I am using RestSharp to access a RubyOnRails API. As you might know, RoR likes when the parameters names are in the form model_name[property]. RestSharp, on the
model_name[property]
Since RestSharp version 106.4.0 you can just use ParameterType.QueryStringWithoutEncode in request.AddParameter() function:
ParameterType.QueryStringWithoutEncode
request.AddParameter()
request.AddParameter("user_id", @"45454545%6565%65", ParameterType.QueryStringWithoutEncode);