> Markdown version of [Eclipse IDE](https://vaadin.com/docs/v24/getting-started/run/eclipse). Section index: [llms.txt](https://vaadin.com/docs/v24/getting-started/llms.txt)

# Eclipse IDE

You can run and debug your Vaadin application in Eclipse IDE as you would any other Java application. Open the main `Application` class. Then click the **Debug** button in the toolbar indicated by a red circle in this screenshot:

[Image: Eclipse IDE debug menu]

Now click **Debug As** **›** **Java Application**. The application starts up and you can access it at <http://localhost:8080>. Hot deploy of the frontend files is enabled automatically. However, to enable Java hotswap, you have to take some additional actions.

## <a id="enabling-hotswap"></a>Enabling Hotswap

Enabling hotswap manually consists of three steps:

1. Download and install JetBrains Runtime;

2. Download HotswapAgent and install it into JetBrains Runtime; and

3. Create a launch configuration for VS Code that runs the application with JetBrain Runtime and additional JVM parameters.

### <a id="jetbrains-runtime"></a>JetBrains Runtime

You can download the latest version from the [JetBrains GitHub release page](https://github.com/JetBrains/JetBrainsRuntime/releases). Be sure to select the correct architecture. Use JetBrains Runtime to execute your application, not necessarily your IDE.

### <a id="hotswapagent"></a>HotswapAgent

You can download HotswapAgent from the [HotswapAgent GitHub release page](https://github.com/HotswapProjects/HotswapAgent/releases). You’ll need version 1.4.2 or later.

Download the JAR file and place it inside the JetBrains Runtime installation directory as `lib/hotswap/hotswap-agent.jar`. You’ll need to create the `hotswap` folder, and rename the downloaded file to `hotswap-agent.jar`.

If you want to know more about the features of HotswapAgent, the documentation in the [HotswapAgent webpage](https://hotswapagent.org/) is a good resource.

## <a id="debug-configuration"></a>Debug Configuration

Select **Debug** **›** **Debug Configurations**, indicated by a red rectangle on this screenshot:

[Image: Eclipse IDE debug menu]

In the **Debug Configurations** window, select the **Application** configuration. Go to the **Arguments** tab. In the **VM arguments** field, copy-paste the following:

```
-XX:+AllowEnhancedClassRedefinition -XX:+ClassUnloading -XX:HotswapAgent=fatjar
```

[Image: Eclipse IDE debug configurations window with the Arguments tab selected]

Next, go to the **JRE** tab. From the **Alternate JRE** select box, select **JetBrains Runtime**. If you can’t find it in the list, click **Installed JREs** and add it manually.

[Image: Eclipse IDE debug configurations window with the JRE tab selected]

Click **Apply**, then start the application by clicking **Debug**. The application starts up.

Open the application in a browser and verify that everything is working through Vaadin Copilot. Move your mouse pointer over the **Copilot** button at the bottom-right corner:

[Image: Vaadin Copilot menu visible in a browser]

> **Important:** The Copilot button is only available when the application is running in development mode. It is not available in [production mode](https://vaadin.com/docs/v24/getting-started/build.md).

Now click **Development workflow**. Your browser should look something like this:

[Image: Vaadin Copilot development workflow dialog]

The first item is orange because Vaadin does not have an official plugin for Eclipse IDE. However, Java hotswap is enabled.