diff --git a/Atc.SourceGenerators.slnx b/Atc.SourceGenerators.slnx
index 1f6f3d9..fd68529 100644
--- a/Atc.SourceGenerators.slnx
+++ b/Atc.SourceGenerators.slnx
@@ -19,6 +19,7 @@
     <Project Path="sample/Atc.SourceGenerators.DependencyRegistration.Domain/Atc.SourceGenerators.DependencyRegistration.Domain.csproj" />
     <Project Path="sample/Atc.SourceGenerators.DependencyRegistration/Atc.SourceGenerators.DependencyRegistration.csproj" />
     <Project Path="sample/Atc.SourceGenerators.EnumMapping/Atc.SourceGenerators.EnumMapping.csproj" />
+    <Project Path="sample/Atc.SourceGenerators.Mapping.Contract/Atc.SourceGenerators.Mapping.Contract.csproj" />
     <Project Path="sample/Atc.SourceGenerators.Mapping.DataAccess/Atc.SourceGenerators.Mapping.DataAccess.csproj" />
     <Project Path="sample/Atc.SourceGenerators.Mapping.Domain/Atc.SourceGenerators.Mapping.Domain.csproj" />
     <Project Path="sample/Atc.SourceGenerators.Mapping/Atc.SourceGenerators.Mapping.csproj" />
diff --git a/docs/samples/Mapping.md b/docs/samples/Mapping.md
index 82e7378..79d85ac 100644
--- a/docs/samples/Mapping.md
+++ b/docs/samples/Mapping.md
@@ -16,14 +16,18 @@ This sample demonstrates the **MappingGenerator** in a realistic 3-layer archite
 - **Atc.SourceGenerators.Mapping** - ASP.NET Core Minimal API (entry point)
 - **Atc.SourceGenerators.Mapping.Domain** - Domain models and business logic
 - **Atc.SourceGenerators.Mapping.DataAccess** - Data access layer with entities
+- **Atc.SourceGenerators.Mapping.Contract** - API contracts (DTOs)
 
 ## 🏗️ Architecture
 
 ```mermaid
-graph LR
+graph TB
     subgraph "API Layer"
         API[Minimal API Endpoints]
-        DTO[DTOs: UserDto, AddressDto]
+    end
+
+    subgraph "Contract Layer"
+        DTO[DTOs: UserDto, AddressDto, UserStatusDto]
     end
 
     subgraph "Domain Layer"
@@ -36,32 +40,36 @@ graph LR
         EE[Entity Enums: UserStatusEntity]
     end
 
-    subgraph "Generated Mappings"
-        M1["UserEntity.MapToUser()"]
-        M2["User.MapToUserDto()"]
-        M3["AddressEntity.MapToAddress()"]
-        M4["Address.MapToAddressDto()"]
+    subgraph "Generated Bidirectional Mappings"
+        M1["User ↔ UserEntity"]
+        M2["User → UserDto"]
+        M3["Address ↔ AddressEntity"]
+        M4["Address → AddressDto"]
+        M5["UserStatus ↔ UserStatusEntity"]
+        M6["UserStatus → UserStatusDto"]
     end
 
-    ENT -->|MapToUser| M1
-    M1 --> DM
-    DM -->|MapToUserDto| M2
-    M2 --> DTO
-
-    EE -.->|auto cast| DE
-    DE -.->|auto cast| DTO
-
-    ENT -.->|nested| M3
-    M3 --> DM
-    DM -.->|nested| M4
-
     API --> DTO
-    DTO --> API
+    DTO --> DM
+    DM --> M1
+    DM --> M2
+    DM --> M3
+    DM --> M4
+    DE --> M5
+    DE --> M6
+    M1 --> ENT
+    M3 --> ENT
+    M5 --> EE
+    M2 --> DTO
+    M4 --> DTO
+    M6 --> DTO
 
     style M1 fill:#2ea44f
     style M2 fill:#2ea44f
     style M3 fill:#2ea44f
     style M4 fill:#2ea44f
+    style M5 fill:#2ea44f
+    style M6 fill:#2ea44f
 ```
 
 ## 🔄 Mapping Flow
@@ -109,37 +117,42 @@ sequenceDiagram
 ### Data Access Layer
 
 ```csharp
-using Atc.SourceGenerators.Annotations;
-
-namespace Atc.SourceGenerators.Mapping.DataAccess;
+namespace Atc.SourceGenerators.Mapping.DataAccess.Entities;
 
-// Entity with mapping to Domain
-[MapTo(typeof(Domain.User))]
-public partial class UserEntity
+// Entity - NO mapping attribute (mapping defined in Domain)
+public class UserEntity
 {
     public int DatabaseId { get; set; }
     public Guid Id { get; set; }
-    public string Name { get; set; } = string.Empty;
+    public string FirstName { get; set; } = string.Empty;
+    public string LastName { get; set; } = string.Empty;
     public string Email { get; set; } = string.Empty;
     public UserStatusEntity Status { get; set; }
     public AddressEntity? Address { get; set; }
     public DateTimeOffset CreatedAt { get; set; }
+    public DateTimeOffset? UpdatedAt { get; set; }
     public bool IsDeleted { get; set; }  // DB-specific field
+    public byte[] RowVersion { get; set; } = [];  // DB-specific field
 }
 
-[MapTo(typeof(Domain.Address))]
-public partial class AddressEntity
+public class AddressEntity
 {
+    public int Id { get; set; }
     public string Street { get; set; } = string.Empty;
     public string City { get; set; } = string.Empty;
+    public string State { get; set; } = string.Empty;
     public string PostalCode { get; set; } = string.Empty;
+    public string Country { get; set; } = string.Empty;
+    public DateTime CreatedAt { get; set; }
+    public DateTime? UpdatedAt { get; set; }
 }
 
 public enum UserStatusEntity
 {
     Active = 0,
     Inactive = 1,
-    Suspended = 2
+    Suspended = 2,
+    Deleted = 3
 }
 ```
 
@@ -150,49 +163,76 @@ using Atc.SourceGenerators.Annotations;
 
 namespace Atc.SourceGenerators.Mapping.Domain;
 
-// Domain model with mapping to DTO
+// Domain model with BIDIRECTIONAL mapping to Entity and forward mapping to DTO
 [MapTo(typeof(UserDto))]
+[MapTo(typeof(UserEntity), Bidirectional = true)]
 public partial class User
 {
-    public Guid Id { get; init; }
-    public string Name { get; init; } = string.Empty;
-    public string Email { get; init; } = string.Empty;
-    public UserStatus Status { get; init; }
-    public Address? Address { get; init; }
-    public DateTimeOffset CreatedAt { get; init; }
+    public Guid Id { get; set; }
+    public string FirstName { get; set; } = string.Empty;
+    public string LastName { get; set; } = string.Empty;
+    public string Email { get; set; } = string.Empty;
+    public UserStatus Status { get; set; }
+    public Address? Address { get; set; }
+    public DateTimeOffset CreatedAt { get; set; }
+    public DateTimeOffset? UpdatedAt { get; set; }
 }
 
 [MapTo(typeof(AddressDto))]
+[MapTo(typeof(AddressEntity), Bidirectional = true)]
 public partial class Address
 {
-    public string Street { get; init; } = string.Empty;
-    public string City { get; init; } = string.Empty;
-    public string PostalCode { get; init; } = string.Empty;
+    public string Street { get; set; } = string.Empty;
+    public string City { get; set; } = string.Empty;
+    public string State { get; set; } = string.Empty;
+    public string PostalCode { get; set; } = string.Empty;
+    public string Country { get; set; } = string.Empty;
 }
 
+[MapTo(typeof(UserStatusDto))]
+[MapTo(typeof(UserStatusEntity), Bidirectional = true)]
 public enum UserStatus
 {
     Active = 0,
     Inactive = 1,
-    Suspended = 2
+    Suspended = 2,
+    Deleted = 3
 }
+```
+
+### Contract Layer
+
+```csharp
+namespace Atc.SourceGenerators.Mapping.Contract;
 
-// DTOs
+// DTOs - no mapping attributes needed (mapped from Domain)
 public class UserDto
 {
     public Guid Id { get; set; }
-    public string Name { get; set; } = string.Empty;
+    public string FirstName { get; set; } = string.Empty;
+    public string LastName { get; set; } = string.Empty;
     public string Email { get; set; } = string.Empty;
-    public string Status { get; set; } = string.Empty;  // Different type!
+    public UserStatusDto Status { get; set; }
     public AddressDto? Address { get; set; }
     public DateTimeOffset CreatedAt { get; set; }
+    public DateTimeOffset? UpdatedAt { get; set; }
 }
 
 public class AddressDto
 {
     public string Street { get; set; } = string.Empty;
     public string City { get; set; } = string.Empty;
+    public string State { get; set; } = string.Empty;
     public string PostalCode { get; set; } = string.Empty;
+    public string Country { get; set; } = string.Empty;
+}
+
+public enum UserStatusDto
+{
+    Active = 0,
+    Inactive = 1,
+    Suspended = 2,
+    Deleted = 3
 }
 ```
 
@@ -200,81 +240,82 @@ public class AddressDto
 
 ```csharp
 using Atc.Mapping;
+using Atc.SourceGenerators.Mapping.Contract;
 using Atc.SourceGenerators.Mapping.Domain;
 using Microsoft.AspNetCore.Mvc;
 
-var app = WebApplication.Create();
+var builder = WebApplication.CreateBuilder(args);
+
+// Register services
+builder.Services.AddSingleton<IUserRepository, UserRepository>();
+builder.Services.AddSingleton<UserService>();
 
-// POST endpoint - Create user
-app.MapPost("/users", async ([FromBody] CreateUserRequest request) =>
+var app = builder.Build();
+
+// GET endpoint - Retrieve user by ID
+app.MapGet("/users/{id:guid}", (Guid id, UserService userService) =>
 {
-    // Convert DTO → Domain
-    var user = new User
+    var user = userService.GetById(id);
+    if (user is null)
     {
-        Id = Guid.NewGuid(),
-        Name = request.Name,
-        Email = request.Email,
-        Status = UserStatus.Active,
-        CreatedAt = DateTimeOffset.UtcNow
-    };
-
-    // Convert Domain → Entity
-    var entity = user.MapToUserEntity();
-    // Save to database...
-
-    // Convert Domain → DTO for response
-    var dto = user.MapToUserDto();
-    return Results.Created($"/users/{user.Id}", dto);
-});
-
-// GET endpoint - Retrieve user
-app.MapGet("/users/{id:guid}", async (Guid id) =>
-{
-    // Fetch from database
-    var entity = await repository.GetByIdAsync(id);
-    if (entity == null) return Results.NotFound();
-
-    // Complete mapping chain: Entity → Domain → DTO
-    var user = entity.MapToUser();      // Auto-converts enum, nested Address
-    var dto = user.MapToUserDto();      // Auto-maps all properties
+        return Results.NotFound(new { message = $"User with ID {id} not found" });
+    }
 
-    return Results.Ok(dto);
-});
+    // ✨ Use generated mapping: Domain → DTO
+    var data = user.MapToUserDto();
+    return Results.Ok(data);
+})
+.WithName("GetUserById")
+.Produces<UserDto>(StatusCodes.Status200OK)
+.Produces(StatusCodes.Status404NotFound);
 
-app.Run();
+// GET endpoint - Retrieve all users
+app.MapGet("/users", (UserService userService) =>
+{
+    // ✨ Use generated mapping: Domain → DTO
+    var data = userService
+        .GetAll()
+        .Select(u => u.MapToUserDto())
+        .ToList();
+    return Results.Ok(data);
+})
+.WithName("GetAllUsers")
+.Produces<List<UserDto>>(StatusCodes.Status200OK);
+
+await app.RunAsync();
 ```
 
 ## 📝 Generated Code
 
-The generator creates extension methods for each mapping:
+The generator creates extension methods for bidirectional mappings:
 
 ```csharp
 // <auto-generated />
 namespace Atc.Mapping;
 
-public static partial class UserEntityExtensions
+// Bidirectional mapping: User ↔ UserEntity
+public static partial class UserExtensions
 {
-    public static Domain.User MapToUser(this UserEntity source)
+    public static UserEntity MapToUserEntity(this User source)
     {
         if (source is null)
         {
             return default!;
         }
 
-        return new Domain.User
+        return new UserEntity
         {
             Id = source.Id,
-            Name = source.Name,
+            FirstName = source.FirstName,
+            LastName = source.LastName,
             Email = source.Email,
-            Status = (Domain.UserStatus)source.Status,  // ✨ Auto enum conversion
-            Address = source.Address?.MapToAddress()!,  // ✨ Auto nested mapping
-            CreatedAt = source.CreatedAt
+            Status = source.Status.MapToUserStatusEntity(),  // ✨ Safe enum mapping (bidirectional)
+            Address = source.Address?.MapToAddressEntity()!, // ✨ Auto nested mapping
+            CreatedAt = source.CreatedAt,
+            UpdatedAt = source.UpdatedAt
         };
     }
-}
 
-public static partial class UserExtensions
-{
     public static UserDto MapToUserDto(this User source)
     {
         if (source is null)
@@ -285,11 +326,37 @@ public static partial class UserExtensions
         return new UserDto
         {
             Id = source.Id,
-            Name = source.Name,
+            FirstName = source.FirstName,
+            LastName = source.LastName,
+            Email = source.Email,
+            Status = source.Status.MapToUserStatusDto(),    // ✨ Safe enum mapping
+            Address = source.Address?.MapToAddressDto()!,   // ✨ Nested mapping
+            CreatedAt = source.CreatedAt,
+            UpdatedAt = source.UpdatedAt
+        };
+    }
+}
+
+public static partial class UserEntityExtensions
+{
+    // Reverse mapping (from Bidirectional = true)
+    public static User MapToUser(this UserEntity source)
+    {
+        if (source is null)
+        {
+            return default!;
+        }
+
+        return new User
+        {
+            Id = source.Id,
+            FirstName = source.FirstName,
+            LastName = source.LastName,
             Email = source.Email,
-            Status = source.Status.ToString(),          // ✨ Enum to string
-            Address = source.Address?.MapToAddressDto()!, // ✨ Nested mapping
-            CreatedAt = source.CreatedAt
+            Status = source.Status.MapToUserStatus(),    // ✨ Safe enum mapping (reverse)
+            Address = source.Address?.MapToAddress()!,   // ✨ Auto nested mapping
+            CreatedAt = source.CreatedAt,
+            UpdatedAt = source.UpdatedAt
         };
     }
 }
diff --git a/sample/Atc.SourceGenerators.Mapping.Domain/ApiContracts/AddressDto.cs b/sample/Atc.SourceGenerators.Mapping.Contract/AddressDto.cs
similarity index 92%
rename from sample/Atc.SourceGenerators.Mapping.Domain/ApiContracts/AddressDto.cs
rename to sample/Atc.SourceGenerators.Mapping.Contract/AddressDto.cs
index f898d78..c72877a 100644
--- a/sample/Atc.SourceGenerators.Mapping.Domain/ApiContracts/AddressDto.cs
+++ b/sample/Atc.SourceGenerators.Mapping.Contract/AddressDto.cs
@@ -1,4 +1,4 @@
-namespace Atc.SourceGenerators.Mapping.Domain.ApiContracts;
+namespace Atc.SourceGenerators.Mapping.Contract;
 
 /// <summary>
 /// Data transfer object for Address (used for API responses).
diff --git a/sample/Atc.SourceGenerators.Mapping.Contract/Atc.SourceGenerators.Mapping.Contract.csproj b/sample/Atc.SourceGenerators.Mapping.Contract/Atc.SourceGenerators.Mapping.Contract.csproj
new file mode 100644
index 0000000..9ed914b
--- /dev/null
+++ b/sample/Atc.SourceGenerators.Mapping.Contract/Atc.SourceGenerators.Mapping.Contract.csproj
@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>
diff --git a/sample/Atc.SourceGenerators.Mapping.Domain/ApiContracts/UserDto.cs b/sample/Atc.SourceGenerators.Mapping.Contract/UserDto.cs
similarity index 95%
rename from sample/Atc.SourceGenerators.Mapping.Domain/ApiContracts/UserDto.cs
rename to sample/Atc.SourceGenerators.Mapping.Contract/UserDto.cs
index 35712bc..c4e506b 100644
--- a/sample/Atc.SourceGenerators.Mapping.Domain/ApiContracts/UserDto.cs
+++ b/sample/Atc.SourceGenerators.Mapping.Contract/UserDto.cs
@@ -1,4 +1,4 @@
-namespace Atc.SourceGenerators.Mapping.Domain.ApiContracts;
+namespace Atc.SourceGenerators.Mapping.Contract;
 
 /// <summary>
 /// Data transfer object for User (used for API responses).
diff --git a/sample/Atc.SourceGenerators.Mapping.Domain/ApiContracts/UserStatusDto.cs b/sample/Atc.SourceGenerators.Mapping.Contract/UserStatusDto.cs
similarity index 88%
rename from sample/Atc.SourceGenerators.Mapping.Domain/ApiContracts/UserStatusDto.cs
rename to sample/Atc.SourceGenerators.Mapping.Contract/UserStatusDto.cs
index 17dc803..fefaeb0 100644
--- a/sample/Atc.SourceGenerators.Mapping.Domain/ApiContracts/UserStatusDto.cs
+++ b/sample/Atc.SourceGenerators.Mapping.Contract/UserStatusDto.cs
@@ -1,4 +1,4 @@
-namespace Atc.SourceGenerators.Mapping.Domain.ApiContracts;
+namespace Atc.SourceGenerators.Mapping.Contract;
 
 /// <summary>
 /// Data transfer object for UserStatus (used for API responses).
diff --git a/sample/Atc.SourceGenerators.Mapping.DataAccess/Atc.SourceGenerators.Mapping.DataAccess.csproj b/sample/Atc.SourceGenerators.Mapping.DataAccess/Atc.SourceGenerators.Mapping.DataAccess.csproj
index f511120..a6da9ce 100644
--- a/sample/Atc.SourceGenerators.Mapping.DataAccess/Atc.SourceGenerators.Mapping.DataAccess.csproj
+++ b/sample/Atc.SourceGenerators.Mapping.DataAccess/Atc.SourceGenerators.Mapping.DataAccess.csproj
@@ -4,13 +4,16 @@
     <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
-    <NoWarn>$(NoWarn);CS0436;SA0001;CS1591;IDE0005</NoWarn>
+    <NoWarn>$(NoWarn);CS0436;IDE0005</NoWarn>
+    <GenerateDocumentationFile>false</GenerateDocumentationFile>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.0" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\..\src\Atc.SourceGenerators\Atc.SourceGenerators.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
-    <ProjectReference Include="..\..\src\Atc.SourceGenerators.Annotations\Atc.SourceGenerators.Annotations.csproj" />
-    <ProjectReference Include="..\Atc.SourceGenerators.Mapping.Domain\Atc.SourceGenerators.Mapping.Domain.csproj" />
   </ItemGroup>
 
 </Project>
\ No newline at end of file
diff --git a/sample/Atc.SourceGenerators.Mapping.DataAccess/Entities/AddressEntity.cs b/sample/Atc.SourceGenerators.Mapping.DataAccess/Entities/AddressEntity.cs
index 42e55ce..8eab964 100644
--- a/sample/Atc.SourceGenerators.Mapping.DataAccess/Entities/AddressEntity.cs
+++ b/sample/Atc.SourceGenerators.Mapping.DataAccess/Entities/AddressEntity.cs
@@ -1,10 +1,9 @@
 namespace Atc.SourceGenerators.Mapping.DataAccess.Entities;
 
 /// <summary>
-/// Database entity for address (maps to Domain.Address).
+/// Database entity for address.
 /// </summary>
-[MapTo(typeof(Address))]
-public partial class AddressEntity
+public class AddressEntity
 {
     /// <summary>
     /// Gets or sets the database ID.
diff --git a/sample/Atc.SourceGenerators.Mapping.DataAccess/Entities/UserEntity.cs b/sample/Atc.SourceGenerators.Mapping.DataAccess/Entities/UserEntity.cs
index d446131..ccb3c63 100644
--- a/sample/Atc.SourceGenerators.Mapping.DataAccess/Entities/UserEntity.cs
+++ b/sample/Atc.SourceGenerators.Mapping.DataAccess/Entities/UserEntity.cs
@@ -1,10 +1,9 @@
 namespace Atc.SourceGenerators.Mapping.DataAccess.Entities;
 
 /// <summary>
-/// Database entity for user (maps to Domain.User).
+/// Database entity for user.
 /// </summary>
-[MapTo(typeof(User))]
-public partial class UserEntity
+public class UserEntity
 {
     /// <summary>
     /// Gets or sets the database ID (auto-increment).
diff --git a/sample/Atc.SourceGenerators.Mapping.DataAccess/GlobalUsings.cs b/sample/Atc.SourceGenerators.Mapping.DataAccess/GlobalUsings.cs
index 3e3b781..fc36262 100644
--- a/sample/Atc.SourceGenerators.Mapping.DataAccess/GlobalUsings.cs
+++ b/sample/Atc.SourceGenerators.Mapping.DataAccess/GlobalUsings.cs
@@ -1,5 +1,2 @@
-global using Atc.Mapping;
-
-global using Atc.SourceGenerators.Annotations;
 global using Atc.SourceGenerators.Mapping.DataAccess.Entities;
-global using Atc.SourceGenerators.Mapping.Domain;
\ No newline at end of file
+global using Atc.SourceGenerators.Mapping.DataAccess.Repositories;
\ No newline at end of file
diff --git a/sample/Atc.SourceGenerators.Mapping.DataAccess/Repositories/IUserRepository.cs b/sample/Atc.SourceGenerators.Mapping.DataAccess/Repositories/IUserRepository.cs
new file mode 100644
index 0000000..a699eef
--- /dev/null
+++ b/sample/Atc.SourceGenerators.Mapping.DataAccess/Repositories/IUserRepository.cs
@@ -0,0 +1,20 @@
+namespace Atc.SourceGenerators.Mapping.DataAccess.Repositories;
+
+/// <summary>
+/// Repository interface for user operations.
+/// </summary>
+public interface IUserRepository
+{
+    /// <summary>
+    /// Gets a user entity by ID.
+    /// </summary>
+    /// <param name="id">The user ID.</param>
+    /// <returns>The user entity, or null if not found.</returns>
+    UserEntity? GetById(Guid id);
+
+    /// <summary>
+    /// Gets all user entities.
+    /// </summary>
+    /// <returns>Collection of user entities.</returns>
+    IEnumerable<UserEntity> GetAll();
+}
\ No newline at end of file
diff --git a/sample/Atc.SourceGenerators.Mapping.DataAccess/UserRepository.cs b/sample/Atc.SourceGenerators.Mapping.DataAccess/Repositories/UserRepository.cs
similarity index 87%
rename from sample/Atc.SourceGenerators.Mapping.DataAccess/UserRepository.cs
rename to sample/Atc.SourceGenerators.Mapping.DataAccess/Repositories/UserRepository.cs
index a115228..1590281 100644
--- a/sample/Atc.SourceGenerators.Mapping.DataAccess/UserRepository.cs
+++ b/sample/Atc.SourceGenerators.Mapping.DataAccess/Repositories/UserRepository.cs
@@ -1,4 +1,4 @@
-namespace Atc.SourceGenerators.Mapping.DataAccess;
+namespace Atc.SourceGenerators.Mapping.DataAccess.Repositories;
 
 /// <summary>
 /// In-memory user repository for demo purposes.
@@ -62,19 +62,19 @@ public class UserRepository : IUserRepository
     };
 
     /// <summary>
-    /// Gets a user by ID.
+    /// Gets a user entity by ID.
     /// </summary>
     /// <param name="id">The user ID.</param>
-    /// <returns>The user domain model, or null if not found.</returns>
-    public User? GetById(Guid id)
+    /// <returns>The user entity, or null if not found.</returns>
+    public UserEntity? GetById(Guid id)
         => !users.TryGetValue(id, out var entity)
             ? null
-            : entity.MapToUser();
+            : entity;
 
     /// <summary>
-    /// Gets all users.
+    /// Gets all user entities.
     /// </summary>
-    /// <returns>Collection of user domain models.</returns>
-    public IEnumerable<User> GetAll()
-        => users.Values.Select(e => e.MapToUser());
+    /// <returns>Collection of user entities.</returns>
+    public IEnumerable<UserEntity> GetAll()
+        => users.Values;
 }
\ No newline at end of file
diff --git a/sample/Atc.SourceGenerators.Mapping.Domain/Address.cs b/sample/Atc.SourceGenerators.Mapping.Domain/Address.cs
index cd7dcc6..134889a 100644
--- a/sample/Atc.SourceGenerators.Mapping.Domain/Address.cs
+++ b/sample/Atc.SourceGenerators.Mapping.Domain/Address.cs
@@ -4,6 +4,7 @@ namespace Atc.SourceGenerators.Mapping.Domain;
 /// Represents a physical address.
 /// </summary>
 [MapTo(typeof(AddressDto))]
+[MapTo(typeof(AddressEntity), Bidirectional = true)]
 public partial class Address
 {
     /// <summary>
diff --git a/sample/Atc.SourceGenerators.Mapping.Domain/Atc.SourceGenerators.Mapping.Domain.csproj b/sample/Atc.SourceGenerators.Mapping.Domain/Atc.SourceGenerators.Mapping.Domain.csproj
index 33a5b0e..4332e79 100644
--- a/sample/Atc.SourceGenerators.Mapping.Domain/Atc.SourceGenerators.Mapping.Domain.csproj
+++ b/sample/Atc.SourceGenerators.Mapping.Domain/Atc.SourceGenerators.Mapping.Domain.csproj
@@ -1,19 +1,26 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <NoWarn>$(NoWarn);CS0436;IDE0005</NoWarn>
+    <GenerateDocumentationFile>false</GenerateDocumentationFile>
+  </PropertyGroup>
+
   <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="10.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="10.0.0" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Options" Version="10.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="10.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Options.DataAnnotations" Version="10.0.0" />
   </ItemGroup>
 
   <ItemGroup>
+    <ProjectReference Include="..\Atc.SourceGenerators.Mapping.Contract\Atc.SourceGenerators.Mapping.Contract.csproj" />
+    <ProjectReference Include="..\Atc.SourceGenerators.Mapping.DataAccess\Atc.SourceGenerators.Mapping.DataAccess.csproj" />
     <ProjectReference Include="..\..\src\Atc.SourceGenerators\Atc.SourceGenerators.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
-    <ProjectReference Include="..\..\src\Atc.SourceGenerators.Annotations\Atc.SourceGenerators.Annotations.csproj" />
   </ItemGroup>
 
-  <PropertyGroup>
-    <TargetFramework>net10.0</TargetFramework>
-    <ImplicitUsings>enable</ImplicitUsings>
-    <Nullable>enable</Nullable>
-    <NoWarn>$(NoWarn);CS0436;SA0001;CS1591;IDE0005</NoWarn>
-  </PropertyGroup>
-
 </Project>
\ No newline at end of file
diff --git a/sample/Atc.SourceGenerators.Mapping.Domain/GlobalUsings.cs b/sample/Atc.SourceGenerators.Mapping.Domain/GlobalUsings.cs
index 0604aea..b38e67c 100644
--- a/sample/Atc.SourceGenerators.Mapping.Domain/GlobalUsings.cs
+++ b/sample/Atc.SourceGenerators.Mapping.Domain/GlobalUsings.cs
@@ -1,3 +1,8 @@
+global using Atc.Mapping;
+
 global using Atc.SourceGenerators.Annotations;
-global using Atc.SourceGenerators.Mapping.Domain.ApiContracts;
+global using Atc.SourceGenerators.Mapping.Contract;
+global using Atc.SourceGenerators.Mapping.DataAccess.Entities;
+global using Atc.SourceGenerators.Mapping.DataAccess.Repositories;
+
 global using Microsoft.Extensions.DependencyInjection;
\ No newline at end of file
diff --git a/sample/Atc.SourceGenerators.Mapping.Domain/IUserRepository.cs b/sample/Atc.SourceGenerators.Mapping.Domain/IUserRepository.cs
deleted file mode 100644
index 8d836da..0000000
--- a/sample/Atc.SourceGenerators.Mapping.Domain/IUserRepository.cs
+++ /dev/null
@@ -1,20 +0,0 @@
-namespace Atc.SourceGenerators.Mapping.Domain;
-
-/// <summary>
-/// Repository interface for user operations.
-/// </summary>
-public interface IUserRepository
-{
-    /// <summary>
-    /// Gets a user by ID.
-    /// </summary>
-    /// <param name="id">The user ID.</param>
-    /// <returns>The user domain model, or null if not found.</returns>
-    User? GetById(Guid id);
-
-    /// <summary>
-    /// Gets all users.
-    /// </summary>
-    /// <returns>Collection of user domain models.</returns>
-    IEnumerable<User> GetAll();
-}
\ No newline at end of file
diff --git a/sample/Atc.SourceGenerators.Mapping.Domain/ServiceCollectionExtensions.cs b/sample/Atc.SourceGenerators.Mapping.Domain/ServiceCollectionExtensions.cs
deleted file mode 100644
index 4614908..0000000
--- a/sample/Atc.SourceGenerators.Mapping.Domain/ServiceCollectionExtensions.cs
+++ /dev/null
@@ -1,20 +0,0 @@
-namespace Atc.SourceGenerators.Mapping.Domain;
-
-/// <summary>
-/// Extension methods for service collection registration.
-/// </summary>
-public static class ServiceCollectionExtensions
-{
-    /// <summary>
-    /// Adds user services to the service collection.
-    /// Note: You must register an IUserRepository implementation separately.
-    /// </summary>
-    /// <param name="services">The service collection.</param>
-    /// <returns>The service collection for chaining.</returns>
-    public static IServiceCollection AddUserServices(
-        this IServiceCollection services)
-    {
-        services.AddSingleton<UserService>();
-        return services;
-    }
-}
\ No newline at end of file
diff --git a/sample/Atc.SourceGenerators.Mapping.Domain/User.cs b/sample/Atc.SourceGenerators.Mapping.Domain/User.cs
index 93353e3..402fa59 100644
--- a/sample/Atc.SourceGenerators.Mapping.Domain/User.cs
+++ b/sample/Atc.SourceGenerators.Mapping.Domain/User.cs
@@ -4,6 +4,7 @@ namespace Atc.SourceGenerators.Mapping.Domain;
 /// Represents a user in the system.
 /// </summary>
 [MapTo(typeof(UserDto))]
+[MapTo(typeof(UserEntity), Bidirectional = true)]
 public partial class User
 {
     /// <summary>
diff --git a/sample/Atc.SourceGenerators.Mapping.Domain/UserService.cs b/sample/Atc.SourceGenerators.Mapping.Domain/UserService.cs
index 4e8b7fd..f97aa96 100644
--- a/sample/Atc.SourceGenerators.Mapping.Domain/UserService.cs
+++ b/sample/Atc.SourceGenerators.Mapping.Domain/UserService.cs
@@ -22,12 +22,14 @@ public UserService(IUserRepository repository)
     /// <param name="id">The user ID.</param>
     /// <returns>The user domain model, or null if not found.</returns>
     public User? GetById(Guid id)
-        => repository.GetById(id);
+        => repository.GetById(id)?.MapToUser();
 
     /// <summary>
     /// Gets all users.
     /// </summary>
     /// <returns>Collection of user domain models.</returns>
     public IEnumerable<User> GetAll()
-        => repository.GetAll();
+        => repository
+            .GetAll()
+            .Select(e => e.MapToUser());
 }
\ No newline at end of file
diff --git a/sample/Atc.SourceGenerators.Mapping.Domain/UserStatus.cs b/sample/Atc.SourceGenerators.Mapping.Domain/UserStatus.cs
index e012cf5..9bbe077 100644
--- a/sample/Atc.SourceGenerators.Mapping.Domain/UserStatus.cs
+++ b/sample/Atc.SourceGenerators.Mapping.Domain/UserStatus.cs
@@ -3,6 +3,8 @@ namespace Atc.SourceGenerators.Mapping.Domain;
 /// <summary>
 /// Represents the status of a user account.
 /// </summary>
+[MapTo(typeof(UserStatusDto))]
+[MapTo(typeof(UserStatusEntity), Bidirectional = true)]
 public enum UserStatus
 {
     /// <summary>
diff --git a/sample/Atc.SourceGenerators.Mapping/Atc.SourceGenerators.Mapping.csproj b/sample/Atc.SourceGenerators.Mapping/Atc.SourceGenerators.Mapping.csproj
index ac3e4e1..acbdb34 100644
--- a/sample/Atc.SourceGenerators.Mapping/Atc.SourceGenerators.Mapping.csproj
+++ b/sample/Atc.SourceGenerators.Mapping/Atc.SourceGenerators.Mapping.csproj
@@ -1,22 +1,37 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <NoWarn>$(NoWarn);CS0436;IDE0005</NoWarn>
+  </PropertyGroup>
+
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="10.0.0" />
     <PackageReference Include="Scalar.AspNetCore" Version="2.10.3" />
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\Atc.SourceGenerators.Mapping.DataAccess\Atc.SourceGenerators.Mapping.DataAccess.csproj" />
     <ProjectReference Include="..\Atc.SourceGenerators.Mapping.Domain\Atc.SourceGenerators.Mapping.Domain.csproj" />
+    <ProjectReference Include="..\Atc.SourceGenerators.Mapping.Contract\Atc.SourceGenerators.Mapping.Contract.csproj" />
     <ProjectReference Include="..\..\src\Atc.SourceGenerators\Atc.SourceGenerators.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
-    <ProjectReference Include="..\..\src\Atc.SourceGenerators.Annotations\Atc.SourceGenerators.Annotations.csproj" />
   </ItemGroup>
 
-  <PropertyGroup>
-    <TargetFramework>net10.0</TargetFramework>
-    <Nullable>enable</Nullable>
-    <ImplicitUsings>enable</ImplicitUsings>
-    <NoWarn>$(NoWarn);CS0436;SA0001;CS1591;IDE0005</NoWarn>
-  </PropertyGroup>
+  <!-- Prevent XML documentation files from referenced projects from being copied -->
+  <Target Name="RemoveReferencedXmlDocs" BeforeTargets="GenerateMSBuildEditorConfigFileShouldRun;CoreCompile">
+    <ItemGroup>
+      <!-- Remove XML files from ReferenceCopyLocalPaths -->
+      <ReferenceCopyLocalPaths Remove="@(ReferenceCopyLocalPaths)" Condition="'%(Extension)' == '.xml' and '%(Filename)' != '$(AssemblyName)'" />
+    </ItemGroup>
+  </Target>
+
+  <!-- Also remove after build for cleanup -->
+  <Target Name="CleanupXmlDocs" AfterTargets="Build">
+    <ItemGroup>
+      <XmlFilesToDelete Include="$(OutputPath)*.xml" Exclude="$(OutputPath)$(AssemblyName).xml" />
+    </ItemGroup>
+    <Delete Files="@(XmlFilesToDelete)" />
+  </Target>
 
 </Project>
\ No newline at end of file
diff --git a/sample/Atc.SourceGenerators.Mapping/GlobalUsings.cs b/sample/Atc.SourceGenerators.Mapping/GlobalUsings.cs
index 02b775c..d375cfc 100644
--- a/sample/Atc.SourceGenerators.Mapping/GlobalUsings.cs
+++ b/sample/Atc.SourceGenerators.Mapping/GlobalUsings.cs
@@ -1,7 +1,7 @@
 global using Atc.Mapping;
 
-global using Atc.SourceGenerators.Mapping.DataAccess;
+global using Atc.SourceGenerators.Mapping.Contract;
+global using Atc.SourceGenerators.Mapping.DataAccess.Repositories;
 global using Atc.SourceGenerators.Mapping.Domain;
-global using Atc.SourceGenerators.Mapping.Domain.ApiContracts;
 
 global using Scalar.AspNetCore;
\ No newline at end of file
diff --git a/sample/Atc.SourceGenerators.Mapping/Program.cs b/sample/Atc.SourceGenerators.Mapping/Program.cs
index 9b0deb4..9d89a84 100644
--- a/sample/Atc.SourceGenerators.Mapping/Program.cs
+++ b/sample/Atc.SourceGenerators.Mapping/Program.cs
@@ -7,7 +7,7 @@
 builder.Services.AddSingleton<IUserRepository, UserRepository>();
 
 // Register domain services
-builder.Services.AddUserServices();
+builder.Services.AddSingleton<UserService>();
 
 // Add OpenAPI
 builder.Services.AddOpenApi();
@@ -25,7 +25,9 @@
 app
     .MapGet("/", context =>
     {
-        if (context.RequestServices.GetRequiredService<IWebHostEnvironment>().IsDevelopment())
+        if (context.RequestServices
+            .GetRequiredService<IWebHostEnvironment>()
+            .IsDevelopment())
         {
             context.Response.Redirect("/scalar/v1");
             return Task.CompletedTask;
diff --git a/sample/PetStore.Api/Program.cs b/sample/PetStore.Api/Program.cs
index 592e623..c80638b 100644
--- a/sample/PetStore.Api/Program.cs
+++ b/sample/PetStore.Api/Program.cs
@@ -3,7 +3,7 @@
 
 var builder = WebApplication.CreateBuilder(args);
 
-// ✨ Scenario B: Register all services transitively (Domain + DataAccess)
+// ✨ Register all services transitively (Domain + DataAccess)
 // This single call registers:
 //   - PetService from PetStore.Domain
 //   - PetRepository from PetStore.DataAccess (auto-detected as referenced assembly)
@@ -34,7 +34,9 @@
 app
     .MapGet("/", context =>
     {
-        if (context.RequestServices.GetRequiredService<IWebHostEnvironment>().IsDevelopment())
+        if (context.RequestServices
+            .GetRequiredService<IWebHostEnvironment>()
+            .IsDevelopment())
         {
             context.Response.Redirect("/scalar/v1");
             return Task.CompletedTask;