Overview

The RUM Browser SDK can be configured to send requests through a proxy. When you set the SDK’s proxy initialization parameter to a URL such as https://www.example-proxy.com/any-endpoint, all RUM data is sent to that URL using the POST method. The RUM data still needs to be forwarded to Datadog from the proxy.

Prerequisite proxy setup

To successfully forward a request to Datadog, your proxy must

  1. Build the Datadog intake URL.
  2. Add an X-Forwarded-For header containing the request client IP address for accurate geoIP.
  3. Forward the request to the Datadog intake URL using the POST method.
  4. Leave the request body unchanged.
  • For security reasons, remove any HTTP headers that potentially contain sensitive information, such as the cookie header.
  • The request body can contain binary data and should not be converted to a string. Make sure your proxy implementation forwards the raw body without conversion.
  • Make sure your proxy implementation does not allow a malicious actor to send requests to a different server (ex: https://browser-intake-datadoghq.com.malicious.com).

Build the Datadog intake URL

A Datadog intake URL (example: https://browser-intake-datadoghq.eu/api/v2/rum?ddsource=browser&...) has three parts:

  • the Datadog intake origin corresponding to your site initialization parameter (example: https://browser-intake-datadoghq.eu)
  • the path containing the API version and the product (example: /api/v2/rum for RUM data or /api/v2/replay for Session Replay data)
  • the parameters (example: ddsource=browser&...)

The Datadog intake origin corresponding to your site parameter should be defined in your proxy implementation. The path and parameters for each request sent to the proxy can be accessed in the request’s ddforward parameter (for example, https://www.example-proxy.com/any-endpoint?ddforward=%2Fapi%2Fv2%2Frum%3Fddsource%3Dbrowser).

The Datadog intake origins for each site are listed below:

SiteSite ParameterDatadog intake origin
US1datadoghq.com (default)https://browser-intake-datadoghq.com
US3us3.datadoghq.comhttps://browser-intake-us3-datadoghq.com
US5us5.datadoghq.comhttps://browser-intake-us5-datadoghq.com
EU1datadoghq.euhttps://browser-intake-datadoghq.eu
US1-FEDddog-gov.comhttps://browser-intake-ddog-gov.com
AP1ap1.datadoghq.comhttps://browser-intake-ap1-datadoghq.com

Configure the URL of the proxy in the proxy initialization parameter. The RUM Browser SDK adds a ddforward query parameter to all requests to your proxy. This query parameter contains the URL path and parameters that all data must be forwarded to.

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

datadogRum.init({
    applicationId: '<DATADOG_APPLICATION_ID>',
    clientToken: '<DATADOG_CLIENT_TOKEN>',
    site: '<DATADOG_SITE>',
    proxy: '<YOUR_PROXY_URL>',
});
window.DD_RUM.onReady(function() {
    window.DD_RUM.init({
        clientToken: '<CLIENT_TOKEN>',
        applicationId: '<APPLICATION_ID>',
        proxy: '<YOUR_PROXY_URL>',
    });
});
window.DD_RUM &&
    window.DD_RUM.init({
        clientToken: '<CLIENT_TOKEN>',
        applicationId: '<APPLICATION_ID>',
        proxy: '<YOUR_PROXY_URL>'
    });

For example, with a site set to datadoghq.eu and a proxy set to https://example.org/datadog-intake-proxy, the RUM Browser SDK sends requests to a URL like this: https://example.org/datadog-intake-proxy?ddforward=%2Fapi%2Fv2%2Frum%3Fddsource%3Dbrowser. The proxy forwards the request to https://browser-intake-datadoghq.eu/api/v2/rum?ddsource=browser.

Alternate SDK setup

From Browser SDK v5.4.0, the proxy initialization parameter supports a function input. This function allows you to have more control on how the path and parameters are added to the proxy URL.

This function receives an object with the following properties:

  • path: the path for the Datadog requests (example: /api/v2/rum)
  • parameters: the parameters of the Datadog requests (example: ddsource=browser&...)
import { Datacenter, datadogRum } from '@datadog/browser-rum';

datadogRum.init({
    applicationId: '<DATADOG_APPLICATION_ID>',
    clientToken: '<DATADOG_CLIENT_TOKEN>',
    site: '<DATADOG_SITE>',
    proxy: (options) => `https://www.proxy.com/foo${options.path}/bar?${options.parameters}`,
});
window.DD_RUM.onReady(function() {
    window.DD_RUM.init({
        clientToken: '<CLIENT_TOKEN>',
        applicationId: '<APPLICATION_ID>',
        proxy: (options) => `https://www.proxy.com/foo${options.path}/bar?${options.parameters}`,
    })
})
window.DD_RUM &&
    window.DD_RUM.init({
        clientToken: '<CLIENT_TOKEN>',
        applicationId: '<APPLICATION_ID>',
        proxy: (options) => `https://www.proxy.com/foo${options.path}/bar?${options.parameters}`
    });

For example, with a site set to datadoghq.eu and the proxy configuration from the example, the RUM Browser SDK sends requests to an URL that looks this: https://www.proxy.com/foo/api/v2/rum/bar?ddsource=browser. The proxy will need to forward the request to the URL https://browser-intake-datadoghq.eu/api/v2/rum?ddsource=browser.

Note:

  • Some privacy blockers already target the intake URL patterns, so you may want to take that into account when building your proxy URL.
  • The proxy function is called for each request, so it should avoid any heavy computation.

Legacy SDK setup (<4.34.0)

Before Browser SDK v4.34.0, the proxyUrl initialization parameter was used, and the Datadog intake origin was included in the ddforward attribute. The proxy implementation was in charge of validating this host, and failure to do so resulted in various vulnerabilities.

The Datadog intake origin needs to be defined in your proxy implementation to ensure security. If you are still using a proxy with an older version of the Browser SDK, upgrade to a newer version of the Browser SDK to avoid vulnerabilities.

Further Reading

Additional helpful documentation, links, and articles: