Create alert using Web API in ASP.Net MVC

How to check that my web api is working or not?

How to create an alert in web api?

below is my code for crud operation.

        public HttpResponseMessage PostCategories(Categories cat)
        {
            cat = repository.Insert(cat);
            var response = Request.CreateResponse<Categories>(HttpStatusCode.Created, cat);

            string uri = Url.Link("DefaultApi", new { categoryID = cat.CategoryID });
            response.Headers.Location = new Uri(uri);
            return response;
        }

        public HttpResponseMessage PutCategories(int CategoryID, Categories cat)
        {
            cat.CategoryID = CategoryID;
            if (!repository.Update(cat))
            {
                return Request.CreateErrorResponse(HttpStatusCode.NotFound, " CategoryID :" + CategoryID);
            }
            else
            {
                return Request.CreateResponse(HttpStatusCode.OK);
            }
        }