Memgraph Graph RAG

Memgraph GraphRAG for Agent Systems (Language-Agnostic)

Build Graph Retrieval-Augmented Generation systems that combine vector similarity search with graph traversal, and expose retrieval as tools for agents across any programming language.

When to Use

Use this skill when:

• Designing a GraphRAG platform (not a single app)
• Supporting multiple client languages (Python, JS, Java, Go, etc.)
• Building agent tools for ingestion, retrieval, and diagnostics
• Combining document chunk retrieval with entity/relationship context

Do NOT use this skill for:

• Simple vector-only RAG or standalone chatbots
• Pure ETL without retrieval or agent workflows
• Use cases that require strict SQL semantics

Outcomes

By following this skill, you will deliver:

• A graph schema that supports hybrid retrieval
• A repeatable ingestion pipeline
• A retrieval tool contract usable by agents
• An evaluation plan for recall, latency, and groundedness

Architecture Overview

Sources (files, URLs, APIs)
        │
        ▼
┌──────────────────────┐
│ Ingestion Pipeline   │  Parse → chunk → entity extract
└──────────────────────┘
        │
        ▼
┌──────────────────────┐
│ Memgraph             │  Graph + embeddings + indexes
└──────────────────────┘
        │
        ▼
┌──────────────────────┐
│ Hybrid Retriever     │  Vector search + graph expansion
└──────────────────────┘
        │
        ▼
┌──────────────────────┐
│ Agent Tools          │  run_query / retrieve_context
└──────────────────────┘
        │
        ▼
┌──────────────────────┐
│ LLM Response         │  Answer with citations
└──────────────────────┘

Step 1: Define GraphRAG Requirements

Document the following before implementation:

• Use cases: Q&A, research, report generation, troubleshooting
• Source types: PDFs, HTML, Markdown, APIs, databases
• Entity types: People, systems, components, products, errors
• Relationship types: MENTIONS, CONNECTS_TO, DEPENDS_ON, NEXT
• Latency targets: P95 retrieval time, max hops for expansion

Step 2: Choose Ingestion Strategy

Pick one of these:

• Toolkit-based: unstructured2graph + lightrag-memgraph
• Custom ETL: your parser + entity extractor + Cypher loader
• Batch migration: sql2graph for relational sources

Ingestion must always produce:

• Chunk nodes with text + source metadata
• Entity nodes with normalized names
• Relationships that connect entities to chunks and each other

Step 3: Standard Graph Schema (Recommended)

Use a stable schema so any client can query consistently:

Nodes

• Document {id, title, source, created_at}
• Chunk {id, text, source, embedding}
• Entity {id, name, type, description}
• Concept {id, name}

Relationships

• (Document)-[:HAS_CHUNK]->(Chunk)
• (Entity)-[:MENTIONED_IN]->(Chunk)
• (Entity)-[:RELATES_TO]->(Entity)
• (Chunk)-[:NEXT]->(Chunk)

Step 4: Embeddings + Vector Index

• Store embeddings on Chunk.embedding
• Create a vector index for Chunk(embedding)
• Use Memgraph’s vector search in retrieval

Keep embeddings consistent across ingestion and queries.

Step 5: Hybrid Retrieval Strategy

Default retrieval flow:

1. Vector search to get top-$k$ chunks
2. Graph expansion to include related chunks/entities
3. Ranking by degree, recency, or path length
4. Dedup and trim to the model context budget

Recommended query pattern (pseudo-Cypher):

• Vector search on Chunk
• BFS traversal limited to $1–3$ hops
• Return chunk text + related entities

Step 6: Agent Tool Contracts

Expose retrieval and diagnostics as tools. Minimal contract:

Tool: run_query

• Input: { cypher: string, params?: object }
• Output: { rows: array }

Tool: retrieve_context

• Input: { question: string, vector_k?: number, hop_limit?: number }
• Output: { chunks: [{text, source, entities[]}], graph_stats }

Tool: ingest_sources

• Input: { sources: string[], mode?: "append" | "replace" }
• Output: { documents, chunks, entities, duration_ms }

Agents should:

• Call get_schema once per session
• Use parameterized queries
• Log retrieval traces for debugging

Step 7: Language-Agnostic Integration

Memgraph supports the Bolt protocol. Use a Bolt-compatible driver in your language of choice.

Integration responsibilities in each language:

• Create a connection pool
• Execute parameterized Cypher
• Map results to your tool contract
• Handle retries and timeouts

Step 8: Evaluation & Observability

Minimum evaluation suite:

• Recall@k: relevant chunks retrieved
• Groundedness: answer supported by chunks
• Latency: P95 retrieval under target
• Coverage: percent of sources indexed

Log for each request:

• Query text
• Top vector hits
• Expansion hops used
• Final context length

Guardrails

• Always answer from retrieved context
• If context is insufficient, say so
• Avoid unbounded graph traversal
• Enforce per-request timeouts

Optional: Use Memgraph AI Toolkit

Use the Memgraph AI Toolkit for faster setup:

• memgraph-toolbox for core utilities
• unstructured2graph for parsing and ingestion
• lightrag-memgraph for entity extraction
• langchain-memgraph for agent tooling

Treat these as implementation options, not requirements.