diff --git a/SlackNet.AspNetCore/AspNetCoreExtensions.cs b/SlackNet.AspNetCore/AspNetCoreExtensions.cs
index cb6c5c8..34df98d 100644
--- a/SlackNet.AspNetCore/AspNetCoreExtensions.cs
+++ b/SlackNet.AspNetCore/AspNetCoreExtensions.cs
@@ -1,6 +1,8 @@
 using System;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using SlackNet.Interaction;
 
 namespace SlackNet.AspNetCore
 {
@@ -14,6 +16,7 @@ public static IServiceCollection AddSlackNet(this IServiceCollection serviceColl
             serviceCollection.AddSingleton<ISlackEvents, SlackEventsService>();
             serviceCollection.AddSingleton<ISlackActions, SlackActionsService>();
             serviceCollection.AddSingleton<ISlackOptions, SlackOptionsService>();
+            serviceCollection.TryAddSingleton<IDialogSubmissionHandler, NullDialogSubmissionHandler>();
             serviceCollection.AddTransient<ISlackApiClient>(c => new SlackApiClient(c.GetService<IHttp>(), c.GetService<ISlackUrlBuilder>(), c.GetService<SlackJsonSettings>(), configuration.ApiToken));
             
             return serviceCollection;
diff --git a/SlackNet.AspNetCore/NullDialogSubmissionHandler.cs b/SlackNet.AspNetCore/NullDialogSubmissionHandler.cs
new file mode 100644
index 0000000..655b8f4
--- /dev/null
+++ b/SlackNet.AspNetCore/NullDialogSubmissionHandler.cs
@@ -0,0 +1,12 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using SlackNet.Interaction;
+
+namespace SlackNet.AspNetCore
+{
+    public class NullDialogSubmissionHandler : IDialogSubmissionHandler
+    {
+        public Task<IEnumerable<DialogError>> Handle(DialogSubmission dialog) => Task.FromResult(Enumerable.Empty<DialogError>());
+    }
+}
\ No newline at end of file
diff --git a/SlackNet.AspNetCore/ResolvedActionHandler.cs b/SlackNet.AspNetCore/ResolvedActionHandler.cs
index d5f9fe8..926ad76 100644
--- a/SlackNet.AspNetCore/ResolvedActionHandler.cs
+++ b/SlackNet.AspNetCore/ResolvedActionHandler.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Threading.Tasks;
 using Microsoft.Extensions.DependencyInjection;
+using SlackNet.Interaction;
 
 namespace SlackNet.AspNetCore
 {
@@ -24,10 +25,13 @@ public ResolvedActionHandler(IServiceProvider serviceProvider, string actionName
             _serviceProvider = serviceProvider;
         }
 
-        public override Task<MessageResponse> Handle(InteractiveMessage message)
+        public override async Task<MessageResponse> Handle(InteractiveMessage message)
         {
-            var handler = _serviceProvider.GetRequiredService<T>();
-            return handler.Handle(message);
+            using (var scope = _serviceProvider.CreateScope())
+            {
+                var handler = scope.ServiceProvider.GetRequiredService<T>();
+                return await handler.Handle(message).ConfigureAwait(false);
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/SlackNet.AspNetCore/ResolvedDialogSubmissionHandler.cs b/SlackNet.AspNetCore/ResolvedDialogSubmissionHandler.cs
new file mode 100644
index 0000000..cf6443e
--- /dev/null
+++ b/SlackNet.AspNetCore/ResolvedDialogSubmissionHandler.cs
@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Microsoft.Extensions.DependencyInjection;
+using SlackNet.Interaction;
+
+namespace SlackNet.AspNetCore
+{
+    public class ResolvedDialogSubmissionHandler<T> : IDialogSubmissionHandler
+        where T : IDialogSubmissionHandler
+    {
+        private readonly IServiceProvider _serviceProvider;
+        public ResolvedDialogSubmissionHandler(IServiceProvider serviceProvider) => _serviceProvider = serviceProvider;
+
+        public async Task<IEnumerable<DialogError>> Handle(DialogSubmission dialog)
+        {
+            using (var scope = _serviceProvider.CreateScope())
+            {
+                var handler = scope.ServiceProvider.GetRequiredService<T>();
+                return await handler.Handle(dialog).ConfigureAwait(false);
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet.AspNetCore/ResolvedOptionProvider.cs b/SlackNet.AspNetCore/ResolvedOptionProvider.cs
index 59558af..5c91d52 100644
--- a/SlackNet.AspNetCore/ResolvedOptionProvider.cs
+++ b/SlackNet.AspNetCore/ResolvedOptionProvider.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Threading.Tasks;
 using Microsoft.Extensions.DependencyInjection;
+using SlackNet.Interaction;
 
 namespace SlackNet.AspNetCore
 {
diff --git a/SlackNet.AspNetCore/SlackActionsService.cs b/SlackNet.AspNetCore/SlackActionsService.cs
index b79535d..1a509c7 100644
--- a/SlackNet.AspNetCore/SlackActionsService.cs
+++ b/SlackNet.AspNetCore/SlackActionsService.cs
@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
+using SlackNet.Interaction;
 
 namespace SlackNet.AspNetCore
 {
diff --git a/SlackNet.AspNetCore/SlackEventsMiddleware.cs b/SlackNet.AspNetCore/SlackEventsMiddleware.cs
index 247770b..22ddbd6 100644
--- a/SlackNet.AspNetCore/SlackEventsMiddleware.cs
+++ b/SlackNet.AspNetCore/SlackEventsMiddleware.cs
@@ -1,3 +1,4 @@
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Net;
@@ -5,6 +6,7 @@
 using Microsoft.AspNetCore.Http;
 using Newtonsoft.Json;
 using SlackNet.Events;
+using SlackNet.Interaction;
 
 namespace SlackNet.AspNetCore
 {
@@ -15,14 +17,16 @@ class SlackEventsMiddleware
         private readonly ISlackEvents _slackEvents;
         private readonly ISlackActions _slackActions;
         private readonly ISlackOptions _slackOptions;
+        private readonly IDialogSubmissionHandler _dialogSubmissionHandler;
         private readonly SlackJsonSettings _jsonSettings;
 
         public SlackEventsMiddleware(
-            RequestDelegate next, 
-            SlackEndpointConfiguration configuration, 
-            ISlackEvents slackEvents, 
-            ISlackActions slackActions, 
+            RequestDelegate next,
+            SlackEndpointConfiguration configuration,
+            ISlackEvents slackEvents,
+            ISlackActions slackActions,
             ISlackOptions slackOptions,
+            IDialogSubmissionHandler dialogSubmissionHandler,
             SlackJsonSettings jsonSettings)
         {
             _next = next;
@@ -30,6 +34,7 @@ public SlackEventsMiddleware(
             _slackEvents = slackEvents;
             _slackActions = slackActions;
             _slackOptions = slackOptions;
+            _dialogSubmissionHandler = dialogSubmissionHandler;
             _jsonSettings = jsonSettings;
         }
 
@@ -60,8 +65,9 @@ private async Task<HttpResponse> HandleSlackEvent(HttpContext context)
 
             if (body is EventCallback eventCallback && IsValidToken(eventCallback.Token))
             {
+                var response = context.Respond(HttpStatusCode.OK).ConfigureAwait(false);
                 _slackEvents.Handle(eventCallback);
-                return await context.Respond(HttpStatusCode.OK).ConfigureAwait(false);
+                return await response;
             }
 
             return await context.Respond(HttpStatusCode.BadRequest, body: "Invalid token or unrecognized content").ConfigureAwait(false);
@@ -72,22 +78,43 @@ private async Task<HttpResponse> HandleSlackAction(HttpContext context)
             if (context.Request.Method != "POST")
                 return await context.Respond(HttpStatusCode.MethodNotAllowed).ConfigureAwait(false);
 
-            var interactiveMessage = await DeserializePayload<InteractiveMessage>(context).ConfigureAwait(false);
+            var interactionRequest = await DeserializePayload<InteractionRequest>(context).ConfigureAwait(false);
 
-            if (interactiveMessage != null && IsValidToken(interactiveMessage.Token))
+            if (interactionRequest != null && IsValidToken(interactionRequest.Token))
             {
-                var response = await _slackActions.Handle(interactiveMessage).ConfigureAwait(false);
-
-                var responseJson = response == null ? null
-                    : interactiveMessage.IsAppUnfurl ? Serialize(new AttachmentUpdateResponse(response))
-                    : Serialize(new MessageUpdateResponse(response));
-
-                return await context.Respond(HttpStatusCode.OK, "application/json", responseJson).ConfigureAwait(false);
+                switch (interactionRequest)
+                {
+                    case InteractiveMessage interactiveMessage:
+                        return await HandleInteractiveMessage(context, interactiveMessage).ConfigureAwait(false);
+                    case DialogSubmission dialogSubmission:
+                        return await HandleDialogSubmission(context, dialogSubmission).ConfigureAwait(false);
+                }
             }
 
             return await context.Respond(HttpStatusCode.BadRequest, body: "Invalid token or unrecognized content").ConfigureAwait(false);
         }
 
+        private async Task<HttpResponse> HandleInteractiveMessage(HttpContext context, InteractiveMessage interactiveMessage)
+        {
+            var response = await _slackActions.Handle(interactiveMessage).ConfigureAwait(false);
+
+            var responseJson = response == null ? null
+                : interactiveMessage.IsAppUnfurl ? Serialize(new AttachmentUpdateResponse(response))
+                : Serialize(new MessageUpdateResponse(response));
+
+            return await context.Respond(HttpStatusCode.OK, "application/json", responseJson).ConfigureAwait(false);
+        }
+
+        private async Task<HttpResponse> HandleDialogSubmission(HttpContext context, DialogSubmission dialog)
+        {
+            var errors = (await _dialogSubmissionHandler.Handle(dialog).ConfigureAwait(false))?.ToList()
+                ?? new List<DialogError>();
+
+            return errors.Any()
+                ? await context.Respond(HttpStatusCode.OK, "application/json", Serialize(new DialogErrorResponse { Errors = errors })).ConfigureAwait(false)
+                : await context.Respond(HttpStatusCode.OK).ConfigureAwait(false);
+        }
+
         private async Task<HttpResponse> HandleSlackOptions(HttpContext context)
         {
             if (context.Request.Method != "POST")
diff --git a/SlackNet.AspNetCore/SlackOptionsService.cs b/SlackNet.AspNetCore/SlackOptionsService.cs
index 55fa5c9..d44b8b1 100644
--- a/SlackNet.AspNetCore/SlackOptionsService.cs
+++ b/SlackNet.AspNetCore/SlackOptionsService.cs
@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
+using SlackNet.Interaction;
 
 namespace SlackNet.AspNetCore
 {
diff --git a/SlackNet.AspNetCore/SlackServiceConfiguration.cs b/SlackNet.AspNetCore/SlackServiceConfiguration.cs
index 1c52c72..91a5d67 100644
--- a/SlackNet.AspNetCore/SlackServiceConfiguration.cs
+++ b/SlackNet.AspNetCore/SlackServiceConfiguration.cs
@@ -1,5 +1,6 @@
 using Microsoft.Extensions.DependencyInjection;
 using SlackNet.Events;
+using SlackNet.Interaction;
 
 namespace SlackNet.AspNetCore
 {
@@ -43,6 +44,13 @@ public SlackServiceConfiguration RegisterOptionProvider<TProvider>(string action
             return this;
         }
 
+        public SlackServiceConfiguration RegisterDialogSubmissionHandler<THandler>()
+            where THandler : IDialogSubmissionHandler
+        {
+            _serviceCollection.AddSingleton<IDialogSubmissionHandler>(c => new ResolvedDialogSubmissionHandler<THandler>(c));
+            return this;
+        }
+
         public string ApiToken { get; private set; }
     }
 }
\ No newline at end of file
diff --git a/SlackNet.EventsExample/ColorSelector.cs b/SlackNet.EventsExample/ColorSelector.cs
index c00df94..e8e9cee 100644
--- a/SlackNet.EventsExample/ColorSelector.cs
+++ b/SlackNet.EventsExample/ColorSelector.cs
@@ -2,6 +2,7 @@
 using System.Drawing;
 using System.Linq;
 using System.Threading.Tasks;
+using SlackNet.Interaction;
 
 namespace SlackNet.EventsExample
 {
@@ -11,12 +12,13 @@ public class ColorSelector : IActionHandler, IOptionProvider
 
         public async Task<MessageResponse> Handle(InteractiveMessage message)
         {
-            message.OriginalAttachment.Color = message.Action.SelectedValue;
-            message.OriginalAttachment.Actions[0].SelectedOptions = new List<Option>
+            var menu = (Menu)message.Action;
+            message.OriginalAttachment.Color = menu.SelectedValue;
+            ((Menu)message.OriginalAttachment.Actions[0]).SelectedOptions = new List<Option>
                 {
                     GetOptions(string.Empty)
-                        .FirstOrDefault(o => o.Value == message.Action.SelectedValue)
-                    ?? new Option { Text = message.Action.SelectedValue, Value = message.Action.SelectedValue }
+                        .FirstOrDefault(o => o.Value == menu.SelectedValue)
+                    ?? new Option { Text = menu.SelectedValue, Value = menu.SelectedValue }
                 };
 
             return new MessageResponse
@@ -35,11 +37,10 @@ private static List<Option> GetOptions(string search) =>
                 .Select(c => new Option { Text = c.Name, Value = $"#{c.R:X2}{c.G:X2}{c.B:X2}" })
                 .ToList();
 
-        public static IList<Action> Actions => new List<Action>
+        public static IList<ActionElement> Actions => new List<ActionElement>
             {
-                new Action
+                new Menu
                     {
-                        Type = ActionType.Select,
                         Name = ActionName,
                         Text = "Select a color",
                         DataSource = DataSource.External
diff --git a/SlackNet.EventsExample/Counter.cs b/SlackNet.EventsExample/Counter.cs
index 2ac2701..4ec5012 100644
--- a/SlackNet.EventsExample/Counter.cs
+++ b/SlackNet.EventsExample/Counter.cs
@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using System.Text.RegularExpressions;
 using System.Threading.Tasks;
+using SlackNet.Interaction;
 
 namespace SlackNet.EventsExample
 {
@@ -28,21 +29,21 @@ public async Task<MessageResponse> Handle(InteractiveMessage message)
             return null;
         }
 
-        public static IList<Action> Actions => new List<Action>
+        public static IList<ActionElement> Actions => new List<ActionElement>
             {
-                new Action
+                new Button
                     {
                         Name = ActionName,
                         Value = "1",
                         Text = "Add 1"
                     },
-                new Action
+                new Button
                     {
                         Name = ActionName,
                         Value = "5",
                         Text = "Add 5"
                     },
-                new Action
+                new Button
                     {
                         Name = ActionName,
                         Value = "10",
diff --git a/SlackNet.EventsExample/DialogDemo.cs b/SlackNet.EventsExample/DialogDemo.cs
new file mode 100644
index 0000000..89b4210
--- /dev/null
+++ b/SlackNet.EventsExample/DialogDemo.cs
@@ -0,0 +1,115 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using SlackNet.Interaction;
+using SlackNet.WebApi;
+
+namespace SlackNet.EventsExample
+{
+    public class DialogDemo : IDialogSubmissionHandler, IActionHandler
+    {
+        internal const string EchoDialog = "echo-dialog";
+        internal const string ErrorDialog = "error-dialog";
+
+        private readonly ISlackApiClient _slack;
+        public DialogDemo(ISlackApiClient slack) => _slack = slack;
+
+        public async Task<MessageResponse> Handle(InteractiveMessage message)
+        {
+            string title;
+            string submitLabel;
+
+            if (message.Action.Name == EchoDialog)
+            {
+                title = "Echo Dialog";
+                submitLabel = "Echo";
+            }
+            else
+            {
+                title = "Error Dialog";
+                submitLabel = "Fail";
+            }
+
+            await _slack.Dialog.Open(message.TriggerId, new Dialog
+                {
+                    Title = title,
+                    SubmitLabel = submitLabel,
+                    CallbackId = message.Action.Name,
+                    Elements =
+                        {
+                            new TextElement
+                                {
+                                    Name = "text",
+                                    Label = "Text",
+                                    Placeholder = "Enter some text"
+                                },
+                            new TextArea
+                                {
+                                    Name = "textarea",
+                                    Label = "Text Area",
+                                    Placeholder = "Enter some more text"
+                                },
+                            new SelectElement
+                                {
+                                    Name = "select",
+                                    Label = "Select",
+                                    Placeholder = "Select an option",
+                                    Options =
+                                        {
+                                            new SelectOption { Label = "Cats", Value = "felines" },
+                                            new SelectOption { Label = "Dogs", Value = "canines" }
+                                        }
+                                }
+                        }
+
+                }).ConfigureAwait(false);
+
+            return null;
+        }
+
+        public async Task<IEnumerable<DialogError>> Handle(DialogSubmission dialog)
+        {
+            if (dialog.CallbackId == EchoDialog)
+            {
+                await _slack.Chat.PostMessage(new Message
+                    {
+                        Channel = dialog.Channel.Id,
+                        Attachments =
+                            {
+                                new Attachment
+                                    {
+                                        Text = "Dialog fields",
+                                        Fields = dialog.Submission
+                                            .Select(e => new Field
+                                                {
+                                                    Title = e.Key,
+                                                    Value = e.Value
+                                                })
+                                            .ToList()
+                                    }
+                            }
+                    }).ConfigureAwait(false);
+                return null;
+            }
+            else
+            {
+                return dialog.Submission.Keys
+                    .Select(name => new DialogError { Name = name, Error = $"Not {name}-y enough!" });
+            }
+        }
+
+        public static IList<ActionElement> Actions => new List<ActionElement>
+            {
+                new Button
+                    {
+                        Text = "Echo dialog",
+                        Name = EchoDialog
+                    },
+                new Button
+                    {
+                        Text = "Error dialog",
+                        Name = ErrorDialog
+                    }
+            };
+    }
+}
\ No newline at end of file
diff --git a/SlackNet.EventsExample/MessageHandler.cs b/SlackNet.EventsExample/MessageHandler.cs
index 267f1d0..0c28bdb 100644
--- a/SlackNet.EventsExample/MessageHandler.cs
+++ b/SlackNet.EventsExample/MessageHandler.cs
@@ -22,6 +22,7 @@ await _slack.Chat.PostMessage(new Message
                                 new Attachment
                                     {
                                         Text = "Counter: 0",
+                                        Fallback = "No counter for you",
                                         CallbackId = "counter",
                                         Actions = Counter.Actions
                                     },
@@ -31,6 +32,13 @@ await _slack.Chat.PostMessage(new Message
                                         Fallback = "No color for you",
                                         CallbackId = "color",
                                         Actions = ColorSelector.Actions
+                                    },
+                                new Attachment
+                                    {
+                                        Text = "Dialogs",
+                                        Fallback = "No dialogs for you",
+                                        CallbackId = "dialog",
+                                        Actions = DialogDemo.Actions
                                     }
                             }
                     }).ConfigureAwait(false);
diff --git a/SlackNet.EventsExample/Properties/launchSettings.json b/SlackNet.EventsExample/Properties/launchSettings.json
new file mode 100644
index 0000000..b0a1977
--- /dev/null
+++ b/SlackNet.EventsExample/Properties/launchSettings.json
@@ -0,0 +1,25 @@
+{
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:51076/",
+      "sslPort": 0
+    }
+  },
+  "profiles": {
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "SlackNet.EventsExample": {
+      "commandName": "Project",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      },
+      "applicationUrl": "http://localhost:51077/"
+    }
+  }
+}
\ No newline at end of file
diff --git a/SlackNet.EventsExample/Startup.cs b/SlackNet.EventsExample/Startup.cs
index 90925fb..a871fe3 100644
--- a/SlackNet.EventsExample/Startup.cs
+++ b/SlackNet.EventsExample/Startup.cs
@@ -21,7 +21,10 @@ public void ConfigureServices(IServiceCollection services)
                 .RegisterEventHandler<MessageEvent, MessageHandler>()
                 .RegisterActionHandler<Counter>(Counter.ActionName)
                 .RegisterActionHandler<ColorSelector>(ColorSelector.ActionName)
-                .RegisterOptionProvider<ColorSelector>(ColorSelector.ActionName));
+                .RegisterOptionProvider<ColorSelector>(ColorSelector.ActionName)
+                .RegisterActionHandler<DialogDemo>(DialogDemo.EchoDialog)
+                .RegisterActionHandler<DialogDemo>(DialogDemo.ErrorDialog)
+                .RegisterDialogSubmissionHandler<DialogDemo>());
             services.AddMvc();
         }
 
diff --git a/SlackNet.Tests/ApiLintTest.cs b/SlackNet.Tests/ApiLintTest.cs
new file mode 100644
index 0000000..2e881f4
--- /dev/null
+++ b/SlackNet.Tests/ApiLintTest.cs
@@ -0,0 +1,182 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Net.Http;
+using System.Reflection;
+using System.Threading;
+using System.Threading.Tasks;
+using EasyAssertions;
+using NUnit.Framework;
+using SlackNet.Interaction;
+using SlackNet.WebApi;
+using Args = System.Collections.Generic.Dictionary<string, object>;
+
+namespace SlackNet.Tests
+{
+    public class ApiLintTest
+    {
+        [TestCaseSource(nameof(ApiClasses))]
+        public void Lint(Type api)
+        {
+            var client = new FakeClient();
+            var instance = Activator.CreateInstance(api, client);
+
+            ApiClientHasAPropertyForApi(api);
+
+            var apiMethods = api.GetMethods(BindingFlags.Public | BindingFlags.DeclaredOnly | BindingFlags.Instance);
+            apiMethods.ShouldNotBeEmpty();
+
+            string slackMethodGroup = null;
+
+            foreach (var method in apiMethods)
+            {
+                client.Reset();
+                method.Invoke(instance, method.GetParameters().Select(DummyValue).ToArray());
+
+                LastParamShouldBeOptionalCancellationToken(method);
+                AllMethodsShouldUseSameSlackMethodGroup(client, method, ref slackMethodGroup);
+                AllArgsShouldBeSnakeCase(client.Args, method);
+            }
+        }
+
+        private static void ApiClientHasAPropertyForApi(Type api)
+        {
+            api.GetInterfaces().ShouldBeSingular($"{api.Name} doesn't implement an interface");
+            var apiInterface = api.GetInterfaces().Single();
+            typeof(ISlackApiClient).GetProperties()
+                .Any(p => p.PropertyType == apiInterface)
+                .ShouldBe(true, $"{api.Name} doesn't have a property on {nameof(ISlackApiClient)}");
+        }
+
+        private static void LastParamShouldBeOptionalCancellationToken(MethodInfo method)
+        {
+            var lastParam = method.GetParameters().Last();
+            lastParam.ParameterType.ShouldBe(typeof(CancellationToken?), $"{method.DeclaringType.Name}.{method.Name} is missing CancellationToken param");
+            lastParam.DefaultValue.ShouldBeNull($"{method.DeclaringType.Name}.{method.Name} CancellationToken param isn't null by default");
+        }
+
+        private static void AllMethodsShouldUseSameSlackMethodGroup(FakeClient client, MethodInfo method, ref string slackMethodGroup)
+        {
+            var methodGroup = string.Join('.', client.SlackMethod.Split('.').SkipLast(1));
+            if (slackMethodGroup == null)
+                slackMethodGroup = methodGroup;
+            else
+                methodGroup.ShouldBe(slackMethodGroup, $"{method.DeclaringType.Name}.{method.Name} uses a different API method group than other methods");
+        }
+
+        private static void AllArgsShouldBeSnakeCase(Args args, MethodInfo method) =>
+            args.Keys.AllItemsSatisfy(arg => arg.ShouldMatch("[a-z_]", $"{method.DeclaringType.Name}.{method.Name} has incorrect casing for argument {arg}"));
+
+        private static object DummyValue(ParameterInfo param) =>
+              param.ParameterType == typeof(string) && param.Name == "contentType" ? "text/png"
+            : param.ParameterType == typeof(string) ? string.Empty
+            : param.ParameterType == typeof(int) ? 0
+            : param.ParameterType == typeof(int?) ? null
+            : param.ParameterType == typeof(bool) ? false
+            : param.ParameterType == typeof(IEnumerable<string>) ? Enumerable.Empty<string>()
+            : param.ParameterType == typeof(Message) ? new Message()
+            : param.ParameterType == typeof(Dialog) ? new Dialog()
+            : param.ParameterType == typeof(MessageUpdate) ? new MessageUpdate()
+            : param.ParameterType == typeof(DateTime) ? DateTime.Now
+            : param.ParameterType == typeof(TimeSpan) ? TimeSpan.Zero
+            : param.ParameterType == typeof(SortBy) ? SortBy.Score
+            : param.ParameterType == typeof(SortDirection) ? SortDirection.Ascending
+            : param.ParameterType == typeof(ProfileFieldVisibility) ? ProfileFieldVisibility.All
+            : param.ParameterType == typeof(Presence) ? Presence.Active
+            : param.ParameterType == typeof(ChangeType?) ? null
+            : param.ParameterType == typeof(IEnumerable<ConversationType>) ? Enumerable.Empty<ConversationType>()
+            : param.ParameterType == typeof(IEnumerable<FileType>) ? Enumerable.Empty<FileType>()
+            : param.ParameterType == typeof(UserProfile) ? new UserProfile()
+            : param.ParameterType == typeof(byte[]) ? new byte[0]
+            : param.ParameterType == typeof(Stream) ? Stream.Null
+            : param.ParameterType == typeof(Args) ? new Args()
+            : param.ParameterType == typeof(IDictionary<string, Attachment>) ? new Dictionary<string, Attachment>()
+            : param.ParameterType == typeof(CancellationToken?) ? (object)null
+            : throw new AssertionException($"Unexpected param type {param.ParameterType.Name} in {param.Member.DeclaringType.Name}.{param.Member.Name}");
+
+        static IEnumerable<Type> ApiClasses => typeof(ApiApi).Assembly
+            .GetExportedTypes()
+            .Where(t => t.IsClass && t.Name.EndsWith("Api"));
+
+        class FakeClient : ISlackApiClient
+        {
+            public string HttpMethod { get; set; }
+            public string SlackMethod { get; set; }
+            public Args Args { get; set; }
+            public CancellationToken? CancellationToken { get; set; }
+
+            public void Reset()
+            {
+                HttpMethod = null;
+                SlackMethod = null;
+                Args = null;
+            }
+
+            public Task Get(string apiMethod, Args args, CancellationToken? cancellationToken)
+            {
+                HttpMethod = "GET";
+                SlackMethod = apiMethod;
+                Args = args;
+                CancellationToken = cancellationToken;
+                return Task.FromResult(0);
+            }
+
+            public Task<T> Get<T>(string apiMethod, Args args, CancellationToken? cancellationToken) where T : class
+            {
+                HttpMethod = "GET";
+                SlackMethod = apiMethod;
+                Args = args;
+                CancellationToken = cancellationToken;
+                return Task.FromResult(Activator.CreateInstance<T>());
+            }
+
+            public Task Post(string apiMethod, Args args, string bodyName, HttpContent bodyContent, CancellationToken? cancellationToken)
+            {
+                HttpMethod = "POST";
+                SlackMethod = apiMethod;
+                Args = args;
+                CancellationToken = cancellationToken;
+                return Task.FromResult(0);
+            }
+
+            public Task<T> Post<T>(string apiMethod, Args args, string bodyName, HttpContent bodyContent, CancellationToken? cancellationToken) where T : class
+            {
+                HttpMethod = "POST";
+                SlackMethod = apiMethod;
+                Args = args;
+                CancellationToken = cancellationToken;
+                return Task.FromResult(Activator.CreateInstance<T>());
+            }
+
+            public IApiApi Api { get; }
+            public IAuthApi Auth { get; }
+            public IBotsApi Bots { get; }
+            public IChannelsApi Channels { get; }
+            public IChatApi Chat { get; }
+            public IConversationsApi Conversations { get; }
+            public IDialogApi Dialog { get; }
+            public IDndApi Dnd { get; }
+            public IEmojiApi Emoji { get; }
+            public IFileCommentsApi FileComments { get; }
+            public IFilesApi Files { get; }
+            public IGroupsApi Groups { get; }
+            public IImApi Im { get; }
+            public IMigrationApi Migration { get; }
+            public IMpimApi Mpim { get; }
+            public IOAuthApi OAuth { get; }
+            public IPinsApi Pins { get; }
+            public IReactionsApi Reactions { get; }
+            public IRemindersApi Reminders { get; }
+            public IRtmApi Rtm { get; }
+            public ISearchApi Search { get; }
+            public IStarsApi Stars { get; }
+            public ITeamApi Team { get; }
+            public ITeamProfileApi TeamProfile { get; }
+            public IUserGroupsApi UserGroups { get; }
+            public IUserGroupUsersApi UserGroupUsers { get; }
+            public IUsersApi Users { get; }
+            public IUserProfileApi UserProfile { get; }
+        }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet.Tests/SerializationTests.cs b/SlackNet.Tests/SerializationTests.cs
index ac8c3e2..074cc90 100644
--- a/SlackNet.Tests/SerializationTests.cs
+++ b/SlackNet.Tests/SerializationTests.cs
@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Runtime.Serialization;
 using EasyAssertions;
 using Newtonsoft.Json;
 using NUnit.Framework;
@@ -44,6 +45,20 @@ public void EnumValues_SerializedToSnakeCase()
             result.ShouldBe(@"{""property"":""test_value""}");
         }
 
+        [Test]
+        public void EnumValues_WithEnumMemberAttribute_DeserializedFromAttributeValue()
+        {
+            var result = JsonConvert.DeserializeObject<EnumProperty>(@"{ ""property"": ""other_value"" }", _sut);
+            result.Property.ShouldBe(TestEnum.RenamedValue);
+        }
+
+        [Test]
+        public void EnumValues_WithEnumMemberAttribute_SerializedToAttributeValue()
+        {
+            var result = JsonConvert.SerializeObject(new EnumProperty { Property = TestEnum.RenamedValue }, _sut);
+            result.ShouldBe(@"{""property"":""other_value""}");
+        }
+
         [Test]
         public void SlackTypesCanBeDeserialized()
         {
@@ -97,7 +112,9 @@ class EnumProperty
         enum TestEnum
         {
             Default,
-            TestValue
+            TestValue,
+            [EnumMember(Value = "other_value")]
+            RenamedValue
         }
 
         class HasSlackTypeProperty
diff --git a/SlackNet.Tests/SlackBotTests.cs b/SlackNet.Tests/SlackBotTests.cs
index 6e189c7..fe8e41d 100644
--- a/SlackNet.Tests/SlackBotTests.cs
+++ b/SlackNet.Tests/SlackBotTests.cs
@@ -473,8 +473,8 @@ public void GetUsers_ReturnsFullUserList()
             var user1 = new User { Id = "U1" };
             var user2 = new User { Id = "U2" };
             var user3 = new User { Id = "U3" };
-            _api.Users.List().Returns(new UserListResponse { Members = { user1 }, ResponseMetadata = new UserListResponseMetadata { NextCursor = "foo" } });
-            _api.Users.List("foo").Returns(new UserListResponse { Members = { user2 }, ResponseMetadata = new UserListResponseMetadata { NextCursor = "bar" } });
+            _api.Users.List().Returns(new UserListResponse { Members = { user1 }, ResponseMetadata = new ResponseMetadata { NextCursor = "foo" } });
+            _api.Users.List("foo").Returns(new UserListResponse { Members = { user2 }, ResponseMetadata = new ResponseMetadata { NextCursor = "bar" } });
             _api.Users.List("bar").Returns(new UserListResponse { Members = { user3 } });
 
             _sut.GetUsers()
diff --git a/SlackNet/Default.cs b/SlackNet/Default.cs
index c3df4ee..3d1efe5 100644
--- a/SlackNet/Default.cs
+++ b/SlackNet/Default.cs
@@ -3,6 +3,7 @@
 using System.Reflection;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Serialization;
+using SlackNet.Interaction;
 
 namespace SlackNet
 {
diff --git a/SlackNet/EnumNameConverter.cs b/SlackNet/EnumNameConverter.cs
index dc987ce..47b2624 100644
--- a/SlackNet/EnumNameConverter.cs
+++ b/SlackNet/EnumNameConverter.cs
@@ -2,6 +2,7 @@
 using System.Globalization;
 using System.Linq;
 using System.Reflection;
+using System.Runtime.Serialization;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Serialization;
 
@@ -15,18 +16,9 @@ class EnumNameConverter : JsonConverter
         public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
         {
             if (value == null)
-            {
                 writer.WriteNull();
-            }
             else
-            {
-                var enumValue = (Enum)value;
-                var enumText = enumValue.ToString("G");
-                if (char.IsNumber(enumText[0]) || enumText[0] == '-')
-                    throw new JsonSerializationException(string.Format("Integer value {0} is not allowed.", CultureInfo.InvariantCulture, enumText));
-
-                writer.WriteValue(_namingStrategy.GetPropertyName(enumText, false));
-            }
+                writer.WriteValue(SerializedName((Enum)value));
         }
 
         public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
@@ -54,7 +46,22 @@ public override object ReadJson(JsonReader reader, Type objectType, object exist
         private object ParseEnumName(Type type, string name) => 
             Enum.GetValues(type)
                 .Cast<Enum>()
-                .FirstOrDefault(e => _namingStrategy.GetPropertyName(e.ToString("G"), false) == name);
+                .FirstOrDefault(e => SerializedName(e) == name);
+
+        private string SerializedName(Enum enumValue)
+        {
+            var enumText = enumValue.ToString("G");
+
+            if (char.IsNumber(enumText[0]) || enumText[0] == '-')
+                throw new JsonSerializationException(string.Format("Integer value {0} is not allowed.", CultureInfo.InvariantCulture, enumText));
+
+            var explicitName = enumValue.GetType()
+                .GetRuntimeField(enumText)?
+                .GetCustomAttribute<EnumMemberAttribute>()?
+                .Value;
+
+            return _namingStrategy.GetPropertyName(explicitName ?? enumText, explicitName != null);
+        }
 
         public override bool CanConvert(Type objectType) => typeof(Enum).GetTypeInfo().IsAssignableFrom(UnderlyingType(objectType).GetTypeInfo());
 
diff --git a/SlackNet/Interaction/ActionElement.cs b/SlackNet/Interaction/ActionElement.cs
new file mode 100644
index 0000000..4bad2b0
--- /dev/null
+++ b/SlackNet/Interaction/ActionElement.cs
@@ -0,0 +1,13 @@
+namespace SlackNet.Interaction
+{
+    public abstract class ActionElement
+    {
+        protected ActionElement(string type) => Type = type;
+
+        public string Type { get; }
+        public string Name { get; set; }
+        public string Text { get; set; }
+        public string Value { get; set; }
+        public Confirm Confirm { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Actions/AttachmentUpdateResponse.cs b/SlackNet/Interaction/AttachmentUpdateResponse.cs
similarity index 93%
rename from SlackNet/Actions/AttachmentUpdateResponse.cs
rename to SlackNet/Interaction/AttachmentUpdateResponse.cs
index 0810087..0ac98ce 100644
--- a/SlackNet/Actions/AttachmentUpdateResponse.cs
+++ b/SlackNet/Interaction/AttachmentUpdateResponse.cs
@@ -1,9 +1,8 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using SlackNet.WebApi;
 
-namespace SlackNet
+namespace SlackNet.Interaction
 {
     public class AttachmentUpdateResponse: IReadOnlyAttachment
     {
@@ -32,7 +31,7 @@ public class AttachmentUpdateResponse: IReadOnlyAttachment
         public int Ts => Attachment.Ts;
         public DateTime Timestamp => Attachment.Timestamp;
         public string CallbackId => Attachment.CallbackId;
-        public IList<Action> Actions => Attachment.Actions;
+        public IList<ActionElement> Actions => Attachment.Actions;
 
         private Attachment Attachment => _response.Message.Attachments.First();
     }
diff --git a/SlackNet/Interaction/Button.cs b/SlackNet/Interaction/Button.cs
new file mode 100644
index 0000000..05c8f38
--- /dev/null
+++ b/SlackNet/Interaction/Button.cs
@@ -0,0 +1,10 @@
+namespace SlackNet.Interaction
+{
+    public class Button : ActionElement
+    {
+        public Button() : base("button") { }
+
+        public Style Style { get; set; }
+        public string Url { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Interaction/Dialog.cs b/SlackNet/Interaction/Dialog.cs
new file mode 100644
index 0000000..f774225
--- /dev/null
+++ b/SlackNet/Interaction/Dialog.cs
@@ -0,0 +1,12 @@
+using System.Collections.Generic;
+
+namespace SlackNet.Interaction
+{
+    public class Dialog
+    {
+        public string CallbackId { get; set; }
+        public string Title { get; set; }
+        public string SubmitLabel { get; set; }
+        public IList<DialogElement> Elements { get; set; } = new List<DialogElement>();
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Interaction/DialogElement.cs b/SlackNet/Interaction/DialogElement.cs
new file mode 100644
index 0000000..9500049
--- /dev/null
+++ b/SlackNet/Interaction/DialogElement.cs
@@ -0,0 +1,14 @@
+namespace SlackNet.Interaction
+{
+    public abstract class DialogElement
+    {
+        protected DialogElement(DialogElementType type) => Type = type;
+
+        public DialogElementType Type { get; set; }
+        public string Label { get; set; }
+        public string Name { get; set; }
+        public bool Optional { get; set; }
+        public string Value { get; set; }
+        public string Placeholder { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Interaction/DialogElementType.cs b/SlackNet/Interaction/DialogElementType.cs
new file mode 100644
index 0000000..78ed5c0
--- /dev/null
+++ b/SlackNet/Interaction/DialogElementType.cs
@@ -0,0 +1,11 @@
+using System.Runtime.Serialization;
+
+namespace SlackNet.Interaction
+{
+    public enum DialogElementType
+    {
+        Text,
+        [EnumMember(Value = "textarea")] TextArea,
+        Select
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Interaction/DialogError.cs b/SlackNet/Interaction/DialogError.cs
new file mode 100644
index 0000000..b5c53b2
--- /dev/null
+++ b/SlackNet/Interaction/DialogError.cs
@@ -0,0 +1,8 @@
+namespace SlackNet.Interaction
+{
+    public class DialogError
+    {
+        public string Name { get; set; }
+        public string Error { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Interaction/DialogErrorResponse.cs b/SlackNet/Interaction/DialogErrorResponse.cs
new file mode 100644
index 0000000..b62c44f
--- /dev/null
+++ b/SlackNet/Interaction/DialogErrorResponse.cs
@@ -0,0 +1,9 @@
+using System.Collections.Generic;
+
+namespace SlackNet.Interaction
+{
+    public class DialogErrorResponse
+    {
+        public IEnumerable<DialogError> Errors { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Interaction/DialogSubmission.cs b/SlackNet/Interaction/DialogSubmission.cs
new file mode 100644
index 0000000..05254e2
--- /dev/null
+++ b/SlackNet/Interaction/DialogSubmission.cs
@@ -0,0 +1,9 @@
+using System.Collections.Generic;
+
+namespace SlackNet.Interaction
+{
+    public class DialogSubmission : InteractionRequest
+    {
+        public IDictionary<string, string> Submission { get; set; } = new Dictionary<string, string>();
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Actions/IActionHandler.cs b/SlackNet/Interaction/IActionHandler.cs
similarity index 82%
rename from SlackNet/Actions/IActionHandler.cs
rename to SlackNet/Interaction/IActionHandler.cs
index 4826629..59d220d 100644
--- a/SlackNet/Actions/IActionHandler.cs
+++ b/SlackNet/Interaction/IActionHandler.cs
@@ -1,6 +1,6 @@
 using System.Threading.Tasks;
 
-namespace SlackNet
+namespace SlackNet.Interaction
 {
     public interface IActionHandler
     {
diff --git a/SlackNet/Interaction/IDialogSubmissionHandler.cs b/SlackNet/Interaction/IDialogSubmissionHandler.cs
new file mode 100644
index 0000000..ebe6789
--- /dev/null
+++ b/SlackNet/Interaction/IDialogSubmissionHandler.cs
@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace SlackNet.Interaction
+{
+    public interface IDialogSubmissionHandler
+    {
+        Task<IEnumerable<DialogError>> Handle(DialogSubmission dialog);
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Interaction/IOptionProvider.cs b/SlackNet/Interaction/IOptionProvider.cs
new file mode 100644
index 0000000..42393e6
--- /dev/null
+++ b/SlackNet/Interaction/IOptionProvider.cs
@@ -0,0 +1,9 @@
+using System.Threading.Tasks;
+
+namespace SlackNet.Interaction
+{
+    public interface IOptionProvider
+    {
+        Task<OptionsResponse> GetOptions(OptionsRequest request);
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Interaction/InputElementType.cs b/SlackNet/Interaction/InputElementType.cs
new file mode 100644
index 0000000..edaf053
--- /dev/null
+++ b/SlackNet/Interaction/InputElementType.cs
@@ -0,0 +1,10 @@
+namespace SlackNet.Interaction
+{
+    public enum InputElementType
+    {
+        Email,
+        Number,
+        Tel,
+        Url
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Interaction/InteractionRequest.cs b/SlackNet/Interaction/InteractionRequest.cs
new file mode 100644
index 0000000..6f92fc0
--- /dev/null
+++ b/SlackNet/Interaction/InteractionRequest.cs
@@ -0,0 +1,13 @@
+namespace SlackNet.Interaction
+{
+    public abstract class InteractionRequest
+    {
+        public string Type { get; set; }
+        public string Token { get; set; }
+        public string CallbackId { get; set; }
+        public Team Team { get; set; }
+        public Channel Channel { get; set; }
+        public User User { get; set; }
+        public string ActionTs { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Objects/InteractiveMessage.cs b/SlackNet/Interaction/InteractiveMessage.cs
similarity index 54%
rename from SlackNet/Objects/InteractiveMessage.cs
rename to SlackNet/Interaction/InteractiveMessage.cs
index f8ef74c..91287c3 100644
--- a/SlackNet/Objects/InteractiveMessage.cs
+++ b/SlackNet/Interaction/InteractiveMessage.cs
@@ -3,28 +3,21 @@
 using Newtonsoft.Json;
 using SlackNet.WebApi;
 
-namespace SlackNet
+namespace SlackNet.Interaction
 {
-    public class InteractiveMessage
+    public class InteractiveMessage : InteractionRequest
     {
-        public string Type { get; set; }
-        public IList<Action> Actions { get; set; } = new List<Action>();
+        public IList<ActionElement> Actions { get; set; } = new List<ActionElement>();
         [JsonIgnore]
-        public Action Action
+        public ActionElement Action
         {
             get => Actions.First();
-            set => Actions = new List<Action> { value };
+            set => Actions = new List<ActionElement> { value };
         }
-        public string CallbackId { get; set; }
-        public Team Team { get; set; }
-        public Channel Channel { get; set; }
-        public User User { get; set; }
-        public string ActionTs { get; set; }
         public string MessageTs { get; set; }
         public string AttachmentId { get; set; }
         [JsonIgnore]
         public Attachment OriginalAttachment => OriginalMessage.Attachments.FirstOrDefault(a => a.Id == AttachmentId);
-        public string Token { get; set; }
         public bool IsAppUnfurl { get; set; }
         public Message OriginalMessage { get; set; }
         public string ResponseUrl { get; set; }
diff --git a/SlackNet/Objects/Action.cs b/SlackNet/Interaction/Menu.cs
similarity index 66%
rename from SlackNet/Objects/Action.cs
rename to SlackNet/Interaction/Menu.cs
index 0650a83..d879ff2 100644
--- a/SlackNet/Objects/Action.cs
+++ b/SlackNet/Interaction/Menu.cs
@@ -2,20 +2,17 @@
 using System.Linq;
 using Newtonsoft.Json;
 
-namespace SlackNet
+namespace SlackNet.Interaction
 {
-    public class Action
+    [SlackType("select")]
+    public class Menu : ActionElement
     {
-        public string Name { get; set; }
-        public string Text { get; set; }
-        public Style Style { get; set; }
-        public ActionType Type { get; set; }
-        public string Value { get; set; }
-        public string Url { get; set; }
-        public Confirm Confirm { get; set; }
+        public Menu() : base("select") { }
+
         public IList<Option> Options { get; set; }
         public IList<OptionGroup> OptionGroups { get; set; }
         public DataSource DataSource { get; set; }
+        public int MinQueryLength { get; set; } = 1;
         public IList<Option> SelectedOptions { get; set; } = new List<Option>();
 
         [JsonIgnore]
@@ -25,7 +22,5 @@ public string SelectedValue
             set => SelectedOptions = Options?.Where(o => o.Value == value).ToList()
                 ?? new List<Option> { new Option { Value = value } };
         }
-
-        public int MinQueryLength { get; set; } = 1;
     }
 }
\ No newline at end of file
diff --git a/SlackNet/Actions/MessageResponse.cs b/SlackNet/Interaction/MessageResponse.cs
similarity index 89%
rename from SlackNet/Actions/MessageResponse.cs
rename to SlackNet/Interaction/MessageResponse.cs
index eee429f..a84d3eb 100644
--- a/SlackNet/Actions/MessageResponse.cs
+++ b/SlackNet/Interaction/MessageResponse.cs
@@ -1,6 +1,6 @@
 using SlackNet.WebApi;
 
-namespace SlackNet
+namespace SlackNet.Interaction
 {
     public class MessageResponse
     {
diff --git a/SlackNet/Actions/MessageUpdateResponse.cs b/SlackNet/Interaction/MessageUpdateResponse.cs
similarity index 97%
rename from SlackNet/Actions/MessageUpdateResponse.cs
rename to SlackNet/Interaction/MessageUpdateResponse.cs
index 3ead9ea..5d3978c 100644
--- a/SlackNet/Actions/MessageUpdateResponse.cs
+++ b/SlackNet/Interaction/MessageUpdateResponse.cs
@@ -1,12 +1,11 @@
 using System.Collections.Generic;
 using SlackNet.WebApi;
 
-namespace SlackNet
+namespace SlackNet.Interaction
 {
     public class MessageUpdateResponse : IReadOnlyMessage
     {
         private readonly MessageResponse _response;
-
         public MessageUpdateResponse(MessageResponse response) => _response = response;
 
         public ResponseType ResponseType => _response.ResponseType;
diff --git a/SlackNet/Actions/OptionsRequest.cs b/SlackNet/Interaction/OptionsRequest.cs
similarity index 93%
rename from SlackNet/Actions/OptionsRequest.cs
rename to SlackNet/Interaction/OptionsRequest.cs
index 9a3b698..fbf32e5 100644
--- a/SlackNet/Actions/OptionsRequest.cs
+++ b/SlackNet/Interaction/OptionsRequest.cs
@@ -1,4 +1,4 @@
-namespace SlackNet
+namespace SlackNet.Interaction
 {
     public class OptionsRequest
     {
diff --git a/SlackNet/Interaction/OptionsResponse.cs b/SlackNet/Interaction/OptionsResponse.cs
new file mode 100644
index 0000000..1640b4b
--- /dev/null
+++ b/SlackNet/Interaction/OptionsResponse.cs
@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+
+namespace SlackNet.Interaction
+{
+    public class OptionsResponse
+    {
+        public IList<Option> Options { get; set; }
+        public IList<OptionGroup> OptionGroups { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/ResponseType.cs b/SlackNet/Interaction/ResponseType.cs
similarity index 70%
rename from SlackNet/WebApi/ResponseType.cs
rename to SlackNet/Interaction/ResponseType.cs
index d248152..1a19c4f 100644
--- a/SlackNet/WebApi/ResponseType.cs
+++ b/SlackNet/Interaction/ResponseType.cs
@@ -1,4 +1,4 @@
-namespace SlackNet.WebApi
+namespace SlackNet.Interaction
 {
     public enum ResponseType
     {
diff --git a/SlackNet/Interaction/SelectElement.cs b/SlackNet/Interaction/SelectElement.cs
new file mode 100644
index 0000000..4c92faf
--- /dev/null
+++ b/SlackNet/Interaction/SelectElement.cs
@@ -0,0 +1,11 @@
+using System.Collections.Generic;
+
+namespace SlackNet.Interaction
+{
+    public class SelectElement : DialogElement
+    {
+        public SelectElement() : base(DialogElementType.Select) { }
+
+        public IList<SelectOption> Options { get; set; } = new List<SelectOption>();
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Interaction/SelectOption.cs b/SlackNet/Interaction/SelectOption.cs
new file mode 100644
index 0000000..3e1a42c
--- /dev/null
+++ b/SlackNet/Interaction/SelectOption.cs
@@ -0,0 +1,8 @@
+namespace SlackNet.Interaction
+{
+    public class SelectOption
+    {
+        public string Label { get; set; }
+        public string Value { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Actions/SlackActions.cs b/SlackNet/Interaction/SlackActions.cs
similarity index 96%
rename from SlackNet/Actions/SlackActions.cs
rename to SlackNet/Interaction/SlackActions.cs
index 0822062..e49d7f6 100644
--- a/SlackNet/Actions/SlackActions.cs
+++ b/SlackNet/Interaction/SlackActions.cs
@@ -1,7 +1,7 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
 
-namespace SlackNet
+namespace SlackNet.Interaction
 {
     public interface ISlackActions
     {
diff --git a/SlackNet/Actions/SlackOptions.cs b/SlackNet/Interaction/SlackOptions.cs
similarity index 72%
rename from SlackNet/Actions/SlackOptions.cs
rename to SlackNet/Interaction/SlackOptions.cs
index 2dadd45..4b2c38f 100644
--- a/SlackNet/Actions/SlackOptions.cs
+++ b/SlackNet/Interaction/SlackOptions.cs
@@ -1,7 +1,7 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
 
-namespace SlackNet
+namespace SlackNet.Interaction
 {
     public interface ISlackOptions
     {
@@ -20,15 +20,4 @@ public Task<OptionsResponse> Handle(OptionsRequest request) =>
 
         public void SetProvider(string actionName, IOptionProvider provider) => _providers[actionName] = provider;
     }
-
-    public interface IOptionProvider
-    {
-        Task<OptionsResponse> GetOptions(OptionsRequest request);
-    }
-
-    public class OptionsResponse
-    {
-        public IList<Option> Options { get; set; }
-        public IList<OptionGroup> OptionGroups { get; set; }
-    }
 }
\ No newline at end of file
diff --git a/SlackNet/Interaction/TextArea.cs b/SlackNet/Interaction/TextArea.cs
new file mode 100644
index 0000000..094756d
--- /dev/null
+++ b/SlackNet/Interaction/TextArea.cs
@@ -0,0 +1,7 @@
+namespace SlackNet.Interaction
+{
+    public class TextArea : TextElementBase
+    {
+        public TextArea() : base(DialogElementType.TextArea) { }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Interaction/TextElement.cs b/SlackNet/Interaction/TextElement.cs
new file mode 100644
index 0000000..6a16e68
--- /dev/null
+++ b/SlackNet/Interaction/TextElement.cs
@@ -0,0 +1,7 @@
+namespace SlackNet.Interaction
+{
+    public class TextElement : TextElementBase
+    {
+        public TextElement() : base(DialogElementType.Text) { }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Interaction/TextElementBase.cs b/SlackNet/Interaction/TextElementBase.cs
new file mode 100644
index 0000000..d474cb6
--- /dev/null
+++ b/SlackNet/Interaction/TextElementBase.cs
@@ -0,0 +1,11 @@
+namespace SlackNet.Interaction
+{
+    public abstract class TextElementBase : DialogElement
+    {
+        protected TextElementBase(DialogElementType type) : base(type) { }
+        public InputElementType? Subtype { get; set; }
+        public int MaxLength { get; set; } = 150;
+        public int MinLength { get; set; }
+        public string Hint { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Objects/Attachment.cs b/SlackNet/Objects/Attachment.cs
index b6843b6..0237276 100644
--- a/SlackNet/Objects/Attachment.cs
+++ b/SlackNet/Objects/Attachment.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using Newtonsoft.Json;
+using SlackNet.Interaction;
 
 namespace SlackNet
 {
@@ -24,7 +25,7 @@ public interface IReadOnlyAttachment
         int Ts { get; }
         DateTime Timestamp { get; }
         string CallbackId { get; }
-        IList<Action> Actions { get; }
+        IList<ActionElement> Actions { get; }
     }
 
     public class Attachment : IReadOnlyAttachment
@@ -49,6 +50,6 @@ public class Attachment : IReadOnlyAttachment
         [JsonIgnore]
         public DateTime Timestamp => Ts.ToDateTime().GetValueOrDefault();
         public string CallbackId { get; set; }
-        public IList<Action> Actions { get; set; } = new List<Action>();
+        public IList<ActionElement> Actions { get; set; } = new List<ActionElement>();
     }
 }
\ No newline at end of file
diff --git a/SlackNet/Objects/Conversation.cs b/SlackNet/Objects/Conversation.cs
new file mode 100644
index 0000000..14972a2
--- /dev/null
+++ b/SlackNet/Objects/Conversation.cs
@@ -0,0 +1,147 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using Newtonsoft.Json;
+using SlackNet.Events;
+
+namespace SlackNet
+{
+    public class Conversation
+    {
+        public string Id { get; set; }
+
+        /// <summary>
+        /// The name of the channel-like thing, without a leading hash sign. Don't get too attached to that name. It might change.
+        /// Don't bother storing it even. When thinking about channel-like things, think about their IDs and their type and the team/workspace they belong to.
+        /// </summary>
+        public string Name { get; set; }
+
+        /// <summary>
+        /// Indicates whether a conversation is a public channel. Everything said in a public channel can be read by anyone else belonging to a workspace.
+        /// <see cref="IsPrivate"/> will be False. Check both just to be sure, why not?
+        /// </summary>
+        public bool IsChannel { get; set; }
+
+        /// <summary>
+        /// Means the channel is a private channel. <see cref="IsPrivate"/> will also be true. Check yourself before you wreck yourself.
+        /// </summary>
+        public bool IsGroup { get; set; }
+
+        /// <summary>
+        /// Means the conversation is a direct message between two distinguished individuals or a user and a bot. Yes, it's an <see cref="IsPrivate"/> conversation.
+        /// </summary>
+        public bool IsIm { get; set; }
+
+        /// <summary>
+        /// Unix timestamp of when the conversation was created.
+        /// </summary>
+        public int Created { get; set; }
+
+        [JsonIgnore]
+        public DateTime CreatedDate => Created.ToDateTime().GetValueOrDefault();
+
+        /// <summary>
+        /// The user ID of the member that created this channel.
+        /// </summary>
+        public string Creator { get; set; }
+        
+        /// <summary>
+        /// Indicates a conversation is archived. Frozen in time.
+        /// </summary>
+        public bool IsArchived { get; set; }
+
+        /// <summary>
+        /// Means the channel is the workspace's "general" discussion channel (even if it's not named #general but it might be anyway).
+        /// That might be important to your app because almost every user is a member.
+        /// </summary>
+        public bool IsGeneral { get; set; }
+
+        public int Unlinked { get; set; }
+
+        public string NameNormalized { get; set; }
+
+        /// <summary>
+        /// Means the conversation is in some way shared between multiple workspaces. Look for <see cref="IsExtShared"/> and <see cref="IsOrgShared"/>
+        /// to learn which kind it is, and if that matters, act accordingly. Have we mentioned how great <see cref="IsPrivate"/> is yet?
+        /// </summary>
+        public bool IsShared { get; set; }
+
+        /// <summary>
+        /// Represents this conversation as being part of a Shared Channel with a remote organization.
+        /// Your app should make sure the data it shares in such a channel is appropriate for both workspaces.
+        /// <see cref="IsShared"/> will also be True.
+        /// </summary>
+        public bool IsExtShared { get; set; }
+
+        /// <summary>
+        /// Explains whether this shared channel is shared between Enterprise Grid workspaces within the same organization.
+        /// It's a little different from (externally) Shared Channels. Yet, <see cref="IsShared"/> will be True.
+        /// </summary>
+        public bool IsOrgShared { get; set; }
+
+        public object[] PendingShared { get; set; }
+
+        /// <summary>
+        /// Is intriguing. It means the conversation is ready to become an <see cref="IsExtShared"/> channel but isn't quite ready yet
+        /// and needs some kind of approval or sign off. Best to treat it as if it were a shared channel, even if it traverses only one workspace.
+        /// </summary>
+        public bool IsPendingExtShared { get; set; }
+
+        /// <summary>
+        /// Indicates the user or bot user or Slack app associated with the token making the API call is itself a member of the conversation.
+        /// </summary>
+        public bool IsMember { get; set; }
+
+        /// <summary>
+        /// Means the conversation is privileged between two or more members. Meet their privacy expectations.
+        /// </summary>
+        public bool IsPrivate { get; set; }
+
+        /// <summary>
+        /// Represents an unnamed private conversation between multiple users. It's an <see cref="IsPrivate"/> kind of thing.
+        /// </summary>
+        public bool IsMpim { get; set; }
+
+        /// <summary>
+        /// The timestamp for the last message the calling user has read in this channel.
+        /// </summary>
+        public string LastRead { get; set; }
+
+        /// <summary>
+        /// The latest message in the channel.
+        /// </summary>
+        public MessageEvent Latest { get; set; }
+
+        /// <summary>
+        /// Full count of visible messages that the calling user has yet to read.
+        /// </summary>
+        public int UnreadCount { get; set; }
+
+        /// <summary>
+        /// Count of messages that the calling user has yet to read that matter to them (this means it excludes things like join/leave messages).
+        /// </summary>
+        public int UnreadCountDisplay { get; set; }
+
+        public Topic Topic { get; set; }
+
+        public Purpose Purpose { get; set; }
+
+        public string[] PreviousNames { get; set; }
+
+        public int Priority { get; set; }
+
+        /// <summary>
+        /// Means the conversation can't be written to by typical users. Admins may have the ability.
+        /// </summary>
+        public bool IsReadOnly { get; set; }
+
+        public int NumMembers { get; set; }
+
+        public string Locale { get; set; }
+
+        /// <summary>
+        /// A list of user IDs for all users in this channel. This includes any disabled accounts that were in this channel when they were disabled.
+        /// </summary>
+        public IList<string> Members { get; set; } = new List<string>();
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/Objects/Purpose.cs b/SlackNet/Objects/Purpose.cs
new file mode 100644
index 0000000..97286cc
--- /dev/null
+++ b/SlackNet/Objects/Purpose.cs
@@ -0,0 +1,9 @@
+namespace SlackNet
+{
+    public class Purpose
+    {
+        public string Value { get; set; }
+        public string Creator { get; set; }
+        public int LastSet { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/SlackApiClient.cs b/SlackNet/SlackApiClient.cs
index 01bf91a..e84e981 100644
--- a/SlackNet/SlackApiClient.cs
+++ b/SlackNet/SlackApiClient.cs
@@ -14,17 +14,20 @@ public interface ISlackApiClient
         IBotsApi Bots { get; }
         IChannelsApi Channels { get; }
         IChatApi Chat { get; }
+        IConversationsApi Conversations { get; }
+        IDialogApi Dialog { get; }
         IDndApi Dnd { get; }
         IEmojiApi Emoji { get; }
         IFileCommentsApi FileComments { get; }
         IFilesApi Files { get; }
         IGroupsApi Groups { get; }
         IImApi Im { get; }
+        IMigrationApi Migration { get; }
         IMpimApi Mpim { get; }
         IOAuthApi OAuth { get; }
         IPinsApi Pins { get; }
         IReactionsApi Reactions { get; }
-        IRemindersApi Reminder { get; }
+        IRemindersApi Reminders { get; }
         IRtmApi Rtm { get; }
         ISearchApi Search { get; }
         IStarsApi Stars { get; }
@@ -102,17 +105,20 @@ public SlackApiClient(IHttp http, ISlackUrlBuilder urlBuilder, SlackJsonSettings
         public IBotsApi Bots => new BotsApi(this);
         public IChannelsApi Channels => new ChannelsApi(this);
         public IChatApi Chat => new ChatApi(this);
+        public IConversationsApi Conversations => new ConversationsApi(this);
+        public IDialogApi Dialog => new DialogApi(this);
         public IDndApi Dnd => new DndApi(this);
         public IEmojiApi Emoji => new EmojiApi(this);
         public IFileCommentsApi FileComments => new FileCommentsApi(this);
         public IFilesApi Files => new FilesApi(this);
         public IGroupsApi Groups => new GroupsApi(this);
         public IImApi Im => new ImApi(this);
+        public IMigrationApi Migration => new MigrationApi(this);
         public IMpimApi Mpim => new MpimApi(this);
         public IOAuthApi OAuth => new OAuthApi(this);
         public IPinsApi Pins => new PinsApi(this);
         public IReactionsApi Reactions => new ReactionsApi(this);
-        public IRemindersApi Reminder => new RemindersApi(this);
+        public IRemindersApi Reminders => new RemindersApi(this);
         public IRtmApi Rtm => new RtmApi(this);
         public ISearchApi Search => new SearchApi(this);
         public IStarsApi Stars => new StarsApi(this);
@@ -175,6 +181,6 @@ private string Url(string apiMethod, Args args)
         private T Deserialize<T>(WebApiResponse response) where T : class =>
             response.Ok
                 ? response.Data?.ToObject<T>(JsonSerializer.Create(_jsonSettings.SerializerSettings))
-                : throw new SlackException(response.Error);
+                : throw new SlackException(response.Data?.ToObject<ErrorResponse>(JsonSerializer.Create(_jsonSettings.SerializerSettings)));
     }
 }
\ No newline at end of file
diff --git a/SlackNet/SlackException.cs b/SlackNet/SlackException.cs
index 18765ca..382e7fb 100644
--- a/SlackNet/SlackException.cs
+++ b/SlackNet/SlackException.cs
@@ -1,15 +1,20 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
+using SlackNet.WebApi;
 
 namespace SlackNet
 {
     public class SlackException : Exception
     {
-        public string SlackError { get; }
+        public string ErrorCode { get; }
+        public IReadOnlyList<string> ErrorMessages { get; }
 
-        public SlackException(string slackError, string message = null) 
-            : base(message ?? $"Slack returned an error response: {slackError}.")
+        public SlackException(ErrorResponse errorResponse) 
+            : base($"Slack returned an error response: {errorResponse.Error}.")
         {
-            SlackError = slackError;
+            ErrorCode = errorResponse.Error;
+            ErrorMessages = errorResponse.ResponseMetadata.Messages.ToList();
         }
     }
 }
\ No newline at end of file
diff --git a/SlackNet/SlackNet.csproj b/SlackNet/SlackNet.csproj
index 8a009d5..a01f6e5 100644
--- a/SlackNet/SlackNet.csproj
+++ b/SlackNet/SlackNet.csproj
@@ -15,6 +15,10 @@
     <DocumentationFile>bin\Release\netstandard1.4\SlackNet.xml</DocumentationFile>
   </PropertyGroup>
 
+  <ItemGroup>
+    <None Remove="SlackNet.csproj.DotSettings" />
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="Newtonsoft.Json" Version="10.0.3" />
     <PackageReference Include="System.Reactive.Linq" Version="3.1.1" />
diff --git a/SlackNet/SlackNet.csproj.DotSettings b/SlackNet/SlackNet.csproj.DotSettings
index cee4ed9..67a84d9 100644
--- a/SlackNet/SlackNet.csproj.DotSettings
+++ b/SlackNet/SlackNet.csproj.DotSettings
@@ -1,5 +1,4 @@
 <wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
-	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=actions/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=events_005Cmessages/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=objects/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=webapi_005Cresponses/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>
\ No newline at end of file
+	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=webapi_005Cresponses/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>
diff --git a/SlackNet/Utils.cs b/SlackNet/Utils.cs
index a0bf04c..41ad102 100644
--- a/SlackNet/Utils.cs
+++ b/SlackNet/Utils.cs
@@ -66,7 +66,7 @@ public static async Task<T> NullIfNotFound<T>(this Task<T> apiTask) where T : cl
             {
                 return await apiTask.ConfigureAwait(false);
             }
-            catch (SlackException e) when (e.SlackError.EndsWith("_not_found", StringComparison.Ordinal))
+            catch (SlackException e) when (e.ErrorCode.EndsWith("_not_found", StringComparison.Ordinal))
             {
                 return null;
             }
diff --git a/SlackNet/WebApi/AuthApi.cs b/SlackNet/WebApi/AuthApi.cs
index 150869f..d7cdf3f 100644
--- a/SlackNet/WebApi/AuthApi.cs
+++ b/SlackNet/WebApi/AuthApi.cs
@@ -33,7 +33,7 @@ public class AuthApi : IAuthApi
         /// <param name="test">Setting this parameter to True triggers a testing mode where the specified token will not actually be revoked.</param>
         /// <param name="cancellationToken"></param>
         /// <returns>Whether or not the access token was revoked.</returns>
-        public async Task<bool> Revoke(bool test, CancellationToken? cancellationToken) =>
+        public async Task<bool> Revoke(bool test, CancellationToken? cancellationToken = null) =>
             (await _client.Get<RevokeResponse>("auth.revoke", new Args { { "test", test } }, cancellationToken).ConfigureAwait(false)).Revoked;
 
         /// <summary>
diff --git a/SlackNet/WebApi/ChatApi.cs b/SlackNet/WebApi/ChatApi.cs
index 37c3d3a..0d8eaf0 100644
--- a/SlackNet/WebApi/ChatApi.cs
+++ b/SlackNet/WebApi/ChatApi.cs
@@ -72,7 +72,20 @@ public Task<MessageTsResponse> Delete(string ts, string channelId, bool asUser =
                 {
                     { "ts", ts },
                     { "channel", channelId },
-                    { "asUser", asUser }
+                    { "as_user", asUser }
+                }, cancellationToken);
+
+        /// <summary>
+        /// Retrieve a permalink URL for a specific extant message.
+        /// </summary>
+        /// <param name="channelId">The ID of the conversation or channel containing the message.</param>
+        /// <param name="messageTs">A message's timestamp, uniquely identifying it within a channel.</param>
+        /// <param name="cancellationToken"></param>
+        public Task<PermalinkResponse> GetPermalink(string channelId, string messageTs, CancellationToken? cancellationToken = null) =>
+            _client.Get<PermalinkResponse>("chat.getPermalink", new Args
+                {
+                    { "channel", channelId },
+                    { "message_ts", messageTs }
                 }, cancellationToken);
 
         /// <summary>
@@ -91,7 +104,7 @@ public Task<MessageTsResponse> MeMessage(string channel, string text, Cancellati
         /// <summary>
         /// Posts a message to a public channel, private channel, or direct message/IM channel.
         /// </summary>
-        /// <param name="message">The message to post</param>
+        /// <param name="message">The message to post.</param>
         /// <param name="cancellationToken"></param>
         public Task<PostMessageResponse> PostMessage(Message message, CancellationToken? cancellationToken = null) =>
             _client.Get<PostMessageResponse>("chat.postMessage", new Args
@@ -112,6 +125,25 @@ public Task<PostMessageResponse> PostMessage(Message message, CancellationToken?
                     },
                 cancellationToken);
 
+        /// <summary>
+        /// Sends an ephemeral message to a user in a channel.
+        /// </summary>
+        /// <param name="userId">ID of the user who will receive the ephemeral message. The user should be in the channel specified by the channel argument.</param>
+        /// <param name="message">The message to post. Not all message properties are supported by <c>PostEphemeral</c>.</param>
+        /// <param name="cancellationToken"></param>
+        public Task<PostMessageResponse> PostEphemeral(string userId, Message message, CancellationToken? cancellationToken = null) =>
+            _client.Get<PostMessageResponse>("chat.postEphemeral", new Args
+                    {
+                        { "channel", message.Channel },
+                        { "text", message.Text },
+                        { "user", userId },
+                        { "as_user", message.AsUser },
+                        { "attachments", message.Attachments },
+                        { "link_names", message.LinkNames },
+                        { "parse", message.Parse }
+                    },
+                cancellationToken);
+
         /// <summary>
         /// Attaches Slack app unfurl behavior to a specified and relevant message. 
         /// A user token is required as this method does not support bot user tokens.
diff --git a/SlackNet/WebApi/ConversationType.cs b/SlackNet/WebApi/ConversationType.cs
new file mode 100644
index 0000000..4621cdc
--- /dev/null
+++ b/SlackNet/WebApi/ConversationType.cs
@@ -0,0 +1,10 @@
+namespace SlackNet.WebApi
+{
+    public enum ConversationType
+    {
+        PublicChannel,
+        PrivateChannel,
+        Mpim,
+        Im
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/ConversationsApi.cs b/SlackNet/WebApi/ConversationsApi.cs
new file mode 100644
index 0000000..b4c2383
--- /dev/null
+++ b/SlackNet/WebApi/ConversationsApi.cs
@@ -0,0 +1,426 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Args = System.Collections.Generic.Dictionary<string, object>;
+
+namespace SlackNet.WebApi
+{
+    public interface IConversationsApi
+    {
+        /// <summary>
+        /// Archives a conversation. Not all types of conversations can be archived.
+        /// </summary>
+        /// <param name="channelId">ID of conversation to archive.</param>
+        /// <param name="cancellationToken"></param>
+        Task Archive(string channelId, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Closes a direct message or multi-person direct message.
+        /// </summary>
+        /// <param name="channelId">Conversation to close.</param>
+        /// <param name="cancellationToken"></param>
+        /// <returns></returns>
+        Task Close(string channelId, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Initiates a public or private channel-based conversation.
+        /// Use <see cref="ConversationsApi.Open"/> to initiate or resume a direct message or multi-person direct message.
+        /// </summary>
+        /// <param name="name">Name of the public or private channel to create.</param>
+        /// <param name="isPrivate">Create a private channel instead of a public one.</param>
+        /// <param name="cancellationToken"></param>
+        Task<Conversation> Create(string name, bool isPrivate, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Fetches a conversation's history of messages and events.
+        /// </summary>
+        /// <param name="channelId">Conversation ID to fetch history for.</param>
+        /// <param name="latestTs">End of time range of messages to include in results.</param>
+        /// <param name="oldestTs">Start of time range of messages to include in results.</param>
+        /// <param name="inclusive">Include messages with latest or oldest timestamp in results only when either timestamp is specified.</param>
+        /// <param name="limit">The maximum number of items to return. Fewer than the requested number of items may be returned, even if the end of the users list hasn't been reached.</param>
+        /// <param name="cursor">
+        /// Paginate through collections of data by setting the cursor parameter to a <see cref="ResponseMetadata.NextCursor"/> property
+        /// returned by a previous request's <see cref="ConversationHistoryResponse.ResponseMetadata"/>.
+        /// Default value fetches the first "page" of the collection.
+        /// </param>
+        /// <param name="cancellationToken"></param>
+        Task<ConversationHistoryResponse> History(string channelId, string latestTs = null, string oldestTs = null, bool inclusive = false, int limit = 100, string cursor = null, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Retrieve information about a conversation.
+        /// </summary>
+        /// <param name="channelId">Conversation ID to learn more about.</param>
+        /// <param name="includeLocale">Set this to true to receive the locale for this conversation.</param>
+        /// <param name="cancellationToken"></param>
+        Task<Conversation> Info(string channelId, bool includeLocale = false, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Invites users to a channel.
+        /// </summary>
+        /// <param name="channelId">The ID of the public or private channel to invite user(s) to.</param>
+        /// <param name="userIds">A comma separated list of user IDs. Up to 30 users may be listed.</param>
+        /// <param name="cancellationToken"></param>
+        Task<Conversation> Invite(string channelId, IEnumerable<string> userIds, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Joins an existing conversation.
+        /// </summary>
+        /// <param name="channelId">ID of conversation to join.</param>
+        /// <param name="cancellationToken"></param>
+        Task<ConversationJoinResponse> Join(string channelId, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Removes a user from a conversation.
+        /// </summary>
+        /// <param name="channelId">ID of conversation to remove user from.</param>
+        /// <param name="userId">User ID to be removed.</param>
+        /// <param name="cancellationToken"></param>
+        Task Kick(string channelId, string userId, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Leaves a conversation.
+        /// </summary>
+        /// <param name="channelId">Conversation to leave.</param>
+        /// <param name="cancellationToken"></param>
+        Task Leave(string channelId, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Lists all channels in a Slack team.
+        /// </summary>
+        /// <param name="excludeArchived">Set to True to exclude archived channels from the list.</param>
+        /// <param name="limit">The maximum number of items to return. Fewer than the requested number of items may be returned, even if the end of the list hasn't been reached. Must be an integer no larger than 1000.</param>
+        /// <param name="types">Types of conversations to include. Default is <see cref="ConversationType.PublicChannel"/>.</param>
+        /// <param name="cursor">
+        /// Paginate through collections of data by setting the cursor parameter to a <see cref="ResponseMetadata.NextCursor"/> property
+        /// returned by a previous request's <see cref="ConversationListResponse.ResponseMetadata"/>.
+        /// Default value fetches the first "page" of the collection.
+        /// </param>
+        /// <param name="cancellationToken"></param>
+        Task<ConversationListResponse> List(bool excludeArchived = false, int limit = 100, IEnumerable<ConversationType> types = null, string cursor = null, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Retrieve members of a conversation.
+        /// </summary>
+        /// <param name="channelId">ID of the conversation to retrieve members for.</param>
+        /// <param name="limit">The maximum number of items to return. Fewer than the requested number of items may be returned, even if the end of the users list hasn't been reached.</param>
+        /// <param name="cursor">
+        /// Paginate through collections of data by setting the cursor parameter to a <see cref="ResponseMetadata.NextCursor"/> property
+        /// returned by a previous request's <see cref="ConversationMembersResponse.ResponseMetadata"/>.
+        /// Default value fetches the first "page" of the collection.
+        /// </param>
+        /// <param name="cancellationToken"></param>
+        Task<ConversationMembersResponse> Members(string channelId, int limit = 100, string cursor = null, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Opens or resumes a direct message or multi-person direct message.
+        /// Use <see cref="ConversationsApi.Create"/> for public or private channels.
+        /// </summary>
+        /// <param name="channelId">Resume a conversation by supplying an im or mpim's ID. Or provide the <paramref name="userIds"/> argument instead.</param>
+        /// <param name="returnIm">Indicates you want the full IM channel definition in the response.</param>
+        /// <param name="userIds">Lists of users. If only one user is included, this creates a 1:1 DM. The ordering of the users is preserved whenever a multi-person direct message is returned. Supply a <paramref name="channelId"/> when not supplying users.</param>
+        /// <param name="cancellationToken"></param>
+        Task<ConversationOpenResponse> Open(string channelId = null, bool returnIm = false, IEnumerable<string> userIds = null, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Renames a conversation.
+        /// </summary>
+        /// <param name="channelId">ID of conversation to rename.</param>
+        /// <param name="name">New name for conversation.</param>
+        /// <param name="cancellationToken"></param>
+        Task<Conversation> Rename(string channelId, string name, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Retrieve a thread of messages posted to a conversation.
+        /// </summary>
+        /// <param name="channelId">Conversation ID to fetch thread from.</param>
+        /// <param name="threadTs">Unique identifier of a thread's parent message.</param>
+        /// <param name="latestTs">End of time range of messages to include in results.</param>
+        /// <param name="oldestTs">Start of time range of messages to include in results.</param>
+        /// <param name="inclusive">Include messages with latest or oldest timestamp in results only when either timestamp is specified.</param>
+        /// <param name="limit">The maximum number of items to return. Fewer than the requested number of items may be returned, even if the end of the users list hasn't been reached.</param>
+        /// <param name="cursor">
+        /// Paginate through collections of data by setting the cursor parameter to a <see cref="ResponseMetadata.NextCursor"/> property
+        /// returned by a previous request's <see cref="ConversationMessagesResponse.ResponseMetadata"/>.
+        /// Default value fetches the first "page" of the collection.
+        /// </param>
+        /// <param name="cancellationToken"></param>
+        Task<ConversationMessagesResponse> Replies(string channelId, string threadTs, string latestTs = null, string oldestTs = null, bool inclusive = false, int limit = 10, string cursor = null, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Sets the purpose for a conversation.
+        /// </summary>
+        /// <param name="channelId">Conversation to set the purpose of.</param>
+        /// <param name="purpose">A new, specialer purpose.</param>
+        /// <param name="cancellationToken"></param>
+        Task<string> SetPurpose(string channelId, string purpose, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Sets the topic for a conversation.
+        /// </summary>
+        /// <param name="channelId">Conversation to set the topic of.</param>
+        /// <param name="topic">The new topic string. Does not support formatting or linkification.</param>
+        /// <param name="cancellationToken"></param>
+        Task<string> SetTopic(string channelId, string topic, CancellationToken? cancellationToken = null);
+
+        /// <summary>
+        /// Reverses conversation archival.
+        /// </summary>
+        /// <param name="channelId">ID of conversation to unarchive.</param>
+        /// <param name="cancellationToken"></param>
+        Task Unarchive(string channelId, CancellationToken? cancellationToken = null);
+    }
+
+    public class ConversationsApi : IConversationsApi
+    {
+        private readonly ISlackApiClient _client;
+        public ConversationsApi(ISlackApiClient client) => _client = client;
+
+        /// <summary>
+        /// Archives a conversation. Not all types of conversations can be archived.
+        /// </summary>
+        /// <param name="channelId">ID of conversation to archive.</param>
+        /// <param name="cancellationToken"></param>
+        public Task Archive(string channelId, CancellationToken? cancellationToken = null) =>
+            _client.Get("conversations.archive", new Args { { "channel", channelId } }, cancellationToken);
+
+        /// <summary>
+        /// Closes a direct message or multi-person direct message.
+        /// </summary>
+        /// <param name="channelId">Conversation to close.</param>
+        /// <param name="cancellationToken"></param>
+        /// <returns></returns>
+        public Task Close(string channelId, CancellationToken? cancellationToken = null) =>
+            _client.Get("conversations.close", new Args { { "channel", channelId } }, cancellationToken);
+
+        /// <summary>
+        /// Initiates a public or private channel-based conversation.
+        /// Use <see cref="Open"/> to initiate or resume a direct message or multi-person direct message.
+        /// </summary>
+        /// <param name="name">Name of the public or private channel to create.</param>
+        /// <param name="isPrivate">Create a private channel instead of a public one.</param>
+        /// <param name="cancellationToken"></param>
+        public async Task<Conversation> Create(string name, bool isPrivate, CancellationToken? cancellationToken = null) =>
+            (await _client.Get<ConversationResponse>("conversations.create", new Args
+                {
+                    { "name", name },
+                    { "is_private", isPrivate }
+                }, cancellationToken).ConfigureAwait(false))
+            .Channel;
+
+        /// <summary>
+        /// Fetches a conversation's history of messages and events.
+        /// </summary>
+        /// <param name="channelId">Conversation ID to fetch history for.</param>
+        /// <param name="latestTs">End of time range of messages to include in results.</param>
+        /// <param name="oldestTs">Start of time range of messages to include in results.</param>
+        /// <param name="inclusive">Include messages with latest or oldest timestamp in results only when either timestamp is specified.</param>
+        /// <param name="limit">The maximum number of items to return. Fewer than the requested number of items may be returned, even if the end of the users list hasn't been reached.</param>
+        /// <param name="cursor">
+        /// Paginate through collections of data by setting the cursor parameter to a <see cref="ResponseMetadata.NextCursor"/> property
+        /// returned by a previous request's <see cref="ConversationHistoryResponse.ResponseMetadata"/>.
+        /// Default value fetches the first "page" of the collection.
+        /// </param>
+        /// <param name="cancellationToken"></param>
+        public Task<ConversationHistoryResponse> History(string channelId, string latestTs = null, string oldestTs = null, bool inclusive = false, int limit = 100, string cursor = null, CancellationToken? cancellationToken = null) =>
+            _client.Get<ConversationHistoryResponse>("conversations.history", new Args
+                {
+                    { "channel", channelId },
+                    { "cursor", cursor },
+                    { "inclusive", inclusive },
+                    { "latest", latestTs },
+                    { "limit", limit },
+                    { "oldest", oldestTs }
+                }, cancellationToken);
+
+        /// <summary>
+        /// Retrieve information about a conversation.
+        /// </summary>
+        /// <param name="channelId">Conversation ID to learn more about.</param>
+        /// <param name="includeLocale">Set this to true to receive the locale for this conversation.</param>
+        /// <param name="cancellationToken"></param>
+        public async Task<Conversation> Info(string channelId, bool includeLocale = false, CancellationToken? cancellationToken = null) =>
+            (await _client.Get<ConversationResponse>("conversations.info", new Args
+                {
+                    { "channel", channelId },
+                    { "include_locale", includeLocale }
+                }, cancellationToken).ConfigureAwait(false))
+            .Channel;
+
+        /// <summary>
+        /// Invites users to a channel.
+        /// </summary>
+        /// <param name="channelId">The ID of the public or private channel to invite user(s) to.</param>
+        /// <param name="userIds">A comma separated list of user IDs. Up to 30 users may be listed.</param>
+        /// <param name="cancellationToken"></param>
+        public async Task<Conversation> Invite(string channelId, IEnumerable<string> userIds, CancellationToken? cancellationToken = null) =>
+            (await _client.Get<ConversationResponse>("conversations.invite", new Args
+                {
+                    { "channel", channelId },
+                    { "users", userIds }
+                }, cancellationToken).ConfigureAwait(false))
+            .Channel;
+
+        /// <summary>
+        /// Joins an existing conversation.
+        /// </summary>
+        /// <param name="channelId">ID of conversation to join.</param>
+        /// <param name="cancellationToken"></param>
+        public Task<ConversationJoinResponse> Join(string channelId, CancellationToken? cancellationToken = null) =>
+            _client.Get<ConversationJoinResponse>("conversations.join", new Args { { "channel", channelId } }, cancellationToken);
+
+        /// <summary>
+        /// Removes a user from a conversation.
+        /// </summary>
+        /// <param name="channelId">ID of conversation to remove user from.</param>
+        /// <param name="userId">User ID to be removed.</param>
+        /// <param name="cancellationToken"></param>
+        public Task Kick(string channelId, string userId, CancellationToken? cancellationToken = null) =>
+            _client.Get("conversations.kick", new Args
+                {
+                    { "channel", channelId },
+                    { "user", userId }
+                }, cancellationToken);
+
+        /// <summary>
+        /// Leaves a conversation.
+        /// </summary>
+        /// <param name="channelId">Conversation to leave.</param>
+        /// <param name="cancellationToken"></param>
+        public Task Leave(string channelId, CancellationToken? cancellationToken = null) =>
+            _client.Get("conversations.leave", new Args { { "channel", channelId } }, cancellationToken);
+
+        /// <summary>
+        /// Lists all channels in a Slack team.
+        /// </summary>
+        /// <param name="excludeArchived">Set to True to exclude archived channels from the list.</param>
+        /// <param name="limit">The maximum number of items to return. Fewer than the requested number of items may be returned, even if the end of the list hasn't been reached. Must be an integer no larger than 1000.</param>
+        /// <param name="types">Types of conversations to include. Default is <see cref="ConversationType.PublicChannel"/>.</param>
+        /// <param name="cursor">
+        /// Paginate through collections of data by setting the cursor parameter to a <see cref="ResponseMetadata.NextCursor"/> property
+        /// returned by a previous request's <see cref="ConversationListResponse.ResponseMetadata"/>.
+        /// Default value fetches the first "page" of the collection.
+        /// </param>
+        /// <param name="cancellationToken"></param>
+        public Task<ConversationListResponse> List(bool excludeArchived = false, int limit = 100, IEnumerable<ConversationType> types = null, string cursor = null, CancellationToken? cancellationToken = null) =>
+            _client.Get<ConversationListResponse>("conversations.list", new Args
+                {
+                    { "cursor", cursor },
+                    { "exclude_archived", excludeArchived },
+                    { "limit", limit },
+                    { "types", types }
+                }, cancellationToken);
+
+        /// <summary>
+        /// Retrieve members of a conversation.
+        /// </summary>
+        /// <param name="channelId">ID of the conversation to retrieve members for.</param>
+        /// <param name="limit">The maximum number of items to return. Fewer than the requested number of items may be returned, even if the end of the users list hasn't been reached.</param>
+        /// <param name="cursor">
+        /// Paginate through collections of data by setting the cursor parameter to a <see cref="ResponseMetadata.NextCursor"/> property
+        /// returned by a previous request's <see cref="ConversationMembersResponse.ResponseMetadata"/>.
+        /// Default value fetches the first "page" of the collection.
+        /// </param>
+        /// <param name="cancellationToken"></param>
+        public Task<ConversationMembersResponse> Members(string channelId, int limit = 100, string cursor = null, CancellationToken? cancellationToken = null) =>
+            _client.Get<ConversationMembersResponse>("conversations.members", new Args
+                {
+                    { "channel", channelId },
+                    { "cursor", cursor },
+                    { "limit", limit }
+                }, cancellationToken);
+
+        /// <summary>
+        /// Opens or resumes a direct message or multi-person direct message.
+        /// Use <see cref="Create"/> for public or private channels.
+        /// </summary>
+        /// <param name="channelId">Resume a conversation by supplying an im or mpim's ID. Or provide the <paramref name="userIds"/> argument instead.</param>
+        /// <param name="returnIm">Indicates you want the full IM channel definition in the response.</param>
+        /// <param name="userIds">Lists of users. If only one user is included, this creates a 1:1 DM. The ordering of the users is preserved whenever a multi-person direct message is returned. Supply a <paramref name="channelId"/> when not supplying users.</param>
+        /// <param name="cancellationToken"></param>
+        public Task<ConversationOpenResponse> Open(string channelId = null, bool returnIm = false, IEnumerable<string> userIds = null, CancellationToken? cancellationToken = null) =>
+            _client.Get<ConversationOpenResponse>("conversations.open", new Args
+                {
+                    { "channel", channelId },
+                    { "return_im", returnIm },
+                    { "users", userIds }
+                }, cancellationToken);
+
+        /// <summary>
+        /// Renames a conversation.
+        /// </summary>
+        /// <param name="channelId">ID of conversation to rename.</param>
+        /// <param name="name">New name for conversation.</param>
+        /// <param name="cancellationToken"></param>
+        public async Task<Conversation> Rename(string channelId, string name, CancellationToken? cancellationToken = null) =>
+            (await _client.Get<ConversationResponse>("conversations.rename", new Args
+                {
+                    { "channel", channelId },
+                    { "name", name }
+                }, cancellationToken).ConfigureAwait(false))
+            .Channel;
+
+        /// <summary>
+        /// Retrieve a thread of messages posted to a conversation.
+        /// </summary>
+        /// <param name="channelId">Conversation ID to fetch thread from.</param>
+        /// <param name="threadTs">Unique identifier of a thread's parent message.</param>
+        /// <param name="latestTs">End of time range of messages to include in results.</param>
+        /// <param name="oldestTs">Start of time range of messages to include in results.</param>
+        /// <param name="inclusive">Include messages with latest or oldest timestamp in results only when either timestamp is specified.</param>
+        /// <param name="limit">The maximum number of items to return. Fewer than the requested number of items may be returned, even if the end of the users list hasn't been reached.</param>
+        /// <param name="cursor">
+        /// Paginate through collections of data by setting the cursor parameter to a <see cref="ResponseMetadata.NextCursor"/> property
+        /// returned by a previous request's <see cref="ConversationMessagesResponse.ResponseMetadata"/>.
+        /// Default value fetches the first "page" of the collection.
+        /// </param>
+        /// <param name="cancellationToken"></param>
+        public Task<ConversationMessagesResponse> Replies(string channelId, string threadTs, string latestTs = null, string oldestTs = null, bool inclusive = false, int limit = 10, string cursor = null, CancellationToken? cancellationToken = null) =>
+            _client.Get<ConversationMessagesResponse>("conversations.replies", new Args
+                {
+                    { "channel", channelId },
+                    { "ts", threadTs },
+                    { "cursor", cursor },
+                    { "inclusive", inclusive },
+                    { "latest", latestTs },
+                    { "limit", limit },
+                    { "oldest", oldestTs }
+                }, cancellationToken);
+
+        /// <summary>
+        /// Sets the purpose for a conversation.
+        /// </summary>
+        /// <param name="channelId">Conversation to set the purpose of.</param>
+        /// <param name="purpose">A new, specialer purpose.</param>
+        /// <param name="cancellationToken"></param>
+        public async Task<string> SetPurpose(string channelId, string purpose, CancellationToken? cancellationToken = null) =>
+            (await _client.Get<PurposeResponse>("conversations.setPurpose", new Args
+                {
+                    { "channel", channelId },
+                    { "purpose", purpose }
+                }, cancellationToken).ConfigureAwait(false))
+            .Purpose;
+
+        /// <summary>
+        /// Sets the topic for a conversation.
+        /// </summary>
+        /// <param name="channelId">Conversation to set the topic of.</param>
+        /// <param name="topic">The new topic string. Does not support formatting or linkification.</param>
+        /// <param name="cancellationToken"></param>
+        public async Task<string> SetTopic(string channelId, string topic, CancellationToken? cancellationToken = null) =>
+            (await _client.Get<TopicResponse>("conversations.setTopic", new Args
+                {
+                    { "channel", channelId },
+                    { "topic", topic }
+                }, cancellationToken).ConfigureAwait(false))
+            .Topic;
+
+        /// <summary>
+        /// Reverses conversation archival.
+        /// </summary>
+        /// <param name="channelId">ID of conversation to unarchive.</param>
+        /// <param name="cancellationToken"></param>
+        public Task Unarchive(string channelId, CancellationToken? cancellationToken = null) =>
+            _client.Get("conversations.unarchive", new Args { { "channel", channelId } }, cancellationToken);
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/DialogApi.cs b/SlackNet/WebApi/DialogApi.cs
new file mode 100644
index 0000000..c35a548
--- /dev/null
+++ b/SlackNet/WebApi/DialogApi.cs
@@ -0,0 +1,37 @@
+using System.Threading;
+using System.Threading.Tasks;
+using SlackNet.Interaction;
+using Args = System.Collections.Generic.Dictionary<string, object>;
+
+namespace SlackNet.WebApi
+{
+    public interface IDialogApi
+    {
+        /// <summary>
+        /// Open a dialog with a user.
+        /// </summary>
+        /// <param name="triggerId">Exchange a trigger to post to the user.</param>
+        /// <param name="dialog">The dialog definition.</param>
+        /// <param name="cancellationToken"></param>
+        Task Open(string triggerId, Dialog dialog, CancellationToken? cancellationToken = null);
+    }
+
+    public class DialogApi : IDialogApi
+    {
+        private readonly ISlackApiClient _client;
+        public DialogApi(ISlackApiClient client) => _client = client;
+
+        /// <summary>
+        /// Open a dialog with a user.
+        /// </summary>
+        /// <param name="triggerId">Exchange a trigger to post to the user.</param>
+        /// <param name="dialog">The dialog definition.</param>
+        /// <param name="cancellationToken"></param>
+        public Task Open(string triggerId, Dialog dialog, CancellationToken? cancellationToken = null) =>
+            _client.Get("dialog.open", new Args
+                {
+                    { "dialog", dialog },
+                    { "trigger_id", triggerId }
+                }, cancellationToken);
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/DndApi.cs b/SlackNet/WebApi/DndApi.cs
index cff553b..c45207b 100644
--- a/SlackNet/WebApi/DndApi.cs
+++ b/SlackNet/WebApi/DndApi.cs
@@ -89,7 +89,7 @@ public Task<DndResponse> Info(string userId, CancellationToken? cancellationToke
         /// </summary>
         /// <param name="numMinutes">Number of minutes, from now, to snooze until.</param>
         /// <param name="cancellationToken"></param>
-        public Task<SnoozeResponse> SetSnooze(int numMinutes, CancellationToken? cancellationToken) =>
+        public Task<SnoozeResponse> SetSnooze(int numMinutes, CancellationToken? cancellationToken = null) =>
             _client.Get<SnoozeResponse>("dnd.setSnooze", new Args { { "num_minutes", numMinutes } }, cancellationToken);
 
         /// <summary>
diff --git a/SlackNet/WebApi/FileCommentsApi.cs b/SlackNet/WebApi/FileCommentsApi.cs
index 8b32c7b..9466e78 100644
--- a/SlackNet/WebApi/FileCommentsApi.cs
+++ b/SlackNet/WebApi/FileCommentsApi.cs
@@ -47,7 +47,7 @@ public class FileCommentsApi : IFileCommentsApi
         /// <param name="comment">Text of the comment to add.</param>
         /// <param name="cancellationToken"></param>
         public async Task<FileComment> Add(string fileId, string comment, CancellationToken? cancellationToken = null) =>
-            (await _client.Get<FileCommentResponse>("file.comments.add", new Args
+            (await _client.Get<FileCommentResponse>("files.comments.add", new Args
                 {
                     { "file", fileId },
                     { "comment", comment }
@@ -62,7 +62,7 @@ public async Task<FileComment> Add(string fileId, string comment, CancellationTo
         /// <param name="commentId">The comment to delete.</param>
         /// <param name="cancellationToken"></param>
         public Task Delete(string fileId, string commentId, CancellationToken? cancellationToken = null) =>
-            _client.Get("file.comments.delete", new Args
+            _client.Get("files.comments.delete", new Args
                 {
                     { "file", fileId },
                     { "id", commentId }
diff --git a/SlackNet/WebApi/GroupsApi.cs b/SlackNet/WebApi/GroupsApi.cs
index b025b8d..072acb5 100644
--- a/SlackNet/WebApi/GroupsApi.cs
+++ b/SlackNet/WebApi/GroupsApi.cs
@@ -254,7 +254,7 @@ public async Task<Channel> Info(string channelId, CancellationToken? cancellatio
         /// <param name="channelId">Private channel to invite user to.</param>
         /// <param name="userId">User to invite.</param>
         /// <param name="cancellationToken"></param>
-        public async Task<Channel> Invite(string channelId, string userId, CancellationToken? cancellationToken) =>
+        public async Task<Channel> Invite(string channelId, string userId, CancellationToken? cancellationToken = null) =>
             (await _client.Get<GroupResponse>("groups.invite", new Args
                 {
                     { "channel", channelId },
@@ -269,7 +269,7 @@ public async Task<Channel> Invite(string channelId, string userId, CancellationT
         /// <param name="userId">User to remove from private channel.</param>
         /// <param name="cancellationToken"></param>
         /// <returns></returns>
-        public Task Kick(string channelId, string userId, CancellationToken? cancellationToken) =>
+        public Task Kick(string channelId, string userId, CancellationToken? cancellationToken = null) =>
             _client.Get("groups.kick", new Args
                 {
                     { "channel", channelId },
@@ -349,7 +349,7 @@ public async Task<IReadOnlyList<MessageEvent>> Replies(string channelId, string
         /// <param name="cancellationToken"></param>
         /// <returns>The group's new purpose.</returns>
         public async Task<string> SetPurpose(string channelId, string purpose, CancellationToken? cancellationToken = null) =>
-            (await _client.Get<PurposeResponse>("channels.setPurpose", new Args
+            (await _client.Get<PurposeResponse>("groups.setPurpose", new Args
                 {
                     { "channel", channelId },
                     { "purpose", purpose }
@@ -364,7 +364,7 @@ public async Task<string> SetPurpose(string channelId, string purpose, Cancellat
         /// <param name="cancellationToken"></param>
         /// <returns>The private channel's new topic.</returns>
         public async Task<string> SetTopic(string channelId, string topic, CancellationToken? cancellationToken = null) =>
-            (await _client.Get<TopicResponse>("channels.setTopic", new Args
+            (await _client.Get<TopicResponse>("groups.setTopic", new Args
                 {
                     { "channel", channelId },
                     { "topic", topic }
@@ -377,6 +377,6 @@ public async Task<string> SetTopic(string channelId, string topic, CancellationT
         /// <param name="channelId">Private channel to unarchive.</param>
         /// <param name="cancellationToken"></param>
         public Task Unarchive(string channelId, CancellationToken? cancellationToken = null) =>
-            _client.Get("channels.unarchive", new Args { { "channel", channelId } }, cancellationToken);
+            _client.Get("groups.unarchive", new Args { { "channel", channelId } }, cancellationToken);
     }
 }
\ No newline at end of file
diff --git a/SlackNet/WebApi/Message.cs b/SlackNet/WebApi/Message.cs
index 40f0e6d..d90d002 100644
--- a/SlackNet/WebApi/Message.cs
+++ b/SlackNet/WebApi/Message.cs
@@ -95,14 +95,17 @@ public class Message : IReadOnlyMessage
         public IList<Attachment> Attachments { get; set; } = new List<Attachment>();
         /// <summary>
         /// Pass True to enable unfurling of primarily text-based content.
+        /// Not supported when posting an ephemeral message.
         /// </summary>
         public bool UnfurlLinks { get; set; }
         /// <summary>
         /// Pass False to disable unfurling of media content.
+        /// Not supported when posting an ephemeral message.
         /// </summary>
         public bool UnfurlMedia { get; set; } = true;
         /// <summary>
         /// Set your bot's user name. Must be used in conjunction with <see cref="AsUser"/> set to False, otherwise ignored.
+        /// Not supported when posting an ephemeral message.
         /// </summary>
         public string Username { get; set; }
         /// <summary>
@@ -111,18 +114,22 @@ public class Message : IReadOnlyMessage
         public bool AsUser { get; set; }
         /// <summary>
         /// URL to an image to use as the icon for this message. Must be used in conjunction with <see cref="AsUser"/> set to False, otherwise ignored.
+        /// Not supported when posting an ephemeral message.
         /// </summary>
         public string IconUrl { get; set; }
         /// <summary>
         /// Emoji to use as the icon for this message. Overrides <see cref="IconUrl"/>. Must be used in conjunction with <see cref="AsUser"/> set to False, otherwise ignored.
+        /// Not supported when posting an ephemeral message.
         /// </summary>
         public string IconEmoji { get; set; }
         /// <summary>
-        /// Provide another message's <see cref="MessageEvent.Ts"/> value to make this message a reply. Avoid using a reply's ts value; use its parent instead.
+        /// Provide another message's <see cref="MessageEvent.Ts"/> value to make this message a reply. Avoid using a reply's <c>Ts</c> value; use its parent instead.
+        /// Not supported when posting an ephemeral message.
         /// </summary>
         public string ThreadTs { get; set; }
         /// <summary>
         /// Used in conjunction with <see cref="ThreadTs"/> and indicates whether reply should be made visible to everyone in the channel or conversation. 
+        /// Not supported when posting an ephemeral message.
         /// </summary>
         public bool ReplyBroadcast { get; set; }
     }
diff --git a/SlackNet/WebApi/MigrationApi.cs b/SlackNet/WebApi/MigrationApi.cs
new file mode 100644
index 0000000..653c8bf
--- /dev/null
+++ b/SlackNet/WebApi/MigrationApi.cs
@@ -0,0 +1,37 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Args = System.Collections.Generic.Dictionary<string, object>;
+
+namespace SlackNet.WebApi
+{
+    public interface IMigrationApi
+    {
+        /// <summary>
+        /// For Enterprise Grid workspaces, map local user IDs to global user IDs.
+        /// </summary>
+        /// <param name="userIds">List of user ids, up to 400 per request.</param>
+        /// <param name="toOld">Specify true to convert W global user IDs to workspace-specific U IDs. Defaults to False.</param>
+        /// <param name="cancellationToken"></param>
+        Task<MigrationResponse> Exchange(IEnumerable<string> userIds, bool toOld = false, CancellationToken? cancellationToken = null);
+    }
+
+    public class MigrationApi : IMigrationApi
+    {
+        private readonly ISlackApiClient _client;
+        public MigrationApi(ISlackApiClient client) => _client = client;
+
+        /// <summary>
+        /// For Enterprise Grid workspaces, map local user IDs to global user IDs.
+        /// </summary>
+        /// <param name="userIds">List of user ids, up to 400 per request.</param>
+        /// <param name="toOld">Specify true to convert W global user IDs to workspace-specific U IDs. Defaults to False.</param>
+        /// <param name="cancellationToken"></param>
+        public Task<MigrationResponse> Exchange(IEnumerable<string> userIds, bool toOld = false, CancellationToken? cancellationToken = null) =>
+            _client.Get<MigrationResponse>("migration.exchange", new Args
+                {
+                    { "users", userIds },
+                    { "to_old", toOld }
+                }, cancellationToken);
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/RemindersApi.cs b/SlackNet/WebApi/RemindersApi.cs
index 0e35086..b8830f1 100644
--- a/SlackNet/WebApi/RemindersApi.cs
+++ b/SlackNet/WebApi/RemindersApi.cs
@@ -137,7 +137,7 @@ public Task Complete(string reminderId, CancellationToken? cancellationToken = n
         /// </summary>
         /// <param name="reminderId">The ID of the reminder.</param>
         /// <param name="cancellationToken"></param>
-        public Task Delete(string reminderId, CancellationToken? cancellationToken) =>
+        public Task Delete(string reminderId, CancellationToken? cancellationToken = null) =>
             _client.Get("reminders.delete", new Args { { "reminder", reminderId } }, cancellationToken);
 
         /// <summary>
diff --git a/SlackNet/WebApi/Responses/ConversationHistoryResponse.cs b/SlackNet/WebApi/Responses/ConversationHistoryResponse.cs
new file mode 100644
index 0000000..424a05e
--- /dev/null
+++ b/SlackNet/WebApi/Responses/ConversationHistoryResponse.cs
@@ -0,0 +1,8 @@
+namespace SlackNet.WebApi
+{
+    public class ConversationHistoryResponse : ConversationMessagesResponse
+    {
+        public string Latest { get; set; }
+        public int PinCount { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/ConversationJoinResponse.cs b/SlackNet/WebApi/Responses/ConversationJoinResponse.cs
new file mode 100644
index 0000000..ff7b500
--- /dev/null
+++ b/SlackNet/WebApi/Responses/ConversationJoinResponse.cs
@@ -0,0 +1,9 @@
+namespace SlackNet.WebApi
+{
+    public class ConversationJoinResponse
+    {
+        public Conversation Channel { get; set; }
+        public string Warning { get; set; }
+        public ConversationJoinResponseMetadata ResponseMetadata { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/ConversationJoinResponseMetadata.cs b/SlackNet/WebApi/Responses/ConversationJoinResponseMetadata.cs
new file mode 100644
index 0000000..3e29006
--- /dev/null
+++ b/SlackNet/WebApi/Responses/ConversationJoinResponseMetadata.cs
@@ -0,0 +1,9 @@
+using System.Collections.Generic;
+
+namespace SlackNet.WebApi
+{
+    public class ConversationJoinResponseMetadata
+    {
+        public IList<string> Warnings { get; set; } = new List<string>();
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/ConversationListResponse.cs b/SlackNet/WebApi/Responses/ConversationListResponse.cs
new file mode 100644
index 0000000..dc1770c
--- /dev/null
+++ b/SlackNet/WebApi/Responses/ConversationListResponse.cs
@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+
+namespace SlackNet.WebApi
+{
+    public class ConversationListResponse
+    {
+        public IList<Conversation> Channels { get; set; }
+        public ResponseMetadata ResponseMetadata { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/ConversationMembersResponse.cs b/SlackNet/WebApi/Responses/ConversationMembersResponse.cs
new file mode 100644
index 0000000..df8e315
--- /dev/null
+++ b/SlackNet/WebApi/Responses/ConversationMembersResponse.cs
@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+
+namespace SlackNet.WebApi
+{
+    public class ConversationMembersResponse
+    {
+        public IList<string> Members { get; set; } = new List<string>();
+        public ResponseMetadata ResponseMetadata { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/ConversationMessagesResponse.cs b/SlackNet/WebApi/Responses/ConversationMessagesResponse.cs
new file mode 100644
index 0000000..78e466c
--- /dev/null
+++ b/SlackNet/WebApi/Responses/ConversationMessagesResponse.cs
@@ -0,0 +1,12 @@
+using System.Collections.Generic;
+using SlackNet.Events;
+
+namespace SlackNet.WebApi
+{
+    public class ConversationMessagesResponse
+    {
+        public IList<MessageEvent> Messages { get; set; } = new List<MessageEvent>();
+        public bool HasMore { get; set; }
+        public ResponseMetadata ResponseMetadata { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/ConversationOpenResponse.cs b/SlackNet/WebApi/Responses/ConversationOpenResponse.cs
new file mode 100644
index 0000000..ed99a4b
--- /dev/null
+++ b/SlackNet/WebApi/Responses/ConversationOpenResponse.cs
@@ -0,0 +1,9 @@
+namespace SlackNet.WebApi
+{
+    public class ConversationOpenResponse
+    {
+        public bool NoOp { get; set; }
+        public bool AlreadyOpen { get; set; }
+        public Conversation Channel { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/ConversationResponse.cs b/SlackNet/WebApi/Responses/ConversationResponse.cs
new file mode 100644
index 0000000..b830429
--- /dev/null
+++ b/SlackNet/WebApi/Responses/ConversationResponse.cs
@@ -0,0 +1,7 @@
+namespace SlackNet.WebApi
+{
+    class ConversationResponse
+    {
+        public Conversation Channel { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/ErrorResponse.cs b/SlackNet/WebApi/Responses/ErrorResponse.cs
new file mode 100644
index 0000000..1cfe334
--- /dev/null
+++ b/SlackNet/WebApi/Responses/ErrorResponse.cs
@@ -0,0 +1,8 @@
+namespace SlackNet.WebApi
+{
+    public class ErrorResponse
+    {
+        public string Error { get; set; }
+        public ErrorResponseMetadata ResponseMetadata { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/ErrorResponseMetadata.cs b/SlackNet/WebApi/Responses/ErrorResponseMetadata.cs
new file mode 100644
index 0000000..f0858f9
--- /dev/null
+++ b/SlackNet/WebApi/Responses/ErrorResponseMetadata.cs
@@ -0,0 +1,9 @@
+using System.Collections.Generic;
+
+namespace SlackNet.WebApi
+{
+    public class ErrorResponseMetadata
+    {
+        public IList<string> Messages { get; set; } = new List<string>();
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/MigrationResponse.cs b/SlackNet/WebApi/Responses/MigrationResponse.cs
new file mode 100644
index 0000000..5201979
--- /dev/null
+++ b/SlackNet/WebApi/Responses/MigrationResponse.cs
@@ -0,0 +1,12 @@
+using System.Collections.Generic;
+
+namespace SlackNet.WebApi
+{
+    public class MigrationResponse
+    {
+        public string TeamId { get; set; }
+        public string EnterpriseId { get; set; }
+        public IDictionary<string, string> UserIdMap { get; set; } = new Dictionary<string, string>();
+        public string[] InvalidUserIds { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/PermalinkResponse.cs b/SlackNet/WebApi/Responses/PermalinkResponse.cs
new file mode 100644
index 0000000..c5f8e40
--- /dev/null
+++ b/SlackNet/WebApi/Responses/PermalinkResponse.cs
@@ -0,0 +1,8 @@
+namespace SlackNet.WebApi
+{
+    public class PermalinkResponse
+    {
+        public string Channel { get; set; }
+        public string Permalink { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/PostEphemeralResponse.cs b/SlackNet/WebApi/Responses/PostEphemeralResponse.cs
new file mode 100644
index 0000000..36e1b10
--- /dev/null
+++ b/SlackNet/WebApi/Responses/PostEphemeralResponse.cs
@@ -0,0 +1,7 @@
+namespace SlackNet.WebApi
+{
+    public class PostEphemeralResponse
+    {
+        public string MessageTs { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/SlackNet/WebApi/Responses/UserListResponseMetadata.cs b/SlackNet/WebApi/Responses/ResponseMetadata.cs
similarity index 68%
rename from SlackNet/WebApi/Responses/UserListResponseMetadata.cs
rename to SlackNet/WebApi/Responses/ResponseMetadata.cs
index c226a7c..8179d9e 100644
--- a/SlackNet/WebApi/Responses/UserListResponseMetadata.cs
+++ b/SlackNet/WebApi/Responses/ResponseMetadata.cs
@@ -1,6 +1,6 @@
 namespace SlackNet.WebApi
 {
-    public class UserListResponseMetadata
+    public class ResponseMetadata
     {
         public string NextCursor { get; set; }
     }
diff --git a/SlackNet/WebApi/Responses/UserListResponse.cs b/SlackNet/WebApi/Responses/UserListResponse.cs
index 38d6c55..c298566 100644
--- a/SlackNet/WebApi/Responses/UserListResponse.cs
+++ b/SlackNet/WebApi/Responses/UserListResponse.cs
@@ -10,6 +10,6 @@ public class UserListResponse
         public int CacheTs { get; set; }
         [JsonIgnore]
         public DateTime CacheTime => CacheTs.ToDateTime().GetValueOrDefault();
-        public UserListResponseMetadata ResponseMetadata { get; set; }
+        public ResponseMetadata ResponseMetadata { get; set; }
     }
 }
\ No newline at end of file
diff --git a/SlackNet/WebApi/UsersApi.cs b/SlackNet/WebApi/UsersApi.cs
index c439293..a1678f9 100644
--- a/SlackNet/WebApi/UsersApi.cs
+++ b/SlackNet/WebApi/UsersApi.cs
@@ -43,7 +43,7 @@ public interface IUsersApi
         /// This includes deleted/deactivated users.
         /// </summary>
         /// <param name="cursor">
-        /// Paginate through collections of data by setting the cursor parameter to a <see cref="UserListResponseMetadata.NextCursor"/> property
+        /// Paginate through collections of data by setting the cursor parameter to a <see cref="ResponseMetadata.NextCursor"/> property
         /// returned by a previous request's <see cref="UserListResponse.ResponseMetadata"/>.
         /// Default value fetches the first "page" of the collection.
         /// </param>
@@ -52,6 +52,13 @@ public interface IUsersApi
         /// <param name="cancellationToken"></param>
         Task<UserListResponse> List(string cursor = null, int limit = 0, bool presence = false, CancellationToken? cancellationToken = null);
 
+        /// <summary>
+        /// Find a user with an email address.
+        /// </summary>
+        /// <param name="email">An email address belonging to a user in the workspace.</param>
+        /// <param name="cancellationToken"></param>
+        Task<User> LookupByEmail(string email, CancellationToken? cancellationToken = null);
+
         /// <summary>
         /// Lets the Slack messaging server know that the authenticated user is currently active.
         /// </summary>
@@ -139,7 +146,7 @@ public async Task<User> Info(string userId, CancellationToken? cancellationToken
         /// This includes deleted/deactivated users.
         /// </summary>
         /// <param name="cursor">
-        /// Paginate through collections of data by setting the cursor parameter to a <see cref="UserListResponseMetadata.NextCursor"/> property
+        /// Paginate through collections of data by setting the cursor parameter to a <see cref="ResponseMetadata.NextCursor"/> property
         /// returned by a previous request's <see cref="UserListResponse.ResponseMetadata"/>.
         /// Default value fetches the first "page" of the collection.
         /// </param>
@@ -154,6 +161,14 @@ public Task<UserListResponse> List(string cursor = null, int limit = 0, bool pre
                     { "presence", presence }
                 }, cancellationToken);
 
+        /// <summary>
+        /// Find a user with an email address.
+        /// </summary>
+        /// <param name="email">An email address belonging to a user in the workspace.</param>
+        /// <param name="cancellationToken"></param>
+        public async Task<User> LookupByEmail(string email, CancellationToken? cancellationToken = null) =>
+            (await _client.Get<UserResponse>("users.lookupByEmail", new Args { { "email", email } }, cancellationToken).ConfigureAwait(false)).User;
+
         /// <summary>
         /// Lets the Slack messaging server know that the authenticated user is currently active.
         /// </summary>
diff --git a/SlackNet/WebApi/WebApiResponse.cs b/SlackNet/WebApi/WebApiResponse.cs
index 03ae13c..17ac1ce 100644
--- a/SlackNet/WebApi/WebApiResponse.cs
+++ b/SlackNet/WebApi/WebApiResponse.cs
@@ -6,7 +6,6 @@ namespace SlackNet.WebApi
     public class WebApiResponse
     {
         public bool Ok { get; set; }
-        public string Error { get; set; }
         [JsonExtensionData]
         public JObject Data { get; set; }
     }