diff --git a/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/ICreateAppService.cs b/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/ICreateAppService.cs
new file mode 100644
index 0000000000..a5d75b0b4b
--- /dev/null
+++ b/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/ICreateAppService.cs
@@ -0,0 +1,16 @@
+using System.Threading.Tasks;
+
+namespace Volo.Abp.Application.Services
+{
+    public interface ICreateAppService<TEntityDto>
+        : ICreateAppService<TEntityDto, TEntityDto>
+    {
+
+    }
+
+    public interface ICreateAppService<TGetOutputDto, in TCreateInput>
+        : IApplicationService
+    {
+        Task<TGetOutputDto> CreateAsync(TCreateInput input);
+    }
+}
diff --git a/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/ICreateUpdateAppService.cs b/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/ICreateUpdateAppService.cs
new file mode 100644
index 0000000000..ce3698405c
--- /dev/null
+++ b/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/ICreateUpdateAppService.cs
@@ -0,0 +1,21 @@
+namespace Volo.Abp.Application.Services
+{
+    public interface ICreateUpdateAppService<TEntityDto, in TKey>
+        : ICreateUpdateAppService<TEntityDto, TKey, TEntityDto, TEntityDto>
+    {
+
+    }
+
+    public interface ICreateUpdateAppService<TEntityDto, in TKey, in TCreateUpdateInput>
+        : ICreateUpdateAppService<TEntityDto, TKey, TCreateUpdateInput, TCreateUpdateInput>
+    {
+
+    }
+
+    public interface ICreateUpdateAppService<TGetOutputDto, in TKey, in TCreateUpdateInput, in TUpdateInput>
+        : ICreateAppService<TGetOutputDto, TCreateUpdateInput>,
+            IUpdateAppService<TGetOutputDto, TKey, TUpdateInput>
+    {
+
+    }
+}
diff --git a/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/ICrudAppService.cs b/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/ICrudAppService.cs
index 12f3b51d11..10f88db22a 100644
--- a/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/ICrudAppService.cs
+++ b/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/ICrudAppService.cs
@@ -1,4 +1,3 @@
-using System.Threading.Tasks;
 using Volo.Abp.Application.Dtos;
 
 namespace Volo.Abp.Application.Services
@@ -28,16 +27,10 @@ namespace Volo.Abp.Application.Services
     }
 
     public interface ICrudAppService<TGetOutputDto, TGetListOutputDto, in TKey, in TGetListInput, in TCreateInput, in TUpdateInput>
-        : IApplicationService
+        : IReadOnlyAppService<TGetOutputDto, TGetListOutputDto, TKey, TGetListInput>,
+            ICreateUpdateAppService<TGetOutputDto, TKey, TCreateInput, TUpdateInput>,
+            IDeleteAppService<TKey>
     {
-        Task<TGetOutputDto> GetAsync(TKey id);
 
-        Task<PagedResultDto<TGetListOutputDto>> GetListAsync(TGetListInput input);
-
-        Task<TGetOutputDto> CreateAsync(TCreateInput input);
-
-        Task<TGetOutputDto> UpdateAsync(TKey id, TUpdateInput input);
-
-        Task DeleteAsync(TKey id);
     }
 }
diff --git a/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/IDeleteAppService.cs b/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/IDeleteAppService.cs
new file mode 100644
index 0000000000..50badcead9
--- /dev/null
+++ b/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/IDeleteAppService.cs
@@ -0,0 +1,9 @@
+using System.Threading.Tasks;
+
+namespace Volo.Abp.Application.Services
+{
+    public interface IDeleteAppService<in TKey> : IApplicationService
+    {
+        Task DeleteAsync(TKey id);
+    }
+}
diff --git a/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/IReadOnlyAppService.cs b/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/IReadOnlyAppService.cs
new file mode 100644
index 0000000000..09df0dc9cd
--- /dev/null
+++ b/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/IReadOnlyAppService.cs
@@ -0,0 +1,25 @@
+using System.Threading.Tasks;
+using Volo.Abp.Application.Dtos;
+
+namespace Volo.Abp.Application.Services
+{
+    public interface IReadOnlyAppService<TEntityDto, in TKey>
+        : IReadOnlyAppService<TEntityDto, TEntityDto, TKey, PagedAndSortedResultRequestDto>
+    {
+
+    }
+
+    public interface IReadOnlyAppService<TEntityDto, in TKey, in TGetListInput>
+        : IReadOnlyAppService<TEntityDto, TEntityDto, TKey, TGetListInput>
+    {
+
+    }
+
+    public interface IReadOnlyAppService<TGetOutputDto, TGetListOutputDto, in TKey, in TGetListInput>
+        : IApplicationService
+    {
+        Task<TGetOutputDto> GetAsync(TKey id);
+
+        Task<PagedResultDto<TGetListOutputDto>> GetListAsync(TGetListInput input);
+    }
+}
diff --git a/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/IUpdateAppService.cs b/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/IUpdateAppService.cs
new file mode 100644
index 0000000000..c0904709bf
--- /dev/null
+++ b/framework/src/Volo.Abp.Ddd.Application.Contracts/Volo/Abp/Application/Services/IUpdateAppService.cs
@@ -0,0 +1,16 @@
+using System.Threading.Tasks;
+
+namespace Volo.Abp.Application.Services
+{
+    public interface IUpdateAppService<TEntityDto, in TKey>
+        : IUpdateAppService<TEntityDto, TKey, TEntityDto>
+    {
+
+    }
+
+    public interface IUpdateAppService<TGetOutputDto, in TKey, in TUpdateInput>
+        : IApplicationService
+    {
+        Task<TGetOutputDto> UpdateAsync(TKey id, TUpdateInput input);
+    }
+}
diff --git a/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/AbstractKeyCrudAppService.cs b/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/AbstractKeyCrudAppService.cs
index e6f433cad6..11550c456f 100644
--- a/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/AbstractKeyCrudAppService.cs
+++ b/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/AbstractKeyCrudAppService.cs
@@ -1,9 +1,6 @@
 using System;
-using System.Linq;
-using System.Linq.Dynamic.Core;
 using System.Threading.Tasks;
 using Volo.Abp.Application.Dtos;
-using Volo.Abp.Auditing;
 using Volo.Abp.Domain.Entities;
 using Volo.Abp.Domain.Repositories;
 using Volo.Abp.MultiTenancy;
@@ -61,17 +58,12 @@ namespace Volo.Abp.Application.Services
     }
 
     public abstract class AbstractKeyCrudAppService<TEntity, TGetOutputDto, TGetListOutputDto, TKey, TGetListInput, TCreateInput, TUpdateInput>
-        : ApplicationService,
+        : AbstractKeyReadOnlyAppService<TEntity, TGetOutputDto, TGetListOutputDto, TKey, TGetListInput>,
             ICrudAppService<TGetOutputDto, TGetListOutputDto, TKey, TGetListInput, TCreateInput, TUpdateInput>
         where TEntity : class, IEntity
     {
-
         protected IRepository<TEntity> Repository { get; }
 
-        protected virtual string GetPolicyName { get; set; }
-
-        protected virtual string GetListPolicyName { get; set; }
-
         protected virtual string CreatePolicyName { get; set; }
 
         protected virtual string UpdatePolicyName { get; set; }
@@ -79,37 +71,11 @@ namespace Volo.Abp.Application.Services
         protected virtual string DeletePolicyName { get; set; }
 
         protected AbstractKeyCrudAppService(IRepository<TEntity> repository)
+            : base(repository)
         {
             Repository = repository;
         }
 
-        public virtual async Task<TGetOutputDto> GetAsync(TKey id)
-        {
-            await CheckGetPolicyAsync();
-
-            var entity = await GetEntityByIdAsync(id);
-            return MapToGetOutputDto(entity);
-        }
-
-        public virtual async Task<PagedResultDto<TGetListOutputDto>> GetListAsync(TGetListInput input)
-        {
-            await CheckGetListPolicyAsync();
-
-            var query = CreateFilteredQuery(input);
-
-            var totalCount = await AsyncExecuter.CountAsync(query);
-
-            query = ApplySorting(query, input);
-            query = ApplyPaging(query, input);
-
-            var entities = await AsyncExecuter.ToListAsync(query);
-
-            return new PagedResultDto<TGetListOutputDto>(
-                totalCount,
-                entities.Select(MapToGetListOutputDto).ToList()
-            );
-        }
-
         public virtual async Task<TGetOutputDto> CreateAsync(TCreateInput input)
         {
             await CheckCreatePolicyAsync();
@@ -144,18 +110,6 @@ namespace Volo.Abp.Application.Services
 
         protected abstract Task DeleteByIdAsync(TKey id);
 
-        protected abstract Task<TEntity> GetEntityByIdAsync(TKey id);
-
-        protected virtual async Task CheckGetPolicyAsync()
-        {
-            await CheckPolicyAsync(GetPolicyName);
-        }
-
-        protected virtual async Task CheckGetListPolicyAsync()
-        {
-            await CheckPolicyAsync(GetListPolicyName);
-        }
-
         protected virtual async Task CheckCreatePolicyAsync()
         {
             await CheckPolicyAsync(CreatePolicyName);
@@ -171,101 +125,6 @@ namespace Volo.Abp.Application.Services
             await CheckPolicyAsync(DeletePolicyName);
         }
 
-        /// <summary>
-        /// Should apply sorting if needed.
-        /// </summary>
-        /// <param name="query">The query.</param>
-        /// <param name="input">The input.</param>
-        protected virtual IQueryable<TEntity> ApplySorting(IQueryable<TEntity> query, TGetListInput input)
-        {
-            //Try to sort query if available
-            if (input is ISortedResultRequest sortInput)
-            {
-                if (!sortInput.Sorting.IsNullOrWhiteSpace())
-                {
-                    return query.OrderBy(sortInput.Sorting);
-                }
-            }
-
-            //IQueryable.Task requires sorting, so we should sort if Take will be used.
-            if (input is ILimitedResultRequest)
-            {
-                return ApplyDefaultSorting(query);
-            }
-
-            //No sorting
-            return query;
-        }
-
-        /// <summary>
-        /// Applies sorting if no sorting specified but a limited result requested.
-        /// </summary>
-        /// <param name="query">The query.</param>
-        protected virtual IQueryable<TEntity> ApplyDefaultSorting(IQueryable<TEntity> query)
-        {
-            if (typeof(TEntity).IsAssignableTo<ICreationAuditedObject>())
-            {
-                return query.OrderByDescending(e => ((ICreationAuditedObject)e).CreationTime);
-            }
-
-            throw new AbpException("No sorting specified but this query requires sorting. Override the ApplyDefaultSorting method for your application service derived from AbstractKeyCrudAppService!");
-        }
-
-        /// <summary>
-        /// Should apply paging if needed.
-        /// </summary>
-        /// <param name="query">The query.</param>
-        /// <param name="input">The input.</param>
-        protected virtual IQueryable<TEntity> ApplyPaging(IQueryable<TEntity> query, TGetListInput input)
-        {
-            //Try to use paging if available
-            if (input is IPagedResultRequest pagedInput)
-            {
-                return query.PageBy(pagedInput);
-            }
-
-            //Try to limit query result if available
-            if (input is ILimitedResultRequest limitedInput)
-            {
-                return query.Take(limitedInput.MaxResultCount);
-            }
-
-            //No paging
-            return query;
-        }
-
-        /// <summary>
-        /// This method should create <see cref="IQueryable{TEntity}"/> based on given input.
-        /// It should filter query if needed, but should not do sorting or paging.
-        /// Sorting should be done in <see cref="ApplySorting"/> and paging should be done in <see cref="ApplyPaging"/>
-        /// methods.
-        /// </summary>
-        /// <param name="input">The input.</param>
-        protected virtual IQueryable<TEntity> CreateFilteredQuery(TGetListInput input)
-        {
-            return Repository;
-        }
-
-        /// <summary>
-        /// Maps <see cref="TEntity"/> to <see cref="TGetOutputDto"/>.
-        /// It uses <see cref="IObjectMapper"/> by default.
-        /// It can be overriden for custom mapping.
-        /// </summary>
-        protected virtual TGetOutputDto MapToGetOutputDto(TEntity entity)
-        {
-            return ObjectMapper.Map<TEntity, TGetOutputDto>(entity);
-        }
-
-        /// <summary>
-        /// Maps <see cref="TEntity"/> to <see cref="TGetListOutputDto"/>.
-        /// It uses <see cref="IObjectMapper"/> by default.
-        /// It can be overriden for custom mapping.
-        /// </summary>
-        protected virtual TGetListOutputDto MapToGetListOutputDto(TEntity entity)
-        {
-            return ObjectMapper.Map<TEntity, TGetListOutputDto>(entity);
-        }
-
         /// <summary>
         /// Maps <see cref="TCreateInput"/> to <see cref="TEntity"/> to create a new entity.
         /// It uses <see cref="IObjectMapper"/> by default.
@@ -284,18 +143,14 @@ namespace Volo.Abp.Application.Services
         /// </summary>
         protected virtual void SetIdForGuids(TEntity entity)
         {
-            var entityWithGuidId = entity as IEntity<Guid>;
-
-            if (entityWithGuidId == null || entityWithGuidId.Id != Guid.Empty)
+            if (entity is IEntity<Guid> entityWithGuidId && entityWithGuidId.Id == Guid.Empty)
             {
-                return;
+                EntityHelper.TrySetId(
+                    entityWithGuidId,
+                    () => GuidGenerator.Create(),
+                    true
+                );
             }
-
-            EntityHelper.TrySetId(
-                entityWithGuidId,
-                () => GuidGenerator.Create(),
-                true
-            );
         }
 
         /// <summary>
diff --git a/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/AbstractKeyReadOnlyAppService.cs b/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/AbstractKeyReadOnlyAppService.cs
new file mode 100644
index 0000000000..9085434211
--- /dev/null
+++ b/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/AbstractKeyReadOnlyAppService.cs
@@ -0,0 +1,184 @@
+using System;
+using System.Linq;
+using System.Linq.Dynamic.Core;
+using System.Threading.Tasks;
+using Volo.Abp.Application.Dtos;
+using Volo.Abp.Auditing;
+using Volo.Abp.Domain.Entities;
+using Volo.Abp.Domain.Repositories;
+
+namespace Volo.Abp.Application.Services
+{
+    public abstract class AbstractKeyReadOnlyAppService<TEntity, TEntityDto, TKey>
+        : AbstractKeyReadOnlyAppService<TEntity, TEntityDto, TEntityDto, TKey, PagedAndSortedResultRequestDto>
+        where TEntity : class, IEntity
+    {
+        protected AbstractKeyReadOnlyAppService(IReadOnlyRepository<TEntity> repository)
+            : base(repository)
+        {
+
+        }
+    }
+
+    public abstract class AbstractKeyReadOnlyAppService<TEntity, TEntityDto, TKey, TGetListInput>
+        : AbstractKeyReadOnlyAppService<TEntity, TEntityDto, TEntityDto, TKey, TGetListInput>
+        where TEntity : class, IEntity
+    {
+        protected AbstractKeyReadOnlyAppService(IReadOnlyRepository<TEntity> repository)
+            : base(repository)
+        {
+
+        }
+    }
+
+    public abstract class AbstractKeyReadOnlyAppService<TEntity, TGetOutputDto, TGetListOutputDto, TKey, TGetListInput>
+        : ApplicationService
+        , IReadOnlyAppService<TGetOutputDto, TGetListOutputDto, TKey, TGetListInput>
+        where TEntity : class, IEntity
+    {
+        protected IReadOnlyRepository<TEntity> ReadOnlyRepository { get; }
+
+        protected virtual string GetPolicyName { get; set; }
+
+        protected virtual string GetListPolicyName { get; set; }
+
+        protected AbstractKeyReadOnlyAppService(IReadOnlyRepository<TEntity> repository)
+        {
+            ReadOnlyRepository = repository;
+        }
+
+        public virtual async Task<TGetOutputDto> GetAsync(TKey id)
+        {
+            await CheckGetPolicyAsync();
+
+            var entity = await GetEntityByIdAsync(id);
+            return MapToGetOutputDto(entity);
+        }
+
+        public virtual async Task<PagedResultDto<TGetListOutputDto>> GetListAsync(TGetListInput input)
+        {
+            await CheckGetListPolicyAsync();
+
+            var query = CreateFilteredQuery(input);
+
+            var totalCount = await AsyncExecuter.CountAsync(query);
+
+            query = ApplySorting(query, input);
+            query = ApplyPaging(query, input);
+
+            var entities = await AsyncExecuter.ToListAsync(query);
+
+            return new PagedResultDto<TGetListOutputDto>(
+                totalCount,
+                entities.Select(MapToGetListOutputDto).ToList()
+            );
+        }
+
+        protected abstract Task<TEntity> GetEntityByIdAsync(TKey id);
+
+        protected virtual async Task CheckGetPolicyAsync()
+        {
+            await CheckPolicyAsync(GetPolicyName);
+        }
+
+        protected virtual async Task CheckGetListPolicyAsync()
+        {
+            await CheckPolicyAsync(GetListPolicyName);
+        }
+
+        /// <summary>
+        /// Should apply sorting if needed.
+        /// </summary>
+        /// <param name="query">The query.</param>
+        /// <param name="input">The input.</param>
+        protected virtual IQueryable<TEntity> ApplySorting(IQueryable<TEntity> query, TGetListInput input)
+        {
+            //Try to sort query if available
+            if (input is ISortedResultRequest sortInput)
+            {
+                if (!sortInput.Sorting.IsNullOrWhiteSpace())
+                {
+                    return query.OrderBy(sortInput.Sorting);
+                }
+            }
+
+            //IQueryable.Task requires sorting, so we should sort if Take will be used.
+            if (input is ILimitedResultRequest)
+            {
+                return ApplyDefaultSorting(query);
+            }
+
+            //No sorting
+            return query;
+        }
+
+        /// <summary>
+        /// Applies sorting if no sorting specified but a limited result requested.
+        /// </summary>
+        /// <param name="query">The query.</param>
+        protected virtual IQueryable<TEntity> ApplyDefaultSorting(IQueryable<TEntity> query)
+        {
+            if (typeof(TEntity).IsAssignableTo<ICreationAuditedObject>())
+            {
+                return query.OrderByDescending(e => ((ICreationAuditedObject)e).CreationTime);
+            }
+
+            throw new AbpException("No sorting specified but this query requires sorting. Override the ApplyDefaultSorting method for your application service derived from AbstractKeyReadOnlyAppService!");
+        }
+
+        /// <summary>
+        /// Should apply paging if needed.
+        /// </summary>
+        /// <param name="query">The query.</param>
+        /// <param name="input">The input.</param>
+        protected virtual IQueryable<TEntity> ApplyPaging(IQueryable<TEntity> query, TGetListInput input)
+        {
+            //Try to use paging if available
+            if (input is IPagedResultRequest pagedInput)
+            {
+                return query.PageBy(pagedInput);
+            }
+
+            //Try to limit query result if available
+            if (input is ILimitedResultRequest limitedInput)
+            {
+                return query.Take(limitedInput.MaxResultCount);
+            }
+
+            //No paging
+            return query;
+        }
+
+        /// <summary>
+        /// This method should create <see cref="IQueryable{TEntity}"/> based on given input.
+        /// It should filter query if needed, but should not do sorting or paging.
+        /// Sorting should be done in <see cref="ApplySorting"/> and paging should be done in <see cref="ApplyPaging"/>
+        /// methods.
+        /// </summary>
+        /// <param name="input">The input.</param>
+        protected virtual IQueryable<TEntity> CreateFilteredQuery(TGetListInput input)
+        {
+            return ReadOnlyRepository;
+        }
+
+        /// <summary>
+        /// Maps <see cref="TEntity"/> to <see cref="TGetOutputDto"/>.
+        /// It uses <see cref="IObjectMapper"/> by default.
+        /// It can be overriden for custom mapping.
+        /// </summary>
+        protected virtual TGetOutputDto MapToGetOutputDto(TEntity entity)
+        {
+            return ObjectMapper.Map<TEntity, TGetOutputDto>(entity);
+        }
+
+        /// <summary>
+        /// Maps <see cref="TEntity"/> to <see cref="TGetListOutputDto"/>.
+        /// It uses <see cref="IObjectMapper"/> by default.
+        /// It can be overriden for custom mapping.
+        /// </summary>
+        protected virtual TGetListOutputDto MapToGetListOutputDto(TEntity entity)
+        {
+            return ObjectMapper.Map<TEntity, TGetListOutputDto>(entity);
+        }
+    }
+}
diff --git a/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/CrudAppService.cs b/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/CrudAppService.cs
index a2af0592a4..7832e8a4ab 100644
--- a/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/CrudAppService.cs
+++ b/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/CrudAppService.cs
@@ -70,7 +70,7 @@ namespace Volo.Abp.Application.Services
         protected new IRepository<TEntity, TKey> Repository { get; }
 
         protected CrudAppService(IRepository<TEntity, TKey> repository)
-        : base(repository)
+            : base(repository)
         {
             Repository = repository;
         }
diff --git a/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/ReadOnlyAppService.cs b/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/ReadOnlyAppService.cs
new file mode 100644
index 0000000000..d99928126c
--- /dev/null
+++ b/framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/ReadOnlyAppService.cs
@@ -0,0 +1,66 @@
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+using Volo.Abp.Application.Dtos;
+using Volo.Abp.Auditing;
+using Volo.Abp.Domain.Entities;
+using Volo.Abp.Domain.Repositories;
+
+namespace Volo.Abp.Application.Services
+{
+    public abstract class ReadOnlyAppService<TEntity, TEntityDto, TKey>
+        : ReadOnlyAppService<TEntity, TEntityDto, TEntityDto, TKey, PagedAndSortedResultRequestDto>
+        where TEntity : class, IEntity<TKey>
+        where TEntityDto : IEntityDto<TKey>
+    {
+        protected ReadOnlyAppService(IReadOnlyRepository<TEntity, TKey> repository)
+            : base(repository)
+        {
+
+        }
+    }
+
+    public abstract class ReadOnlyAppService<TEntity, TEntityDto, TKey, TGetListInput>
+        : ReadOnlyAppService<TEntity, TEntityDto, TEntityDto, TKey, TGetListInput>
+        where TEntity : class, IEntity<TKey>
+        where TEntityDto : IEntityDto<TKey>
+    {
+        protected ReadOnlyAppService(IReadOnlyRepository<TEntity, TKey> repository)
+            : base(repository)
+        {
+
+        }
+    }
+
+    public abstract class ReadOnlyAppService<TEntity, TGetOutputDto, TGetListOutputDto, TKey, TGetListInput>
+        : AbstractKeyReadOnlyAppService<TEntity, TGetOutputDto, TGetListOutputDto, TKey, TGetListInput>
+        where TEntity : class, IEntity<TKey>
+        where TGetOutputDto : IEntityDto<TKey>
+        where TGetListOutputDto : IEntityDto<TKey>
+    {
+        protected new IReadOnlyRepository<TEntity, TKey> Repository { get; }
+
+        protected ReadOnlyAppService(IReadOnlyRepository<TEntity, TKey> repository)
+        : base(repository)
+        {
+            Repository = repository;
+        }
+
+        protected override async Task<TEntity> GetEntityByIdAsync(TKey id)
+        {
+            return await Repository.GetAsync(id);
+        }
+
+        protected override IQueryable<TEntity> ApplyDefaultSorting(IQueryable<TEntity> query)
+        {
+            if (typeof(TEntity).IsAssignableTo<ICreationAuditedObject>())
+            {
+                return query.OrderByDescending(e => ((ICreationAuditedObject)e).CreationTime);
+            }
+            else
+            {
+                return query.OrderByDescending(e => e.Id);
+            }
+        }
+    }
+}