refactor(form): vbproj aktualisieren, um mit .net 8 zu konfigurieren.

- Verwandte Referenzen für net 9 hinzufügen.
 - Backup-XML-Datei für altes vbproj erstellen.

EnvelopeGenerator.Application/Common/Configurations/AuthenticatorParams.cs

@@ -1,4 +1,4 @@
-namespace EnvelopeGenerator.Application.Configurations;
+namespace EnvelopeGenerator.Application.Common.Configurations;
 
 /// <summary>
 /// 

EnvelopeGenerator.Application/Common/Configurations/DbTriggerParams.cs

@@ -1,4 +1,4 @@
-namespace EnvelopeGenerator.Application.Configurations;
+namespace EnvelopeGenerator.Application.Common.Configurations;
 
 /// <summary>
 /// 

EnvelopeGenerator.Application/Common/Configurations/DispatcherParams.cs

@@ -1,4 +1,4 @@
-namespace EnvelopeGenerator.Application.Configurations;
+namespace EnvelopeGenerator.Application.Common.Configurations;
 
 /// <summary>
 /// 
@@ -23,5 +23,5 @@ public class DispatcherParams
     /// <summary>
     /// Default value is string.Empty
     /// </summary>
-    public string EmailAttmt1 { get; init; } = string.Empty;
+    public string? EmailAttmt1 { get; init; } = null;
 }

EnvelopeGenerator.Application/Common/Configurations/GtxMessagingParams.cs

@@ -1,5 +1,5 @@
 using DigitalData.Core.Client.Interface;
-namespace EnvelopeGenerator.Application.Configurations;
+namespace EnvelopeGenerator.Application.Common.Configurations;
 
 /// <summary>
 /// https://www.gtx-messaging.com/en/api-docs/sms-rest-api/

EnvelopeGenerator.Application/Common/Configurations/MailParams.cs

@@ -1,4 +1,4 @@
-namespace EnvelopeGenerator.Application.Configurations;
+namespace EnvelopeGenerator.Application.Common.Configurations;
 
 /// <summary>
 /// 

EnvelopeGenerator.Application/Common/Configurations/TotpSmsParams.cs

@@ -1,7 +1,7 @@
 using OtpNet;
 using System.Globalization;
 
-namespace EnvelopeGenerator.Application.Configurations;
+namespace EnvelopeGenerator.Application.Common.Configurations;
 
 /// <summary>
 /// 

EnvelopeGenerator.Application/Common/Dto/ConfigDto.cs

@@ -1,6 +1,6 @@
 using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs;
+namespace EnvelopeGenerator.Application.Common.Dto;
 
 /// <summary>
 /// Data Transfer Object representing configuration settings.

EnvelopeGenerator.Application/Common/Dto/DocumentDto.cs

@@ -1,12 +1,12 @@
 using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs;
+namespace EnvelopeGenerator.Application.Common.Dto;
 
 /// <summary>
 /// Data Transfer Object representing a document within an envelope, including optional binary data and form elements.
 /// </summary>
 [ApiExplorerSettings(IgnoreApi = true)]
-public class EnvelopeDocumentDto
+public class DocumentDto
 {
     /// <summary>
     /// Gets or sets the unique identifier of the document.
@@ -31,5 +31,5 @@ public class EnvelopeDocumentDto
     /// <summary>
     /// Gets or sets the collection of elements associated with the document for receiver interactions, if any.
     /// </summary>
-    public IEnumerable<DocumentReceiverElementDto>? Elements { get; set; }
+    public IEnumerable<SignatureDto>? Elements { get; set; }
 }

EnvelopeGenerator.Application/Common/Dto/DocumentStatusDto.cs

@@ -1,6 +1,7 @@
-using Microsoft.AspNetCore.Mvc;
+using EnvelopeGenerator.Domain.Constants;
+using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs;
+namespace EnvelopeGenerator.Application.Common.Dto;
 
 /// <summary>
 /// Data Transfer Object representing the status of a document for a specific receiver.
@@ -26,7 +27,7 @@ public class DocumentStatusDto
     /// <summary>
     /// Gets or sets the current status code.
     /// </summary>
-    public int Status { get; set; }
+    public EnvelopeStatus Status { get; set; }
 
     /// <summary>
     /// Gets or sets the timestamp when the status was changed.

EnvelopeGenerator.Application/Common/Dto/EmailTemplateDto.cs

@@ -1,6 +1,6 @@
 using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs
+namespace EnvelopeGenerator.Application.Common.Dto
 {
     /// <summary>
     /// 

EnvelopeGenerator.Application/Common/Dto/EnvelopeDto.cs

@@ -1,9 +1,10 @@
 using DigitalData.EmailProfilerDispatcher.Abstraction.Attributes;
 using DigitalData.UserManager.Application.DTOs.User;
+using EnvelopeGenerator.Domain.Constants;
 using EnvelopeGenerator.Domain.Entities;
 using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs;
+namespace EnvelopeGenerator.Application.Common.Dto;
 
 /// <summary>
 /// 
@@ -24,7 +25,7 @@ public record EnvelopeDto
     /// <summary>
     /// 
     /// </summary>
-    public int Status { get; set; }
+    public required EnvelopeStatus Status { get; set; }
 
     /// <summary>
     /// Default value is string.Empty
@@ -116,5 +117,5 @@ public record EnvelopeDto
     /// <summary>
     /// 
     /// </summary>
-    public IEnumerable<EnvelopeDocumentDto>? Documents { get; set; }
+    public IEnumerable<DocumentDto>? Documents { get; set; }
 }

EnvelopeGenerator.Application/Common/Dto/EnvelopeReceiver/EnvelopeReceiverDto.cs

@@ -1,14 +1,25 @@
 using DigitalData.EmailProfilerDispatcher.Abstraction.Attributes;
+using EnvelopeGenerator.Application.Common.Dto.Receiver;
 using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs.EnvelopeReceiver;
+namespace EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiver;
 
 /// <summary>
 /// 
 /// </summary>
 [ApiExplorerSettings(IgnoreApi = true)]
-public record EnvelopeReceiverBasicDto
+public record EnvelopeReceiverDto
 {
+    /// <summary>
+    /// 
+    /// </summary>
+    public EnvelopeDto? Envelope { get; set; }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public ReceiverDto? Receiver { get; set; }
+
     /// <summary>
     /// 
     /// </summary>

EnvelopeGenerator.Application/Common/Dto/EnvelopeReceiver/EnvelopeReceiverSecretDto.cs

@@ -1,6 +1,6 @@
 using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs.EnvelopeReceiver;
+namespace EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiver;
 
 /// <summary>
 /// 

EnvelopeGenerator.Application/Common/Dto/EnvelopeReceiverReadOnly/EnvelopeReceiverReadOnlyCreateDto.cs

@@ -2,7 +2,7 @@
 using System.ComponentModel.DataAnnotations;
 using System.Text.Json.Serialization;
 
-namespace EnvelopeGenerator.Application.DTOs.EnvelopeReceiverReadOnly;
+namespace EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiverReadOnly;
 
 /// <summary>
 /// 

EnvelopeGenerator.Application/Common/Dto/EnvelopeReceiverReadOnly/EnvelopeReceiverReadOnlyDto.cs

@@ -1,7 +1,8 @@
-using EnvelopeGenerator.Application.DTOs.Receiver;
+using EnvelopeGenerator.Application.Common.Dto;
+using EnvelopeGenerator.Application.Common.Dto.Receiver;
 using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs.EnvelopeReceiverReadOnly;
+namespace EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiverReadOnly;
 
 /// <summary>
 /// Represents a read-only Data Transfer Object (DTO) for an envelope receiver.
@@ -59,5 +60,5 @@ public class EnvelopeReceiverReadOnlyDto
     /// <summary>
     /// Gets or inits the associated receiver details.
     /// </summary>
-    public ReceiverReadDto? Receiver { get; set; }
+    public ReceiverDto? Receiver { get; set; }
 }

EnvelopeGenerator.Application/Common/Dto/EnvelopeReceiverReadOnly/EnvelopeReceiverReadOnlyUpdateDto.cs

@@ -1,6 +1,6 @@
 using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs.EnvelopeReceiverReadOnly;
+namespace EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiverReadOnly;
 
 /// <summary>
 /// Data Transfer Object for updating a read-only envelope receiver.

EnvelopeGenerator.Application/Common/Dto/EnvelopeTypeDto.cs

@@ -1,6 +1,6 @@
 using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs;
+namespace EnvelopeGenerator.Application.Common.Dto;
 
 /// <summary>
 /// Data Transfer Object representing a type of envelope with its configuration settings.

EnvelopeGenerator.Application/Common/Dto/History/HistoryCreateDto.cs

@@ -1,11 +1,9 @@
-using Microsoft.AspNetCore.Mvc;
-
-namespace EnvelopeGenerator.Application.DTOs.EnvelopeHistory;
+namespace EnvelopeGenerator.Application.Common.Dto.History;
 
 /// <summary>
 /// Data Transfer Object for creating a new envelope history record.
 /// </summary>
-public class EnvelopeHistoryCreateDto
+public class HistoryCreateDto
 {
     /// <summary>
     /// Gets or sets the identifier of the envelope.

EnvelopeGenerator.Application/Common/Dto/History/HistoryDto.cs

@@ -1,13 +1,13 @@
 using DigitalData.UserManager.Application.DTOs.User;
-using EnvelopeGenerator.Application.DTOs.Receiver;
-using static EnvelopeGenerator.Domain.Constants;
+using EnvelopeGenerator.Application.Common.Dto.Receiver;
+using EnvelopeGenerator.Domain.Constants;
 
-namespace EnvelopeGenerator.Application.DTOs.EnvelopeHistory;
+namespace EnvelopeGenerator.Application.Common.Dto.History;
 
 /// <summary>
 /// Data Transfer Object representing the history of an envelope, including status, sender, receiver, and related metadata.
 /// </summary>
-public record EnvelopeHistoryDto
+public record HistoryDto
 {
     /// <summary>
     /// Unique identifier for the envelope history entry.
@@ -25,9 +25,19 @@ public record EnvelopeHistoryDto
     public required string UserReference { get; set; }
 
     /// <summary>
-    /// Status code of the envelope at this history point.
+    /// Include code of the envelope at this history point.
     /// </summary>
-    public int Status { get; set; }
+    public EnvelopeStatus Status { get; set; }
+
+    /// <summary>
+    /// Type of reference for this history entry.
+    /// </summary>
+    public ReferenceType ReferenceType => ((int)Status).ToString().FirstOrDefault() switch
+    {
+        '1' => ReferenceType.Sender,
+        '2' => ReferenceType.Receiver,
+        _ => ReferenceType.System,
+    };
 
     /// <summary>
     /// Human-readable name of the status.
@@ -52,12 +62,7 @@ public record EnvelopeHistoryDto
     /// <summary>
     /// Information about the receiver associated with this history entry.
     /// </summary>
-    public ReceiverReadDto? Receiver { get; set; }
-
-    /// <summary>
-    /// Type of reference for this history entry.
-    /// </summary>
-    public ReferenceType ReferenceType { get; set; }
+    public ReceiverDto? Receiver { get; set; }
 
     /// <summary>
     /// Optional comment related to this history entry.

EnvelopeGenerator.Application/Common/Dto/MappingProfile.cs

@@ -1,13 +1,13 @@
 using AutoMapper;
-using EnvelopeGenerator.Application.DTOs.EnvelopeHistory;
-using EnvelopeGenerator.Application.DTOs.EnvelopeReceiver;
-using EnvelopeGenerator.Application.DTOs.EnvelopeReceiverReadOnly;
-using EnvelopeGenerator.Application.DTOs.Messaging;
-using EnvelopeGenerator.Application.DTOs.Receiver;
-using EnvelopeGenerator.Application.Extensions;
+using EnvelopeGenerator.Application.Common.Dto.History;
+using EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiver;
+using EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiverReadOnly;
+using EnvelopeGenerator.Application.Common.Dto.Messaging;
+using EnvelopeGenerator.Application.Common.Dto.Receiver;
+using EnvelopeGenerator.Application.Common.Extensions;
 using EnvelopeGenerator.Domain.Entities;
 
-namespace EnvelopeGenerator.Application.DTOs;
+namespace EnvelopeGenerator.Application.Common.Dto;
 
 /// <summary>
 /// Represents the AutoMapper profile configuration for mapping between
@@ -23,38 +23,31 @@ public class MappingProfile : Profile
     {
         // Entity to DTO mappings
         CreateMap<Config, ConfigDto>();
-        CreateMap<DocumentReceiverElement, DocumentReceiverElementDto>();
+        CreateMap<Signature, SignatureDto>();
         CreateMap<DocumentStatus, DocumentStatusDto>();
         CreateMap<EmailTemplate, EmailTemplateDto>();
         CreateMap<Envelope, EnvelopeDto>();
-        CreateMap<EnvelopeCertificate, EnvelopeCertificateDto>();
-        CreateMap<EnvelopeDocument, EnvelopeDocumentDto>();
-        CreateMap<Domain.Entities.EnvelopeHistory, EnvelopeHistoryDto>();
-        CreateMap<Domain.Entities.EnvelopeHistory, EnvelopeHistoryCreateDto>();
+        CreateMap<Document, DocumentDto>();
+        CreateMap<Domain.Entities.History, HistoryDto>();
+        CreateMap<Domain.Entities.History, HistoryCreateDto>();
         CreateMap<Domain.Entities.EnvelopeReceiver, EnvelopeReceiverDto>();
         CreateMap<Domain.Entities.EnvelopeReceiver, EnvelopeReceiverSecretDto>();
         CreateMap<EnvelopeType, EnvelopeTypeDto>();
-        CreateMap<Domain.Entities.Receiver, ReceiverReadDto>();
-        CreateMap<Domain.Entities.Receiver, ReceiverCreateDto>();
-        CreateMap<Domain.Entities.Receiver, ReceiverUpdateDto>();
+        CreateMap<Domain.Entities.Receiver, ReceiverDto>();
         CreateMap<Domain.Entities.EnvelopeReceiverReadOnly, EnvelopeReceiverReadOnlyDto>();
 
         // DTO to Entity mappings
         CreateMap<ConfigDto, Config>();
-        CreateMap<DocumentReceiverElementDto, DocumentReceiverElement>();
+        CreateMap<SignatureDto, Signature>();
         CreateMap<DocumentStatusDto, DocumentStatus>();
         CreateMap<EmailTemplateDto, EmailTemplate>();
         CreateMap<EnvelopeDto, Envelope>();
-        CreateMap<EnvelopeCertificateDto, EnvelopeCertificate>();
-        CreateMap<EnvelopeDocumentDto, EnvelopeDocument>();
-        CreateMap<EnvelopeHistoryDto, Domain.Entities.EnvelopeHistory>();
-        CreateMap<EnvelopeHistoryCreateDto, Domain.Entities.EnvelopeHistory>();
+        CreateMap<DocumentDto, Document>();
+        CreateMap<HistoryDto, Domain.Entities.History>();
+        CreateMap<HistoryCreateDto, Domain.Entities.History>();
         CreateMap<EnvelopeReceiverDto, Domain.Entities.EnvelopeReceiver>();
         CreateMap<EnvelopeTypeDto, EnvelopeType>();
-        CreateMap<ReceiverReadDto, Domain.Entities.Receiver>().ForMember(rcv => rcv.EnvelopeReceivers, rcvReadDto => rcvReadDto.Ignore());
-        CreateMap<ReceiverCreateDto, Domain.Entities.Receiver>();
-        CreateMap<ReceiverUpdateDto, Domain.Entities.Receiver>();
-        CreateMap<EnvelopeReceiverBase, EnvelopeReceiverBasicDto>();
+        CreateMap<ReceiverDto, Domain.Entities.Receiver>().ForMember(rcv => rcv.EnvelopeReceivers, rcvReadDto => rcvReadDto.Ignore());
         CreateMap<EnvelopeReceiverReadOnlyCreateDto, Domain.Entities.EnvelopeReceiverReadOnly>();
         CreateMap<EnvelopeReceiverReadOnlyUpdateDto, Domain.Entities.EnvelopeReceiverReadOnly>();
 

EnvelopeGenerator.Application/Common/Dto/Messaging/GtxMessagingResponse.cs

@@ -1,6 +1,6 @@
 using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs.Messaging;
+namespace EnvelopeGenerator.Application.Common.Dto.Messaging;
 
 /// <summary>
 /// 

EnvelopeGenerator.Application/Common/Dto/Messaging/SmsResponse.cs

@@ -1,6 +1,6 @@
 using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs.Messaging;
+namespace EnvelopeGenerator.Application.Common.Dto.Messaging;
 
 /// <summary>
 /// 

EnvelopeGenerator.Application/Common/Dto/Receiver/ReceiverDto.cs

@@ -1,14 +1,14 @@
-using EnvelopeGenerator.Application.DTOs.EnvelopeReceiver;
+using EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiver;
 using Microsoft.AspNetCore.Mvc;
 using System.Text.Json.Serialization;
 
-namespace EnvelopeGenerator.Application.DTOs.Receiver;
+namespace EnvelopeGenerator.Application.Common.Dto.Receiver;
 
 /// <summary>
 /// 
 /// </summary>
 [ApiExplorerSettings(IgnoreApi = true)]
-public class ReceiverReadDto
+public class ReceiverDto
 {
     /// <summary>
     /// 
@@ -25,6 +25,12 @@ public class ReceiverReadDto
     /// </summary>
     public required string Signature { get; set; }
 
+    /// <summary>
+    /// 
+    /// </summary>
+    [JsonIgnore]
+    public string? TotpSecretkey { get; set; }
+
     /// <summary>
     /// 
     /// </summary>
@@ -34,18 +40,13 @@ public class ReceiverReadDto
     /// 
     /// </summary>
     [JsonIgnore]
-    public IEnumerable<EnvelopeReceiverBasicDto>? EnvelopeReceivers { get; set; }
+    public IEnumerable<EnvelopeReceiverDto>? EnvelopeReceivers { get; set; }
 
     /// <summary>
     /// 
     /// </summary>
     public string? LastUsedName => EnvelopeReceivers?.LastOrDefault()?.Name;
 
-    /// <summary>
-    /// 
-    /// </summary>
-    public string? TotpSecretkey { get; set; } = null;
-
     /// <summary>
     /// 
     /// </summary>

EnvelopeGenerator.Application/Common/Dto/SignatureDto.cs

@@ -1,12 +1,12 @@
 using Microsoft.AspNetCore.Mvc;
 
-namespace EnvelopeGenerator.Application.DTOs;
+namespace EnvelopeGenerator.Application.Common.Dto;
 
 /// <summary>
 /// Data Transfer Object representing a positioned element assigned to a document receiver.
 /// </summary>
 [ApiExplorerSettings(IgnoreApi = true)]
-public class DocumentReceiverElementDto
+public class SignatureDto
 {
     /// <summary>
     /// Gets or sets the unique identifier of the element.
@@ -86,10 +86,10 @@ public class DocumentReceiverElementDto
     /// <summary>
     /// Gets or sets the top position of the element (in layout terms).
     /// </summary>
-    public double Top { get; set; }
+    public double Top => Y;
 
     /// <summary>
     /// Gets or sets the left position of the element (in layout terms).
     /// </summary>
-    public double Left { get; set; }
+    public double Left => X;
 }

EnvelopeGenerator.Application/Common/EnvelopeFlag.cs

@@ -0,0 +1,27 @@
+namespace EnvelopeGenerator.Application.Common;
+
+/// <summary>
+/// 
+/// </summary>
+public enum EnvelopeFlag
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    EnvelopeOrReceiverNonexists,
+
+    /// <summary>
+    /// 
+    /// </summary>
+    NonDecodableEnvelopeReceiverId,
+
+    /// <summary>
+    /// 
+    /// </summary>
+    WrongEnvelopeReceiverId,
+
+    /// <summary>
+    /// 
+    /// </summary>
+    AccessCodeNull
+}

EnvelopeGenerator.Application/Common/Extensions/CacheExtensions.cs

@@ -1,6 +1,6 @@
 using Microsoft.Extensions.Caching.Distributed;
 
-namespace EnvelopeGenerator.Application.Extensions;
+namespace EnvelopeGenerator.Application.Common.Extensions;
 
 /// <summary>
 /// 

EnvelopeGenerator.Application/Common/Extensions/DecodingExtensions.cs

@@ -0,0 +1,182 @@
+using EnvelopeGenerator.Domain.Constants;
+using System.Text;
+
+namespace EnvelopeGenerator.Application.Common.Extensions;
+
+/// <summary>
+/// 
+/// </summary>
+public static class DecodingExtensions
+{
+    /// <summary>
+    /// Validates whether a given string is a correctly formatted Base-64 encoded string.
+    /// </summary>
+    /// <remarks>
+    /// This method checks the string for proper Base-64 formatting, which includes validating
+    /// the length of the string (must be divisible by 4). It also checks each character to ensure
+    /// it belongs to the Base-64 character set (A-Z, a-z, 0-9, '+', '/', and '=' for padding).
+    /// The method ensures that padding characters ('=') only appear at the end of the string and
+    /// are in a valid configuration (either one '=' at the end if the string's length % 4 is 3,
+    /// or two '==' if the length % 4 is 2).
+    /// </remarks>
+    /// <param name="input">The Base-64 encoded string to validate.</param>
+    /// <returns>
+    /// <c>true</c> if the string is a valid Base-64 encoded string; otherwise, <c>false</c>.
+    /// </returns>
+    /// <example>
+    /// <code>
+    /// string testString = "TWFuIGlzIGRpc3Rpbmd1aXNoZWQsIG5vdCBvbmx5IGJ5IGhpcyByZWFzb24sIGJ1dCBieSB0aGlzIHNpbmd1bGFyIHBhc3Npb24gZnJvbSBvdGhlciBhbmltYWxzLCB3aGljaCBpcyBhIGx1c3Qgb2YgdGhlIG1pbmQsIHRoYXQgYnk=";
+    /// bool isValid = IsValidBase64String(testString);
+    /// Console.WriteLine(isValid); // Output: true
+    /// </code>
+    /// </example>
+    public static bool IsBase64String(this string input)
+    {
+        // Check if the string is null or empty
+        if (string.IsNullOrEmpty(input))
+        {
+            return false;
+        }
+
+        // Replace valid base-64 padding
+        input = input.Trim();
+        int mod4 = input.Length % 4;
+        if (mod4 > 0)
+        {
+            // Base-64 string lengths should be divisible by 4
+            return false;
+        }
+
+        // Check each character to ensure it is valid base-64
+        foreach (char c in input)
+        {
+            if (!char.IsLetterOrDigit(c) && c != '+' && c != '/' && c != '=')
+            {
+                // Invalid character detected
+                return false;
+            }
+        }
+
+        // Ensure no invalid padding scenarios exist
+        if (input.EndsWith("==") && input.Length % 4 == 0 ||
+            input.EndsWith("=") && input.Length % 4 == 3)
+        {
+            return true;
+        }
+
+        return input.IndexOf('=') == -1; // No padding allowed except at the end
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="encodedKey"></param>
+    /// <param name="decodedKeys"></param>
+    /// <returns></returns>
+    public static bool TryDecode(this string encodedKey, out string[] decodedKeys)
+    {
+        try
+        {
+            byte[] bytes = Convert.FromBase64String(encodedKey);
+            string decodedString = Encoding.UTF8.GetString(bytes);
+            decodedKeys = decodedString.Split(new string[] { "::" }, StringSplitOptions.None);
+            return true;
+        }
+        catch(ArgumentNullException) { }
+        catch (FormatException) { }
+        catch(ArgumentException) { }
+
+        decodedKeys = Array.Empty<string>();
+        return false;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="decodedKeys"></param>
+    /// <returns></returns>
+    public static EncodeType GetEncodeType(this string[] decodedKeys) => decodedKeys.Length switch
+    {
+        2 => EncodeType.EnvelopeReceiver,
+        3 => long.TryParse(decodedKeys[1], out var _) ? EncodeType.EnvelopeReceiverReadOnly : EncodeType.Undefined,
+        _ => EncodeType.Undefined,
+    };
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="decodedKeys"></param>
+    /// <returns></returns>
+    /// <exception cref="InvalidOperationException"></exception>
+    public static (string? EnvelopeUuid, string? ReceiverSignature) ParseEnvelopeReceiverId(this string[] decodedKeys)
+        => decodedKeys.GetEncodeType() == EncodeType.EnvelopeReceiver
+        ? (EnvelopeUuid: decodedKeys[0], ReceiverSignature: decodedKeys[1])
+        : throw new InvalidOperationException("Attempted to convert a decoded other than type EnvelopeReceiver to EnvelopeReceiver.");
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="decodedKeys"></param>
+    /// <returns></returns>
+    /// <exception cref="InvalidOperationException"></exception>
+    public static long ParseReadOnlyId(this string[] decodedKeys)
+        => decodedKeys.GetEncodeType() == EncodeType.EnvelopeReceiverReadOnly
+        ? long.Parse(decodedKeys[1])
+        : throw new InvalidOperationException("Attempted to convert a decoded other than type EnvelopeReceiver to EnvelopeReceiver. ");
+
+    /// <summary>
+    /// Decodes the envelope receiver ID and extracts the envelope UUID and receiver signature.
+    /// </summary>
+    /// <param name="envelopeReceiverId">The base64 encoded string containing the envelope UUID and receiver signature.</param>
+    /// <returns>A tuple containing the envelope UUID and receiver signature.</returns>
+    public static (string? EnvelopeUuid, string? ReceiverSignature) DecodeEnvelopeReceiverId(this string envelopeReceiverId)
+    {
+        if (!envelopeReceiverId.IsBase64String())
+        {
+            return (null, null);
+        }
+        byte[] bytes = Convert.FromBase64String(envelopeReceiverId);
+        string decodedString = Encoding.UTF8.GetString(bytes);
+        string[] parts = decodedString.Split(new string[] { "::" }, StringSplitOptions.None);
+
+        if (parts.Length > 1)
+            return (EnvelopeUuid: parts[0], ReceiverSignature: parts[1]);
+        else
+            return (string.Empty, string.Empty);
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="envelopeReceiverReadOnlyId"></param>
+    /// <returns></returns>
+    public static long? DecodeEnvelopeReceiverReadOnlyId(this string envelopeReceiverReadOnlyId)
+    {
+        if (!envelopeReceiverReadOnlyId.IsBase64String())
+        {
+            return null;
+        }
+        byte[] bytes = Convert.FromBase64String(envelopeReceiverReadOnlyId);
+        string decodedString = Encoding.UTF8.GetString(bytes);
+        string[] parts = decodedString.Split(new string[] { "::" }, StringSplitOptions.None);
+
+        if (parts.Length > 2)
+            return long.TryParse(parts[1], out long readOnlyId) ? readOnlyId : null;
+        else
+            return null;
+    }
+
+    /// <summary>
+    /// Gets the envelope UUID from the decoded envelope receiver ID.
+    /// </summary>
+    /// <param name="envelopeReceiverId">The base64 encoded string to decode.</param>
+    /// <returns>The envelope UUID.</returns>
+    public static string? GetEnvelopeUuid(this string envelopeReceiverId) => envelopeReceiverId.DecodeEnvelopeReceiverId().EnvelopeUuid;
+
+    /// <summary>
+    /// Gets the receiver signature from the decoded envelope receiver ID.
+    /// </summary>
+    /// <param name="envelopeReceiverId">The base64 encoded string to decode.</param>
+    /// <returns>The receiver signature.</returns>
+    public static string? GetReceiverSignature(this string envelopeReceiverId) => envelopeReceiverId.DecodeEnvelopeReceiverId().ReceiverSignature;
+}

EnvelopeGenerator.Application/Common/Extensions/EncodingExtensions.cs

@@ -0,0 +1,38 @@
+using System.Text;
+
+namespace EnvelopeGenerator.Application.Common.Extensions;
+
+/// <summary>
+/// Provides extension methods for decoding and extracting information from an envelope receiver ID.
+/// </summary>
+public static class EncodingExtensions
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="readOnlyId"></param>
+    /// <returns></returns>
+    public static string ToEnvelopeKey(this long readOnlyId)
+    {
+        //The random number is used as a salt to increase security but it is not saved in the database.
+        string combinedString = $"{Random.Shared.Next()}::{readOnlyId}::{Random.Shared.Next()}";
+        byte[] bytes = Encoding.UTF8.GetBytes(combinedString);
+        string base64String = Convert.ToBase64String(bytes);
+
+        return base64String;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="input"></param>
+    /// <returns></returns>
+    public static string ToEnvelopeKey(this (string envelopeUuid, string receiverSignature) input)
+    {
+        string combinedString = $"{input.envelopeUuid}::{input.receiverSignature}";
+        byte[] bytes = Encoding.UTF8.GetBytes(combinedString);
+        string base64String = Convert.ToBase64String(bytes);
+
+        return base64String;
+    }
+}

EnvelopeGenerator.Application/Common/Extensions/LoggerExtensions.cs

@@ -1,7 +1,7 @@
 using Microsoft.Extensions.Logging;
 using System.Text;
 
-namespace EnvelopeGenerator.Extensions
+namespace EnvelopeGenerator.Application.Common.Extensions
 {
     public static class LoggerExtensions
     {

EnvelopeGenerator.Application/Common/Extensions/MappingExtensions.cs

@@ -1,6 +1,6 @@
-using EnvelopeGenerator.Application.DTOs.Messaging;
+using EnvelopeGenerator.Application.Common.Dto.Messaging;
 
-namespace EnvelopeGenerator.Application.Extensions;
+namespace EnvelopeGenerator.Application.Common.Extensions;
 
 /// <summary>
 /// Provides extension methods for common mapping and conversion operations.

EnvelopeGenerator.Application/Common/Extensions/MemoryCacheExtensions.cs

@@ -1,11 +1,24 @@
-using Microsoft.Extensions.Caching.Memory;
+using EnvelopeGenerator.Application.Common.Extensions;
+using Microsoft.Extensions.Caching.Memory;
 
-namespace EnvelopeGenerator.Extensions;
+namespace EnvelopeGenerator.Application.Common.Extensions;
 
+/// <summary>
+/// 
+/// </summary>
 public static class MemoryCacheExtensions
 {
     private static readonly Guid BaseId = Guid.NewGuid();
 
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <typeparam name="TEnum"></typeparam>
+    /// <param name="memoryCache"></param>
+    /// <param name="key"></param>
+    /// <param name="ignores"></param>
+    /// <returns></returns>
+    /// <exception cref="InvalidOperationException"></exception>
     public static IDictionary<string, int> GetEnumAsDictionary<TEnum>(this IMemoryCache memoryCache, string key = "", params object[] ignores)
         where TEnum : Enum
         => memoryCache.GetOrCreate(BaseId + typeof(TEnum).FullName + key, _ =>

EnvelopeGenerator.Application/Common/Extensions/QueryExtensions.cs

@@ -0,0 +1,125 @@
+using DigitalData.Core.Exceptions;
+using EnvelopeGenerator.Application.Common.Extensions;
+using EnvelopeGenerator.Application.Common.Query;
+using EnvelopeGenerator.Domain.Entities;
+using EnvelopeGenerator.Domain.Interfaces;
+
+namespace EnvelopeGenerator.Application.Common.Extensions;
+
+/// <summary>
+/// 
+/// </summary>
+public static class QueryExtensions
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <typeparam name="TEntity"></typeparam>
+    /// <param name="root"></param>
+    /// <param name="query"></param>
+    /// <param name="notnull"></param>
+    /// <returns></returns>
+    /// <exception cref="BadRequestException"></exception>
+    public static IQueryable<TEntity> Where<TEntity>(this IQueryable<TEntity> root, EnvelopeQueryBase query, bool notnull = true)
+        where TEntity : IHasEnvelope
+    {
+        if (query.Id is not null)
+            root = root.Where(e => e.Envelope!.Id == query.Id);
+        else if (query.Uuid is not null)
+            root = root.Where(e => e.Envelope!.Uuid == query.Uuid);
+        else if (notnull)
+            throw new BadRequestException(
+                "Either Envelope Id or Envelope Uuid must be provided in the query."
+            );
+
+        return root;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="root"></param>
+    /// <param name="query"></param>
+    /// <param name="notnull"></param>
+    /// <returns></returns>
+    /// <exception cref="BadRequestException"></exception>
+    public static IQueryable<Envelope> Where(this IQueryable<Envelope> root, EnvelopeQueryBase query, bool notnull = true)
+    {
+        if (query.Id is not null)
+            root = root.Where(e => e.Id == query.Id);
+        else if (query.Uuid is not null)
+            root = root.Where(e => e.Uuid == query.Uuid);
+        else if (notnull)
+            throw new BadRequestException(
+                "Either Envelope Id or Envelope Uuid must be provided in the query."
+            );
+
+        return root;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <typeparam name="TEntity"></typeparam>
+    /// <param name="root"></param>
+    /// <param name="query"></param>
+    /// <param name="notnull"></param>
+    /// <returns></returns>
+    /// <exception cref="BadRequestException"></exception>
+    public static IQueryable<TEntity> Where<TEntity>(this IQueryable<TEntity> root, ReceiverQueryBase query, bool notnull = true)
+        where TEntity : IHasReceiver
+    {
+        if (query.Id is not null)
+            root = root.Where(e => e.Receiver!.Id == query.Id);
+        else if (query.EmailAddress is not null)
+            root = root.Where(e => e.Receiver!.EmailAddress == query.EmailAddress);
+        else if (query.Signature is not null)
+            root = root.Where(e => e.Receiver!.Signature == query.Signature);
+        else if (notnull)
+            throw new BadRequestException(
+                "Receiver must have at least one identifier (Id, EmailAddress, or Signature)."
+            );
+
+        return root;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="root"></param>
+    /// <param name="query"></param>
+    /// <param name="notnull"></param>
+    /// <returns></returns>
+    /// <exception cref="BadRequestException"></exception>
+    public static IQueryable<Receiver> Where(this IQueryable<Receiver> root, ReceiverQueryBase query, bool notnull = true)
+    {
+        if (query.Id is not null)
+            root = root.Where(e => e.Id == query.Id);
+        else if (query.EmailAddress is not null)
+            root = root.Where(e => e.EmailAddress == query.EmailAddress);
+        else if (query.Signature is not null)
+            root = root.Where(e => e.Signature == query.Signature);
+        else if (notnull)
+            throw new BadRequestException(
+                "Receiver must have at least one identifier (Id, EmailAddress, or Signature)."
+            );
+
+        return root;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <typeparam name="TEntity"></typeparam>
+    /// <typeparam name="TEnvelopeQuery"></typeparam>
+    /// <typeparam name="TReceiverQuery"></typeparam>
+    /// <param name="root"></param>
+    /// <param name="query"></param>
+    /// <param name="notnull"></param>
+    /// <returns></returns>
+    public static IQueryable<TEntity> Where<TEntity, TEnvelopeQuery, TReceiverQuery>(this IQueryable<TEntity> root, EnvelopeReceiverQueryBase<TEnvelopeQuery, TReceiverQuery> query, bool notnull = true)
+        where TEntity : IHasEnvelope, IHasReceiver
+        where TEnvelopeQuery : EnvelopeQueryBase, new()
+        where TReceiverQuery : ReceiverQueryBase, new() 
+        => root.Where(query.Envelope, notnull).Where(query.Receiver, notnull);
+}

EnvelopeGenerator.Application/Common/Extensions/StringExtension.cs

@@ -1,6 +1,6 @@
 using OtpNet;
 
-namespace EnvelopeGenerator.Extensions
+namespace EnvelopeGenerator.Application.Common.Extensions
 {
     public static class StringExtension
     {

EnvelopeGenerator.Application/Common/Extensions/TaskExtensions.cs

@@ -0,0 +1,78 @@
+using DigitalData.Core.Exceptions;
+
+namespace EnvelopeGenerator.Application.Common.Extensions;
+
+/// <summary>
+/// Extension methods for tasks
+/// </summary>
+public static class TaskExtensions
+{
+    /// <summary>
+    /// Awaits the specified task and ensures that the result is not <c>null</c>.
+    /// If the result is <c>null</c>, the exception created by factory-method is thrown.
+    /// </summary>
+    /// <typeparam name="T">The type of the result.</typeparam>
+    /// <typeparam name="TException">The type of the exception.</typeparam>
+    /// <param name="task">The task to await.</param>
+    /// <param name="factory">Exception provider</param>
+    /// <returns>The awaited result if not <c>null</c>.</returns>
+    /// <exception>Thrown if the result is <c>null</c>.</exception>
+    public static async Task<T> ThrowIfNull<T, TException>(this Task<T?> task, Func<TException> factory) where TException : Exception
+    {
+        var result = await task;
+        return result ?? throw factory();
+    }
+
+    /// <summary>
+    /// Awaits the specified task and ensures that the result is not <c>empty</c>.
+    /// If the result contains no elements, the exception created by factory-method is thrown.
+    /// </summary>
+    /// <typeparam name="T">The element type of the collection.</typeparam>
+    /// <typeparam name="TException">The type of the exception.</typeparam>
+    /// <param name="task">The task to await.</param>
+    /// <param name="factory">Exception provider</param>
+    /// <returns>The awaited collection if it is not <c>null</c> or empty.</returns>
+    /// <exception cref="NotFoundException">Thrown if the result is <c>null</c> or empty.</exception>
+    public static async Task<IEnumerable<T>> ThrowIfEmpty<T, TException>(this Task<IEnumerable<T>> task, Func<TException> factory) where TException : Exception
+    {
+        var result = await task;
+        return result?.Any() ?? false ? result : throw factory();
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    /// <typeparam name="I"></typeparam>
+    /// <param name="task"></param>
+    /// <param name="act"></param>
+    /// <returns></returns>
+    public static async Task<I> Then<T, I>(this Task<T> task, Func<T, I> act)
+    {
+        var res = await task;
+        return act(res);
+    }
+}
+
+/// <summary>
+/// 
+/// </summary>
+public static class Exceptions
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public static NotFoundException NotFound() => new();
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    public static BadRequestException BadRequest() => new();
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    public static ForbiddenException Forbidden() => new();
+}

EnvelopeGenerator.Application/Common/Extensions/XSSExtensions.cs

@@ -2,7 +2,7 @@
 using Microsoft.Extensions.Localization;
 using System.Text.Encodings.Web;
 
-namespace EnvelopeGenerator.Extensions
+namespace EnvelopeGenerator.Application.Common.Extensions
 {
     public static class XSSExtensions
     {

EnvelopeGenerator.Application/Common/Notifications/DocSigned/DocSignedNotification.cs

@@ -0,0 +1,55 @@
+using EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiver;
+using EnvelopeGenerator.Domain.Constants;
+using MediatR;
+using Newtonsoft.Json;
+using System.Dynamic;
+
+namespace EnvelopeGenerator.Application.Common.Notifications.DocSigned;
+
+/// <summary>
+/// 
+/// </summary>
+/// <param name="Original"></param>
+public record DocSignedNotification(EnvelopeReceiverDto Original) : EnvelopeReceiverDto(Original), INotification, ISendMailNotification
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public required ExpandoObject Annotations { get; init; }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public EmailTemplateType TemplateType => EmailTemplateType.DocumentSigned;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public string EmailAddress => Receiver?.EmailAddress
+        ?? throw new InvalidOperationException($"Receiver is null." +
+            $"DocSignedNotification:\n{JsonConvert.SerializeObject(this, Format.Json.ForDiagnostics)}");
+}
+
+/// <summary>
+/// 
+/// </summary>
+public static class DocSignedNotificationExtensions
+{
+    /// <summary>
+    /// Converts an <see cref="EnvelopeReceiverDto"/> to a <see cref="DocSignedNotification"/>.
+    /// </summary>
+    /// <param name="dto">The DTO to convert.</param>
+    /// <param name="annotations"></param>
+    /// <returns>A new <see cref="DocSignedNotification"/> instance.</returns>
+    public static DocSignedNotification ToDocSignedNotification(this EnvelopeReceiverDto dto, ExpandoObject annotations)
+        => new(dto) { Annotations = annotations };
+
+    /// <summary>
+    /// Asynchronously converts a <see cref="Task{EnvelopeReceiverDto}"/> to a <see cref="DocSignedNotification"/>.
+    /// </summary>
+    /// <param name="dtoTask">The task that returns the DTO to convert.</param>
+    /// <param name="annotations"></param>
+    /// <returns>A task that represents the asynchronous conversion operation.</returns>
+    public static async Task<DocSignedNotification?> ToDocSignedNotification(this Task<EnvelopeReceiverDto?> dtoTask, ExpandoObject annotations)
+        => await dtoTask is EnvelopeReceiverDto dto ? new(dto) { Annotations = annotations } : null;
+}

EnvelopeGenerator.Application/Common/Notifications/DocSigned/Handlers/AnnotationHandler.cs

@@ -0,0 +1,40 @@
+using EnvelopeGenerator.Application.Common.Notifications.DocSigned;
+using EnvelopeGenerator.Application.DocStatus.Commands;
+using EnvelopeGenerator.Domain.Constants;
+using MediatR;
+using Newtonsoft.Json;
+
+namespace EnvelopeGenerator.Application.Common.Notifications.DocSigned.Handlers;
+
+/// <summary>
+/// 
+/// </summary>
+public class AnnotationHandler : INotificationHandler<DocSignedNotification>
+{
+    private readonly ISender _sender;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="sender"></param>
+    public AnnotationHandler(ISender sender)
+    {
+        _sender = sender;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="notification"></param>
+    /// <param name="cancel"></param>
+    /// <returns></returns>
+    public async Task Handle(DocSignedNotification notification, CancellationToken cancel)
+    {
+        await _sender.Send(new SaveDocStatusCommand()
+        {
+            Envelope = new() { Id = notification.EnvelopeId },
+            Receiver = new() { Id = notification.ReceiverId},
+            Value = JsonConvert.SerializeObject(notification.Annotations, Format.Json.ForAnnotations)
+        }, cancel);
+    }
+}

EnvelopeGenerator.Application/Common/Notifications/DocSigned/Handlers/HistoryHandler.cs

@@ -0,0 +1,45 @@
+using EnvelopeGenerator.Application.Common.Notifications.DocSigned;
+using EnvelopeGenerator.Application.Histories.Commands;
+using EnvelopeGenerator.Domain.Constants;
+using MediatR;
+using Newtonsoft.Json;
+
+namespace EnvelopeGenerator.Application.Common.Notifications.DocSigned.Handlers;
+
+/// <summary>
+/// 
+/// </summary>
+public class HistoryHandler : INotificationHandler<DocSignedNotification>
+{
+    private readonly ISender _sender;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="sender"></param>
+    public HistoryHandler(ISender sender)
+    {
+        _sender = sender;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="notification"></param>
+    /// <param name="cancel"></param>
+    /// <returns></returns>
+    public async Task Handle(DocSignedNotification notification, CancellationToken cancel)
+    {
+        if(notification.Receiver is null)
+            if (notification.Receiver is null)
+                throw new InvalidOperationException($"Receiver information is missing in the notification. DocSignedNotification:\n {JsonConvert.SerializeObject(notification, Format.Json.ForDiagnostics)}");
+
+        await _sender.Send(new CreateHistoryCommand()
+        {
+            EnvelopeId = notification.EnvelopeId,
+            UserReference = notification.Receiver.EmailAddress,
+            Status = EnvelopeStatus.DocumentSigned,
+            Comment = JsonConvert.SerializeObject(notification.Annotations, Format.Json.ForAnnotations)
+        }, cancel);
+    }
+}

EnvelopeGenerator.Application/Common/Notifications/DocSigned/Handlers/SendSignedMailHandler.cs

@@ -0,0 +1,50 @@
+using DigitalData.Core.Abstraction.Application.Repository;
+using DigitalData.EmailProfilerDispatcher.Abstraction.Entities;
+using EnvelopeGenerator.Application.Common.Configurations;
+using EnvelopeGenerator.Domain.Entities;
+using Microsoft.Extensions.Options;
+
+namespace EnvelopeGenerator.Application.Common.Notifications.DocSigned.Handlers;
+
+/// <summary>
+/// 
+/// </summary>
+public class SendSignedMailHandler : SendMailHandler<DocSignedNotification>
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="tempRepo"></param>
+    /// <param name="emailOutRepo"></param>
+    /// <param name="mailParamsOptions"></param>
+    /// <param name="dispatcherParamsOptions"></param>
+    public SendSignedMailHandler(IRepository<EmailTemplate> tempRepo, IRepository<EmailOut> emailOutRepo, IOptions<MailParams> mailParamsOptions, IOptions<DispatcherParams> dispatcherParamsOptions) : base(tempRepo, emailOutRepo, mailParamsOptions, dispatcherParamsOptions)
+    {
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="notification"></param>
+    /// <param name="emailOut"></param>
+    protected override void ConfigureEmailOut(DocSignedNotification notification, EmailOut emailOut)
+    {
+        emailOut.ReferenceString = notification.EmailAddress;
+        emailOut.ReferenceId = notification.ReceiverId;
+    }
+
+    /// <summary>
+    /// </summary>
+    /// <param name="notification"></param>
+    /// <returns></returns>
+    protected override Dictionary<string, string> CreatePlaceHolders(DocSignedNotification notification)
+    {
+        var placeHolders = new Dictionary<string, string>()
+        {
+            { "[NAME_RECEIVER]", notification.Name ?? string.Empty },
+            { "[DOCUMENT_TITLE]", notification.Envelope?.Title ?? string.Empty },
+        };
+
+        return placeHolders;
+    }
+}

EnvelopeGenerator.Application/Common/Notifications/SendMailHandler.cs

@@ -0,0 +1,152 @@
+using DigitalData.Core.Abstraction.Application.Repository;
+using DigitalData.EmailProfilerDispatcher.Abstraction.Entities;
+using EnvelopeGenerator.Application.Common.Configurations;
+using EnvelopeGenerator.Domain.Constants;
+using EnvelopeGenerator.Domain.Entities;
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Options;
+using Newtonsoft.Json;
+
+namespace EnvelopeGenerator.Application.Common.Notifications;
+
+/// <summary>
+/// 
+/// </summary>
+public interface ISendMailNotification : INotification
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public EmailTemplateType TemplateType { get; }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public string EmailAddress { get; }
+}
+
+/// <summary>
+/// 
+/// </summary>
+public abstract class SendMailHandler<TNotification> : INotificationHandler<TNotification>
+    where TNotification : ISendMailNotification
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    protected readonly IRepository<EmailTemplate> TempRepo;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    protected readonly IRepository<EmailOut> EmailOutRepo;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    protected abstract Dictionary<string, string> CreatePlaceHolders(TNotification notification);
+
+    /// <summary>
+    ///{ "[MESSAGE]", notification.Message },<br/>
+    ///{ "[DOCUMENT_ACCESS_CODE]", notification.ReceiverAccessCode },<br/>
+    ///{ "[REASON]", pReason }<br/>
+    ///{ "[NAME_SENDER]", notification.Envelope.User?.FullName},<br/>
+    ///{ "[NAME_PORTAL]", DispatcherParams. },<br/>
+    ///{ "[SIGNATURE_TYPE]", "signieren" },<br/>
+    ///{ "[LINK_TO_DOCUMENT]", notification.SignatureLink },<br/>
+    ///{ "[LINK_TO_DOCUMENT_TEXT]", $"{notification.SignatureLink.Truncate(40)}.." },
+    /// </summary>
+    protected readonly MailParams MailParams;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    protected readonly DispatcherParams DispatcherParams;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="notification"></param>
+    /// <param name="emailOut"></param>
+    protected abstract void ConfigureEmailOut(TNotification notification, EmailOut emailOut);
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="tempRepo"></param>
+    /// <param name="emailOutRepo"></param>
+    /// <param name="mailParamsOptions"></param>
+    /// <param name="dispatcherParamsOptions"></param>
+    protected SendMailHandler(IRepository<EmailTemplate> tempRepo, IRepository<EmailOut> emailOutRepo, IOptions<MailParams> mailParamsOptions, IOptions<DispatcherParams> dispatcherParamsOptions)
+    {
+        TempRepo = tempRepo;
+        EmailOutRepo = emailOutRepo;
+        MailParams = mailParamsOptions.Value;
+        DispatcherParams = dispatcherParamsOptions.Value;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="notification"></param>
+    /// <param name="cancel"></param>
+    /// <returns></returns>
+    /// <exception cref="NotImplementedException"></exception>
+    public virtual async Task Handle(TNotification notification, CancellationToken cancel)
+    {
+        var placeHolders = CreatePlaceHolders(notification);
+
+        var temp = await TempRepo
+            .ReadOnly()
+            .SingleOrDefaultAsync(x => x.Name == notification.TemplateType.ToString(), cancel)
+                ?? throw new InvalidOperationException($"Receiver information is missing in the notification." +
+                $"{typeof(TNotification)}:\n {JsonConvert.SerializeObject(notification, Format.Json.ForDiagnostics)}");
+
+        temp.Subject = ReplacePlaceHolders(temp.Subject, placeHolders, MailParams.Placeholders);
+
+        temp.Body = ReplacePlaceHolders(temp.Body, placeHolders, MailParams.Placeholders);
+
+        var emailOut = new EmailOut
+        {
+            EmailAddress = notification.EmailAddress,
+            EmailBody = TextToHtml(temp.Body),
+            EmailSubj = temp.Subject,
+            AddedWhen = DateTime.UtcNow,
+            AddedWho = DispatcherParams.AddedWho,
+            SendingProfile = DispatcherParams.SendingProfile,
+            ReminderTypeId = DispatcherParams.ReminderTypeId,
+            EmailAttmt1 = DispatcherParams.EmailAttmt1,
+            WfId = (int)EnvelopeStatus.MessageConfirmationSent,
+            
+        };
+        ConfigureEmailOut(notification, emailOut);
+        await EmailOutRepo.CreateAsync(emailOut, cancel);
+    }
+
+    private static string ReplacePlaceHolders(string text, params Dictionary<string, string>[] placeHoldersList)
+    {
+        foreach (var placeHolders in placeHoldersList)
+            foreach (var ph in placeHolders)
+                text = text.Replace(ph.Key, ph.Value);
+        return text;
+    }
+
+    private static string TextToHtml(string input)
+    {
+        if (string.IsNullOrEmpty(input)) return "";
+
+        // HTML encoding special characters
+        string encoded = System.Net.WebUtility.HtmlEncode(input);
+
+        // Convert tabs to &nbsp; (4 non-breaking spaces)
+        encoded = encoded.Replace("\t", "&nbsp;&nbsp;&nbsp;&nbsp;");
+
+        // Convert line breaks to <br />
+        encoded = encoded.Replace("\r\n", "<br />"); // Windows
+        encoded = encoded.Replace("\r", "<br />");   // Mac old
+        encoded = encoded.Replace("\n", "<br />");   // Unix/Linux
+
+        return encoded;
+    }
+}

EnvelopeGenerator.Application/Common/Query/EnvelopeQueryBase.cs

@@ -0,0 +1,17 @@
+namespace EnvelopeGenerator.Application.Common.Query;
+
+/// <summary>
+/// Repräsentiert eine Abfrage für Umschläge.
+/// </summary>
+public record EnvelopeQueryBase
+{
+    /// <summary>
+    /// Die eindeutige Kennung des Umschlags.
+    /// </summary>
+    public virtual int? Id { get; set; }
+
+    /// <summary>
+    /// Die universell eindeutige Kennung des Umschlags.
+    /// </summary>
+    public virtual string? Uuid { get; set; }
+}

EnvelopeGenerator.Application/Common/Query/EnvelopeReceiverQueryBase.cs

@@ -0,0 +1,62 @@
+using DigitalData.Core.Exceptions;
+using EnvelopeGenerator.Application.Common.Extensions;
+
+namespace EnvelopeGenerator.Application.Common.Query;
+
+/// <summary>
+/// 
+/// </summary>
+public record EnvelopeReceiverQueryBase : EnvelopeReceiverQueryBase<EnvelopeQueryBase, ReceiverQueryBase>;
+
+/// <summary>
+/// 
+/// </summary>
+/// <typeparam name="TEnvelopeQuery"></typeparam>
+/// <typeparam name="TReceiverQuery"></typeparam>
+public record EnvelopeReceiverQueryBase<TEnvelopeQuery, TReceiverQuery>
+    where TEnvelopeQuery : EnvelopeQueryBase, new()
+    where TReceiverQuery : ReceiverQueryBase, new()
+{
+    private string? _key;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public virtual string? Key
+    {
+        get => _key;
+        set
+        {
+            if (value is null)
+            {
+                _key = null;
+                return;
+            }
+
+            (string? EnvelopeUuid, string? ReceiverSignature) = value.DecodeEnvelopeReceiverId();
+            if (string.IsNullOrEmpty(EnvelopeUuid) || string.IsNullOrEmpty(ReceiverSignature))
+                throw new BadRequestException("Der EnvelopeReceiverKey muss ein gültiger Base64-kodierter String sein, der die EnvelopeUuid und die ReceiverSignature enthält.");
+
+            Envelope = new TEnvelopeQuery()
+            {
+                Uuid = EnvelopeUuid
+            };
+            Receiver = new TReceiverQuery()
+            {
+                Signature = ReceiverSignature
+            };
+            _key = value;
+        }
+    }
+
+    /// <summary>
+    /// Repräsentiert eine Abfrage für Umschläge.
+    /// </summary>
+    public virtual TEnvelopeQuery Envelope { get; set; } = new();
+
+    /// <summary>
+    /// Stellt eine Abfrage dar, um die Details eines Empfängers zu lesen.
+    /// um spezifische Informationen über einen Empfänger abzurufen.
+    /// </summary>
+    public virtual TReceiverQuery Receiver { get; set; } = new();
+}

EnvelopeGenerator.Application/Common/Query/MappingProfile.cs

@@ -0,0 +1,20 @@
+using AutoMapper;
+using EnvelopeGenerator.Domain.Entities;
+
+namespace EnvelopeGenerator.Application.Common.Query;
+
+/// <summary>
+/// 
+/// </summary>
+public class MappingProfile : Profile
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public MappingProfile()
+    {
+        CreateMap<EnvelopeQueryBase, Envelope>();
+        CreateMap<ReceiverQueryBase, Receiver>();
+        CreateMap<EnvelopeReceiverQueryBase, EnvelopeReceiver>();
+    }
+}

EnvelopeGenerator.Application/Common/Query/ReceiverQueryBase.cs

@@ -0,0 +1,23 @@
+namespace EnvelopeGenerator.Application.Common.Query;
+
+/// <summary>
+/// Stellt eine Abfrage dar, um die Details eines Empfängers zu lesen.
+/// um spezifische Informationen über einen Empfänger abzurufen.
+/// </summary>
+public record ReceiverQueryBase
+{
+    /// <summary>
+    /// ID des Empfängers
+    /// </summary>
+    public virtual int? Id { get; set; }
+
+    /// <summary>
+    /// E-Mail Adresse des Empfängers
+    /// </summary>
+    public virtual string? EmailAddress { get; set; }
+
+    /// <summary>
+    /// Eindeutige Signatur des Empfängers
+    /// </summary>
+    public virtual string? Signature { get; set; }
+}

EnvelopeGenerator.Application/Common/SQL/DocumentCreateReadSQL.cs

@@ -1,14 +1,14 @@
 using Dapper;
-using EnvelopeGenerator.Application.Contracts.SQLExecutor;
-using EnvelopeGenerator.Application.Exceptions;
+using EnvelopeGenerator.Application.Interfaces.SQLExecutor;
+using DigitalData.Core.Exceptions;
 using EnvelopeGenerator.Domain.Entities;
 
-namespace EnvelopeGenerator.Application.SQL;
+namespace EnvelopeGenerator.Application.Common.SQL;
 
 /// <summary>
 /// 
 /// </summary>
-public class DocumentCreateReadSQL : ISQL<EnvelopeDocument>
+public class DocumentCreateReadSQL : ISQL<Document>
 {
     /// <summary>
     /// Base64, OUT_UID

EnvelopeGenerator.Application/Common/SQL/EnvelopeCreateReadSQL.cs

@@ -1,9 +1,9 @@
 using Dapper;
-using EnvelopeGenerator.Application.Contracts.SQLExecutor;
+using EnvelopeGenerator.Application.Interfaces.SQLExecutor;
 using EnvelopeGenerator.Domain.Entities;
 using System.Data;
 
-namespace EnvelopeGenerator.Application.SQL;
+namespace EnvelopeGenerator.Application.Common.SQL;
 
 /// <summary>
 /// 

EnvelopeGenerator.Application/Common/SQL/EnvelopeReceiverAddReadSQL.cs

@@ -1,8 +1,8 @@
 using Dapper;
-using EnvelopeGenerator.Application.Contracts.SQLExecutor;
+using EnvelopeGenerator.Application.Interfaces.SQLExecutor;
 using EnvelopeGenerator.Domain.Entities;
 
-namespace EnvelopeGenerator.Application.SQL;
+namespace EnvelopeGenerator.Application.Common.SQL;
 
 /// <summary>
 /// 

EnvelopeGenerator.Application/Common/SQL/ParamsExtensions.cs

@@ -1,6 +1,6 @@
 using System.Globalization;
 
-namespace EnvelopeGenerator.Application.SQL;
+namespace EnvelopeGenerator.Application.Common.SQL;
 
 /// <summary>
 /// Extension method for converting objects to SQL parameter strings.

EnvelopeGenerator.Application/Contracts/Repositories/IEnvelopeCertificateRepository.cs

@@ -1,12 +0,0 @@
-using DigitalData.Core.Abstraction.Application.Repository;
-using EnvelopeGenerator.Domain.Entities;
-
-namespace EnvelopeGenerator.Application.Contracts.Repositories;
-
-/// <summary>
-/// 
-/// </summary>
-[Obsolete("Use Read-method returning IReadQuery<TEntity> instead.")]
-public interface IEnvelopeCertificateRepository : ICRUDRepository<EnvelopeCertificate, int>
-{
-}

EnvelopeGenerator.Application/Contracts/Services/IEnvelopeCertificateService.cs

@@ -1,13 +0,0 @@
-using DigitalData.Core.Abstraction.Application;
-using EnvelopeGenerator.Application.DTOs;
-using EnvelopeGenerator.Domain.Entities;
-
-namespace EnvelopeGenerator.Application.Contracts.Services;
-
-/// <summary>
-/// 
-/// </summary>
-[Obsolete("Use MediatR")]
-public interface IEnvelopeCertificateService : IBasicCRUDService<EnvelopeCertificateDto, EnvelopeCertificate, int>
-{
-}

EnvelopeGenerator.Application/Contracts/Services/IEnvelopeDocumentService.cs

@@ -1,13 +0,0 @@
-using DigitalData.Core.Abstraction.Application;
-using EnvelopeGenerator.Application.DTOs;
-using EnvelopeGenerator.Domain.Entities;
-
-namespace EnvelopeGenerator.Application.Contracts.Services;
-
-/// <summary>
-/// 
-/// </summary>
-[Obsolete("Use MediatR")]
-public interface IEnvelopeDocumentService : IBasicCRUDService<EnvelopeDocumentDto, EnvelopeDocument, int>
-{
-}

EnvelopeGenerator.Application/DTOs/EnvelopeCertificateDto.cs

@@ -1,50 +0,0 @@
-using Microsoft.AspNetCore.Mvc;
-
-namespace EnvelopeGenerator.Application.DTOs;
-
-/// <summary>
-/// Data Transfer Object representing certificate information for an envelope.
-/// </summary>
-[ApiExplorerSettings(IgnoreApi = true)]
-public class EnvelopeCertificateDto
-{
-    /// <summary>
-    /// Gets the unique identifier of the certificate.
-    /// </summary>
-    public int Id { get; init; }
-
-    /// <summary>
-    /// Gets the envelope ID associated with the certificate.
-    /// </summary>
-    public int EnvelopeId { get; init; }
-
-    /// <summary>
-    /// Gets the UUID of the envelope.
-    /// </summary>
-    public string EnvelopeUuid { get; init; } = string.Empty;
-
-    /// <summary>
-    /// Gets the subject of the envelope.
-    /// </summary>
-    public string EnvelopeSubject { get; init; } = string.Empty;
-
-    /// <summary>
-    /// Gets the ID of the creator of the envelope.
-    /// </summary>
-    public int CreatorId { get; init; }
-
-    /// <summary>
-    /// Gets the name of the creator.
-    /// </summary>
-    public string CreatorName { get; init; } = string.Empty;
-
-    /// <summary>
-    /// Gets the email address of the creator.
-    /// </summary>
-    public string CreatorEmail { get; init; } = string.Empty;
-
-    /// <summary>
-    /// Gets the current status of the envelope.
-    /// </summary>
-    public int EnvelopeStatus { get; init; }
-}

EnvelopeGenerator.Application/DTOs/EnvelopeReceiver/EnvelopeReceiverDto.cs

@@ -1,22 +0,0 @@
-using EnvelopeGenerator.Application.DTOs.Receiver;
-using Microsoft.AspNetCore.Mvc;
-
-namespace EnvelopeGenerator.Application.DTOs.EnvelopeReceiver;
-
-/// <summary>
-/// 
-/// </summary>
-
-[ApiExplorerSettings(IgnoreApi = true)]
-public record EnvelopeReceiverDto() : EnvelopeReceiverBasicDto()
-{
-    /// <summary>
-    /// 
-    /// </summary>
-    public EnvelopeDto? Envelope { get; set; }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    public ReceiverReadDto? Receiver { get; set; }
-}

EnvelopeGenerator.Application/DTOs/Receiver/ReceiverCreateDto.cs

@@ -1,53 +0,0 @@
-using Microsoft.AspNetCore.Mvc;
-using System.ComponentModel.DataAnnotations;
-using System.Security.Cryptography;
-using System.Text;
-
-namespace EnvelopeGenerator.Application.DTOs.Receiver;
-
-/// <summary>
-/// 
-/// </summary>
-[ApiExplorerSettings(IgnoreApi = true)]
-public record ReceiverCreateDto
-{
-    /// <summary>
-    /// 
-    /// </summary>
-    public ReceiverCreateDto()
-    {
-        _sha256HexOfMail = new(() =>
-        {
-            var bytes_arr = Encoding.UTF8.GetBytes(EmailAddress!.ToUpper());
-            var hash_arr = SHA256.HashData(bytes_arr);
-            var hexa_str = BitConverter.ToString(hash_arr);
-            return hexa_str.Replace("-", string.Empty);
-        });
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    [EmailAddress]
-    public required string EmailAddress { get; init; }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    public string? TotpSecretkey { get; init; }
-
-    /// <summary>
-    /// var bytes_arr = Encoding.UTF8.GetBytes(EmailAddress.ToUpper());<br/>
-    /// var hash_arr = SHA256.HashData(bytes_arr);
-    /// var hexa_str = BitConverter.ToString(hash_arr);
-    /// return hexa_str.Replace("-", string.Empty);
-    /// </summary>
-    public string Signature => _sha256HexOfMail.Value;
-
-    private readonly Lazy<string> _sha256HexOfMail;
-
-    /// <summary>
-    /// Default value is DateTime.Now
-    /// </summary>
-    public DateTime AddedWhen { get; } = DateTime.Now;
-};

EnvelopeGenerator.Application/DependencyInjection.cs

@@ -1,13 +1,12 @@
-using EnvelopeGenerator.Application.Configurations;
+using DigitalData.Core.Client;
+using EnvelopeGenerator.Application.Common.Configurations;
+using EnvelopeGenerator.Application.Interfaces.Services;
 using EnvelopeGenerator.Application.Services;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
-using DigitalData.Core.Client;
 using QRCoder;
-using EnvelopeGenerator.Application.Contracts.Services;
 using System.Reflection;
-using EnvelopeGenerator.Application.EnvelopeReceivers.Commands.Create;
 
 namespace EnvelopeGenerator.Application;
 
@@ -33,7 +32,6 @@ public static class DependencyInjection
         services.TryAddScoped<IDocumentStatusService, DocumentStatusService>();
         services.TryAddScoped<IEmailTemplateService, EmailTemplateService>();
         services.TryAddScoped<IEnvelopeService, EnvelopeService>();
-        services.TryAddScoped<IEnvelopeCertificateService, EnvelopeCertificateService>();
         services.TryAddScoped<IEnvelopeDocumentService, EnvelopeDocumentService>();
         services.TryAddScoped<IEnvelopeReceiverService, EnvelopeReceiverService>();
         services.TryAddScoped<IEnvelopeTypeService, EnvelopeTypeService>();
@@ -59,7 +57,6 @@ public static class DependencyInjection
         services.AddMediatR(cfg =>
         {
             cfg.RegisterServicesFromAssembly(Assembly.GetExecutingAssembly());
-            cfg.RegisterServicesFromAssembly(typeof(CreateEnvelopeReceiverCommandHandler).Assembly);
         });
 
         return services;

EnvelopeGenerator.Application/DocStatus/Commands/CreateDocStatusCommand.cs

@@ -0,0 +1,12 @@
+namespace EnvelopeGenerator.Application.DocStatus.Commands;
+
+/// <summary>
+/// 
+/// </summary>
+public record CreateDocStatusCommand : ModifyDocStatusCommandBase
+{
+    /// <summary>
+    /// Gets timestamp when this record was added. Returns the StatusChangedWhen value.
+    /// </summary>
+    public DateTime AddedWhen => StatusChangedWhen;
+}

EnvelopeGenerator.Application/DocStatus/Commands/ModifyDocStatusCommandBase.cs

@@ -0,0 +1,54 @@
+using EnvelopeGenerator.Application.Common.Query;
+using EnvelopeGenerator.Domain.Constants;
+
+namespace EnvelopeGenerator.Application.DocStatus.Commands;
+
+/// <summary>
+/// 
+/// </summary>
+public record ModifyDocStatusCommandBase : EnvelopeReceiverQueryBase
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public int? EnvelopeId => Envelope.Id;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public int? ReceiverId => Receiver.Id;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public override ReceiverQueryBase Receiver { get => base.Receiver; set => base.Receiver = value; }
+
+    /// <summary>
+    /// Gets the current status code.
+    /// </summary>
+    public DocumentStatus Status => Value is null ? DocumentStatus.Created : DocumentStatus.Signed;
+
+    /// <summary>
+    /// Gets or sets the display value associated with the status.
+    /// </summary>
+    public string? Value { get; set; }
+
+    /// <summary>
+    /// Gets timestamp when this record was added.
+    /// </summary>
+    public DateTime StatusChangedWhen { get; } = DateTime.Now;
+
+    /// <summary>
+    /// Maps the current command to a new instance of the specified type.
+    /// </summary>
+    /// <typeparam name="TDest"></typeparam>
+    /// <returns></returns>
+    public TDest To<TDest>() where TDest : ModifyDocStatusCommandBase, new()
+        => new()
+        {
+            Key = Key,
+            Envelope = Envelope,
+            Receiver = Receiver,
+            Value = Value
+        };
+}

EnvelopeGenerator.Application/DocStatus/Commands/SaveDocStatusCommand.cs

@@ -0,0 +1,77 @@
+using DigitalData.Core.Abstraction.Application.Repository;
+using EnvelopeGenerator.Domain.Entities;
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+using AutoMapper;
+using EnvelopeGenerator.Application.Common.Dto;
+using EnvelopeGenerator.Application.Common.Extensions;
+
+namespace EnvelopeGenerator.Application.DocStatus.Commands;
+
+/// <summary>
+/// Represents a command to save the status of a document, either by creating a new status or updating an existing one based on the provided envelope and receiver identifiers.
+/// It returns the identifier of the saved document status.
+/// </summary>
+public record SaveDocStatusCommand : ModifyDocStatusCommandBase, IRequest<DocumentStatusDto?>;
+
+/// <summary>
+/// 
+/// </summary>
+public class SaveDocStatusCommandHandler : IRequestHandler<SaveDocStatusCommand, DocumentStatusDto?>
+{
+    private readonly IMapper _mapper;
+
+    private readonly IRepository<DocumentStatus> _repo;
+
+    private readonly IRepository<Envelope> _envRepo;
+
+    private readonly IRepository<Receiver> _rcvRepo;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="mapper"></param>
+    /// <param name="repo"></param>
+    /// <param name="rcvRepo"></param>
+    /// <param name="envRepo"></param>
+    public SaveDocStatusCommandHandler(IMapper mapper, IRepository<DocumentStatus> repo, IRepository<Receiver> rcvRepo, IRepository<Envelope> envRepo)
+    {
+        _mapper = mapper;
+        _repo = repo;
+        _rcvRepo = rcvRepo;
+        _envRepo = envRepo;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="request"></param>
+    /// <param name="cancel"></param>
+    /// <returns></returns>
+    public async Task<DocumentStatusDto?> Handle(SaveDocStatusCommand request, CancellationToken cancel)
+    {
+        // ceck if exists
+        bool isExists = await _repo.ReadOnly().Where(request).AnyAsync(cancel);
+
+        var env = await _envRepo.ReadOnly().Where(request.Envelope).FirstAsync(cancel);
+        var rcv = await _rcvRepo.ReadOnly().Where(request.Receiver).FirstAsync(cancel);
+
+        request.Envelope.Id = env.Id;
+        request.Receiver.Id = rcv.Id;
+
+        if (isExists)
+        {
+            var uReq = request.To<UpdateDocStatusCommand>();
+            await _repo.UpdateAsync(uReq, q => q.Where(request), cancel);
+        }
+        else
+        {
+            var cReq = request.To<CreateDocStatusCommand>();
+            await _repo.CreateAsync(cReq, cancel);
+        }
+
+        var docStatus = await _repo.ReadOnly().Where(request).SingleOrDefaultAsync(cancel);
+        
+        return _mapper.Map<DocumentStatusDto>(docStatus);
+    }
+}

EnvelopeGenerator.Application/DocStatus/Commands/UpdateDocStatusCommand.cs

@@ -0,0 +1,14 @@
+using EnvelopeGenerator.Domain;
+
+namespace EnvelopeGenerator.Application.DocStatus.Commands;
+
+/// <summary>
+/// 
+/// </summary>
+public record UpdateDocStatusCommand : ModifyDocStatusCommandBase
+{
+    /// <summary>
+    /// Gets timestamp when this record was added. Returns the StatusChangedWhen value.
+    /// </summary>
+    public DateTime? ChangedWhen => StatusChangedWhen;
+}

EnvelopeGenerator.Application/DocStatus/MappingProfile.cs

@@ -0,0 +1,25 @@
+using AutoMapper;
+using EnvelopeGenerator.Application.DocStatus.Commands;
+using EnvelopeGenerator.Domain.Entities;
+
+namespace EnvelopeGenerator.Application.DocStatus;
+
+/// <summary>
+/// 
+/// </summary>
+public class MappingProfile : Profile
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public MappingProfile()
+    {
+        CreateMap<CreateDocStatusCommand, DocumentStatus>()
+        .ForMember(dest => dest.Envelope, opt => opt.Ignore())
+        .ForMember(dest => dest.Receiver, opt => opt.Ignore());
+
+        CreateMap<UpdateDocStatusCommand, DocumentStatus>()
+        .ForMember(dest => dest.Envelope, opt => opt.Ignore())
+        .ForMember(dest => dest.Receiver, opt => opt.Ignore());
+    }
+}

EnvelopeGenerator.Application/Documents/Queries/Read/ReadDocumentMappingProfile.cs

@@ -1,18 +0,0 @@
-using AutoMapper;
-using EnvelopeGenerator.Domain.Entities;
-
-namespace EnvelopeGenerator.Application.Documents.Queries.Read;
-
-/// <summary>
-/// 
-/// </summary>
-public class ReadDocumentMappingProfile : Profile
-{
-    /// <summary>
-    /// 
-    /// </summary>
-    public ReadDocumentMappingProfile()
-    {
-        CreateMap<EnvelopeDocument, ReadDocumentResponse>();
-    }
-}

EnvelopeGenerator.Application/Documents/Queries/Read/ReadDocumentQuery.cs

@@ -1,12 +0,0 @@
-using MediatR;
-
-namespace EnvelopeGenerator.Application.Documents.Queries.Read;
-
-/// <summary>
-/// Represents a query to read a document based on its unique identifier or associated envelope identifier.
-/// </summary>
-/// <param name="Id">The unique identifier of the document. Optional.</param>
-/// <param name="EnvelopeId">The identifier of the envelope associated with the document. Optional.</param>
-public record ReadDocumentQuery(int? Id = null, int? EnvelopeId = null) : IRequest<ReadDocumentResponse?>
-{
-}

EnvelopeGenerator.Application/Documents/Queries/Read/ReadDocumentQueryHandler.cs

@@ -1,48 +0,0 @@
-using DigitalData.Core.Abstraction.Application.Repository;
-using EnvelopeGenerator.Domain.Entities;
-using MediatR;
-
-namespace EnvelopeGenerator.Application.Documents.Queries.Read;
-
-/// <summary>
-/// Handles queries for reading <see cref="EnvelopeDocument"/> data based on either the document ID or the envelope ID.
-/// </summary>
-public class ReadDocumentQueryHandler : IRequestHandler<ReadDocumentQuery, ReadDocumentResponse?>
-{
-    /// <summary>
-    /// Repository for accessing <see cref="EnvelopeDocument"/> entities.
-    /// </summary>
-    private readonly IRepository<EnvelopeDocument> _repo;
-
-    /// <summary>
-    /// Initializes a new instance of the <see cref="ReadDocumentQueryHandler"/> class.
-    /// </summary>
-    /// <param name="envelopeDocumentRepository">The repository used to access <see cref="EnvelopeDocument"/> entities.</param>
-    public ReadDocumentQueryHandler(IRepository<EnvelopeDocument> envelopeDocumentRepository)
-    {
-        _repo = envelopeDocumentRepository;
-    }
-
-    /// <summary>
-    /// Handles the <see cref="ReadDocumentQuery"/> and returns a <see cref="ReadDocumentResponse"/> based on the provided identifiers.
-    /// </summary>
-    /// <param name="query">The query containing the document ID or envelope ID to search for.</param>
-    /// <param name="cancellationToken">A token to monitor for cancellation requests.</param>
-    /// <returns>
-    /// A <see cref="ReadDocumentResponse"/> if a matching document is found; otherwise, <c>null</c>.
-    /// </returns>
-    /// <exception cref="InvalidOperationException">
-    /// Thrown when neither <see cref="ReadDocumentQuery.Id"/> nor <see cref="ReadDocumentQuery.EnvelopeId"/> is provided.
-    /// </exception>
-    [Obsolete("Use MediatR")]
-    public async Task<ReadDocumentResponse?> Handle(ReadDocumentQuery query, CancellationToken cancellationToken)
-    {
-        if (query.Id is not null)
-            return await _repo.ReadOrDefaultAsync<ReadDocumentResponse>(d => d.Id == query.Id);
-        else if (query.EnvelopeId is not null)
-            return await _repo.ReadOrDefaultAsync<ReadDocumentResponse>(d => d.EnvelopeId == query.EnvelopeId);
-
-        throw new InvalidOperationException(
-            $"Invalid {nameof(ReadDocumentQuery)}: either {nameof(query.Id)} or {nameof(query.EnvelopeId)} must be provided.");
-    }
-}

EnvelopeGenerator.Application/Documents/Queries/Read/ReadDocumentResponse.cs

@@ -1,12 +0,0 @@
-namespace EnvelopeGenerator.Application.Documents.Queries.Read;
-
-/// <summary>
-/// Represents the response for reading a document.
-/// </summary>
-public class ReadDocumentResponse : ReadDocumentResponseBase
-{
-    /// <summary>
-    /// The binary data of the document, if available.
-    /// </summary>
-    public byte[]? ByteData { get; init; }
-}

EnvelopeGenerator.Application/Documents/Queries/Read/ReadDocumentResponseBase.cs

@@ -1,22 +0,0 @@
-namespace EnvelopeGenerator.Application.Documents.Queries.Read;
-
-/// <summary>
-/// Represents the response for reading a document.
-/// </summary>
-public class ReadDocumentResponseBase
-{
-    /// <summary>
-    /// The unique identifier of the document.
-    /// </summary>
-    public int Guid { get; init; }
-
-    /// <summary>
-    /// The identifier of the associated envelope.
-    /// </summary>
-    public int EnvelopeId { get; init; }
-
-    /// <summary>
-    /// The date and time when the document was added.
-    /// </summary>
-    public DateTime AddedWhen { get; init; }
-}

EnvelopeGenerator.Application/Documents/Queries/ReadDocumentQuery.cs

@@ -0,0 +1,69 @@
+using DigitalData.Core.Abstraction.Application.Repository;
+using MediatR;
+using EnvelopeGenerator.Domain.Entities;
+using Microsoft.EntityFrameworkCore;
+using AutoMapper;
+using EnvelopeGenerator.Application.Common.Dto;
+
+namespace EnvelopeGenerator.Application.Documents.Queries;
+
+/// <summary>
+/// Represents a query to read a document based on its unique identifier or associated envelope identifier.
+/// </summary>
+/// <param name="Id">The unique identifier of the document. Optional.</param>
+/// <param name="EnvelopeId">The identifier of the envelope associated with the document. Optional.</param>
+public record ReadDocumentQuery(int? Id = null, int? EnvelopeId = null) : IRequest<DocumentDto?>
+{
+}
+
+/// <summary>
+/// Handles queries for reading <see cref="Document"/> data based on either the document ID or the envelope ID.
+/// </summary>
+public class ReadDocumentQueryHandler : IRequestHandler<ReadDocumentQuery, DocumentDto?>
+{
+    /// <summary>
+    /// TempRepo for accessing <see cref="Document"/> entities.
+    /// </summary>
+    private readonly IRepository<Document> _repo;
+
+    private readonly IMapper _mapper;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ReadDocumentQueryHandler"/> class.
+    /// </summary>
+    /// <param name="envelopeDocumentRepository">The repository used to access <see cref="Document"/> entities.</param>
+    /// <param name="mapper"></param>
+    public ReadDocumentQueryHandler(IRepository<Document> envelopeDocumentRepository, IMapper mapper)
+    {
+        _repo = envelopeDocumentRepository;
+        _mapper = mapper;
+    }
+
+    /// <summary>
+    /// Handles the <see cref="ReadDocumentQuery"/> and returns a <see cref="DocumentDto"/> based on the provided identifiers.
+    /// </summary>
+    /// <param name="query">The query containing the document ID or envelope ID to search for.</param>
+    /// <param name="cancel">A token to monitor for cancellation requests.</param>
+    /// <returns>
+    /// A <see cref="DocumentDto"/> if a matching document is found; otherwise, <c>null</c>.
+    /// </returns>
+    /// <exception cref="InvalidOperationException">
+    /// Thrown when neither <see cref="ReadDocumentQuery.Id"/> nor <see cref="ReadDocumentQuery.EnvelopeId"/> is provided.
+    /// </exception>
+    public async Task<DocumentDto?> Handle(ReadDocumentQuery query, CancellationToken cancel)
+    {
+        if (query.Id is not null)
+        {
+            var doc = await _repo.ReadOnly().Where(d => d.Id == query.Id).FirstOrDefaultAsync(cancel);
+            return _mapper.Map<DocumentDto>(doc);
+        }            
+        else if (query.EnvelopeId is not null)
+        {
+            var doc = await _repo.ReadOnly().Where(d => d.EnvelopeId == query.EnvelopeId).FirstOrDefaultAsync(cancel);
+            return _mapper.Map<DocumentDto>(doc);
+        }
+
+        throw new InvalidOperationException(
+            $"Invalid {nameof(ReadDocumentQuery)}: either {nameof(query.Id)} or {nameof(query.EnvelopeId)} must be provided.");
+    }
+}

EnvelopeGenerator.Application/EmailTemplates/Commands/Reset/ResetEmailTemplateCommand.cs

@@ -1,4 +1,5 @@
 using EnvelopeGenerator.Domain;
+using EnvelopeGenerator.Domain.Constants;
 using MediatR;
 
 namespace EnvelopeGenerator.Application.EmailTemplates.Commands.Reset;
@@ -33,8 +34,8 @@ public record ResetEmailTemplateCommand : EmailTemplateQuery, IRequest
     /// 
     /// </summary>
     /// <param name="Id">Die optionale ID der E-Mail-Vorlage, die zurückgesetzt werden soll.</param>
-    /// <param name="Type">Der Typ der E-Mail-Vorlage, z. B. <see cref="Constants.EmailTemplateType"/> (optional).</param>
-    public ResetEmailTemplateCommand(int? Id = null, Constants.EmailTemplateType? Type = null) : base(Id, Type)
+    /// <param name="Type">Der Typ der E-Mail-Vorlage, z. B. <see cref="EmailTemplateType"/> (optional).</param>
+    public ResetEmailTemplateCommand(int? Id = null, EmailTemplateType? Type = null) : base(Id, Type)
     {
     }
 };

EnvelopeGenerator.Application/EmailTemplates/Commands/Reset/ResetEmailTemplateCommandHandler.cs

@@ -1,7 +1,9 @@
 using DigitalData.Core.Abstraction.Application.Repository;
-using EnvelopeGenerator.Application.DTOs;
+using EnvelopeGenerator.Application.Common.Dto;
 using EnvelopeGenerator.Domain.Entities;
 using MediatR;
+using Microsoft.EntityFrameworkCore;
+using System.Linq;
 
 namespace EnvelopeGenerator.Application.EmailTemplates.Commands.Reset;
 
@@ -31,10 +33,10 @@ public class ResetEmailTemplateCommandHandler : IRequestHandler<ResetEmailTempla
     public async Task Handle(ResetEmailTemplateCommand request, CancellationToken cancel)
     {
         var temps = request.Id is not null
-            ? await _repository.ReadAllAsync<EmailTemplateDto>(t => t.Id == request.Id, cancel)
+            ? await _repository.ReadOnly().Where(t => t.Id == request.Id).ToListAsync(cancel)
             : request.Type is not null
-                ? await _repository.ReadAllAsync<EmailTemplateDto>(t => t.Name == request.Type.ToString(), cancel)
-                : await _repository.ReadAllAsync<EmailTemplateDto>(cancellation: cancel);
+                ? await _repository.ReadOnly().Where(t => t.Name == request.Type.ToString()).ToListAsync(cancel)
+                : await _repository.ReadOnly().ToListAsync(cancel);
 
         foreach (var temp in temps)
         {
@@ -82,7 +84,7 @@ public class ResetEmailTemplateCommandHandler : IRequestHandler<ResetEmailTempla
         new(){
         Id = 6,
         Name = "DocumentRejected_ADM",
-        Body = "Guten Tag [NAME_SENDER],<p><B><I>[NAME_RECEIVER]</I></B> hat den Umschlag <B><I>'[DOCUMENT_TITLE]'</I></B> mit folgendem Grund abgelehnt: <p>\r\n[REASON] \r\n<p>Der Umschlag wurde auf den Status Rejected gesetzt. <p> \r\nMit freundlichen Grüßen<br />\r\n<br />\r\n[NAME_PORTAL]",
+        Body = "Guten Tag [NAME_SENDER],<p><B><I>[NAME_RECEIVER]</I></B> hat den Umschlag <B><I>'[DOCUMENT_TITLE]'</I></B> mit folgendem Grund abgelehnt: <p>\r\n[REASON] \r\n<p>Der Umschlag wurde auf den Include Rejected gesetzt. <p> \r\nMit freundlichen Grüßen<br />\r\n<br />\r\n[NAME_PORTAL]",
         Subject = "'[DOCUMENT_TITLE]' - Unterzeichnungsvorgang zurückgezogen"
         },
         new(){

EnvelopeGenerator.Application/EmailTemplates/Commands/Update/UpdateEmailTemplateCommandHandler.cs

@@ -1,9 +1,11 @@
-using DigitalData.Core.Abstraction.Application.Repository;
-using EnvelopeGenerator.Application.DTOs;
-using EnvelopeGenerator.Application.Exceptions;
-using EnvelopeGenerator.Domain;
+using AutoMapper;
+using DigitalData.Core.Abstraction.Application.Repository;
+using DigitalData.Core.Exceptions;
 using EnvelopeGenerator.Domain.Entities;
 using MediatR;
+using Microsoft.EntityFrameworkCore;
+using EnvelopeGenerator.Domain.Constants;
+using EnvelopeGenerator.Application.Common.Dto;
 
 namespace EnvelopeGenerator.Application.EmailTemplates.Commands.Update;
 
@@ -13,14 +15,17 @@ namespace EnvelopeGenerator.Application.EmailTemplates.Commands.Update;
 public class UpdateEmailTemplateCommandHandler : IRequestHandler<UpdateEmailTemplateCommand>
 {
     private readonly IRepository<EmailTemplate> _repository;
+    
+    private readonly IMapper _mapper;
 
     /// <summary>
     /// 
     /// </summary>
     /// <param name="repository"></param>
-    public UpdateEmailTemplateCommandHandler(IRepository<EmailTemplate> repository)
+    public UpdateEmailTemplateCommandHandler(IRepository<EmailTemplate> repository, IMapper mapper)
     {
         _repository = repository;
+        _mapper = mapper;
     }
 
     /// <summary>
@@ -34,32 +39,34 @@ public class UpdateEmailTemplateCommandHandler : IRequestHandler<UpdateEmailTemp
     [Obsolete("Use Read-method returning IReadQuery<TEntity> instead.")]
     public async Task Handle(UpdateEmailTemplateCommand request, CancellationToken cancel)
     {
-        EmailTemplateDto? temp;
+        EmailTemplateDto? tempDto;
 
         if (request.EmailTemplateQuery?.Id is int id)
         {
-            temp = await _repository.ReadOrDefaultAsync<EmailTemplateDto>(t => t.Id == id, single: false, cancel);
+            var temp = await _repository.ReadOnly().Where(t => t.Id == id).FirstOrDefaultAsync(cancel);
+            tempDto = _mapper.Map<EmailTemplateDto>(temp);
         }
-        else if (request!.EmailTemplateQuery!.Type is Constants.EmailTemplateType type)
+        else if (request!.EmailTemplateQuery!.Type is EmailTemplateType type)
         {
-            temp = await _repository.ReadOrDefaultAsync<EmailTemplateDto>(t => t.Name == type.ToString(), single: false, cancel);
+            var temp = await _repository.ReadOnly().Where(t => t.Name == type.ToString()).FirstOrDefaultAsync(cancel);
+            tempDto = _mapper.Map<EmailTemplateDto>(temp);
         }
         else
         {
             throw new InvalidOperationException("Both id and type is null. Id: " + request.EmailTemplateQuery.Id +". Type: " + request.EmailTemplateQuery.Type.ToString());
         }
 
-        if (temp == null)
+        if (tempDto == null)
         {
             throw new NotFoundException();
         }
 
         if (request.Body is not null)
-            temp.Body = request.Body;
+            tempDto.Body = request.Body;
 
         if (request.Subject is not null)
-            temp.Subject = request.Subject;
+            tempDto.Subject = request.Subject;
 
-        await _repository.UpdateAsync(temp, t => t.Id == temp.Id, cancel);
+        await _repository.UpdateAsync(tempDto, t => t.Id == tempDto.Id, cancel);
     }
 }

EnvelopeGenerator.Application/EmailTemplates/EmailTemplateQuery.cs

@@ -1,4 +1,4 @@
-using EnvelopeGenerator.Domain;
+using EnvelopeGenerator.Domain.Constants;
 
 namespace EnvelopeGenerator.Application.EmailTemplates;
 
@@ -7,7 +7,7 @@ namespace EnvelopeGenerator.Application.EmailTemplates;
 /// Die Standardkultur ist "de-DE".
 /// </summary>
 /// <param name="Id">Die eindeutige Kennung der E-Mail-Vorlage (optional).</param>
-/// <param name="Type">Der Typ der E-Mail-Vorlage, z. B. <see cref="Constants.EmailTemplateType"/> (optional). Beispiele:
+/// <param name="Type">Der Typ der E-Mail-Vorlage, z. B. <see cref="EmailTemplateType"/> (optional). Beispiele:
 /// 0 - DocumentReceived: Benachrichtigung über den Empfang eines Dokuments.
 /// 1 - DocumentSigned: Benachrichtigung über die Unterzeichnung eines Dokuments.
 /// 2 - DocumentDeleted: Benachrichtigung über das Löschen eines Dokuments.
@@ -19,6 +19,6 @@ namespace EnvelopeGenerator.Application.EmailTemplates;
 /// 8 - DocumentRejected_REC (Für den ablehnenden Empfänger): Mail an den ablehnenden Empfänger, wenn das Dokument abgelehnt wird.
 /// 9 - DocumentRejected_REC_2 (Für sonstige Empfänger): Mail an andere Empfänger (Brief), wenn das Dokument abgelehnt wird.
 /// </param>
-public record EmailTemplateQuery(int? Id = null, Constants.EmailTemplateType? Type = null)
+public record EmailTemplateQuery(int? Id = null, EmailTemplateType? Type = null)
 {
 }

EnvelopeGenerator.Application/EmailTemplates/MappingProfile.cs

@@ -1,4 +1,5 @@
 using AutoMapper;
+using EnvelopeGenerator.Application.EmailTemplates.Queries.Read;
 using EnvelopeGenerator.Domain.Entities;
 using System;
 using System.Collections.Generic;
@@ -6,17 +7,17 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 
-namespace EnvelopeGenerator.Application.EmailTemplates.Queries.Read;
+namespace EnvelopeGenerator.Application.EmailTemplates;
 
 /// <summary>
 /// 
 /// </summary>
-public class ReadEmailTemplateMappingProfile : Profile
+public class MappingProfile : Profile
 {
     /// <summary>
     /// 
     /// </summary>
-    public ReadEmailTemplateMappingProfile()
+    public MappingProfile()
     {
         CreateMap<EmailTemplate, ReadEmailTemplateResponse>();
     }

EnvelopeGenerator.Application/EmailTemplates/Queries/Read/ReadEmailTemplateQueryHandler.cs

@@ -1,6 +1,6 @@
 using AutoMapper;
-using EnvelopeGenerator.Application.Contracts.Repositories;
-using EnvelopeGenerator.Domain;
+using EnvelopeGenerator.Application.Interfaces.Repositories;
+using EnvelopeGenerator.Domain.Constants;
 using MediatR;
 
 namespace EnvelopeGenerator.Application.EmailTemplates.Queries.Read;
@@ -41,7 +41,7 @@ public class ReadEmailTemplateQueryHandler : IRequestHandler<ReadEmailTemplateQu
     {
         var temp = request.Id is int id
             ? await _repository.ReadByIdAsync(id)
-            : request.Type is Constants.EmailTemplateType type
+            : request.Type is EmailTemplateType type
                 ? await _repository.ReadByNameAsync(type)
                 : throw new InvalidOperationException("Either a valid integer ID or a valid EmailTemplateType must be provided in the request.");
 

EnvelopeGenerator.Application/EnvelopeFlag.cs

@@ -1,10 +0,0 @@
-namespace EnvelopeGenerator.Application
-{
-    public enum EnvelopeFlag
-    {
-        EnvelopeOrReceiverNonexists,
-        NonDecodableEnvelopeReceiverId,
-        WrongEnvelopeReceiverId,
-        AccessCodeNull
-    }
-}

EnvelopeGenerator.Application/EnvelopeGenerator.Application.csproj

@@ -14,22 +14,34 @@
 
 	<ItemGroup>
 		<PackageReference Include="Dapper" Version="2.1.66" />
-		<PackageReference Include="DigitalData.Core.Abstraction.Application" Version="1.0.0" />
-		<PackageReference Include="DigitalData.Core.Application" Version="3.3.4" />
+		<PackageReference Include="DigitalData.Core.Abstraction.Application" Version="1.2.1" />
+		<PackageReference Include="DigitalData.Core.Application" Version="3.4.0" />
 		<PackageReference Include="DigitalData.Core.Client" Version="2.1.0" />
+		<PackageReference Include="DigitalData.Core.Exceptions" Version="1.1.0" />
 		<PackageReference Include="DigitalData.EmailProfilerDispatcher" Version="3.1.1" />
+		<PackageReference Include="HtmlSanitizer" Version="8.0.865" />
 		<PackageReference Include="MediatR" Version="12.5.0" />
 		<PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="7.0.18" />
-		<PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="9.0.5" />
 		<PackageReference Include="Otp.NET" Version="1.4.0" />
 		<PackageReference Include="QRCoder" Version="1.6.0" />
 		<PackageReference Include="QRCoder-ImageSharp" Version="0.10.0" />
-		<PackageReference Include="UserManager" Version="1.1.1" />
+		<PackageReference Include="UserManager" Version="1.1.3" />
+	</ItemGroup>
+
+	<ItemGroup Condition="'$(TargetFramework)' == 'net7.0'">
+		<PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
+	</ItemGroup>
+
+	<ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
+		<PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="9.0.5" />
+	</ItemGroup>
+
+	<ItemGroup Condition="'$(TargetFramework)' == 'net9.0'">
+		<PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="9.0.5" />
 	</ItemGroup>
 
 	<ItemGroup>
 		<ProjectReference Include="..\EnvelopeGenerator.Domain\EnvelopeGenerator.Domain.csproj" />
-		<ProjectReference Include="..\EnvelopeGenerator.Extensions\EnvelopeGenerator.Extensions.csproj" />
 	</ItemGroup>
 
 	<ItemGroup>

EnvelopeGenerator.Application/EnvelopeReceivers/Commands/Create/CreateEnvelopeReceiverCommand.cs

@@ -1,21 +0,0 @@
-using EnvelopeGenerator.Application.Envelopes.Commands;
-using MediatR;
-using System.ComponentModel.DataAnnotations;
-
-namespace EnvelopeGenerator.Application.EnvelopeReceivers.Commands.Create;
-
-/// <summary>
-/// Befehl zur Erstellung eines Umschlags.
-/// </summary>
-/// <param name="Title">Der Titel des Umschlags. Dies ist ein Pflichtfeld.</param>
-/// <param name="Message">Die Nachricht, die im Umschlag enthalten sein soll. Dies ist ein Pflichtfeld.</param>
-/// <param name="Document">Das mit dem Umschlag verknüpfte Dokument. Dies ist ein Pflichtfeld.</param>
-/// <param name="Receivers">Eine Sammlung von Empfängern, die den Umschlag erhalten. Dies ist ein Pflichtfeld.</param>
-/// <param name="TFAEnabled">Gibt an, ob die Zwei-Faktor-Authentifizierung für den Umschlag aktiviert ist. Standardmäßig false.</param>
-public record CreateEnvelopeReceiverCommand(
-    [Required] string Title,
-    [Required] string Message,
-    [Required] DocumentCreateCommand Document,
-    [Required] IEnumerable<ReceiverGetOrCreateCommand> Receivers,
-    bool TFAEnabled = false
-    ) : CreateEnvelopeCommand(Title, Message, TFAEnabled), IRequest<CreateEnvelopeReceiverResponse>;

EnvelopeGenerator.Application/EnvelopeReceivers/Commands/Create/CreateEnvelopeReceiverDtos.cs

@@ -1,48 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.ComponentModel.DataAnnotations;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace EnvelopeGenerator.Application.EnvelopeReceivers.Commands.Create;
-
-#region DTOs
-/// <summary>
-/// Signaturposition auf einem Dokument.
-/// </summary>
-/// <param name="X">X-Position</param>
-/// <param name="Y">Y-Position</param>
-/// <param name="Page">Seite, auf der sie sich befindet</param>
-public record Signature([Required] double X, [Required] double Y, [Required] int Page);
-
-/// <summary>
-/// DTO für Empfänger, die erstellt oder abgerufen werden sollen.
-/// Wenn nicht, wird sie erstellt und mit einer Signatur versehen.
-/// </summary>
-/// <param name="Signatures">Unterschriften auf Dokumenten.</param>
-/// <param name="Salution">Der Name, mit dem der Empfänger angesprochen werden soll. Bei Null oder keinem Wert wird der zuletzt verwendete Name verwendet.</param>
-/// <param name="PhoneNumber">Sollte mit Vorwahl geschrieben werden</param>
-public record ReceiverGetOrCreateCommand([Required] IEnumerable<Signature> Signatures, string? Salution = null, string? PhoneNumber = null)
-{
-    private string _emailAddress = string.Empty;
-
-    /// <summary>
-    /// E-Mail-Adresse des Empfängers.
-    /// </summary>
-    [Required]
-    public string EmailAddress { get => _emailAddress.ToLower(); init => _emailAddress = value.ToLower(); }
-};
-
-/// <summary>
-/// DTO zum Erstellen eines Dokuments.
-/// </summary>
-public record DocumentCreateCommand()
-{
-    /// <summary>
-    /// Die Dokumentdaten im Base64-String-Format. Wird verwendet, wenn das Dokument als Base64-codierter String bereitgestellt wird.
-    /// </summary>
-    [Required]
-    public required string DataAsBase64 { get; init; }
-};
-#endregion

EnvelopeGenerator.Application/EnvelopeReceivers/Commands/Create/CreateEnvelopeReceiverMappingProfile.cs

@@ -1,21 +0,0 @@
-using AutoMapper;
-using EnvelopeGenerator.Application.DTOs.Receiver;
-using EnvelopeGenerator.Application.Envelopes.Commands;
-using EnvelopeGenerator.Domain.Entities;
-
-namespace EnvelopeGenerator.Application.EnvelopeReceivers.Commands.Create;
-
-/// <summary>
-/// 
-/// </summary>
-public class CreateEnvelopeReceiverMappingProfile : Profile
-{
-    /// <summary>
-    /// 
-    /// </summary>
-    public CreateEnvelopeReceiverMappingProfile()
-    {
-        CreateMap<Envelope, CreateEnvelopeResponse>();
-        CreateMap<Receiver, ReceiverReadDto>();
-    }
-}

EnvelopeGenerator.Application/EnvelopeReceivers/Commands/Create/CreateEnvelopeReceiverResponse.cs

@@ -1,39 +0,0 @@
-using DigitalData.UserManager.Domain.Entities;
-using EnvelopeGenerator.Application.DTOs.Receiver;
-using EnvelopeGenerator.Application.Envelopes.Commands;
-
-namespace EnvelopeGenerator.Application.EnvelopeReceivers.Commands.Create;
-
-/// <summary>
-/// 
-/// </summary>
-public record CreateEnvelopeReceiverResponse : CreateEnvelopeResponse
-{
-    /// <summary>
-    /// 
-    /// </summary>
-    /// <param name="Id"></param>
-    /// <param name="UserId"></param>
-    /// <param name="Status"></param>
-    /// <param name="Uuid"></param>
-    /// <param name="Message"></param>
-    /// <param name="AddedWhen"></param>
-    /// <param name="ChangedWhen"></param>
-    /// <param name="Title"></param>
-    /// <param name="Language"></param>
-    /// <param name="TFAEnabled"></param>
-    /// <param name="User"></param>
-    public CreateEnvelopeReceiverResponse(int Id, int UserId, int Status, string Uuid, string? Message, DateTime AddedWhen, DateTime? ChangedWhen, string? Title, string Language, bool TFAEnabled, User User) : base(Id, UserId, Status, Uuid, Message, AddedWhen, ChangedWhen, Title, Language, TFAEnabled, User)
-    {
-    }
-
-    /// <summary>
-    /// 
-    /// </summary>
-    public IEnumerable<ReceiverReadDto> SentReceiver { get; set; } = new List<ReceiverReadDto>();
-
-    /// <summary>
-    /// 
-    /// </summary>
-    public IEnumerable<ReceiverGetOrCreateCommand> UnsentReceivers { get; set; } = new List<ReceiverGetOrCreateCommand>();
-}

EnvelopeGenerator.Application/EnvelopeReceivers/Commands/CreateEnvelopeReceiverCommand.cs

@@ -0,0 +1,81 @@
+using EnvelopeGenerator.Application.Envelopes.Commands;
+using MediatR;
+using System.ComponentModel.DataAnnotations;
+
+namespace EnvelopeGenerator.Application.EnvelopeReceivers.Commands;
+
+/// <summary>
+/// Befehl zur Erstellung eines Umschlags.
+/// </summary>
+public record CreateEnvelopeReceiverCommand : CreateEnvelopeCommand, IRequest<CreateEnvelopeReceiverResponse>
+{
+    /// <summary>
+    /// Das mit dem Umschlag verknüpfte Dokument. Dies ist ein Pflichtfeld.
+    /// </summary>
+    [Required]
+    public required DocumentCreateCommand Document { get; set; }
+
+    /// <summary>
+    /// Eine Sammlung von Empfängern, die den Umschlag erhalten. Dies ist ein Pflichtfeld.
+    /// </summary>
+    [Required]
+    public List<ReceiverGetOrCreateCommand> Receivers { get; set; } = new();
+}
+
+#region Subcommands
+/// <summary>
+/// Signaturposition auf einem Dokument.
+/// </summary>
+/// <param name="X">X-Position</param>
+/// <param name="Y">Y-Position</param>
+/// <param name="Page">Seite, auf der sie sich befindet</param>
+public record Signature([Required] double X, [Required] double Y, [Required] int Page);
+
+/// <summary>
+/// DTO für Empfänger, die erstellt oder abgerufen werden sollen.
+/// Wenn nicht, wird sie erstellt und mit einer Signatur versehen.
+/// </summary>
+public class ReceiverGetOrCreateCommand
+{
+    /// <summary>
+    /// Unterschriften auf Dokumenten.
+    /// </summary>
+    [Required]
+    public List<Signature> Signatures { get; init; } = new();
+
+    /// <summary>
+    /// Der Name, mit dem der Empfänger angesprochen werden soll.
+    /// Bei Null oder keinem Wert wird der zuletzt verwendete Name verwendet.
+    /// </summary>
+    public string? Salution { get; init; }
+
+    /// <summary>
+    /// Sollte mit Vorwahl geschrieben werden
+    /// </summary>
+    public string? PhoneNumber { get; init; }
+
+    private string _emailAddress = string.Empty;
+
+    /// <summary>
+    /// E-Mail-Adresse des Empfängers.
+    /// </summary>
+    [Required]
+    public string EmailAddress
+    {
+        get => _emailAddress.ToLower();
+        init => _emailAddress = value.ToLower();
+    }
+}
+
+/// <summary>
+/// DTO zum Erstellen eines Dokuments.
+/// </summary>
+public record DocumentCreateCommand()
+{
+    /// <summary>
+    /// Die Dokumentdaten im Base64-String-Format. Wird verwendet, wenn das Dokument als Base64-codierter String bereitgestellt wird.
+    /// </summary>
+    [Required]
+    public required string DataAsBase64 { get; init; }
+};
+#endregion

EnvelopeGenerator.Application/EnvelopeReceivers/Commands/CreateEnvelopeReceiverCommandHandler.cs

@@ -1,10 +1,10 @@
 using AutoMapper;
-using EnvelopeGenerator.Application.Contracts.SQLExecutor;
-using EnvelopeGenerator.Application.DTOs.Receiver;
+using EnvelopeGenerator.Application.Interfaces.SQLExecutor;
 using EnvelopeGenerator.Domain.Entities;
 using MediatR;
+using EnvelopeGenerator.Application.Common.Dto.Receiver;
 
-namespace EnvelopeGenerator.Application.EnvelopeReceivers.Commands.Create;
+namespace EnvelopeGenerator.Application.EnvelopeReceivers.Commands;
 
 /// <summary>
 /// Handles the creation of an envelope along with its associated document and recipients.
@@ -42,9 +42,7 @@ public class CreateEnvelopeReceiverCommandHandler : IRequestHandler<CreateEnvelo
     /// <returns>A task representing the asynchronous operation.</returns>
     public async Task<CreateEnvelopeReceiverResponse> Handle(CreateEnvelopeReceiverCommand request, CancellationToken cancel)
     {
-        int userId = request.UserId ?? throw new InvalidOperationException("UserId cannot be null when creating an envelope.");
-
-        var envelope = await _envelopeExecutor.CreateEnvelopeAsync(userId, request.Title, request.Message, request.TFAEnabled, cancel);
+        var envelope = await _envelopeExecutor.CreateEnvelopeAsync(request.UserId, request.Title, request.Message, request.TFAEnabled, cancel);
 
         List<EnvelopeReceiver> sentRecipients = new();
         List<ReceiverGetOrCreateCommand> unsentRecipients = new();
@@ -61,7 +59,7 @@ public class CreateEnvelopeReceiverCommandHandler : IRequestHandler<CreateEnvelo
 
         var res = _mapper.Map<CreateEnvelopeReceiverResponse>(envelope);
         res.UnsentReceivers = unsentRecipients;
-        res.SentReceiver = _mapper.Map<IEnumerable<ReceiverReadDto>>(sentRecipients);
+        res.SentReceiver = _mapper.Map<IEnumerable<ReceiverDto>>(sentRecipients);
         return res;
     }
 }

EnvelopeGenerator.Application/EnvelopeReceivers/Commands/CreateEnvelopeReceiverResponse.cs

@@ -0,0 +1,20 @@
+using EnvelopeGenerator.Application.Common.Dto;
+using EnvelopeGenerator.Application.Common.Dto.Receiver;
+
+namespace EnvelopeGenerator.Application.EnvelopeReceivers.Commands;
+
+/// <summary>
+/// 
+/// </summary>
+public record CreateEnvelopeReceiverResponse : EnvelopeDto
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public IEnumerable<ReceiverDto> SentReceiver { get; set; } = new List<ReceiverDto>();
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public IEnumerable<ReceiverGetOrCreateCommand> UnsentReceivers { get; set; } = new List<ReceiverGetOrCreateCommand>();
+}

EnvelopeGenerator.Application/EnvelopeReceivers/MappingProfile.cs

@@ -0,0 +1,20 @@
+using AutoMapper;
+using EnvelopeGenerator.Application.Common.Dto.Receiver;
+using EnvelopeGenerator.Application.Envelopes.Commands;
+using EnvelopeGenerator.Domain.Entities;
+
+namespace EnvelopeGenerator.Application.EnvelopeReceivers;
+
+/// <summary>
+/// 
+/// </summary>
+public class MappingProfile : Profile
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public MappingProfile()
+    {
+        CreateMap<Receiver, ReceiverDto>();
+    }
+}

EnvelopeGenerator.Application/EnvelopeReceivers/Queries/Read/ReadEnvelopeReceiverQuery.cs

@@ -1,30 +0,0 @@
-using EnvelopeGenerator.Application.Histories;
-using EnvelopeGenerator.Application.Envelopes.Queries.Read;
-using EnvelopeGenerator.Application.Receivers.Queries.Read;
-using MediatR;
-
-namespace EnvelopeGenerator.Application.EnvelopeReceivers.Queries.Read;
-
-/// <summary>
-/// Repräsentiert eine Abfrage zum Lesen eines Envelope-Empfängers.
-/// </summary>
-/// <remarks>
-/// Diese Abfrage kombiniert Informationen über einen Umschlag (<see cref="ReadEnvelopeQuery"/>) 
-/// und einen Empfänger (<see cref="ReadReceiverQuery"/>), um eine vollständige Antwort 
-/// (<see cref="ReadEnvelopeReceiverResponse"/>) zu generieren. 
-/// Die Antwort enthält Details wie den Status, die Zuordnung zwischen Umschlag und Empfänger 
-/// sowie zusätzliche Metadaten.
-/// </remarks>
-/// <param name="Status">Umschlag oder Empfängerstatus.</param>
-public record ReadEnvelopeReceiverQuery(EnvelopeStatusQuery? Status = null) : EnvelopeReceiverQuery(Status), IRequest<ReadEnvelopeReceiverResponse>
-{
-    /// <summary>
-    /// Der Umschlag, der mit dem Empfänger verknüpft ist.
-    /// </summary>
-    public ReadEnvelopeQuery? Envelope { get; init; }
-
-    /// <summary>
-    /// Der Empfänger, der mit dem Umschlag verknüpft ist.
-    /// </summary>
-    public ReadReceiverQuery? Receiver { get; init; }
-};

EnvelopeGenerator.Application/EnvelopeReceivers/Queries/Read/ReadEnvelopeReceiverResponse.cs

@@ -1,94 +0,0 @@
-using DigitalData.EmailProfilerDispatcher.Abstraction.Attributes;
-using EnvelopeGenerator.Application.Envelopes.Queries.Read;
-using EnvelopeGenerator.Application.Receivers.Queries.Read;
-using System.ComponentModel.DataAnnotations;
-using System.ComponentModel.DataAnnotations.Schema;
-
-namespace EnvelopeGenerator.Application.EnvelopeReceivers.Queries.Read;
-
-/// <summary>
-/// Repräsentiert die Antwort für das Lesen eines Envelope-Empfängers.
-/// </summary>
-/// <remarks>
-/// Diese Klasse enthält Informationen über einen spezifischen Empfänger eines Umschlags (Envelope).
-/// Sie verknüpft die Empfängerinformationen mit den zugehörigen Umschlagsdaten und bietet zusätzliche Metadaten.
-/// </remarks>
-/// <param name="UserId">Die eindeutige Kennung des Benutzers, der den Empfänger erstellt hat.</param>
-/// <param name="Status">Der Status des Empfängers als numerischer Wert.</param>
-public record ReadEnvelopeReceiverResponse(int UserId, int Status)
-{
-    /// <summary>
-    /// Gibt die zusammengesetzte Kennung des Empfängers zurück, bestehend aus der Umschlags-ID und der Empfänger-ID.
-    /// </summary>
-    /// <remarks>
-    /// Diese Eigenschaft kombiniert die eindeutige Kennung des Umschlags (EnvelopeId) und die des Empfängers (ReceiverId) 
-    /// zu einer einzigen, leicht zugänglichen Struktur.
-    /// </remarks>
-    [NotMapped]
-    public (int Envelope, int Receiver) Id => (Envelope: EnvelopeId, Receiver: ReceiverId);
-
-    /// <summary>
-    /// Die eindeutige Kennung des zugehörigen Umschlags.
-    /// </summary>
-    [Required]
-    public int EnvelopeId { get; init; }
-
-    /// <summary>
-    /// Die eindeutige Kennung des Empfängers.
-    /// </summary>
-    [Required]
-    public int ReceiverId { get; init; }
-
-    /// <summary>
-    /// Die Reihenfolge des Empfängers innerhalb des Umschlags.
-    /// </summary>
-    public int Sequence { get; init; }
-
-    /// <summary>
-    /// Der Name des Empfängers. Kann als Platzhalter verwendet werden.
-    /// </summary>
-    [TemplatePlaceholder("[NAME_RECEIVER]")]
-    public string? Name { get; init; }
-
-    /// <summary>
-    /// Die Berufsbezeichnung des Empfängers.
-    /// </summary>
-    public string? JobTitle { get; init; }
-
-    /// <summary>
-    /// Der Firmenname des Empfängers.
-    /// </summary>
-    public string? CompanyName { get; init; }
-
-    /// <summary>
-    /// Eine private Nachricht, die mit dem Empfänger verknüpft ist.
-    /// </summary>
-    public string? PrivateMessage { get; init; }
-
-    /// <summary>
-    /// Das Datum und die Uhrzeit, wann der Empfänger hinzugefügt wurde.
-    /// </summary>
-    public DateTime AddedWhen { get; init; }
-
-    /// <summary>
-    /// Das Datum und die Uhrzeit, wann der Empfänger zuletzt geändert wurde (falls vorhanden).
-    /// </summary>
-    public DateTime? ChangedWhen { get; init; }
-
-    /// <summary>
-    /// Gibt an, ob der Empfänger eine Telefonnummer hat.
-    /// </summary>
-    public bool HasPhoneNumber { get; init; }
-
-    /// <summary>
-    /// Die zugehörigen Umschlagsdaten.
-    /// </summary>
-    [Required]
-    public required ReadEnvelopeResponse Envelope { get; init; }
-
-    /// <summary>
-    /// Die Liste der Empfängerinformationen.
-    /// </summary>
-    [Required]
-    public IEnumerable<ReadReceiverResponse> Receiver { get; init; } = new List<ReadReceiverResponse>();
-}

EnvelopeGenerator.Application/EnvelopeReceivers/Queries/ReadEnvelopeReceiverQuery.cs

@@ -0,0 +1,143 @@
+using AutoMapper;
+using DigitalData.Core.Abstraction.Application.Repository;
+using DigitalData.Core.Exceptions;
+using EnvelopeGenerator.Application.Envelopes.Queries;
+using EnvelopeGenerator.Application.Receivers.Queries;
+using MediatR;
+using EnvelopeGenerator.Domain.Entities;
+using Microsoft.EntityFrameworkCore;
+using EnvelopeGenerator.Application.Common.Dto.EnvelopeReceiver;
+using EnvelopeGenerator.Application.Common.Query;
+using EnvelopeGenerator.Application.Common.Extensions;
+
+namespace EnvelopeGenerator.Application.EnvelopeReceivers.Queries;
+
+/// <summary>
+/// Repräsentiert eine Abfrage zum Lesen eines Envelope-Empfängers.
+/// Invalid (0): Ungültiger Include.
+/// EnvelopeCreated (1001): Der Umschlag wurde erstellt.
+/// EnvelopeSaved (1002): Der Umschlag wurde gespeichert.
+/// EnvelopeQueued (1003): Der Umschlag wurde zur Verarbeitung eingeplant.
+/// EnvelopeSent (1004): Der Umschlag wurde versendet. (Nicht verwendet)
+/// EnvelopePartlySigned (1005): Der Umschlag wurde teilweise unterschrieben.
+/// EnvelopeCompletelySigned (1006): Der Umschlag wurde vollständig unterschrieben.
+/// EnvelopeReportCreated (1007): Ein Abschlussbericht wurde für den Umschlag erstellt.
+/// EnvelopeArchived (1008): Der Umschlag wurde archiviert.
+/// EnvelopeDeleted (1009): Der Umschlag wurde gelöscht.
+/// AccessCodeRequested (2001): Der Zugriffscode wurde angefordert.
+/// AccessCodeCorrect (2002): Der Zugriffscode war korrekt.
+/// AccessCodeIncorrect (2003): Der Zugriffscode war falsch.
+/// DocumentOpened (2004): Das Dokument wurde geöffnet.
+/// DocumentSigned (2005): Ein Dokument wurde unterschrieben.
+/// SignatureConfirmed (2006): Die Signatur wurde bestätigt.
+/// DocumentRejected (2007): Ein Dokument wurde abgelehnt.
+/// EnvelopeShared (2008): Der Umschlag wurde geteilt.
+/// EnvelopeViewed (2009): Der Umschlag wurde angesehen.
+/// DocumentForwarded (4001): Das Dokument wurde weitergeleitet.
+/// MessageInvitationSent (3001): Einladung wurde gesendet (vom Trigger verwendet).
+/// MessageAccessCodeSent (3002): Zugriffscode wurde gesendet.
+/// MessageConfirmationSent (3003): Bestätigungsnachricht wurde gesendet.
+/// MessageDeletionSent (3004): Löschbenachrichtigung wurde gesendet.
+/// MessageCompletionSent (3005): Abschlussbenachrichtigung wurde gesendet.
+/// </summary>
+/// <remarks>
+/// Diese Abfrage kombiniert Informationen über einen Umschlag (<see cref="ReadEnvelopeQuery"/>) 
+/// und einen Empfänger (<see cref="ReadReceiverQuery"/>), um eine vollständige Antwort 
+/// (<see cref="EnvelopeReceiverDto"/>) zu generieren. 
+/// Die Antwort enthält Details wie den Include, die Zuordnung zwischen Umschlag und Empfänger 
+/// sowie zusätzliche Metadaten.
+/// </remarks>
+public record ReadEnvelopeReceiverQuery : EnvelopeReceiverQueryBase<ReadEnvelopeQuery, ReadReceiverQuery>, IRequest<IEnumerable<EnvelopeReceiverDto>>;
+
+/// <summary>
+/// 
+/// </summary>
+public static class Extensions
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="mediator"></param>
+    /// <param name="key"></param>
+    /// <param name="cancel"></param>
+    /// <returns></returns>
+    public static Task<EnvelopeReceiverDto?> ReadEnvelopeReceiverAsync(this IMediator mediator, string key, CancellationToken cancel = default)
+    {
+        var q = new ReadEnvelopeReceiverQuery() { Key = key };
+        return mediator.Send(q, cancel).Then(envRcvs => envRcvs.FirstOrDefault());
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="mediator"></param>
+    /// <param name="uuid"></param>
+    /// <param name="signature"></param>
+    /// <param name="cancel"></param>
+    /// <returns></returns>
+    public static Task<EnvelopeReceiverDto?> ReadEnvelopeReceiverAsync(this IMediator mediator, string uuid, string signature, CancellationToken cancel = default)
+    {
+        var q = new ReadEnvelopeReceiverQuery();
+        q.Envelope.Uuid = uuid;
+        q.Receiver.Signature = signature;
+        return mediator.Send(q, cancel).Then(envRcvs => envRcvs.FirstOrDefault());
+    }
+}
+
+/// <summary>
+/// 
+/// </summary>
+public class ReadEnvelopeReceiverQueryHandler : IRequestHandler<ReadEnvelopeReceiverQuery, IEnumerable<EnvelopeReceiverDto>>
+{
+    private readonly IRepository<EnvelopeReceiver> _repo;
+
+    private readonly IMapper _mapper;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="envelopeReceiver"></param>
+    /// <param name="mapper"></param>
+    public ReadEnvelopeReceiverQueryHandler(IRepository<EnvelopeReceiver> envelopeReceiver, IMapper mapper)
+    {
+        _repo = envelopeReceiver;
+        _mapper = mapper;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="request"></param>
+    /// <param name="cancel"></param>
+    /// <returns></returns>
+    /// <exception cref="BadRequestException"></exception>
+    public async Task<IEnumerable<EnvelopeReceiverDto>> Handle(ReadEnvelopeReceiverQuery request, CancellationToken cancel)
+    {
+        var q = _repo.ReadOnly().Where(request, notnull: false);
+
+        if (request.Envelope.Status is not null)
+        {
+            var status = request.Envelope.Status;
+            if (status.Min is not null)
+                q = q.Where(er => er.Envelope!.Status >= status.Min);
+
+            if (status.Max is not null)
+                q = q.Where(er => er.Envelope!.Status <= status.Max);
+
+            if (status.Include?.Length > 0)
+                q = q.Where(er => status.Include.Contains(er.Envelope!.Status));
+
+            if (status.Ignore is not null)
+                q = q.Where(er => !status.Ignore.Contains(er.Envelope!.Status));
+        }
+
+        var envRcvs = await q
+                        .Include(er => er.Envelope).ThenInclude(e => e!.Documents!).ThenInclude(d => d.Elements)
+                        .Include(er => er.Envelope).ThenInclude(e => e!.Histories)
+                        .Include(er => er.Envelope).ThenInclude(e => e!.User)
+                        .Include(er => er.Receiver)
+                        .ToListAsync(cancel);
+
+        return _mapper.Map<List<EnvelopeReceiverDto>>(envRcvs);
+    }
+} 

EnvelopeGenerator.Application/EnvelopeReceivers/Queries/ReceiverAlreadySignedQuery.cs

@@ -0,0 +1,73 @@
+using DigitalData.Core.Abstraction.Application.Repository;
+using EnvelopeGenerator.Domain.Entities;
+using EnvelopeGenerator.Application.Common.Extensions;
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+using EnvelopeGenerator.Domain.Constants;
+using EnvelopeGenerator.Application.Common.Query;
+
+namespace EnvelopeGenerator.Application.EnvelopeReceivers.Queries;
+
+/// <summary>
+/// 
+/// </summary>
+public record ReceiverAlreadySignedQuery : EnvelopeReceiverQueryBase, IRequest<bool>;
+
+/// <summary>
+/// 
+/// </summary>
+public static class ReceiverAlreadySignedQueryExtensions
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="mediator"></param>
+    /// <param name="key"></param>
+    /// <param name="cancel"></param>
+    /// <returns></returns>
+    public static Task<bool> IsSignedAsync(this IMediator mediator, string key, CancellationToken cancel = default)
+        => mediator.Send(new ReceiverAlreadySignedQuery { Key = key }, cancel);
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="mediator"></param>
+    /// <param name="uuid"></param>
+    /// <param name="signature"></param>
+    /// <param name="cancel"></param>
+    /// <returns></returns>
+    public static Task<bool> IsSignedAsync(this IMediator mediator, string uuid, string signature, CancellationToken cancel = default)
+        => mediator.Send(new ReceiverAlreadySignedQuery
+        { 
+            Envelope = new() { Uuid = uuid },
+            Receiver = new() { Signature = signature } 
+        }, cancel);
+}
+
+/// <summary>
+/// 
+/// </summary>
+public class ReceiverAlreadySignedQueryHandler : IRequestHandler<ReceiverAlreadySignedQuery, bool>
+{
+    private readonly IRepository<History> _repo;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="repo"></param>
+    public ReceiverAlreadySignedQueryHandler(IRepository<History> repo)
+    {
+        _repo = repo;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="request"></param>
+    /// <param name="cancel"></param>
+    /// <returns></returns>
+    public async Task<bool> Handle(ReceiverAlreadySignedQuery request, CancellationToken cancel = default)
+    {
+        return await _repo.ReadOnly().Where(request).Where(h => h.Status == EnvelopeStatus.DocumentSigned).AnyAsync(cancel);
+    }
+}

EnvelopeGenerator.Application/Envelopes/Commands/CreateEnvelopeCommand.cs

@@ -1,6 +1,9 @@
-using MediatR;
-using Microsoft.AspNetCore.Mvc.ModelBinding;
+using DigitalData.Core.Abstraction.Application.Repository;
+using EnvelopeGenerator.Application.Common.Dto;
+using EnvelopeGenerator.Application.Interfaces.SQLExecutor;
+using MediatR;
 using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations.Schema;
 using System.Text.Json.Serialization;
 
 namespace EnvelopeGenerator.Application.Envelopes.Commands;
@@ -8,19 +11,37 @@ namespace EnvelopeGenerator.Application.Envelopes.Commands;
 /// <summary>
 /// Befehl zur Erstellung eines Umschlags.
 /// </summary>
-/// <param name="Title">Der Titel des Umschlags. Dies ist ein Pflichtfeld.</param>
-/// <param name="Message">Die Nachricht, die im Umschlag enthalten sein soll. Dies ist ein Pflichtfeld.</param>
-/// <param name="TFAEnabled">Gibt an, ob die Zwei-Faktor-Authentifizierung für den Umschlag aktiviert ist. Standardmäßig false.</param>
-public record CreateEnvelopeCommand(
-    [Required] string Title,
-    [Required] string Message,
-    bool TFAEnabled = false
-    ) : IRequest<CreateEnvelopeResponse?>
+public record CreateEnvelopeCommand : IRequest<EnvelopeDto?>
 {
     /// <summary>
-    /// Id of receiver
+    /// Der Titel des Umschlags. Dies ist ein Pflichtfeld.
+    /// </summary>
+    [Required]
+    public required string Title { get; set; }
+
+    /// <summary>
+    /// Die Nachricht, die im Umschlag enthalten sein soll. Dies ist ein Pflichtfeld.
+    /// </summary>
+    [Required]
+    public required string Message { get; set; }
+
+    /// <summary>
+    /// Gibt an, ob die Zwei-Faktor-Authentifizierung für den Umschlag aktiviert ist. Standardmäßig false.
+    /// </summary>
+    public bool TFAEnabled { get; set; } = false;
+
+    /// <summary>
+    /// ID des Absenders
+    /// </summary>
+    public int UserId { get; set; }
+
+    /// <summary>
+    /// Determines which component is used for envelope processing.
+    /// When <c>true</c>, processing is delegated to <see cref="IEnvelopeExecutor"/>; 
+    /// when <c>false</c>, <see cref="IRepository{Envelope}"/> is used instead. 
+    /// Note: <see cref="IRepository{Envelope}"/> should only be used in testing scenarios.
     /// </summary>
     [JsonIgnore]
-    [BindNever]
-    public int? UserId { get; set; }
-};
+    [NotMapped]
+    public bool UseSQLExecutor { get; set; } = true;
+}

EnvelopeGenerator.Application/Envelopes/Commands/CreateEnvelopeCommandHandler.cs

@@ -1,26 +1,34 @@
 using AutoMapper;
-using EnvelopeGenerator.Application.Contracts.SQLExecutor;
+using EnvelopeGenerator.Application.Interfaces.SQLExecutor;
 using MediatR;
+using Microsoft.Extensions.DependencyInjection;
+using DigitalData.Core.Abstraction.Application.Repository;
+using EnvelopeGenerator.Domain.Entities;
+using EnvelopeGenerator.Application.Common.Dto;
 
 namespace EnvelopeGenerator.Application.Envelopes.Commands;
 
 /// <summary>
 /// 
 /// </summary>
-public class CreateEnvelopeCommandHandler : IRequestHandler<CreateEnvelopeCommand, CreateEnvelopeResponse?>
+public class CreateEnvelopeCommandHandler : IRequestHandler<CreateEnvelopeCommand, EnvelopeDto?>
 {
-    private readonly IEnvelopeExecutor _envelopeExecutor;
+    private readonly IServiceProvider _provider;
+
+    private IEnvelopeExecutor Executor => _provider.GetRequiredService<IEnvelopeExecutor>();
+
+    private IRepository<Envelope> Repository => _provider.GetRequiredService<IRepository<Envelope>>();
 
     private readonly IMapper _mapper;
 
     /// <summary>
     /// 
     /// </summary>
-    /// <param name="envelopeExecutor"></param>
+    /// <param name="provider"></param>
     /// <param name="mapper"></param>
-    public CreateEnvelopeCommandHandler(IEnvelopeExecutor envelopeExecutor, IMapper mapper)
+    public CreateEnvelopeCommandHandler(IServiceProvider provider, IMapper mapper)
     {
-        _envelopeExecutor = envelopeExecutor;
+        _provider = provider;
         _mapper = mapper;
     }
 
@@ -28,14 +36,14 @@ public class CreateEnvelopeCommandHandler : IRequestHandler<CreateEnvelopeComman
     /// 
     /// </summary>
     /// <param name="request"></param>
-    /// <param name="cancellationToken"></param>
+    /// <param name="cancel"></param>
     /// <returns></returns>
-    public async Task<CreateEnvelopeResponse?> Handle(CreateEnvelopeCommand request, CancellationToken cancellationToken)
+    public async Task<EnvelopeDto?> Handle(CreateEnvelopeCommand request, CancellationToken cancel)
     {
-        int userId = request.UserId ?? throw new InvalidOperationException("UserId cannot be null when creating an envelope.");
+        var envelope = request.UseSQLExecutor
+            ? await Executor.CreateEnvelopeAsync(request.UserId, request.Title, request.Message, request.TFAEnabled, cancel)
+            : await Repository.CreateAsync(request, cancel);
 
-        var envelope = await _envelopeExecutor.CreateEnvelopeAsync(userId, request.Title, request.Message, request.TFAEnabled, cancellationToken);
-
-        return _mapper.Map<CreateEnvelopeResponse>(envelope);
+        return _mapper.Map<EnvelopeDto>(envelope);
     }
-}
+}

EnvelopeGenerator.Application/Envelopes/Commands/CreateEnvelopeMappingProfile.cs

@@ -1,19 +0,0 @@
-using AutoMapper;
-using EnvelopeGenerator.Application.EnvelopeReceivers.Commands.Create;
-using EnvelopeGenerator.Domain.Entities;
-
-namespace EnvelopeGenerator.Application.Envelopes.Commands;
-
-/// <summary>
-/// 
-/// </summary>
-public class CreateEnvelopeMappingProfile : Profile
-{
-    /// <summary>
-    /// 
-    /// </summary>
-    public CreateEnvelopeMappingProfile()
-    {
-        CreateMap<Envelope, CreateEnvelopeReceiverResponse>();
-    }
-}

EnvelopeGenerator.Application/Envelopes/Commands/CreateEnvelopeResponse.cs

@@ -1,20 +0,0 @@
-using EnvelopeGenerator.Application.Envelopes.Queries.Read;
-
-namespace EnvelopeGenerator.Application.Envelopes.Commands;
-
-/// <summary>
-/// 
-/// </summary>
-/// <param name="Id"><inheritdoc/></param>
-/// <param name="UserId"><inheritdoc/></param>
-/// <param name="Status"><inheritdoc/></param>
-/// <param name="Uuid"><inheritdoc/></param>
-/// <param name="Message"><inheritdoc/></param>
-/// <param name="AddedWhen"><inheritdoc/></param>
-/// <param name="ChangedWhen"><inheritdoc/></param>
-/// <param name="Title"><inheritdoc/></param>
-/// <param name="Language"><inheritdoc/></param>
-/// <param name="TFAEnabled"><inheritdoc/></param>
-/// <param name="User"><inheritdoc/></param>
-public record CreateEnvelopeResponse(int Id, int UserId, int Status, string Uuid, string? Message, DateTime AddedWhen, DateTime? ChangedWhen, string? Title, string Language, bool TFAEnabled, DigitalData.UserManager.Domain.Entities.User User) 
-    : ReadEnvelopeResponse(Id, UserId, Status, Uuid, Message, AddedWhen, ChangedWhen, Title, Language, TFAEnabled, User);

EnvelopeGenerator.Application/Envelopes/EnvelopeQuery.cs

@@ -1,16 +0,0 @@
-using MediatR;
-
-namespace EnvelopeGenerator.Application.Envelopes;
-
-/// <summary>
-/// Repräsentiert eine Abfrage für Umschläge.
-/// </summary>
-/// <param name="Id">Die eindeutige Kennung des Umschlags.</param>
-/// <param name="Status">Der Status des Umschlags.</param>
-/// <param name="Uuid">Die universell eindeutige Kennung des Umschlags.</param>
-public record EnvelopeQuery(
-    int? Id = null,
-    int? Status = null,
-    string? Uuid = null) : IRequest
-{
-};

EnvelopeGenerator.Application/Envelopes/MappingProfile.cs

@@ -0,0 +1,22 @@
+using AutoMapper;
+using EnvelopeGenerator.Application.EnvelopeReceivers.Commands;
+using EnvelopeGenerator.Application.Envelopes.Commands;
+using EnvelopeGenerator.Domain.Entities;
+
+namespace EnvelopeGenerator.Application.Envelopes;
+
+/// <summary>
+/// 
+/// </summary>
+public class MappingProfile : Profile
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public MappingProfile()
+    {
+        CreateMap<Envelope, CreateEnvelopeReceiverResponse>();
+        CreateMap<CreateEnvelopeCommand, Envelope>()
+            .ForMember(dest => dest.Uuid, opt => opt.MapFrom(_ => Guid.NewGuid().ToString()));
+    }
+}

EnvelopeGenerator.Application/Envelopes/Queries/Read/ReadEnvelopeQuery.cs

@@ -1,8 +0,0 @@
-namespace EnvelopeGenerator.Application.Envelopes.Queries.Read;
-
-/// <summary>
-/// Stellt eine Abfrage zum Lesen von Briefumschlägen dar.
-/// </summary>
-public record ReadEnvelopeQuery : EnvelopeQuery
-{
-}

EnvelopeGenerator.Application/Envelopes/Queries/Read/ReadEnvelopeResponse.cs

@@ -1,36 +0,0 @@
-using EnvelopeGenerator.Domain;
-
-namespace EnvelopeGenerator.Application.Envelopes.Queries.Read;
-
-/// <summary>
-/// Repräsentiert die Antwort für das Lesen eines Umschlags.
-/// </summary>
-/// <param name="Id">Die eindeutige Kennung des Umschlags.</param>
-/// <param name="UserId">Die Kennung des Benutzers, der den Umschlag erstellt hat.</param>
-/// <param name="Status">Der Status des Umschlags als numerischer Wert.</param>
-/// <param name="Uuid">Die universelle eindeutige Kennung (UUID) des Umschlags.</param>
-/// <param name="Message">Eine optionale Nachricht, die mit dem Umschlag verknüpft ist.</param>
-/// <param name="AddedWhen">Das Datum und die Uhrzeit, wann der Umschlag hinzugefügt wurde.</param>
-/// <param name="ChangedWhen">Das Datum und die Uhrzeit, wann der Umschlag zuletzt geändert wurde (falls vorhanden).</param>
-/// <param name="Title">Ein optionaler Titel des Umschlags.</param>
-/// <param name="Language">Die Sprache, die mit dem Umschlag verknüpft ist.</param>
-/// <param name="TFAEnabled">Gibt an, ob die Zwei-Faktor-Authentifizierung (TFA) aktiviert ist.</param>
-/// <param name="User">Das Benutzerobjekt, das mit dem Umschlag verknüpft ist.</param>
-public record ReadEnvelopeResponse(
-    int Id,
-    int UserId,
-    int Status,
-    string Uuid,
-    string? Message,
-    DateTime AddedWhen,
-    DateTime? ChangedWhen,
-    string? Title,
-    string Language,
-    bool TFAEnabled,
-    DigitalData.UserManager.Domain.Entities.User User)
-{
-    /// <summary>
-    /// Gibt den Namen des Status zurück, der dem numerischen Statuswert entspricht.
-    /// </summary>
-    public string StatusName => ((Constants.EnvelopeStatus)Status).ToString();
-}

EnvelopeGenerator.Application/Envelopes/Queries/ReadEnvelopeQuery.cs

@@ -1,16 +1,23 @@
-using EnvelopeGenerator.Application.Histories;
+using MediatR;
+using EnvelopeGenerator.Domain.Constants;
+using EnvelopeGenerator.Application.Common.Query;
 
-namespace EnvelopeGenerator.Application.EnvelopeReceivers;
+namespace EnvelopeGenerator.Application.Envelopes.Queries;
 
 /// <summary>
-/// Stellt eine Abfrage für einen Envelope-Empfänger dar.
+/// Repräsentiert eine Abfrage für Umschläge.
 /// </summary>
-/// <param name="Status">Der Status der Abfrage, optional.</param>
-public record EnvelopeReceiverQuery(EnvelopeStatusQuery? Status = null);
+public record ReadEnvelopeQuery : EnvelopeQueryBase, IRequest
+{
+    /// <summary>
+    /// Abfrage des Include des Umschlags
+    /// </summary>
+    public EnvelopeStatusQuery? Status { get; init; }
+}
 
 /// <summary>
-/// Repräsentiert den Status eines Umschlags und dessen Beziehung zum Empfänger. (vgl. auch <see cref="Common.Constants.EnvelopeStatus"/>
-/// Invalid (0): Ungültiger Status.
+/// Repräsentiert den Include eines Umschlags und dessen Beziehung zum Empfänger. (vgl. auch <see cref="EnvelopeStatusQuery"/>
+/// Invalid (0): Ungültiger Include.
 /// EnvelopeCreated (1001): Der Umschlag wurde erstellt.
 /// EnvelopeSaved (1002): Der Umschlag wurde gespeichert.
 /// EnvelopeQueued (1003): Der Umschlag wurde zur Verarbeitung eingeplant.
@@ -35,13 +42,27 @@ public record EnvelopeReceiverQuery(EnvelopeStatusQuery? Status = null);
 /// MessageConfirmationSent (3003): Bestätigungsnachricht wurde gesendet.
 /// MessageDeletionSent (3004): Löschbenachrichtigung wurde gesendet.
 /// MessageCompletionSent (3005): Abschlussbenachrichtigung wurde gesendet.
-/// <param name="Min">Der minimale Statuswert, der berücksichtigt werden soll.</param>
-/// <param name="Max">Der maximale Statuswert, der berücksichtigt werden soll.</param>
-/// <param name="Ignore">Eine Liste von Statuswerten, die ignoriert werden sollen.</param>
 /// </summary>
-public record EnvelopeStatusQuery(
-    int? Min = null,
-    int? Max = null,
-    int[]? Ignore = null)
+
+public record EnvelopeStatusQuery
 {
-}
+    /// <summary>
+    /// Der minimale Statuswert, der berücksichtigt werden.
+    /// </summary>
+    public EnvelopeStatus? Min { get; init; }
+
+    /// <summary>
+    /// Der maximale Statuswert, der berücksichtigt werden.
+    /// </summary>
+    public EnvelopeStatus? Max { get; init; }
+
+    /// <summary>
+    /// Eine Liste von Statuswerten, die einbezogen werden.
+    /// </summary>
+    public EnvelopeStatus[]? Include { get; init; }
+
+    /// <summary>
+    /// Eine Liste von Statuswerten, die ignoriert werden werden.
+    /// </summary>
+    public EnvelopeStatus[]? Ignore { get; init; }
+}

EnvelopeGenerator.Application/Envelopes/Queries/ReadReceiverNameQuery.cs

@@ -1,6 +1,6 @@
-using EnvelopeGenerator.Application.Receivers.Queries.Read;
+using EnvelopeGenerator.Application.Receivers.Queries;
 
-namespace EnvelopeGenerator.Application.Envelopes.Queries.ReceiverName;
+namespace EnvelopeGenerator.Application.Envelopes.Queries;
 
 /// <summary>
 /// Eine Abfrage, um die zuletzt verwendete Anrede eines Empfängers zu ermitteln, 

EnvelopeGenerator.Application/Exceptions/BadRequestException.cs

@@ -1,22 +0,0 @@
-namespace EnvelopeGenerator.Application.Exceptions;
-
-/// <summary>
-/// Represents an exception that is thrown when a bad request is encountered.
-/// </summary>
-public class BadRequestException : Exception
-{
-    /// <summary>
-    /// Initializes a new instance of the <see cref="BadRequestException"/> class.
-    /// </summary>
-    public BadRequestException()
-    {
-    }
-
-    /// <summary>
-    /// Initializes a new instance of the <see cref="BadRequestException"/> class with a specified error message.
-    /// </summary>
-    /// <param name="message">The message that describes the error.</param>
-    public BadRequestException(string? message) : base(message)
-    {
-    }
-}

EnvelopeGenerator.Application/Exceptions/NotFoundException.cs

@@ -1,22 +0,0 @@
-namespace EnvelopeGenerator.Application.Exceptions;
-
-/// <summary>
-/// Represents an exception that is thrown when a requested resource is not found.
-/// </summary>
-public class NotFoundException : Exception
-{
-    /// <summary>
-    /// Initializes a new instance of the <see cref="NotFoundException"/> class.
-    /// </summary>
-    public NotFoundException()
-    {
-    }
-
-    /// <summary>
-    /// Initializes a new instance of the <see cref="NotFoundException"/> class with a specified error message.
-    /// </summary>
-    /// <param name="message">The message that describes the error.</param>
-    public NotFoundException(string? message) : base(message)
-    {
-    }
-}

EnvelopeGenerator.Application/Histories/Commands/CreateHistoryCommand.cs

@@ -0,0 +1,108 @@
+using AutoMapper;
+using DigitalData.Core.Abstraction.Application.Repository;
+using DigitalData.Core.Exceptions;
+using EnvelopeGenerator.Application.Common.Dto.History;
+using EnvelopeGenerator.Application.Common.Extensions;
+using EnvelopeGenerator.Application.Common.Query;
+using EnvelopeGenerator.Domain.Constants;
+using EnvelopeGenerator.Domain.Entities;
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+
+namespace EnvelopeGenerator.Application.Histories.Commands;
+
+/// <summary>
+/// 
+/// </summary>
+public record CreateHistoryCommand : EnvelopeReceiverQueryBase, IRequest<HistoryDto?>
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public int? EnvelopeId { get; set; }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public string? UserReference { get; set; }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public EnvelopeStatus Status { get; set; }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public DateTime AddedWhen { get; } = DateTime.Now;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public DateTime ActionDate => AddedWhen;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public string? Comment { get; set; }
+}
+
+/// <summary>
+/// 
+/// </summary>
+public class CreateHistoryCommandHandler : IRequestHandler<CreateHistoryCommand, HistoryDto?>
+{
+    private readonly IRepository<History> _repo;
+
+    private readonly IRepository<EnvelopeReceiver> _erRepo;
+
+    private readonly IMapper _mapper;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="repo"></param>
+    /// <param name="erRepo"></param>
+    /// <param name="mapper"></param>
+    public CreateHistoryCommandHandler(IRepository<History> repo, IRepository<EnvelopeReceiver> erRepo, IMapper mapper)
+    {
+        _repo = repo;
+        _erRepo = erRepo;
+        _mapper = mapper;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="request"></param>
+    /// <param name="cancel"></param>
+    /// <returns></returns>
+    public async Task<HistoryDto?> Handle(CreateHistoryCommand request, CancellationToken cancel)
+    {
+        if(request.UserReference is null)
+        {
+            var receivers = await _erRepo
+                .ReadOnly()
+                .Where(request)
+                .Include(er => er.Receiver)
+                .ToListAsync(cancel);
+
+            if (receivers.Count != 1)
+                throw new BadRequestException(
+                    receivers.Count > 1
+                        ? "Multiple receivers found for the given envelope and receiver criteria."
+                        : "No receiver found for the given envelope and receiver criteria."
+                );
+
+            var receiver = receivers.Single().Receiver
+                           ?? throw new BadRequestException("No receiver found for the given envelope and receiver criteria.");
+
+            request.UserReference = receiver.EmailAddress;
+        }
+
+        // create entitiy
+        var hist = await _repo.CreateAsync(request, cancel);
+        
+        return _mapper.Map<HistoryDto>(hist);
+    }
+}

EnvelopeGenerator.Application/Histories/MappingProfile.cs

@@ -0,0 +1,22 @@
+using AutoMapper;
+using EnvelopeGenerator.Application.Histories.Commands;
+using EnvelopeGenerator.Domain.Entities;
+
+namespace EnvelopeGenerator.Application.Histories;
+
+/// <summary>
+/// 
+/// </summary>
+public class MappingProfile: Profile
+{
+    /// <summary>
+    /// 
+    /// </summary>
+    public MappingProfile()
+    {
+        CreateMap<CreateHistoryCommand, History>()
+            .ForMember(dest => dest.Envelope, opt => opt.Ignore())
+            .ForMember(dest => dest.Sender, opt => opt.Ignore())
+            .ForMember(dest => dest.Receiver, opt => opt.Ignore());
+    }
+}