> ## Documentation Index
> Fetch the complete documentation index at: https://langchain.idochub.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Neo4j

[Neo4j](https://en.wikipedia.org/wiki/Neo4j) is an open-source graph database management system, renowned for its efficient management of highly connected data. Unlike traditional databases that store data in tables, Neo4j uses a graph structure with nodes, edges, and properties to represent and store data. This design allows for high-performance queries on complex data relationships.

This notebook goes over how to use `Neo4j` to store chat message history.

```python theme={null}
from langchain_neo4j import Neo4jChatMessageHistory

history = Neo4jChatMessageHistory(
    url="bolt://localhost:7687",
    username="neo4j",
    password="password",
    session_id="session_id_1",
)

history.add_user_message("hi!")

history.add_ai_message("whats up?")
```

```python theme={null}
history.messages
```

```python theme={null}
```