diff --git a/src/Sentry.Examples.Console/Sentry.Examples.Console.csproj b/src/Sentry.Examples.Console/Sentry.Examples.Console.csproj
index 11f471e..65f467c 100644
--- a/src/Sentry.Examples.Console/Sentry.Examples.Console.csproj
+++ b/src/Sentry.Examples.Console/Sentry.Examples.Console.csproj
@@ -52,6 +52,7 @@
     <Reference Include="System" />
     <Reference Include="System.Configuration" />
     <Reference Include="System.Core" />
+    <Reference Include="System.Net.Http.Formatting, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL" />
     <Reference Include="System.Xml.Linq" />
     <Reference Include="System.Data.DataSetExtensions" />
     <Reference Include="Microsoft.CSharp" />
diff --git a/src/Sentry.Examples.WindowsService/Sentry.Examples.WindowsService.csproj b/src/Sentry.Examples.WindowsService/Sentry.Examples.WindowsService.csproj
index 9d97204..dd22fb6 100644
--- a/src/Sentry.Examples.WindowsService/Sentry.Examples.WindowsService.csproj
+++ b/src/Sentry.Examples.WindowsService/Sentry.Examples.WindowsService.csproj
@@ -52,6 +52,7 @@
     <Reference Include="System" />
     <Reference Include="System.Configuration" />
     <Reference Include="System.Core" />
+    <Reference Include="System.Net.Http.Formatting, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL" />
     <Reference Include="System.Xml.Linq" />
     <Reference Include="System.Data.DataSetExtensions" />
     <Reference Include="Microsoft.CSharp" />
diff --git a/src/Sentry.Watchers.Api/ApiWatcher.cs b/src/Sentry.Watchers.Api/ApiWatcher.cs
index 8a192ee..b45c0fc 100644
--- a/src/Sentry.Watchers.Api/ApiWatcher.cs
+++ b/src/Sentry.Watchers.Api/ApiWatcher.cs
@@ -92,7 +92,7 @@ private void SetRequestHeaders()
         }
 
         private bool HasValidResponse(HttpResponseMessage response)
-            => (_configuration.WhereValidResponseIs?.Invoke(response) ?? true) &&
+            => (_configuration.EnsureThat?.Invoke(response) ?? true) &&
                (response.IsSuccessStatusCode || _configuration.SkipStatusCodeValidation);
 
         public static ApiWatcher Create(string name, string url, HttpRequest request, Action<ApiWatcherConfiguration.Builder> configuration = null)
diff --git a/src/Sentry.Watchers.Api/ApiWatcherConfiguration.cs b/src/Sentry.Watchers.Api/ApiWatcherConfiguration.cs
index 11e17bb..2e6b7e1 100644
--- a/src/Sentry.Watchers.Api/ApiWatcherConfiguration.cs
+++ b/src/Sentry.Watchers.Api/ApiWatcherConfiguration.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Net.Http;
+using System.Threading.Tasks;
 
 namespace Sentry.Watchers.Api
 {
@@ -11,7 +12,8 @@ public class ApiWatcherConfiguration
         public bool SkipStatusCodeValidation { get; protected set; }
         public IDictionary<string, string> Headers { get; protected set; }
         public TimeSpan Timeout { get; protected set; }
-        public Func<HttpResponseMessage, bool> WhereValidResponseIs { get; protected set; }
+        public Func<HttpResponseMessage, bool> EnsureThat { get; protected set; }
+        public Func<HttpResponseMessage, Task<bool>> EnsureThatAsync { get; protected set; }
 
         protected internal ApiWatcherConfiguration(string url, HttpRequest request)
         {
@@ -88,9 +90,22 @@ public Builder SkipStatusCodeValidation()
                 return this;
             }
 
-            public Builder EnsureThat(Func<HttpResponseMessage, bool> predicate)
+            public Builder EnsureThat(Func<HttpResponseMessage, bool> ensureThat)
             {
-                _configuration.WhereValidResponseIs = predicate;
+                if (ensureThat == null)
+                    throw new ArgumentException("Ensure that predicate can not be null.", nameof(ensureThat));
+
+                _configuration.EnsureThat = ensureThat;
+
+                return this;
+            }
+
+            public Builder EnsureThatAsync(Func<HttpResponseMessage, Task<bool>> ensureThat)
+            {
+                if (ensureThat == null)
+                    throw new ArgumentException("Ensure that async predicate can not be null.", nameof(ensureThat));
+
+                _configuration.EnsureThatAsync = ensureThat;
 
                 return this;
             }
diff --git a/src/Sentry.Watchers.Api/HttpRequest.cs b/src/Sentry.Watchers.Api/HttpRequest.cs
index e2e5ecc..d4e1c02 100644
--- a/src/Sentry.Watchers.Api/HttpRequest.cs
+++ b/src/Sentry.Watchers.Api/HttpRequest.cs
@@ -1,6 +1,4 @@
-using System;
-
-namespace Sentry.Watchers.Api
+namespace Sentry.Watchers.Api
 {
     public class HttpRequest
     {
@@ -10,17 +8,19 @@ public class HttpRequest
 
         protected HttpRequest(MethodType type, string endpoint, object data = null)
         {
-            if(string.IsNullOrWhiteSpace(endpoint))
-                throw new ArgumentException("Endpoint can not be empty.", nameof(endpoint));
 
             Type = type;
             Endpoint = endpoint;
             Data = data;
         }
 
+        public static HttpRequest Get() => new HttpRequest(MethodType.Get, string.Empty);
         public static HttpRequest Get(string endpoint) => new HttpRequest(MethodType.Get, endpoint);
+        public static HttpRequest Put(object data) => new HttpRequest(MethodType.Put, string.Empty, data);
         public static HttpRequest Put(string endpoint, object data = null) => new HttpRequest(MethodType.Put, endpoint, data);
+        public static HttpRequest Post(object data) => new HttpRequest(MethodType.Post, string.Empty, data);
         public static HttpRequest Post(string endpoint, object data = null) => new HttpRequest(MethodType.Post, endpoint, data);
+        public static HttpRequest Delete() => new HttpRequest(MethodType.Delete, string.Empty);
         public static HttpRequest Delete(string endpoint) => new HttpRequest(MethodType.Delete, endpoint);
 
         public enum MethodType