Thanks for responding … I’m using HttpSocket in CakePHP 2.x unfortunately, my bad for not being more clear about my environment.
The problem is when I pass in a data array() to Model::save() is it checked against the model’s schema declaration and if values in your data array are not in the schema, they are stripped from the request.
I have found that I can then intercept the data array and re-inject my extra data before calling $this->_request('POST', $url, json_encode($data)), but this feels a bit hacky and wondered how I could get CakePHP’s models setup to accept my original data array.