| sdkFeatureSlug required | string  Example:  sdkFeatureSlug=featureX | 
| session required | string Zephr Session ID, required for trials. Example:  session=xxx-xxx-xxx | 
| foreign_id.xxx required | string Foreign ID used to identify the user. The foreign system is parsed as the remainder of the parameter key name following 'foreign_id.' Example:  foreign_id.xxx=xxx-xxx-xxx | 
| ip required | string Client IP address, defaults to request IP. Example:  ip=x.x.x.x | 
| userAgent required | string  Example:  userAgent=Mozilla/5.0 (Macintosh; Intel Mac OS X 11)... | 
| path required | string Request path, required for trials. Example:  path=/x.html | 
| content_id required | string Content ID, used to perform requests to a 3rd party API for additional content information used in making a decision. Example:  content_id=xxx-xxx-xxx | 
| jwt required | string A Json web token, may include identity or product holding claims. Example:  jwt=xxx-xxx-xxx | 
| raw required |  |