Can Selenium interact with an existing browser session?

This is a duplicate answer **Reconnect to a driver in python selenium ** This is applicable on all drivers and for java api.

1. open a driver

driver = webdriver.Firefox()  #python

2. extract to session_id and _url from driver object.

url = driver.command_executor._url       #"http://127.0.0.1:60622/hub"
session_id = driver.session_id            #'4e167f26-dc1d-4f51-a207-f761eaf73c31'

3. Use these two parameter to connect to your driver.

driver = webdriver.Remote(command_executor=url,desired_capabilities={})
driver.close()   # this prevents the dummy browser
driver.session_id = session_id

And you are connected to your driver again.

driver.get("http://www.mrsmart.in")

This is a pretty old feature request: Allow webdriver to attach to a running browser . So it's officially not supported.

However, there is some working code which claims to support this: https://web.archive.org/web/20171214043703/http://tarunlalwani.com/post/reusing-existing-browser-session-selenium-java/.

This snippet successfully allows to reuse existing browser instance yet avoiding raising the duplicate browser. Found at Tarun Lalwani's blog.

from selenium import webdriver
from selenium.webdriver.remote.webdriver import WebDriver

# executor_url = driver.command_executor._url
# session_id = driver.session_id

def attach_to_session(executor_url, session_id):
    original_execute = WebDriver.execute
    def new_command_execute(self, command, params=None):
        if command == "newSession":
            # Mock the response
            return {'success': 0, 'value': None, 'sessionId': session_id}
        else:
            return original_execute(self, command, params)
    # Patch the function before creating the driver object
    WebDriver.execute = new_command_execute
    driver = webdriver.Remote(command_executor=executor_url, desired_capabilities={})
    driver.session_id = session_id
    # Replace the patched function with original function
    WebDriver.execute = original_execute
    return driver

bro = attach_to_session('http://127.0.0.1:64092', '8de24f3bfbec01ba0d82a7946df1d1c3')
bro.get('http://ya.ru/')

It is possible. But you have to hack it a little, there is a code What you have to do is to run stand alone server and "patch" RemoteWebDriver

public class CustomRemoteWebDriver : RemoteWebDriver
{
    public static bool newSession;
    public static string capPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "TestFiles", "tmp", "sessionCap");
    public static string sessiodIdPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "TestFiles", "tmp", "sessionid");

    public CustomRemoteWebDriver(Uri remoteAddress) 
        : base(remoteAddress, new DesiredCapabilities())
    {
    }

    protected override Response Execute(DriverCommand driverCommandToExecute, Dictionary<string, object> parameters)
    {
        if (driverCommandToExecute == DriverCommand.NewSession)
        {
            if (!newSession)
            {
                var capText = File.ReadAllText(capPath);
                var sidText = File.ReadAllText(sessiodIdPath);

                var cap = JsonConvert.DeserializeObject<Dictionary<string, object>>(capText);
                return new Response
                {
                    SessionId = sidText,
                    Value = cap
                };
            }
            else
            {
                var response = base.Execute(driverCommandToExecute, parameters);
                var dictionary = (Dictionary<string, object>) response.Value;
                File.WriteAllText(capPath, JsonConvert.SerializeObject(dictionary));
                File.WriteAllText(sessiodIdPath, response.SessionId);
                return response;
            }
        }
        else
        {
            var response = base.Execute(driverCommandToExecute, parameters);
            return response;
        }
    }
}