Modifying RUM Data and Context

There are various ways you can modify the data collected by RUM, to support your needs for:

Protecting sensitive data like personally identifiable information.
Connecting a user session with your internal identification of that user, to help with support.
Reducing how much RUM data you’re collecting, through sampling the data.
Providing more context than what the default attributes provide about where the data is coming from.

Enrich and control RUM data

The RUM SDK captures RUM events and populates their main attributes. The beforeSend callback function gives you access to every event collected by the RUM SDK before they are sent to Datadog. Intercepting the RUM events allows you to:

Enrich your RUM events with additional context attributes
Modify your RUM events to alter their content or redact sensitive sequences (see list of editable properties)
Discard selected RUM events

Starting with version 2.13.0, beforeSend takes two arguments: the event generated by the RUM SDK, and the context that triggered the creation of the RUM event.

function beforeSend(event, context)

The potential context values are:

RUM event type	Context
View	Location
Action	Event
Resource (XHR)	XMLHttpRequest and PerformanceResourceTiming
Resource (Fetch)	Request, Response, and PerformanceResourceTiming
Resource (Other)	PerformanceResourceTiming
Error	Error
Long Task	PerformanceLongTaskTiming

Learn more in the Enrich and control RUM data guide.

Enrich RUM events

Along with attributes added with the global context API, you can add more context attributes to the event. For example, tag your RUM resource events with data extracted from a fetch response object:

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import { datadogRum } from '@datadog/browser-rum';

datadogRum.init({
    ...,
    beforeSend: (event, context) => {
        // collect a RUM resource's response headers
        if (event.type === 'resource' && event.resource.type === 'fetch') {
            event.context = {...event.context, responseHeaders: context.response.headers}
        }
    },
    ...
});

DD_RUM.onReady(function() {
    DD_RUM.init({
        ...,
        beforeSend: (event, context) => {
            // collect a RUM resource's response headers
            if (event.type === 'resource' && event.resource.type === 'fetch') {
                event.context = {...event.context, responseHeaders: context.response.headers}
            }
        },
        ...
    })
})

window.DD_RUM &&
    window.DD_RUM.init({
        ...,
        beforeSend: (event, context) => {
            // collect a RUM resource's response headers
            if (event.type === 'resource' && event.resource.type === 'fetch') {
                event.context = {...event.context, responseHeaders: context.response.headers}
            }
        },
        ...
    });

Note: The RUM SDK ignores:

Attributes added outside of event.context.
Modifications made to a RUM view event context.

Modify the content of a RUM event

For example, redact email addresses from your web application URLs:

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import { datadogRum } from '@datadog/browser-rum';

datadogRum.init({
    ...,
    beforeSend: (event) => {
        // remove email from view url
        event.view.url = event.view.url.replace(/email=[^&]*/, "email=REDACTED")
    },
    ...
});

DD_RUM.onReady(function() {
    DD_RUM.init({
        ...,
        beforeSend: (event) => {
            // remove email from view url
            event.view.url = event.view.url.replace(/email=[^&]*/, "email=REDACTED")
        },
        ...
    })
})

window.DD_RUM &&
    window.DD_RUM.init({
        ...,
        beforeSend: (event) => {
            // remove email from view url
            event.view.url = event.view.url.replace(/email=[^&]*/, "email=REDACTED")
        },
        ...
    });

You can update the following event properties:

Attribute	Type	Description
`view.url`	String	The URL of the active web page.
`view.referrer`	String	The URL of the previous web page from which a link to the currently requested page was followed.
`action.target.name`	String	The element that the user interacted with. Only for automatically collected actions.
`error.message`	String	A concise, human-readable, one-line message explaining the error.
`error.stack`	String	The stack trace or complementary information about the error.
`error.resource.url`	String	The resource URL that triggered the error.
`resource.url`	String	The resource URL.
`context`	Object	Attributes added via the global context API or when generating events manually (for example, `addError` and `addAction`). RUM view events `context` is read-only.

Note: The RUM SDK ignores modifications made to event properties not listed above. Find out about all event properties on the Browser SDK repository.

Discard a RUM event

With the beforeSend API, discard a RUM event by returning false:

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import { datadogRum } from '@datadog/browser-rum';

datadogRum.init({
    ...,
    beforeSend: (event) => {
        if (shouldDiscard(event)) {
            return false
        }
        ...
    },
    ...
});

DD_RUM.onReady(function() {
    DD_RUM.init({
        ...,
        beforeSend: (event) => {
            if (shouldDiscard(event)) {
                return false
            },
            ...
        },
        ...
    })
})

window.DD_RUM &&
    window.DD_RUM.init({
        ...,
        beforeSend: (event) => {
            if (shouldDiscard(event)) {
                return false
            }
            ...
        },
        ...
    });

Identify user sessions

Adding user information to your RUM sessions makes it easy to:

Follow the journey of a given user
Know which users are the most impacted by errors
Monitor performance for your most important users

The following attributes are optional but it is recommended to provide at least one of them:

Attribute	Type	Description
`usr.id`	String	Unique user identifier.
`usr.name`	String	User friendly name, displayed by default in the RUM UI.
`usr.email`	String	User email, displayed in the RUM UI if the user name is not present. It is also used to fetch Gravatars.

Note: Increase your filtering capabilities by adding extra attributes on top of the recommended ones. For instance, add information about the user plan, or which user group they belong to.

To identify user sessions, use the setUser API:

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datadogRum.setUser({
    id: '1234',
    name: 'John Doe',
    email: 'john@doe.com',
    plan: 'premium',
    ...
})

DD_RUM.onReady(function() {
    DD_RUM.setUser({
        id: '1234',
        name: 'John Doe',
        email: 'john@doe.com',
        plan: 'premium',
        ...
    })
})

window.DD_RUM && window.DD_RUM.setUser({
    id: '1234',
    name: 'John Doe',
    email: 'john@doe.com',
    plan: 'premium',
    ...
})

Remove the user identification

Clear a previously set user with the removeUser API. All RUM events collected afterwards will not contain user information.

Dropdown

datadogRum.removeUser()

DD_RUM.onReady(function() {
    DD_RUM.removeUser()
})

window.DD_RUM && window.DD_RUM.removeUser()

Sampling

By default, no sampling is applied on the number of collected sessions. To apply a relative sampling (in percent) to the number of sessions collected, use the sampleRate parameter when initializing RUM. The following example collects only 90% of all sessions on a given RUM application:

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import { datadogRum } from '@datadog/browser-rum';

datadogRum.init({
    applicationId: '<DATADOG_APPLICATION_ID>',
    clientToken: '<DATADOG_CLIENT_TOKEN>',
    site: '<DATADOG_SITE>',
    sampleRate: 90,
});

<script>
 (function(h,o,u,n,d) {
   h=h[d]=h[d]||{q:[],onReady:function(c){h.q.push(c)}}
   d=o.createElement(u);d.async=1;d.src=n
   n=o.getElementsByTagName(u)[0];n.parentNode.insertBefore(d,n)
})(window,document,'script','https://www.datadoghq-browser-agent.com/datadog-rum.js','DD_RUM')
  DD_RUM.onReady(function() {
    DD_RUM.init({
        clientToken: '<CLIENT_TOKEN>',
        applicationId: '<APPLICATION_ID>',
        site: '<DATADOG_SITE>',
        sampleRate: 90,
    })
  })
</script>

window.DD_RUM &&
    window.DD_RUM.init({
        clientToken: '<CLIENT_TOKEN>',
        applicationId: '<APPLICATION_ID>',
        site: '<DATADOG_SITE>',
        sampleRate: 90,
    });

Note: For a sampled out session, all page views and associated telemetry for that session are not collected.

Global context

Add global context

Once RUM is initialized, add extra context to all RUM events collected from your application with the addRumGlobalContext(key: string, value: any) API:

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import { datadogRum } from '@datadog/browser-rum';

datadogRum.addRumGlobalContext('<CONTEXT_KEY>', <CONTEXT_VALUE>);

// Code example
datadogRum.addRumGlobalContext('activity', {
    hasPaid: true,
    amount: 23.42
});

DD_RUM.onReady(function() {
    DD_RUM.addRumGlobalContext('<CONTEXT_KEY>', '<CONTEXT_VALUE>');
})

// Code example
DD_RUM.onReady(function() {
    DD_RUM.addRumGlobalContext('activity', {
        hasPaid: true,
        amount: 23.42
    });
})

window.DD_RUM && window.DD_RUM.addRumGlobalContext('<CONTEXT_KEY>', '<CONTEXT_VALUE>');

// Code example
window.DD_RUM && window.DD_RUM.addRumGlobalContext('activity', {
    hasPaid: true,
    amount: 23.42
});

Note: Follow the Datadog naming convention for a better correlation of your data across the product.

Replace global context

Once RUM is initialized, replace the default context for all your RUM events with the setRumGlobalContext(context: Context) API:

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import { datadogRum } from '@datadog/browser-rum';

datadogRum.setRumGlobalContext({ '<CONTEXT_KEY>': '<CONTEXT_VALUE>' });

// Code example
datadogRum.setRumGlobalContext({
    codeVersion: 34,
});

DD_RUM.onReady(function() {
    DD_RUM.setRumGlobalContext({ '<CONTEXT_KEY>': '<CONTEXT_VALUE>' });
})

// Code example
DD_RUM.onReady(function() {
    DD_RUM.setRumGlobalContext({
        codeVersion: 34,
    })
})

window.DD_RUM &&
    DD_RUM.setRumGlobalContext({ '<CONTEXT_KEY>': '<CONTEXT_VALUE>' });

// Code example
window.DD_RUM &&
    DD_RUM.setRumGlobalContext({
        codeVersion: 34,
    });