This feature is the same as https://github.com/projectxyzio/web2driver#direct-connect-urls and https://www.rubydoc.info/github/appium/ruby_lib_core/Appium/Core/Driver#direct_connect-instance_method

Use case:

• If a user has a proxy server such as SeleniumGrid as below, an Appium client communicate with Appium servers via the proxy every command.

  # via proxy server in session creation
  client <--> proxy server <---> appium server <-> devices
                                               `-> appium server <-> devices
  

  • Then, the communication takes additional seconds between the client and servers. The proxy server is if in the US and the Appium server is in Europ, the time increases more.
  • To reduce the delay, we can distribute the proxy server to each reason, but it increases the complexity of the proxy server management.
• If we can make such communication directly with the client and servers, it can reduce the time easily.

  # communicate directly after the session creation
  client <--------> appium server <-> devices
                     `---> appium server <-> devices
  

  • The first create session command takes the additional time, but the following commands can communicate with servers directly with less communication latency.
    • We can manage a bunch of custom urls in a client side, but it increases management complexity in the client side.

I've added direct_connection flag, and it is false by default, to be able to handle the flag.

Different as SeleniumGrid, mobile apps tie to physical locations. Measuring performance including network latency is necessary to manage devices in various locations, for example. In such case, one proxy server and Appium servers in various locations make easy to manage the complexity. The proxy has device selection logic. The client only sends a session creation command to the proxy, no many URLs.

cc @jlipps