diff --git a/back/src/Kyoo.Authentication/AuthenticationModule.cs b/back/src/Kyoo.Authentication/AuthenticationModule.cs
index cd6f154f..8214c101 100644
--- a/back/src/Kyoo.Authentication/AuthenticationModule.cs
+++ b/back/src/Kyoo.Authentication/AuthenticationModule.cs
@@ -61,12 +61,12 @@ namespace Kyoo.Authentication
 		/// <inheritdoc />
 		public void Configure(IServiceCollection services)
 		{
-			string secret = _configuration.GetValue("AUTHENTICATION_SECRET", AuthenticationOption.DefaultSecret);
+			string secret = _configuration.GetValue("AUTHENTICATION_SECRET", AuthenticationOption.DefaultSecret)!;
 			PermissionOption permissions = new()
 			{
-				Default = _configuration.GetValue("UNLOGGED_PERMISSIONS", "overall.read").Split(','),
-				NewUser = _configuration.GetValue("DEFAULT_PERMISSIONS", "overall.read").Split(','),
-				ApiKeys = _configuration.GetValue("KYOO_APIKEYS", string.Empty).Split(','),
+				Default = _configuration.GetValue("UNLOGGED_PERMISSIONS", "overall.read")!.Split(','),
+				NewUser = _configuration.GetValue("DEFAULT_PERMISSIONS", "overall.read")!.Split(','),
+				ApiKeys = _configuration.GetValue("KYOO_APIKEYS", string.Empty)!.Split(','),
 			};
 			services.AddSingleton(permissions);
 			services.AddSingleton(new AuthenticationOption()
diff --git a/back/src/Kyoo.Authentication/Controllers/PermissionValidator.cs b/back/src/Kyoo.Authentication/Controllers/PermissionValidator.cs
index e5b4fa48..9e238045 100644
--- a/back/src/Kyoo.Authentication/Controllers/PermissionValidator.cs
+++ b/back/src/Kyoo.Authentication/Controllers/PermissionValidator.cs
@@ -198,7 +198,7 @@ namespace Kyoo.Authentication
 			{
 				if (!context.HttpContext.Request.Headers.TryGetValue("X-API-Key", out StringValues apiKey))
 					return AuthenticateResult.NoResult();
-				if (!_options.ApiKeys.Contains<string>(apiKey))
+				if (!_options.ApiKeys.Contains<string>(apiKey!))
 					return AuthenticateResult.Fail("Invalid API-Key.");
 				return AuthenticateResult.Success(
 					new AuthenticationTicket(
diff --git a/back/tests/Kyoo.Tests/Database/RepositoryTests.cs b/back/tests/Kyoo.Tests/Database/RepositoryTests.cs
index ff891a55..8e7acc03 100644
--- a/back/tests/Kyoo.Tests/Database/RepositoryTests.cs
+++ b/back/tests/Kyoo.Tests/Database/RepositoryTests.cs
@@ -196,7 +196,7 @@ namespace Kyoo.Tests.Database
 		{
 			string slug = TestSample.Get<T>().Slug[2..4];
 			ICollection<T> ret = await _repository.GetAll(x => x.Slug.Contains(slug));
-			Assert.Equal(1, ret.Count);
+			Assert.Single(ret);
 			KAssert.DeepEqual(TestSample.Get<T>(), ret.First());
 		}
 
diff --git a/back/tests/Kyoo.Tests/Database/SpecificTests/LibraryTests.cs b/back/tests/Kyoo.Tests/Database/SpecificTests/LibraryTests.cs
index 2c7cc9e6..57a7deea 100644
--- a/back/tests/Kyoo.Tests/Database/SpecificTests/LibraryTests.cs
+++ b/back/tests/Kyoo.Tests/Database/SpecificTests/LibraryTests.cs
@@ -91,7 +91,7 @@ namespace Kyoo.Tests.Database
 			await _repository.Create(library);
 			Library retrieved = await _repository.Get(2);
 			await Repositories.LibraryManager.Load(retrieved, x => x.Providers);
-			Assert.Equal(1, retrieved.Providers.Count);
+			Assert.Single(retrieved.Providers);
 			Assert.Equal(TestSample.Get<Provider>().Slug, retrieved.Providers.First().Slug);
 		}
 
diff --git a/back/tests/Kyoo.Tests/Database/SpecificTests/ShowTests.cs b/back/tests/Kyoo.Tests/Database/SpecificTests/ShowTests.cs
index 91be9da9..5d24ff39 100644
--- a/back/tests/Kyoo.Tests/Database/SpecificTests/ShowTests.cs
+++ b/back/tests/Kyoo.Tests/Database/SpecificTests/ShowTests.cs
@@ -316,7 +316,7 @@ namespace Kyoo.Tests.Database
 				.ThenInclude(x => x.Provider)
 				.FirstAsync(x => x.ID == created.ID);
 			KAssert.DeepEqual(expected, retrieved);
-			Assert.Equal(1, retrieved.ExternalIDs.Count);
+			Assert.Single(retrieved.ExternalIDs);
 			Assert.Equal("ID", retrieved.ExternalIDs.First().DataID);
 		}
 
@@ -362,8 +362,8 @@ namespace Kyoo.Tests.Database
 			await Repositories.LibraryManager.Load(show, x => x.Seasons);
 			await Repositories.LibraryManager.Load(show, x => x.Episodes);
 			Assert.Equal(1, await _repository.GetCount());
-			Assert.Equal(1, show.Seasons.Count);
-			Assert.Equal(1, show.Episodes.Count);
+			Assert.Single(show.Seasons);
+			Assert.Single(show.Episodes);
 			await _repository.Delete(show);
 			Assert.Equal(0, await Repositories.LibraryManager.ShowRepository.GetCount());
 			Assert.Equal(0, await Repositories.LibraryManager.SeasonRepository.GetCount());
diff --git a/back/tests/Kyoo.Tests/Utility/MergerTests.cs b/back/tests/Kyoo.Tests/Utility/MergerTests.cs
index dd9c71a2..810e68c9 100644
--- a/back/tests/Kyoo.Tests/Utility/MergerTests.cs
+++ b/back/tests/Kyoo.Tests/Utility/MergerTests.cs
@@ -414,7 +414,7 @@ namespace Kyoo.Tests.Utility
 			};
 			IDictionary<int, string> ret = Merger.CompleteDictionaries(first, second, out bool changed);
 			Assert.True(changed);
-			Assert.Equal(1, ret.Count);
+			Assert.Single(ret);
 			Assert.Equal("new-poster", ret[Images.Poster]);
 		}
 
diff --git a/shell.nix b/shell.nix
index b14ef34d..9e60002d 100644
--- a/shell.nix
+++ b/shell.nix
@@ -10,8 +10,8 @@ in
       nodePackages.expo-cli
       (with dotnetCorePackages;
         combinePackages [
-          sdk_6_0
-          aspnetcore_6_0
+          sdk_7_0
+          aspnetcore_7_0
         ])
       python3
       python3Packages.pip
@@ -19,10 +19,10 @@ in
       cargo-watch
       rustfmt
       rustc
-	  pkgconfig
-	  openssl
-	  mediainfo
-	  ffmpeg
+      pkgconfig
+      openssl
+      mediainfo
+      ffmpeg
     ];
 
     RUST_SRC_PATH = "${pkgs.rust.packages.stable.rustPlatform.rustLibSrc}";