如何确保Rails控制器处理作为JSON发布的数据？

I am setting up a url to receive webhooks from a third party API, but I am struggling with verifying my URL as required by the API. The API will post JSON data with a verification token to my url, but when I see the POST come in, Rails says that the controller is processing it as TEXT instead of JSON and it appears rails tries to convert the JSON to a hash before my controller has a chance to interact with it. I am setting up a url to receive webhooks from