diff --git a/DocumentOperator.Tests/Unit/Client/PdfValidationClientTests.cs b/DocumentOperator.Tests/Unit/Client/PdfValidationClientTests.cs
index dedca82..761bfa0 100644
--- a/DocumentOperator.Tests/Unit/Client/PdfValidationClientTests.cs
+++ b/DocumentOperator.Tests/Unit/Client/PdfValidationClientTests.cs
@@ -1,168 +1,183 @@
 using DocumentService.Client.Clients;
 using DocumentService.Client.Interfaces;
-using DocumentService.Client.Models.Requests;
 using FluentAssertions;
 using Microsoft.Extensions.Logging.Abstractions;
 using System.Net;
 using System.Net.Http;
 using System.Text.Json;
+using Xunit;
 
 namespace DocumentService.Tests.Unit.Client;
 
-/// <summary>
-/// Unit tests for <see cref="PdfValidationClient"/>.
-/// All tests use a fake <see cref="MockHttpMessageHandler"/> — no real HTTP calls are made.
-/// </summary>
 public class PdfValidationClientTests
 {
-    // ?? helpers ?????????????????????????????????????????????????????????????
-
     private static (PdfValidationClient client, MockHttpMessageHandler handler) Build<T>(T responseBody)
     {
         var handler = MockHttpMessageHandler.ReturningJson(responseBody);
         var httpClient = new HttpClient(handler) { BaseAddress = new Uri("http://localhost") };
-        var client = new PdfValidationClient(httpClient, NullLogger<PdfValidationClient>.Instance);
-        return (client, handler);
+        return (new PdfValidationClient(httpClient, NullLogger<PdfValidationClient>.Instance), handler);
     }
 
-    private static byte[] FakePdfBytes() => "fake-pdf-content"u8.ToArray();
+    private static (PdfValidationClient client, MockHttpMessageHandler handler) BuildError(HttpStatusCode code)
+    {
+        var handler = MockHttpMessageHandler.ReturningStatus(code);
+        var httpClient = new HttpClient(handler) { BaseAddress = new Uri("http://localhost") };
+        return (new PdfValidationClient(httpClient, NullLogger<PdfValidationClient>.Instance), handler);
+    }
 
-    // ?? ValidatePdfAsync (Stream) ????????????????????????????????????????????
+    private static byte[] FakePdfBytes() => "fake-pdf"u8.ToArray();
+
+    // ── ValidatePdfAsync (Stream) ────────────────────────────────────────────
 
     [Fact]
     public async Task ValidatePdfAsync_Stream_SendsMultipartPost()
     {
-        // Arrange
-        var expected = new PdfValidationResult { PageCount = 3, PdfVersion = "1.7", FileSizeBytes = 2048 };
+        var expected = new PdfValidationResult { PageCount = 3, PdfVersion = "1.7", FileSizeBytes = 2048, IsEncrypted = false };
         var (client, handler) = Build(expected);
 
-        // Act
         var result = await client.ValidatePdfAsync(new MemoryStream(FakePdfBytes()));
 
-        // Assert
         result.PageCount.Should().Be(3);
         result.PdfVersion.Should().Be("1.7");
+        result.FileSizeBytes.Should().Be(2048);
+        result.IsEncrypted.Should().BeFalse();
         handler.LastRequest!.Method.Should().Be(HttpMethod.Post);
         handler.LastRequest.RequestUri!.PathAndQuery.Should().Be("/api/pdf/validation/validate");
         handler.LastRequest.Content.Should().BeOfType<MultipartFormDataContent>();
     }
 
+    [Fact]
+    public async Task ValidatePdfAsync_Stream_EncryptedPdf_DeserializesIsEncryptedTrue()
+    {
+        var expected = new PdfValidationResult { PageCount = 1, IsEncrypted = true, PdfVersion = "1.6" };
+        var (client, _) = Build(expected);
+
+        var result = await client.ValidatePdfAsync(new MemoryStream(FakePdfBytes()));
+
+        result.IsEncrypted.Should().BeTrue("encrypted PDFs should surface IsEncrypted=true");
+    }
+
     [Fact]
     public async Task ValidatePdfAsync_Stream_ThrowsWhenApiReturnsNull()
     {
-        // Arrange — API returns JSON null
         var handler = MockHttpMessageHandler.ReturningJson<PdfValidationResult?>(null);
         var httpClient = new HttpClient(handler) { BaseAddress = new Uri("http://localhost") };
         var client = new PdfValidationClient(httpClient, NullLogger<PdfValidationClient>.Instance);
 
-        // Act & Assert
         await client.Invoking(c => c.ValidatePdfAsync(new MemoryStream(FakePdfBytes())))
             .Should().ThrowAsync<InvalidOperationException>();
     }
 
-    // ?? ValidatePdfAsync (byte[]) ????????????????????????????????????????????
+    [Fact]
+    public async Task ValidatePdfAsync_Stream_WhenApiReturns400_ThrowsHttpRequestException()
+    {
+        var (client, _) = BuildError(HttpStatusCode.BadRequest);
+        await client.Invoking(c => c.ValidatePdfAsync(new MemoryStream(FakePdfBytes())))
+            .Should().ThrowAsync<HttpRequestException>();
+    }
+
+    [Fact]
+    public async Task ValidatePdfAsync_Stream_WhenApiReturns500_ThrowsHttpRequestException()
+    {
+        var (client, _) = BuildError(HttpStatusCode.InternalServerError);
+        await client.Invoking(c => c.ValidatePdfAsync(new MemoryStream(FakePdfBytes())))
+            .Should().ThrowAsync<HttpRequestException>();
+    }
+
+    // ── ValidatePdfAsync (byte[]) ────────────────────────────────────────────
 
     [Fact]
     public async Task ValidatePdfAsync_Bytes_SendsJsonWithBase64()
     {
-        // Arrange
-        var expected = new PdfValidationResult { PageCount = 1, IsEncrypted = false };
+        var expected = new PdfValidationResult { PageCount = 1, IsEncrypted = false, HasAttachments = true, AttachmentCount = 2 };
         var (client, handler) = Build(expected);
 
-        // Act
         var result = await client.ValidatePdfAsync(FakePdfBytes());
 
-        // Assert
         result.PageCount.Should().Be(1);
-        handler.LastRequest!.Content.Should().NotBeNull();
-        handler.LastRequest.Content!.Headers.ContentType!.MediaType.Should().Be("application/json");
-
+        result.HasAttachments.Should().BeTrue();
+        result.AttachmentCount.Should().Be(2);
+        handler.LastRequest!.Content!.Headers.ContentType!.MediaType.Should().Be("application/json");
         var body = await handler.LastRequest.Content!.ReadAsStringAsync();
         var doc = JsonDocument.Parse(body);
         doc.RootElement.GetProperty("base64Pdf").GetString().Should().NotBeNullOrEmpty();
     }
 
-    // ?? ValidatePdfAAsync (Stream) ???????????????????????????????????????????
+    [Fact]
+    public async Task ValidatePdfAsync_Bytes_WhenApiReturns400_ThrowsHttpRequestException()
+    {
+        var (client, _) = BuildError(HttpStatusCode.BadRequest);
+        await client.Invoking(c => c.ValidatePdfAsync(FakePdfBytes()))
+            .Should().ThrowAsync<HttpRequestException>();
+    }
+
+    // ── ValidatePdfAAsync (Stream) ───────────────────────────────────────────
 
     [Fact]
-    public async Task ValidatePdfAAsync_Stream_SendsMultipartPost()
+    public async Task ValidatePdfAAsync_Stream_DeserializesAllFields()
     {
-        // Arrange
-        var expected = new PdfAValidationResult { IsValid = true, PdfAVersion = "PDF/A-3b", PageCount = 2 };
+        var expected = new PdfAValidationResult
+        {
+            IsValid = true, PdfAVersion = "PDF/A-3b", PageCount = 2,
+            Errors = [], Warnings = []
+        };
         var (client, handler) = Build(expected);
 
-        // Act
         var result = await client.ValidatePdfAAsync(new MemoryStream(FakePdfBytes()));
 
-        // Assert
         result.IsValid.Should().BeTrue();
         result.PdfAVersion.Should().Be("PDF/A-3b");
+        result.PageCount.Should().Be(2);
+        result.Errors.Should().BeEmpty();
         handler.LastRequest!.RequestUri!.PathAndQuery.Should().Be("/api/pdf/validation/validate-pdfa");
         handler.LastRequest.Content.Should().BeOfType<MultipartFormDataContent>();
     }
 
     [Fact]
-    public async Task ValidatePdfAAsync_Stream_WithErrors_ReturnsErrors()
+    public async Task ValidatePdfAAsync_Stream_NonCompliant_ReturnsErrors()
     {
-        // Arrange
         var expected = new PdfAValidationResult
         {
             IsValid = false,
-            Errors = new List<string> { "Missing embedded font", "Encryption not allowed" }
+            Errors = ["Missing embedded font", "Encryption not allowed"],
+            Warnings = ["Manual verification recommended"]
         };
         var (client, _) = Build(expected);
 
-        // Act
         var result = await client.ValidatePdfAAsync(new MemoryStream(FakePdfBytes()));
 
-        // Assert
         result.IsValid.Should().BeFalse();
         result.Errors.Should().HaveCount(2).And.Contain("Missing embedded font");
+        result.Warnings.Should().HaveCount(1);
     }
 
-    // ?? ValidatePdfAAsync (byte[]) ???????????????????????????????????????????
+    [Fact]
+    public async Task ValidatePdfAAsync_Stream_WhenApiReturns400_ThrowsHttpRequestException()
+    {
+        var (client, _) = BuildError(HttpStatusCode.BadRequest);
+        await client.Invoking(c => c.ValidatePdfAAsync(new MemoryStream(FakePdfBytes())))
+            .Should().ThrowAsync<HttpRequestException>();
+    }
+
+    // ── ValidatePdfAAsync (byte[]) ───────────────────────────────────────────
 
     [Fact]
-    public async Task ValidatePdfAAsync_Bytes_SendsJson()
+    public async Task ValidatePdfAAsync_Bytes_SendsJsonToCorrectEndpoint()
     {
-        // Arrange
         var expected = new PdfAValidationResult { IsValid = true };
         var (client, handler) = Build(expected);
 
-        // Act
         await client.ValidatePdfAAsync(FakePdfBytes());
 
-        // Assert
         handler.LastRequest!.RequestUri!.PathAndQuery.Should().Be("/api/pdf/validation/validate-pdfa");
-        handler.LastRequest.Content.Should().NotBeNull();
         handler.LastRequest.Content!.Headers.ContentType!.MediaType.Should().Be("application/json");
     }
 
-    // ?? HTTP error propagation ???????????????????????????????????????????????
-
     [Fact]
-    public async Task ValidatePdfAsync_WhenApiReturns400_ThrowsHttpRequestException()
+    public async Task ValidatePdfAAsync_Bytes_WhenApiReturns500_ThrowsHttpRequestException()
     {
-        // Arrange
-        var handler = MockHttpMessageHandler.ReturningStatus(HttpStatusCode.BadRequest);
-        var httpClient = new HttpClient(handler) { BaseAddress = new Uri("http://localhost") };
-        var client = new PdfValidationClient(httpClient, NullLogger<PdfValidationClient>.Instance);
-
-        // Act & Assert
-        await client.Invoking(c => c.ValidatePdfAsync(new MemoryStream(FakePdfBytes())))
-            .Should().ThrowAsync<HttpRequestException>();
-    }
-
-    [Fact]
-    public async Task ValidatePdfAsync_WhenApiReturns500_ThrowsHttpRequestException()
-    {
-        // Arrange
-        var handler = MockHttpMessageHandler.ReturningStatus(HttpStatusCode.InternalServerError);
-        var httpClient = new HttpClient(handler) { BaseAddress = new Uri("http://localhost") };
-        var client = new PdfValidationClient(httpClient, NullLogger<PdfValidationClient>.Instance);
-
-        // Act & Assert
-        await client.Invoking(c => c.ValidatePdfAsync(new MemoryStream(FakePdfBytes())))
+        var (client, _) = BuildError(HttpStatusCode.InternalServerError);
+        await client.Invoking(c => c.ValidatePdfAAsync(FakePdfBytes()))
             .Should().ThrowAsync<HttpRequestException>();
     }
 }