Appium.WebDriver - JSON protocol API response messages formats

Hello,

Could anyone navigate me to place in appium sources, where I could find the description of api responses to keep my custom product backward compatible with appium ? I mean response models for building jsons returning from remote driver to client. Example for FindElement the response can be:

{“sessionId”:“123”, “value”:“456” }

Thank you.

https://w3c.github.io/webdriver/#