--- title: Browser monitoring and the PHP agent source: https://docs.newrelic.com/docs/apm/agents/php-agent/features/browser-monitoring-php-agent --- By default, the PHP agent automatically adds [browser monitoring](https://docs.newrelic.com/docs/browser/new-relic-browser/getting-started/introduction-new-relic-browser) to your application's web pages. In this automated process, the PHP agent injects the browser agent JavaScript snippet into your webpages. This means you get front-end browser performance monitoring without needing to manually insert the JavaScript snippet into your page's head element. You can enable or disable auto-instrumentation in your PHP agent config file, or you can use the PHP agent API to manually configure browser monitoring. ## Use or disable auto-instrumentation [#auto_instrumentation] By default, the PHP agent automatically injects the browser monitoring's JavaScript snippet into your pages. To change this setting, edit the [`newrelic.browser_monitoring.auto_instrument`](https://docs.newrelic.com/docs/apm/agents/php-agent/configuration/php-agent-configuration/#inivar-autorum) setting in your INI file. ```ini newrelic.browser_monitoring.auto_instrument=1 ``` Auto-instrumentation does not work when the HTTP header field `Content-Length` is set. To use browser monitoring in this situation, disable auto-instrumentation and [manually insert](#manual_instrumentation) the JavaScript header and footer into your templates. ## Manually instrument via agent API [#manual_instrumentation] To manually configure browser monitoring, include the appropriate scripts in your pages. The New Relic PHP agent has an API to automatically generate the required JavaScript header and footer in place. > #### ⚠️ IMPORTANT > > Calls to the PHP agent API are conditional on the `newrelic` extension being loaded so that the PHP agent is running. If the agent is not running, calls to generate the JavaScript header and footer will result in errors, as the functions will not be defined. ### Add custom attributes such as nonce [#nonce-attribute] If your site uses a [Content Security Policy (CSP)](https://developer.mozilla.org/en-US/docs/Web/HTTP/CSP) that requires a `nonce` attribute, you can pass `false` to both API functions so they return the raw JavaScript string without `'; } // Just before the closing tag: if (extension_loaded('newrelic')) { // Ensure PHP agent is available echo "'; } ``` Passing `false` as the argument suppresses the script tags that the functions normally output, so you can wrap the raw JavaScript string with your own `