What isNeo4j?

• Neo4j is anopen-source database management system that specializes in graph database technology.
• Neo4j allows you to represent and store data in nodes and edges, making it ideal for handling connected data and relationships.
• Neo4j provides aCypher Query Language, making it easy to interact with and query your graph data.
• With Neo4j, you can achieve high-performancegraph traversals and queries, suitable for production-level systems.

Get started with Neo4j by visitingtheir website.

Installation and Setup​

• Install the Python SDK withpip install neo4j langchain-neo4j

VectorStore​

The Neo4j vector index is used as a vectorstore,whether for semantic search or example selection.

from langchain_neo4jimport Neo4jVector

See ausage example

GraphCypherQAChain​

There exists a wrapper around Neo4j graph database that allows you to generate Cypher statements based on the user inputand use them to retrieve relevant information from the database.

from langchain_neo4jimport GraphCypherQAChain, Neo4jGraph

See ausage example

Constructing a knowledge graph from text​

Text data often contain rich relationships and insights that can be useful for various analytics, recommendation engines, or knowledge management applications.Diffbot's NLP API allows for the extraction of entities, relationships, and semantic meaning from unstructured text data.By coupling Diffbot's NLP API with Neo4j, a graph database, you can create powerful, dynamic graph structures based on the information extracted from text.These graph structures are fully queryable and can be integrated into various applications.

from langchain_neo4jimport Neo4jGraph
from langchain_experimental.graph_transformers.diffbotimport DiffbotGraphTransformer

See ausage example

Memory​

See ausage example.

from langchain_neo4jimport Neo4jChatMessageHistory