It is fairly easy to get started using the tool. You would first instantiate the proxy service in your WebDriver driver class code, pass that proxy capability to your driver, and turn the capture mode on to retrieve the HTTP responses and requests being sent back and forth during the test as you drive the browser.

The following code sample to integrate with Selenium WebDriver is from the Neustar GitHub site:

// start the proxy
BrowserMobProxy proxy = new BrowserMobProxyServer();
proxy.start(0);

// get the Selenium proxy object
Proxy seleniumProxy = ClientUtil.createSeleniumProxy(proxy);

// configure it as a desired capability
DesiredCapabilities capabilities = new DesiredCapabilities();
capabilities.setCapability(CapabilityType.PROXY, seleniumProxy);

// start the browser up
WebDriver driver = new FirefoxDriver(capabilities);

// enable more detailed HAR capture
proxy.enableHarCaptureTypes(CaptureType.REQUEST_CONTENT, CaptureType.RESPONSE_CONTENT);

// create a new HAR with the label "yahoo.com"
proxy.newHar("yahoo.com");

// open yahoo.com
driver.get("http://yahoo.com");

// get the HAR data
Har har = proxy.getHar();

BrowserMob Proxy also has the ability to test REST API requests and responses, allowing users to capture HTTP data without using the WebDriver. It has full SSL support via the man-in-the-middle (MITM) proxy using a secure certificate, Node.js bindings, logging, native, and custom DNS resolution.