diff --git a/.gitignore b/.gitignore
index 46d3f4b..5c58dbb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -367,5 +367,5 @@ FodyWeavers.xsd
 */**/obj/Debug   
 */**/obj/Release   
 */Migrations
-/workshop.wwwapi/appsettings.json
-/workshop.wwwapi/appsettings.Development.json
\ No newline at end of file
+/exercise.wwwapi/appsettings.json
+/exercise.wwwapi/appsettings.Development.json
\ No newline at end of file
diff --git a/exercise.webapi/DTO/AuthorPayload.cs b/exercise.webapi/DTO/AuthorPayload.cs
new file mode 100644
index 0000000..89a16e2
--- /dev/null
+++ b/exercise.webapi/DTO/AuthorPayload.cs
@@ -0,0 +1,16 @@
+using exercise.webapi.Models;
+
+namespace exercise.webapi.DTO
+{
+    public class AuthorPayload
+    {
+        public int Id { get; set; }
+        public string FirstName { get; set; }
+        public string LastName { get; set; }
+        public string Email { get; set; }
+
+        public IEnumerable<TestBookPayload> Books { get; set; } //= new List<TestBookPayload>(); 
+
+
+    }
+}
diff --git a/exercise.webapi/DTO/BookPaylaod.cs b/exercise.webapi/DTO/BookPaylaod.cs
new file mode 100644
index 0000000..fcd9f62
--- /dev/null
+++ b/exercise.webapi/DTO/BookPaylaod.cs
@@ -0,0 +1,13 @@
+namespace exercise.webapi.DTO
+{
+    public class BookPaylaod<T> where T : class
+    {
+        public T Data { get; set; }
+
+        //public string FirstName { get; set; }
+        //public string LastName { get; set; }
+        //public string Email { get; set; }
+
+        public string Message { get; set; } = "Status";
+    }
+}
diff --git a/exercise.webapi/DTO/BookPost.cs b/exercise.webapi/DTO/BookPost.cs
new file mode 100644
index 0000000..b29222e
--- /dev/null
+++ b/exercise.webapi/DTO/BookPost.cs
@@ -0,0 +1,11 @@
+using exercise.webapi.Models;
+
+namespace exercise.webapi.DTO
+{
+    public class BookPost
+    {
+        public string Title { get; set; }
+
+        public int AuthorId { get; set; }
+    }
+}
diff --git a/exercise.webapi/DTO/BookPut.cs b/exercise.webapi/DTO/BookPut.cs
new file mode 100644
index 0000000..f9f6553
--- /dev/null
+++ b/exercise.webapi/DTO/BookPut.cs
@@ -0,0 +1,15 @@
+using exercise.webapi.Models;
+
+namespace exercise.webapi.DTO
+{
+    public class BookPut
+    {
+        /*
+        public int? Id { get; set; }
+        public string? Title { get; set; }
+        public Author Author { get; set; }
+        */
+
+        public required int AuthorId { get; set; }
+    }
+}
diff --git a/exercise.webapi/DTO/TestBookPayload.cs b/exercise.webapi/DTO/TestBookPayload.cs
new file mode 100644
index 0000000..01efc96
--- /dev/null
+++ b/exercise.webapi/DTO/TestBookPayload.cs
@@ -0,0 +1,14 @@
+namespace exercise.webapi.DTO
+{
+    public class TestBookPayload
+    {
+        public int Id { get; set; }
+        public string Title { get; set; }
+
+        public int? AuthorId { get; set; }
+
+        public string? FirstName { get; set; }
+        public string? LastName { get; set; }
+        public string? Email { get; set; }
+    }
+}
diff --git a/exercise.webapi/Endpoints/AuthorApi.cs b/exercise.webapi/Endpoints/AuthorApi.cs
new file mode 100644
index 0000000..0755f0b
--- /dev/null
+++ b/exercise.webapi/Endpoints/AuthorApi.cs
@@ -0,0 +1,64 @@
+using exercise.webapi.DTO;
+using exercise.webapi.Models;
+using exercise.webapi.Repository;
+
+namespace exercise.webapi.Endpoints
+{
+    public static class AuthorApi
+    {
+        public static void ConfigureAuthorsApi(this WebApplication app)
+        {
+            var author = app.MapGroup("author");
+
+            author.MapGet("/", GetAllAuthors);
+            author.MapGet("/{id}", GetAuthorById);
+        }
+
+        public static async Task<IResult> GetAllAuthors(IRepository<Author> authorRepository)
+        {
+
+            var payload = from a in authorRepository.GetAllEntities().Result
+                          select new AuthorPayload()
+                          {
+                              Id = a.Id,
+                              FirstName = a.FirstName,
+                              LastName = a.LastName,
+                              Email = a.Email,
+                              Books = from b in a.Books
+                                      select new TestBookPayload()
+                                      {
+                                          Id = b.Id,
+                                          Title = b.Title,
+                                          AuthorId = a.Id,
+                                          FirstName = a.FirstName,
+                                          LastName = a.LastName,
+                                          Email = a.Email
+                                      }
+                          };
+
+            return TypedResults.Ok(payload);
+        }
+
+        private static async Task<IResult> GetAuthorById(IRepository<Author> authorRepository, int id)
+        {
+
+            var author = await authorRepository.GetEntityById(id);
+
+            var payload =  new AuthorPayload()
+                          {
+                              Id = author.Id,
+                              FirstName = author.FirstName,
+                              LastName = author.LastName,
+                              Email = author.Email,
+                              Books = from b in author.Books
+                                      select new TestBookPayload()
+                                      {
+                                          Id = b.Id,
+                                          Title = b.Title
+                                      }
+                          };
+
+            return TypedResults.Ok(payload);
+        }
+    }
+}
diff --git a/exercise.webapi/Endpoints/BookApi.cs b/exercise.webapi/Endpoints/BookApi.cs
index 6758215..941042c 100644
--- a/exercise.webapi/Endpoints/BookApi.cs
+++ b/exercise.webapi/Endpoints/BookApi.cs
@@ -1,4 +1,5 @@
-using exercise.webapi.Models;
+using exercise.webapi.DTO;
+using exercise.webapi.Models;
 using exercise.webapi.Repository;
 using static System.Reflection.Metadata.BlobBuilder;
 
@@ -8,13 +9,121 @@ public static class BookApi
     {
         public static void ConfigureBooksApi(this WebApplication app)
         {
-            app.MapGet("/books", GetBooks);
+            var books = app.MapGroup("books");
+
+            books.MapGet("/", GetBooks);
+            books.MapGet("/{id}", GetBookById);
+            books.MapPut("/{id}", UpdateBook);
+            books.MapDelete("/{id}", DeleteBook);
+            books.MapPost("/", CreateBook);
+        }
+
+        private static async Task<IResult> GetBooks(IRepository<Book> bookRepository)
+        {
+
+
+            var payload = from b in bookRepository.GetAllEntities().Result
+                                         select new TestBookPayload()
+                                         {
+                                             Id = b.Id,
+                                             Title = b.Title,
+                                             AuthorId = b.AuthorId,
+                                             FirstName = b.Author.FirstName,
+                                             LastName = b.Author.LastName,
+                                             Email = b.Author.Email
+                                         };
+
+            return TypedResults.Ok(payload);
+        }
+
+        private static async Task<IResult> GetBookById(IRepository<Book> bookRepository, int id)
+        {
+            var book = await bookRepository.GetEntityById(id);
+
+            var payload = new TestBookPayload()
+            {
+                Id = book.Id,
+                Title = book.Title,
+                AuthorId = book.AuthorId,
+                FirstName = book.Author.FirstName,
+                LastName = book.Author.LastName,
+                Email = book.Author.Email
+            };
+
+            return TypedResults.Ok(payload);
+        }
+
+        private static async Task<IResult> UpdateBook(IRepository<Book> bookRepository, IRepository<Author> authorRepository, int id, BookPut model)
+        {
+            var book = await bookRepository.GetEntityById(id);
+            if (book == null) return TypedResults.NotFound("No book matching provided ID");
+
+            try
+            {
+                book.Author = await authorRepository.GetEntityById(model.AuthorId);
+                book.AuthorId = model.AuthorId;
+
+                bookRepository.SaveRepository();
+            }
+            catch (Exception ex) { return TypedResults.BadRequest(ex); }
+
+            var payload = new TestBookPayload()
+            {
+                Id = book.Id,
+                Title = book.Title,
+                AuthorId = book.AuthorId,
+                FirstName = book.Author.FirstName,
+                LastName = book.Author.LastName,
+                Email = book.Author.Email
+            };
+
+            return TypedResults.Ok(payload);
         }
 
-        private static async Task<IResult> GetBooks(IBookRepository bookRepository)
+        private static async Task<IResult> DeleteBook(IRepository<Book> bookRepository, int id)
         {
-            var books = await bookRepository.GetAllBooks();
-            return TypedResults.Ok(books);
+            try
+            {
+                var book = await bookRepository.GetEntityById(id);
+                if (book == null) return TypedResults.NotFound("No book matching provided ID");
+
+                var status = await bookRepository.DeleteEntity(book);
+                bookRepository.SaveRepository();
+
+                return TypedResults.Ok(status);
+
+            } catch (Exception ex) { return TypedResults.BadRequest(ex); }
+        }
+
+
+        private static async Task<IResult> CreateBook(IRepository<Book> bookRepository, IRepository<Author> authorRepository, BookPost model)
+        {
+            try
+            {   
+                var allBooks = await bookRepository.GetAllEntities();
+
+                Book book = new Book() 
+                { 
+                    Id = allBooks.Max(b => b.Id) + 1,
+                    Title = model.Title,
+                    Author = await authorRepository.GetEntityById(model.AuthorId),
+                    AuthorId = model.AuthorId
+                };
+
+                var payload = new TestBookPayload()
+                {
+                    Id = book.Id,
+                    Title = book.Title,
+                    AuthorId = book.AuthorId,
+                    FirstName = book.Author.FirstName,
+                    LastName = book.Author.LastName,
+                    Email = book.Author.Email
+                };
+
+                return TypedResults.Ok(payload);
+
+            }
+            catch (Exception ex) { return TypedResults.BadRequest(ex); }
         }
     }
 }
diff --git a/exercise.webapi/Models/Author.cs b/exercise.webapi/Models/Author.cs
index 9f47878..5698331 100644
--- a/exercise.webapi/Models/Author.cs
+++ b/exercise.webapi/Models/Author.cs
@@ -9,7 +9,7 @@ public class Author
         public string LastName { get; set; }
         public string Email { get; set; }
 
-        [JsonIgnore] // Todo: replace this with DTO approach
+        //[JsonIgnore] // Todo: replace this with DTO approach
         public ICollection<Book> Books { get; set; } = new List<Book>();
     }
 }
diff --git a/exercise.webapi/Program.cs b/exercise.webapi/Program.cs
index 43dec56..cc0d1b6 100644
--- a/exercise.webapi/Program.cs
+++ b/exercise.webapi/Program.cs
@@ -1,5 +1,6 @@
 using exercise.webapi.Data;
 using exercise.webapi.Endpoints;
+using exercise.webapi.Models;
 using exercise.webapi.Repository;
 using Microsoft.EntityFrameworkCore;
 
@@ -10,7 +11,8 @@
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();
 builder.Services.AddDbContext<DataContext>(opt => opt.UseInMemoryDatabase("Library"));
-builder.Services.AddScoped<IBookRepository, BookRepository>();
+builder.Services.AddScoped<IRepository<Book>, BookRepository>();
+builder.Services.AddScoped<IRepository<Author>, AuthorRepository>();
 
 var app = builder.Build();
 
@@ -29,4 +31,5 @@
 
 app.UseHttpsRedirection();
 app.ConfigureBooksApi();
+app.ConfigureAuthorsApi();
 app.Run();
diff --git a/exercise.webapi/Repository/AuthorRepository.cs b/exercise.webapi/Repository/AuthorRepository.cs
new file mode 100644
index 0000000..45a488c
--- /dev/null
+++ b/exercise.webapi/Repository/AuthorRepository.cs
@@ -0,0 +1,36 @@
+using exercise.webapi.Data;
+using exercise.webapi.Models;
+using Microsoft.EntityFrameworkCore;
+
+namespace exercise.webapi.Repository
+{
+    public class AuthorRepository : IRepository<Author>
+    {
+        DataContext _db;
+
+        public AuthorRepository(DataContext db) 
+        {
+            _db = db;
+        }
+        public async void SaveRepository()
+        {
+            await _db.SaveChangesAsync();
+        }
+
+        public async Task<IEnumerable<Author>> GetAllEntities()
+        {
+            return await _db.Authors.Include(a => a.Books).ToListAsync();
+        }
+
+        public async Task<Author> GetEntityById(int id)
+        {
+            return await _db.Authors.Include(a => a.Books).FirstOrDefaultAsync(a => a.Id == id);
+        }
+
+        public Task<bool> DeleteEntity(Author author)
+        {
+            throw new NotImplementedException();
+        }
+
+    }
+}
diff --git a/exercise.webapi/Repository/BookRepository.cs b/exercise.webapi/Repository/BookRepository.cs
index 1f5e64a..73ecd5c 100644
--- a/exercise.webapi/Repository/BookRepository.cs
+++ b/exercise.webapi/Repository/BookRepository.cs
@@ -4,7 +4,7 @@
 
 namespace exercise.webapi.Repository
 {
-    public class BookRepository: IBookRepository
+    public class BookRepository: IRepository<Book>
     {
         DataContext _db;
         
@@ -13,10 +13,29 @@ public BookRepository(DataContext db)
             _db = db;
         }
 
-        public async Task<IEnumerable<Book>> GetAllBooks()
+        public async void SaveRepository()
+        {
+            await _db.SaveChangesAsync();
+        }
+
+        public async Task<IEnumerable<Book>> GetAllEntities()
         {
             return await _db.Books.Include(b => b.Author).ToListAsync();
 
         }
+
+        public async Task<Book> GetEntityById(int id)
+        {
+            return await _db.Books.Include(b => b.Author).FirstOrDefaultAsync(b => b.Id == id);
+        }
+
+        public async Task<bool> DeleteEntity(Book book)
+        {
+            try
+            {
+                _db.Books.Remove(book);
+                return true;
+            }catch (Exception ex) {return false;}
+        }
     }
 }
diff --git a/exercise.webapi/Repository/IBookRepository.cs b/exercise.webapi/Repository/IBookRepository.cs
deleted file mode 100644
index f860016..0000000
--- a/exercise.webapi/Repository/IBookRepository.cs
+++ /dev/null
@@ -1,9 +0,0 @@
-using exercise.webapi.Models;
-
-namespace exercise.webapi.Repository
-{
-    public interface IBookRepository
-    {
-        public Task<IEnumerable<Book>> GetAllBooks();
-    }
-}
diff --git a/exercise.webapi/Repository/IRepository.cs b/exercise.webapi/Repository/IRepository.cs
new file mode 100644
index 0000000..ace14ee
--- /dev/null
+++ b/exercise.webapi/Repository/IRepository.cs
@@ -0,0 +1,15 @@
+using exercise.webapi.Models;
+
+namespace exercise.webapi.Repository
+{
+    public interface IRepository<T>
+    {
+        public void SaveRepository();
+
+        public Task<IEnumerable<T>> GetAllEntities(); //Book
+        public Task<T> GetEntityById(int id); //Book or Author
+
+        public Task<bool> DeleteEntity(T entity);
+
+    }
+}
diff --git a/exercise.webapi/exercise.webapi.csproj b/exercise.webapi/exercise.webapi.csproj
index 0ff4269..152fea4 100644
--- a/exercise.webapi/exercise.webapi.csproj
+++ b/exercise.webapi/exercise.webapi.csproj
@@ -8,10 +8,15 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.0" />
-    <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="8.0.1" />
+    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="9.0.1" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="9.0.1" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="9.0.1">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="9.0.1" />
     <PackageReference Include="Scalar.AspNetCore" Version="2.0.4" />
-    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.4.0" />
+    <PackageReference Include="Swashbuckle.AspNetCore" Version="7.2.0" />
   </ItemGroup>
 
 </Project>