Installation

To create a Neo4j JavaScript application, you first need to install the JavaScript Driver and get a Neo4j database instance to connect to.

Install the driver

Use npm to install the Neo4j JavaScript Driver (requires npm and any LTS version of node.js):

npm i neo4j-driver

Always use the latest version of the driver, as it will always work both with the previous Neo4j LTS release and with the current and next major releases. The latest 5.x driver supports connection to any Neo4j 5 and 4.4 instance, and will also be compatible with Neo4j 6. For a detailed list of changes across versions, see the driver’s changelog.

There is also a lite version of the Neo4j JavaScript Driver, which includes the same features as the regular driver but without support for the Reactive API. You can install it with npm i neo4j-driver-lite.

Include the driver

Unless you are going to use the driver within a web browser, you use the JavaScript driver in a Node.js or TypeScript application. To include the driver in your application, use require:

const neo4j = require('neo4j-driver')

Get a Neo4j instance

You need a running Neo4j database in order to use the driver with it. The easiest way to spin up a local instance is through a Docker container (requires docker.io). The command below runs the latest Neo4j version in Docker, setting the admin username to neo4j and password to secretgraph:

docker run \
   -p7474:7474 \                       # forward port 7474 (HTTP)
   -p7687:7687 \                       # forward port 7687 (Bolt)
   -d \                                # run in background
   -e NEO4J_AUTH=neo4j/secretgraph \   # set login credentials
   neo4j:latest

Alternatively, you can obtain a free cloud instance through Aura. Take a note of the connection URI and of the login credentials.

You can also install Neo4j on your system, or use Neo4j Desktop to create a local development environment (not for production).

Glossary

LTS

A Long Term Support release is one guaranteed to be supported for a number of years. Neo4j 4.4 is LTS, and Neo4j 5 will also have an LTS version.

Aura

Aura is Neo4j’s fully managed cloud service. It comes with both free and paid plans.

Cypher

Cypher is Neo4j’s graph query language that lets you retrieve data from the database. It is like SQL, but for graphs.

APOC

Awesome Procedures On Cypher (APOC) is a library of (many) functions that can not be easily expressed in Cypher itself.

Bolt

Bolt is the protocol used for interaction between Neo4j instances and drivers. It listens on port 7687 by default.

ACID

Atomicity, Consistency, Isolation, Durability (ACID) are properties guaranteeing that database transactions are processed reliably. An ACID-compliant DBMS ensures that the data in the database remains accurate and consistent despite failures.

eventual consistency

A database is eventually consistent if it provides the guarantee that all cluster members will, at some point in time, store the latest version of the data.

causal consistency

A database is causally consistent if read and write queries are seen by every member of the cluster in the same order. This is stronger than eventual consistency.

NULL

The null marker is not a type but a placeholder for absence of value. For more information, see Cypher Manual — Working with null.

transaction

A transaction is a unit of work that is either committed in its entirety or rolled back on failure. An example is a bank transfer: it involves multiple steps, but they must all succeed or be reverted, to avoid money being subtracted from one account but not added to the other.

backpressure

Backpressure is a force opposing the flow of data. It ensures that the client is not being overwhelmed by data faster than it can handle.