Usage within a browser (WebSockets)

There is a special browser version of the driver, which supports connecting to Neo4j over WebSockets. You can include it in an HTML page using one of the following tags:

<!-- Direct reference -->
<script src="lib/browser/neo4j-web.min.js"></script>

<!-- unpkg CDN non-minified -->
<script src="https://unpkg.com/neo4j-driver"></script>
<!-- unpkg CDN minified for production use, version X.Y.Z -->
<script src="https://unpkg.com/neo4j-driver@X.Y.Z/lib/browser/neo4j-web.min.js"></script>

<!-- jsDelivr CDN non-minified -->
<script src="https://cdn.jsdelivr.net/npm/neo4j-driver"></script>
<!-- jsDelivr CDN minified for production use, version X.Y.Z -->
<script src="https://cdn.jsdelivr.net/npm/neo4j-driver@X.Y.Z/lib/browser/neo4j-web.min.js"></script>

Including the driver in the page makes a global neo4j object available, through which you may then connect and query a Neo4j database, in the same way as you would do for a local application.

Driver usage example

const URI = '<URI for Neo4j database>'
const USER = '<Username>'
const PASSWORD = '<Password>'
const driver = neo4j.driver(URI, neo4j.auth.basic(USER, PASSWORD))
const serverInfo = await driver.getServerInfo()

// use driver to run queries

await driver.close()

Code running in a browser is visible to the client, including your database credentials. You have to take extra steps to ensure that no unauthorized access is allowed.

Starting from version 5.4, the browser version is also exported as an ECMA Script Module. You can import it using one of the following statements:

// Direct reference
import neo4j from 'lib/browser/neo4j-web.esm.min.js'

// unpkg CDN non-minified , version X.Y.Z where X.Y.Z >= 5.4.0
import neo4j from 'https://unpkg.com/neo4j-driver@X.Y.Z/lib/browser/neo4j-web.esm.js'

// unpkg CDN minified for production use, version X.Y.Z where X.Y.Z >= 5.4.0
import neo4j from 'https://unpkg.com/neo4j-driver@X.Y.Z/lib/browser/neo4j-web.esm.min.js'

// jsDelivr CDN non-minified, version X.Y.Z where X.Y.Z >= 5.4.0
import neo4j from 'https://cdn.jsdelivr.net/npm/neo4j-driver@X.Y.Z/lib/browser/neo4j-web.esm.js'

// jsDelivr CDN minified for production use, version X.Y.Z where X.Y.Z >= 5.4.0
import neo4j from 'https://cdn.jsdelivr.net/npm/neo4j-driver@X.Y.Z/lib/browser/neo4j-web.esm.min.js'

It is not required to explicitly close the driver on a web page, unless its lifetime does not correspond to the lifetime of the page. The reason for this is that web browsers are supposed to gracefully terminate all open WebSockets when a page is closed.

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 → 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.
transaction function: A transaction function is a callback executed by an executeRead or executeWrite call. The driver automatically re-executes the callback in case of server failure.
Driver: A Driver object holds the details required to establish connections with a Neo4j database.