Swagger Implementation for WCF Rest Services

Question

I am working on WCF Restful service. I need to implement Swagger for our application. But swagger is not supporting WCF Restful services, Any alternates for API documentation similar to Swagger.

Application Type : WCF Rest, No Interface for Data Contracts and No SVC file in WCF Rest.

Sample Code.

    [WebInvoke(UriTemplate = "GetUserDetails", Method = "PUT")]
    [OperationContract]
    public Dictionary<String, int> GetUserDetails(IEnumerable<String> UserId)
    {
        ------- Method Implementation ----------
    }