, so start small. The repository remains available and was updated through October 2026.
GraphRAG is free and open source under the MIT license. The real cost is inference: indexing and querying consume LLM API calls, and large indexing runs can be expensive, so budget and start with a small corpus.
Analysts, investigators and research teams asking sense-making questions over large private document collections, where the answer lives in themes across documents rather than in any single passage.