What is Neo4j?
Neo4j is a leading graph database platform that stores data as nodes, relationships, and properties, optimized for traversing and querying graph-structured information. Unlike relational databases that use tables and joins, Neo4j natively stores graph structures, making it highly efficient for queries that involve following relationships, pattern matching, and multi-hop traversal. It's widely used for knowledge graphs, recommendation engines, fraud detection, and network analysis.
The database uses the Cypher query language, a declarative language specifically designed for graph pattern matching that makes complex graph queries readable and expressive. Neo4j supports ACID transactions, indexes for fast node lookup, and various algorithms for graph analysis. It offers both community and enterprise editions, with enterprise features including clustering, hot backups, and advanced security. The platform provides rich visualization tools, extensive documentation, and integration libraries for major programming languages.
In AI agent systems, Neo4j serves as a powerful backend for knowledge graph storage, enabling agents to maintain and query complex entity-relationship structures. It excels at queries requiring relationship traversal, such as finding connections between entities, path finding, or pattern detection across multiple hops. Neo4j integrates well with RAG frameworks, supporting GraphRAG implementations where structured knowledge complements or replaces traditional vector-based retrieval. The database's native graph processing capabilities make it particularly suitable for agents requiring sophisticated reasoning over interconnected information.