---
title: Websockets
description: "--- ## How to build Websocket APIs in Elements Elements 3.0 offers [Standards Compliant Websockets](https://datatracker.ietf.org/doc/html/rfc6455) built in using the [Jakarta Websocket API 2.1](https://jakarta.ee/specifications/websocket/2.1/). [Websockets](https://namazustudios.com/glossary/websockets/) are useful in creating high performance bi-directional communication between client and server code. Generally speaking, [Websockets](https://namazustudios.com/glossary/websockets/)…"
url: "https://namazustudios.com/docs/custom-code/websockets/"
updated: "2026-08-13"
category: "Your Game Code - Adding Custom Elements"
---

# Websockets

---

## How to build Websocket APIs in Elements

Elements 3.0 offers [Standards Compliant Websockets](https://datatracker.ietf.org/doc/html/rfc6455) built in using the [Jakarta Websocket API 2.1](https://jakarta.ee/specifications/websocket/2.1/). [Websockets](https://namazustudios.com/glossary/websockets/) are useful in creating high performance bi-directional communication between client and server code. Generally speaking, [Websockets](https://namazustudios.com/glossary/websockets/) are considerably faster than HTTP requests for [authoritative](https://namazustudios.com/glossary/authoritative/) code and work well with practically all clients including Web, Unity3d, Unreal, .NET and many other connected services.

## Steps to Defining a Websocket [Element](https://namazustudios.com/glossary/element/)

To use the [Jakarta](https://namazustudios.com/glossary/jakarta/) RS in your own [Element](https://namazustudios.com/glossary/element/), you must perform the following steps:

- [Define the Element](../element-structure#defining-an-element) by annotating the `package-info` type in your code.
- Add all compiled classes and jars into the [Element package structure](../element-structure#packaging-an-element).
- Annotate each Websocket endpoint with the [`ServerEndpoint`](https://jakarta.ee/specifications/websocket/2.1/apidocs/server/jakarta/websocket/server/serverendpoint) annotation.

### Complete Example

The following example walks through the necessary files to define a simple Websocket echo server.

#### Step1: Define the [Element](https://namazustudios.com/glossary/element/)

{% code title="package-info.java" %}

```
@ElementDefinition
package dev.getelements.elements.sdk.test.element.ws;

import dev.getelements.elements.sdk.annotation.ElementDefinition;
```

{% endcode %}

#### Step 2: Define the [Element](https://namazustudios.com/glossary/element/)

{% code title="EchoEndpoint.java" %}

```
package dev.getelements.elements.sdk.test.element.ws;

import jakarta.websocket.*;
import jakarta.websocket.server.ServerEndpoint;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@ServerEndpoint("/echo")
public class EchoEndpoint {

    private static final Logger logger = LoggerFactory.getLogger(EchoEndpoint.class);

    @OnOpen
    public void onOpen(final Session session) {
        logger.info("Opened {}", session.getId());
    }

    @OnMessage
    public String onMessage(final Session session, final String message) {
        logger.info("Received {}. Echoing.", message);
        return message;
    }

    @OnClose
    public void onClose(final Session session, final CloseReason closeReason) {
        logger.info("Closed {} - {}", session.getId(), closeReason);
    }

}
```

{% endcode %}

#### Step 3: Ensure All Dependencies are Included

{% code title="pom.xml" %}

```
<?xml version="1.0"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>dev.getelements.elements</groupId>
        <artifactId>eci-elements</artifactId>
        <version>2.2.0-SNAPSHOT</version>
    </parent>

    <artifactId>sdk-test-element-ws</artifactId>
    <version>2.2.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>dev.getelements.elements</groupId>
            <artifactId>sdk</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>jakarta.websocket</groupId>
            <artifactId>jakarta.websocket-api</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>jakarta.websocket</groupId>
            <artifactId>jakarta.websocket-client-api</artifactId>
            <scope>provided</scope>
        </dependency>
    </dependencies>

</project>
```

{% endcode %}