Invitations.

src/Squidex.Domain.Apps.Core.Operations/HandleRules/EventEnricher.cs

@@ -66,7 +66,7 @@ namespace Squidex.Domain.Apps.Core.HandleRules
                     user = null;
                 }
 
-                if (user == null && actor.Type.Equals(RefTokenType.Client, StringComparison.OrdinalIgnoreCase))
+                if (user == null && actor.IsClient)
                 {
                     user = new ClientUser(actor);
                 }

src/Squidex.Domain.Apps.Entities/Apps/Commands/AssignContributor.cs

@@ -18,5 +18,7 @@ namespace Squidex.Domain.Apps.Entities.Apps.Commands
         public bool IsRestore { get; set; }
 
         public bool IsInviting { get; set; }
+
+        public bool IsCreated { get; set; }
     }
 }

src/Squidex.Domain.Apps.Entities/Apps/Invitiation/IInvitationEmailSender.cs

@@ -0,0 +1,19 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System.Threading.Tasks;
+using Squidex.Shared.Users;
+
+namespace Squidex.Domain.Apps.Entities.Apps.Invitiation
+{
+    public interface IInvitationEmailSender
+    {
+        Task SendNewUserEmailAsync(IUser assigner, IUser assignee, string appName);
+
+        Task SendExistingUserEmailAsync(IUser assigner, IUser assignee, string appName);
+    }
+}

src/Squidex.Domain.Apps.Entities/Apps/Invitiation/InvitationEmailEventConsumer.cs

@@ -0,0 +1,97 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System.Threading.Tasks;
+using Squidex.Domain.Apps.Events.Apps;
+using Squidex.Infrastructure;
+using Squidex.Infrastructure.EventSourcing;
+using Squidex.Infrastructure.Log;
+using Squidex.Infrastructure.Tasks;
+using Squidex.Shared.Users;
+
+namespace Squidex.Domain.Apps.Entities.Apps.Invitiation
+{
+    public sealed class InvitationEmailEventConsumer : IEventConsumer
+    {
+        private readonly IInvitationEmailSender emailSender;
+        private readonly IUserResolver userResolver;
+        private readonly ISemanticLog log;
+
+        public string Name
+        {
+            get { return "InvitationEmailSender"; }
+        }
+
+        public string EventsFilter
+        {
+            get { return "^app-";  }
+        }
+
+        public InvitationEmailEventConsumer(IInvitationEmailSender emailSender, IUserResolver userResolver, ISemanticLog log)
+        {
+            Guard.NotNull(emailSender, nameof(emailSender));
+            Guard.NotNull(userResolver, nameof(userResolver));
+            Guard.NotNull(log, nameof(log));
+
+            this.emailSender = emailSender;
+            this.userResolver = userResolver;
+
+            this.log = log;
+        }
+
+        public bool Handles(StoredEvent @event)
+        {
+            return true;
+        }
+
+        public Task ClearAsync()
+        {
+            return TaskHelper.Done;
+        }
+
+        public async Task On(Envelope<IEvent> @event)
+        {
+            if (@event.Payload is AppContributorAssigned appContributorAssigned && appContributorAssigned.Actor.IsClient)
+            {
+                var assigner = await userResolver.FindByIdOrEmailAsync(appContributorAssigned.Actor.Identifier);
+
+                if (assigner == null)
+                {
+                    LogWarning($"Assigner {appContributorAssigned.Actor.Identifier} not found");
+                    return;
+                }
+
+                var assignee = await userResolver.FindByIdOrEmailAsync(appContributorAssigned.ContributorId);
+
+                if (assignee == null)
+                {
+                    LogWarning($"Assignee {appContributorAssigned.ContributorId} not found");
+                    return;
+                }
+
+                var appName = appContributorAssigned.AppId.Name;
+
+                if (appContributorAssigned.IsCreated)
+                {
+                    await emailSender.SendNewUserEmailAsync(assigner, assignee, appName);
+                }
+                else
+                {
+                    await emailSender.SendExistingUserEmailAsync(assigner, assignee, appName);
+                }
+            }
+        }
+
+        private void LogWarning(string reason)
+        {
+            log.LogWarning(w => w
+                .WriteProperty("action", "InviteUser")
+                .WriteProperty("status", "Failed")
+                .WriteProperty("reason", reason));
+        }
+    }
+}

src/Squidex.Domain.Apps.Entities/Apps/Invitiation/InvitationEmailSender.cs

@@ -0,0 +1,102 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System.Threading.Tasks;
+using Microsoft.Extensions.Options;
+using Squidex.Infrastructure;
+using Squidex.Infrastructure.Email;
+using Squidex.Infrastructure.Log;
+using Squidex.Shared.Users;
+
+namespace Squidex.Domain.Apps.Entities.Apps.Invitiation
+{
+    public sealed class InvitationEmailSender : IInvitationEmailSender
+    {
+        private readonly IEmailSender emailSender;
+        private readonly IEmailUrlGenerator emailUrlGenerator;
+        private readonly ISemanticLog log;
+        private readonly InvitationEmailTextOptions texts;
+
+        public InvitationEmailSender(
+            IOptions<InvitationEmailTextOptions> texts,
+            IEmailSender emailSender,
+            IEmailUrlGenerator emailUrlGenerator,
+            ISemanticLog log)
+        {
+            Guard.NotNull(texts, nameof(texts));
+            Guard.NotNull(emailSender, nameof(emailSender));
+            Guard.NotNull(emailUrlGenerator, nameof(emailUrlGenerator));
+            Guard.NotNull(log, nameof(log));
+
+            this.texts = texts.Value;
+            this.emailSender = emailSender;
+            this.emailUrlGenerator = emailUrlGenerator;
+            this.log = log;
+        }
+
+        public Task SendExistingUserEmailAsync(IUser assigner, IUser assignee, string appName)
+        {
+            return SendEmailAsync(texts.NewUserSubject, texts.NewUserBody, assigner, assignee, appName);
+        }
+
+        public Task SendNewUserEmailAsync(IUser assigner, IUser assignee, string appName)
+        {
+            return SendEmailAsync(texts.ExistingUserBody, texts.ExistingUserSubject, assigner, assignee, appName);
+        }
+
+        private async Task SendEmailAsync(string emailBody, string emailSubj, IUser assigner, IUser assignee, string appName)
+        {
+            if (string.IsNullOrWhiteSpace(texts.NewUserSubject))
+            {
+                LogWarning("No email subject configured for new users");
+                return;
+            }
+
+            if (string.IsNullOrWhiteSpace(texts.NewUserBody))
+            {
+                LogWarning("No email body configured for new users");
+                return;
+            }
+
+            var appUrl = emailUrlGenerator.GenerateUIUrl();
+
+            emailSubj = Format(emailSubj, assigner, assignee, appUrl, appName);
+            emailBody = Format(emailBody, assigner, assignee, appUrl, appName);
+
+            await emailSender.SendAsync(assignee.Email, emailSubj, emailBody);
+        }
+
+        private void LogWarning(string reason)
+        {
+            log.LogWarning(w => w
+                .WriteProperty("action", "InviteUser")
+                .WriteProperty("status", "Failed")
+                .WriteProperty("reason", reason));
+        }
+
+        private string Format(string text, IUser assigner, IUser assignee, string uiUrl, string appName)
+        {
+            text = text.Replace("$APP_NAME", appName);
+
+            text = text.Replace("$UI_URL", uiUrl);
+
+            if (assigner != null)
+            {
+                text = text.Replace("$ASSIGNER_EMAIL", assigner.Email);
+                text = text.Replace("$ASSIGNER_NAME", assigner.DisplayName());
+            }
+
+            if (assignee != null)
+            {
+                text = text.Replace("$ASSIGNEE_EMAIL", assignee.Email);
+                text = text.Replace("$ASSIGNEE_NAME", assignee.DisplayName());
+            }
+
+            return text;
+        }
+    }
+}

src/Squidex.Domain.Apps.Entities/Apps/Invitiation/InvitationEmailTextOptions.cs

@@ -0,0 +1,20 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+namespace Squidex.Domain.Apps.Entities.Apps.Invitiation
+{
+    public sealed class InvitationEmailTextOptions
+    {
+        public string NewUserSubject { get; set; }
+
+        public string NewUserBody { get; set; }
+
+        public string ExistingUserSubject { get; set; }
+
+        public string ExistingUserBody { get; set; }
+    }
+}

src/Squidex.Domain.Apps.Entities/Apps/InviteUserCommandMiddleware.cs → src/Squidex.Domain.Apps.Entities/Apps/Invitiation/InviteUserCommandMiddleware.cs

@@ -12,7 +12,7 @@ using Squidex.Infrastructure;
 using Squidex.Infrastructure.Commands;
 using Squidex.Shared.Users;
 
-namespace Squidex.Domain.Apps.Entities.Apps
+namespace Squidex.Domain.Apps.Entities.Apps.Invitiation
 {
     public sealed class InviteUserCommandMiddleware : ICommandMiddleware
     {
@@ -31,11 +31,11 @@ namespace Squidex.Domain.Apps.Entities.Apps
             {
                 if (assignContributor.IsInviting && assignContributor.ContributorId.IsEmail())
                 {
-                    var isInvited = await userResolver.CreateUserIfNotExists(assignContributor.ContributorId);
+                    assignContributor.IsCreated = await userResolver.CreateUserIfNotExists(assignContributor.ContributorId);
 
                     await next();
 
-                    if (isInvited && context.PlainResult is EntityCreatedResult<string> id)
+                    if (assignContributor.IsCreated && context.PlainResult is EntityCreatedResult<string> id)
                     {
                         context.Complete(new InvitedResult { Id = id });
                     }

src/Squidex.Domain.Apps.Entities/Apps/InvitedResult.cs → src/Squidex.Domain.Apps.Entities/Apps/Invitiation/InvitedResult.cs

@@ -7,7 +7,7 @@
 
 using Squidex.Infrastructure.Commands;
 
-namespace Squidex.Domain.Apps.Entities.Apps
+namespace Squidex.Domain.Apps.Entities.Apps.Invitiation
 {
     public sealed class InvitedResult
     {

src/Squidex.Domain.Apps.Entities/Backup/RestoreGrain.cs

@@ -239,7 +239,7 @@ namespace Squidex.Domain.Apps.Entities.Backup
         {
             var actor = CurrentJob.Actor;
 
-            if (string.Equals(actor?.Type, RefTokenType.Subject))
+            if (actor?.IsSubject == true)
             {
                 await commandBus.PublishAsync(new AssignContributor
                 {

src/Squidex.Domain.Apps.Entities/Contents/Text/GrainTextIndexer.cs

@@ -17,6 +17,7 @@ using Squidex.Infrastructure;
 using Squidex.Infrastructure.EventSourcing;
 using Squidex.Infrastructure.Log;
 using Squidex.Infrastructure.Orleans;
+using Squidex.Infrastructure.Tasks;
 
 namespace Squidex.Domain.Apps.Entities.Contents.Text
 {
@@ -48,7 +49,7 @@ namespace Squidex.Domain.Apps.Entities.Contents.Text
 
         public Task ClearAsync()
         {
-            return Task.CompletedTask;
+            return TaskHelper.Done;
         }
 
         public async Task On(Envelope<IEvent> @event)

src/Squidex.Domain.Apps.Entities/IEmailUrlGenerator.cs

@@ -0,0 +1,14 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+namespace Squidex.Domain.Apps.Entities
+{
+    public interface IEmailUrlGenerator
+    {
+        string GenerateUIUrl();
+    }
+}

src/Squidex.Domain.Apps.Entities/Rules/UsageTracking/UsageTrackerGrain.cs

@@ -58,7 +58,7 @@ namespace Squidex.Domain.Apps.Entities.Rules.UsageTracking
             RegisterOrUpdateReminder("Default", TimeSpan.Zero, TimeSpan.FromMinutes(10));
             RegisterTimer(x => CheckUsagesAsync(), null, TimeSpan.Zero, TimeSpan.FromMinutes(10));
 
-            return Task.CompletedTask;
+            return TaskHelper.Done;
         }
 
         public Task ActivateAsync()

src/Squidex.Domain.Apps.Events/Apps/AppContributorAssigned.cs

@@ -15,5 +15,7 @@ namespace Squidex.Domain.Apps.Events.Apps
         public string ContributorId { get; set; }
 
         public string Role { get; set; }
+
+        public bool IsCreated { get; set; }
     }
 }

src/Squidex.Infrastructure.Azure/EventSourcing/CosmosDbEventStore_Reader.cs

@@ -34,7 +34,7 @@ namespace Squidex.Infrastructure.EventSourcing
 
             ThrowIfDisposed();
 
-            return Task.CompletedTask;
+            return TaskHelper.Done;
         }
 
         public async Task<IReadOnlyList<StoredEvent>> QueryAsync(string streamName, long streamPosition = 0)

src/Squidex.Infrastructure.Azure/EventSourcing/CosmosDbSubscription.cs

@@ -103,7 +103,7 @@ namespace Squidex.Infrastructure.EventSourcing
 
         public Task OpenAsync(IChangeFeedObserverContext context)
         {
-            return Task.CompletedTask;
+            return TaskHelper.Done;
         }
 
         public async Task ProcessChangesAsync(IChangeFeedObserverContext context, IReadOnlyList<Document> docs, CancellationToken cancellationToken)

src/Squidex.Infrastructure/Email/IEmailSender.cs

@@ -0,0 +1,16 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System.Threading.Tasks;
+
+namespace Squidex.Infrastructure.Email
+{
+    public interface IEmailSender
+    {
+        Task SendAsync(string recipient, string subject, string text);
+    }
+}

src/Squidex.Infrastructure/Email/SmptOptions.cs

@@ -0,0 +1,33 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+namespace Squidex.Infrastructure.Email
+{
+    public sealed class SmptOptions
+    {
+        public string Server { get; set; }
+
+        public string Sender { get; set; }
+
+        public string Username { get; set; }
+
+        public string Password { get; set; }
+
+        public bool EnableSsl { get; set; }
+
+        public int Port { get; set; } = 587;
+
+        public bool IsConfigured()
+        {
+            return
+                !string.IsNullOrWhiteSpace(Server) &&
+                !string.IsNullOrWhiteSpace(Sender) &&
+                !string.IsNullOrWhiteSpace(Username) &&
+                !string.IsNullOrWhiteSpace(Password);
+        }
+    }
+}

src/Squidex.Infrastructure/Email/SmtpEmailSender.cs

@@ -0,0 +1,42 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System.Net;
+using System.Net.Mail;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Options;
+
+namespace Squidex.Infrastructure.Email
+{
+    public sealed class SmtpEmailSender : IEmailSender
+    {
+        private readonly SmtpClient smtpClient;
+        private readonly string sender;
+
+        public SmtpEmailSender(IOptions<SmptOptions> options)
+        {
+            Guard.NotNull(options, nameof(options));
+
+            var config = options.Value;
+
+            smtpClient = new SmtpClient(config.Server, config.Port)
+            {
+                Credentials = new NetworkCredential(
+                    config.Username,
+                    config.Password),
+                EnableSsl = config.EnableSsl
+            };
+
+            sender = config.Sender;
+        }
+
+        public Task SendAsync(string recipient, string subject, string body)
+        {
+            return smtpClient.SendMailAsync(sender, recipient, subject, body);
+        }
+    }
+}

src/Squidex.Infrastructure/EventSourcing/Grains/EventConsumerGrain.cs

@@ -53,7 +53,7 @@ namespace Squidex.Infrastructure.EventSourcing.Grains
 
             eventConsumer = eventConsumerFactory(key);
 
-            return Task.CompletedTask;
+            return TaskHelper.Done;
         }
 
         public Task<Immutable<EventConsumerInfo>> GetStateAsync()

src/Squidex.Infrastructure/RefToken.cs

@@ -15,6 +15,16 @@ namespace Squidex.Infrastructure
 
         public string Identifier { get; }
 
+        public bool IsClient
+        {
+            get { return string.Equals(Type, RefTokenType.Client, StringComparison.OrdinalIgnoreCase); }
+        }
+
+        public bool IsSubject
+        {
+            get { return string.Equals(Type, RefTokenType.Subject, StringComparison.OrdinalIgnoreCase); }
+        }
+
         public RefToken(string type, string identifier)
         {
             Guard.NotNullOrEmpty(type, nameof(type));

src/Squidex.Web/Services/UrlGenerator.cs

@@ -9,6 +9,7 @@ using System;
 using Microsoft.Extensions.Options;
 using Squidex.Domain.Apps.Core.ConvertContent;
 using Squidex.Domain.Apps.Core.HandleRules;
+using Squidex.Domain.Apps.Entities;
 using Squidex.Domain.Apps.Entities.Apps;
 using Squidex.Domain.Apps.Entities.Assets;
 using Squidex.Domain.Apps.Entities.Contents;
@@ -19,7 +20,7 @@ using Squidex.Infrastructure.Assets;
 
 namespace Squidex.Web.Services
 {
-    public sealed class UrlGenerator : IGraphQLUrlGenerator, IRuleUrlGenerator, IAssetUrlGenerator
+    public sealed class UrlGenerator : IGraphQLUrlGenerator, IRuleUrlGenerator, IAssetUrlGenerator, IEmailUrlGenerator
     {
         private readonly IAssetStore assetStore;
         private readonly UrlsOptions urlsOptions;
@@ -64,6 +65,11 @@ namespace Squidex.Web.Services
             return urlsOptions.BuildUrl($"app/{appId.Name}/content/{schemaId.Name}/{contentId}/history");
         }
 
+        public string GenerateUIUrl()
+        {
+            return urlsOptions.BuildUrl("app/");
+        }
+
         public string GenerateAssetSourceUrl(IAppEntity app, IAssetEntity asset)
         {
             return assetStore.GeneratePublicUrl(asset.Id.ToString(), asset.FileVersion, null);

src/Squidex/Areas/Api/Controllers/Apps/AppContributorsController.cs

@@ -11,6 +11,7 @@ using Microsoft.Net.Http.Headers;
 using Squidex.Areas.Api.Controllers.Apps.Models;
 using Squidex.Domain.Apps.Entities.Apps;
 using Squidex.Domain.Apps.Entities.Apps.Commands;
+using Squidex.Domain.Apps.Entities.Apps.Invitiation;
 using Squidex.Domain.Apps.Entities.Apps.Services;
 using Squidex.Infrastructure.Commands;
 using Squidex.Shared;

src/Squidex/Areas/Api/Controllers/Apps/Models/ContributorAssignedDto.cs

@@ -20,11 +20,11 @@ namespace Squidex.Areas.Api.Controllers.Apps.Models
         /// <summary>
         /// Indicates if the user was created.
         /// </summary>
-        public bool WasInvited { get; set; }
+        public bool IsCreated { get; set; }
 
-        public static ContributorAssignedDto FromId(string id, bool wasInvited)
+        public static ContributorAssignedDto FromId(string id, bool isCreated)
         {
-            return new ContributorAssignedDto { ContributorId = id, WasInvited = wasInvited };
+            return new ContributorAssignedDto { ContributorId = id, IsCreated = isCreated };
         }
     }
 }

src/Squidex/Config/Domain/EntitiesServices.cs

@@ -22,6 +22,7 @@ using Squidex.Domain.Apps.Entities;
 using Squidex.Domain.Apps.Entities.Apps;
 using Squidex.Domain.Apps.Entities.Apps.Commands;
 using Squidex.Domain.Apps.Entities.Apps.Indexes;
+using Squidex.Domain.Apps.Entities.Apps.Invitiation;
 using Squidex.Domain.Apps.Entities.Apps.Templates;
 using Squidex.Domain.Apps.Entities.Assets;
 using Squidex.Domain.Apps.Entities.Assets.Commands;
@@ -44,6 +45,7 @@ using Squidex.Domain.Apps.Entities.Schemas.Indexes;
 using Squidex.Domain.Apps.Entities.Tags;
 using Squidex.Infrastructure.Assets;
 using Squidex.Infrastructure.Commands;
+using Squidex.Infrastructure.Email;
 using Squidex.Infrastructure.EventSourcing;
 using Squidex.Infrastructure.Migrations;
 using Squidex.Infrastructure.Orleans;
@@ -63,7 +65,7 @@ namespace Squidex.Config.Domain
                     c.GetRequiredService<IOptions<UrlsOptions>>(),
                     c.GetRequiredService<IAssetStore>(),
                     exposeSourceUrl))
-                .As<IGraphQLUrlGenerator>().As<IRuleUrlGenerator>().As<IAssetUrlGenerator>();
+                .As<IGraphQLUrlGenerator>().As<IRuleUrlGenerator>().As<IAssetUrlGenerator>().As<IEmailUrlGenerator>();
 
             services.AddSingletonAs<HistoryService>()
                 .As<IEventConsumer>().As<IHistoryService>();
@@ -147,6 +149,25 @@ namespace Squidex.Config.Domain
 
                 return result;
             });
+
+            var emailOptions = config.GetValue<SmptOptions>("email:smtp");
+
+            if (emailOptions.IsConfigured())
+            {
+                services.AddSingleton(Options.Create(emailOptions));
+
+                services.AddSingletonAs<SmtpEmailSender>()
+                    .As<IEmailSender>();
+
+                services.AddSingletonAs<InvitationEmailEventConsumer>()
+                    .As<IEventConsumer>();
+
+                services.AddSingletonAs<InvitationEmailSender>()
+                    .AsOptional<IInvitationEmailSender>();
+
+                services.Configure<InvitationEmailTextOptions>(
+                    config.GetSection("email:invitations"));
+            }
         }
 
         private static void AddCommandPipeline(this IServiceCollection services)

src/Squidex/appsettings.json

@@ -58,22 +58,69 @@
        *
        * Supported: GoogleMaps, OSM
        */
-    "type": "OSM",
+      "type": "OSM",
-    "googleMaps": {
+      "googleMaps": {
-      /*
+        /*
          * The optional google maps API key. CREATE YOUR OWN PLEASE.
          */
-      "key": "AIzaSyB_Z8l3nwUxZhMJykiDUJy6bSHXXlwcYMg"
+        "key": "AIzaSyB_Z8l3nwUxZhMJykiDUJy6bSHXXlwcYMg"
+      }
+    }
+  },
+
+  "email": {
+    "smtp": {
+      /*
+       * The host name to your email server.
+       */
+      "server": "",
+      /*
+       * The sender email address.
+       */
+      "sender": "hello@squidex.io",
+      /*
+       * The username to authenticate to your email server.
+       */
+      "username": "",
+      /*
+       * The password to authenticate to your email server.
+       */
+      "password": "",
+      /*
+       * Always use SSL if possible.
+       */
+      "enableSsl": true,
+      /*
+       * The port to your email server.
+       */
+      "port": 587
+    },
+    "invitiations": {
+      /*
+       * The email subject when a new user is added as contributor.
+       */
+      "newUserSubject": "Welcome to Squidex, you have been invited to app $APP_NAME",
+      /*
+       * The email body when a new user is added as contributor.
+       */
+      "newUserBody": "Welcome\n\nYou have been invited to Squidex CMS by $ASSIGNER_NAME ($ASSIGNER_EMAIL) and to app $",
+      /*
+       * The email subject when an existing user is added as contributor.
+       */
+      "existingUserSubject": "[Squidex CMS] You have been invited to app $APP_NAME",
+      /*
+       * The email body when an existing user is added as contributor.
+       */
+      "existingUserBody": ""
     }
-  }
   },
 
   "robots": {
     /*
      * The text for the robots.txt file
      */
-    "text": "User-agent: *\nAllow: /api/assets/*"
+      "text": "User-agent: *\nAllow: /api/assets/*"
-  },
+    },
 
   "healthz": {
     "gc": {

tests/Squidex.Infrastructure.Tests/RefTokenTests.cs

@@ -30,6 +30,16 @@ namespace Squidex.Infrastructure
 
             Assert.Equal("client", token.Type);
             Assert.Equal("client1", token.Identifier);
+
+            Assert.True(token.IsClient);
+        }
+
+        [Fact]
+        public void Should_instantiate_subject_token()
+        {
+            var token = new RefToken("subject", "client1");
+
+            Assert.True(token.IsSubject);
         }
 
         [Fact]