# Installing as an Embedded Script The CloudWatch RUM web client can be dynamically loaded into the application using a code snippet. The code snippet is a self-executing function created by the CloudWatch RUM console. The snippet (1) asynchronously downloads the web client from a content delivery network (CDN) or the application server and (2) configures the web client for the application it is monitoring. ## Generate a code snippet Use the CloudWatch RUM console to generate a code snippet. See the [CloudWatch RUM documentation ](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch-RUM.html) for instructions on how to create an AppMonitor and generate a code snippet. The snippet will look similar to the following: ```html ``` ## Instrument the application Copy the code snippet into the `` tag of each HTML file in the web application. Modify the arguments to match your AppMonitor. See [Arguments](#arguments) for details. > **:warning: Ad blockers may block the default CDN** > > For convenience, AWS distributes a copy of the CloudWatch RUM web client through a content delivery network (CDN). The generated code snippet uses this CDN by default. However, ad blockers may block this CDN's domain. This disables application monitoring for users with ad blockers. > > To mitigate this we recommend one of the following: > 1. Have the web application host the CloudWatch RUM web client:
> a) Copy [`cwr.js`](https://client.rum.us-east-1.amazonaws.com/1.x/cwr.js) to the assets directory of the web application
> b) Modify the code snippet to use the copy of `cwr.js` from (a). > 2. Install the CloudWatch RUM web client as a [JavaScript module](https://www.npmjs.com/package/aws-rum-web). Modify the `config` object to configure how the web client should behave. At a minimum, configure the following: (1) how the data will be authenticated, and (2) what aspects of the application will be monitored. See [Application-specific Configurations](configuration.md) for details. ## Arguments The code snippet accepts six arguments. The snippet below shows these arguments with the body of the snippet's function omitted for readability: ```html ``` | Position | Argument Name | Type | Description | | --- | --- | --- | --- | | 1 | Namespace | String | The name of the global variable that the application will use to execute commands on the web client. This will typically be `'cwr'`. | | 2 | AppMonitor ID | String | A globally unique identifier for the CloudWatch RUM AppMonitor which monitors your application. | | 3 | Application Version | String | Your application's semantic version. If you do not wish to use this field then add any placeholder, such as `'0.0.0'`. | | 4 | Region | String | The AWS region of the AppMonitor. For example, `'us-east-1'` or '`eu-west-2'`. | | 5 | Web Client URL | String | The URL of the web client bundle. For example, `'https://client.rum.us-east-1.amazonaws.com/1.0.2/cwr.js'`| | 6 | Configuration | [Configuration](configuration.md) | An application-specific configuration for the web client. | ## Configuring the CloudWatch RUM web client The application-specific web client configuration is a JavaScript object whose fields are all optional. While these fields are optional, depending on your application the web client may not function properly if certain fields are omitted. For example, `identityPoolId` and `guestRoleArn` are both required unless your application performs its own AWS authentication and passes the credentials to the web client using the command `cwr('setAwsCredentials', {...});`. The snippet below shows several configuration options with the body of the snippet's function omitted for readability: ```html ``` For a complete list of configuration options, see [Application-specific Configurations](configuration.md).