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+# API Client Tests Implementation Plan
+
+> **For Claude:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development to implement this plan task-by-task.
+
+**Goal:** Update existing integration tests to use `ApiRoutes.*` constants and add comprehensive unit tests for API clients using `ApiResult<T>` pattern.
+
+**Architecture:** Unit tests use `MockHttpMessageHandler` to mock HTTP responses and verify ApiClientBase maps status codes correctly. Integration tests use `TestWebApplicationFactory` with shared `HttpClient` for cookie-based auth. All 6 `ApiResult<T>` cases tested once in `ApiClientBaseTests`, with lean coverage (success + representative error) per client.
+
+**Tech Stack:** xUnit, RichardSzalay.MockHttp, Shouldly, NSubstitute, Microsoft.AspNetCore.Mvc.Testing
+
+---
+
+## Task 1: Update AuthenticationTests to Use ApiRoutes Constants
+
+**Files:**
+- Modify: `tests/JdeScoping.Api.IntegrationTests/AuthenticationTests.cs`
+
+**Step 1: Add using for ApiRoutes**
+
+Add at top of file:
+```csharp
+using JdeScoping.Core.ApiContracts;
+```
+
+**Step 2: Replace hardcoded routes**
+
+Replace all occurrences:
+```csharp
+// Before:
+"/api/auth/public-key"  -> ApiRoutes.Auth.PublicKey
+"/api/auth/login"       -> ApiRoutes.Auth.Login
+"/api/auth/logout"      -> ApiRoutes.Auth.Logout
+"/api/auth/me"          -> ApiRoutes.Auth.Me
+"/api/search"           -> ApiRoutes.Search.Base
+"/api/lookup/items?q=test"          -> $"{ApiRoutes.Lookup.Items}?q=test"
+"/api/lookup/profit-centers?q=test" -> $"{ApiRoutes.Lookup.ProfitCenters}?q=test"
+"/api/lookup/work-centers?q=test"   -> $"{ApiRoutes.Lookup.WorkCenters}?q=test"
+"/api/lookup/operators?q=test"      -> $"{ApiRoutes.Lookup.Operators}?q=test"
+```
+
+**Step 3: Run tests to verify**
+
+Run: `dotnet test tests/JdeScoping.Api.IntegrationTests --filter "FullyQualifiedName~AuthenticationTests" -v quiet`
+Expected: All tests pass
+
+**Step 4: Commit**
+
+```bash
+git add tests/JdeScoping.Api.IntegrationTests/AuthenticationTests.cs
+git commit -m "refactor: use ApiRoutes constants in AuthenticationTests"
+```
+
+---
+
+## Task 2: Update FileControllerIntegrationTests to Use ApiRoutes Constants
+
+**Files:**
+- Modify: `tests/JdeScoping.Api.IntegrationTests/FileControllerIntegrationTests.cs`
+
+**Step 1: Add using for ApiRoutes**
+
+Add at top of file:
+```csharp
+using JdeScoping.Core.ApiContracts;
+```
+
+**Step 2: Review and update routes**
+
+The file uses `/api/file/...` routes which may not match `ApiRoutes.FileIO.*` constants. Check if the routes align:
+- Current: `/api/file/work-orders/template/{key}`, `/api/file/part-numbers/template/{key}`
+- ApiRoutes: `api/fileio/workorders/download`, `api/fileio/items/download`
+
+Note: These are different endpoints (legacy download by cache key vs new download). Leave these tests as-is if they test different endpoints, or update to test the new FileIO routes if those old endpoints were removed.
+
+**Step 3: Run tests to verify**
+
+Run: `dotnet test tests/JdeScoping.Api.IntegrationTests --filter "FullyQualifiedName~FileControllerIntegrationTests" -v quiet`
+Expected: All tests pass (or determine if tests need updating based on route analysis)
+
+**Step 4: Commit**
+
+```bash
+git add tests/JdeScoping.Api.IntegrationTests/FileControllerIntegrationTests.cs
+git commit -m "refactor: add ApiRoutes import to FileControllerIntegrationTests"
+```
+
+---
+
+## Task 3: Create TestableApiClient for Unit Testing ApiClientBase
+
+**Files:**
+- Create: `tests/JdeScoping.Client.Tests/Services/TestableApiClient.cs`
+
+**Step 1: Write the test helper class**
+
+```csharp
+using JdeScoping.Client.Services;
+using JdeScoping.Core.ApiContracts.Results;
+
+namespace JdeScoping.Client.Tests.Services;
+
+/// <summary>
+/// Test wrapper to expose protected ApiClientBase methods for unit testing.
+/// </summary>
+public class TestableApiClient : ApiClientBase
+{
+    public TestableApiClient(HttpClient httpClient) : base(httpClient) { }
+
+    public new Task<ApiResult<T>> GetAsync<T>(string route, CancellationToken ct = default)
+        => base.GetAsync<T>(route, ct);
+
+    public new Task<ApiResult<T>> PostAsync<T, TBody>(string route, TBody body, CancellationToken ct = default)
+        => base.PostAsync<T, TBody>(route, body, ct);
+
+    public new Task<ApiResult<T>> PostAsync<T>(string route, CancellationToken ct = default)
+        => base.PostAsync<T>(route, ct);
+
+    public new Task<ApiResult<byte[]>> GetBytesAsync(string route, CancellationToken ct = default)
+        => base.GetBytesAsync(route, ct);
+
+    public new Task<ApiResult<byte[]>> PostForBytesAsync<TBody>(string route, TBody body, CancellationToken ct = default)
+        => base.PostForBytesAsync<TBody>(route, body, ct);
+
+    public new Task<ApiResult<T>> PostMultipartAsync<T>(string route, Stream fileStream, string fileName, CancellationToken ct = default)
+        => base.PostMultipartAsync<T>(route, fileStream, fileName, ct);
+}
+```
+
+**Step 2: Verify file compiles**
+
+Run: `dotnet build tests/JdeScoping.Client.Tests`
+Expected: Build succeeds
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Client.Tests/Services/TestableApiClient.cs
+git commit -m "test: add TestableApiClient helper for ApiClientBase unit tests"
+```
+
+---
+
+## Task 4: Create ApiClientBaseTests - Status Code Mappings (GET)
+
+**Files:**
+- Create: `tests/JdeScoping.Client.Tests/Services/ApiClientBaseTests.cs`
+
+**Step 1: Write the failing test for 200 OK**
+
+```csharp
+using System.Net;
+using System.Text.Json;
+using JdeScoping.Core.ApiContracts.Results;
+using RichardSzalay.MockHttp;
+using Shouldly;
+
+namespace JdeScoping.Client.Tests.Services;
+
+public class ApiClientBaseTests
+{
+    private readonly MockHttpMessageHandler _mockHttp;
+    private readonly TestableApiClient _client;
+
+    public ApiClientBaseTests()
+    {
+        _mockHttp = new MockHttpMessageHandler();
+        var httpClient = new HttpClient(_mockHttp) { BaseAddress = new Uri("http://localhost/") };
+        _client = new TestableApiClient(httpClient);
+    }
+
+    public record TestDto(int Id, string Name);
+
+    [Fact]
+    public async Task GetAsync_Returns200_MapsToSuccessValue()
+    {
+        // Arrange
+        var expected = new TestDto(42, "Test");
+        _mockHttp.When("/api/test")
+            .Respond("application/json", JsonSerializer.Serialize(expected));
+
+        // Act
+        var result = await _client.GetAsync<TestDto>("/api/test");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Id.ShouldBe(42);
+        result.Value.Name.ShouldBe("Test");
+    }
+}
+```
+
+**Step 2: Run test to verify it passes**
+
+Run: `dotnet test tests/JdeScoping.Client.Tests --filter "GetAsync_Returns200_MapsToSuccessValue" -v normal`
+Expected: PASS
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Client.Tests/Services/ApiClientBaseTests.cs
+git commit -m "test: add ApiClientBaseTests with 200 OK mapping test"
+```
+
+---
+
+## Task 5: ApiClientBaseTests - Add All 6 Status Code Tests
+
+**Files:**
+- Modify: `tests/JdeScoping.Client.Tests/Services/ApiClientBaseTests.cs`
+
+**Step 1: Add remaining status code tests**
+
+Add after the first test:
+
+```csharp
+    [Fact]
+    public async Task GetAsync_Returns404_MapsToNotFound()
+    {
+        // Arrange
+        _mockHttp.When("/api/test")
+            .Respond(HttpStatusCode.NotFound);
+
+        // Act
+        var result = await _client.GetAsync<TestDto>("/api/test");
+
+        // Assert
+        result.IsNotFound.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task GetAsync_Returns400_WithValidationErrors_MapsToValidationError()
+    {
+        // Arrange - use actual ValidationProblemDetails structure to match production
+        var validationProblem = new Microsoft.AspNetCore.Mvc.ValidationProblemDetails
+        {
+            Errors =
+            {
+                ["Name"] = new[] { "Name is required" },
+                ["Id"] = new[] { "Id must be positive" }
+            }
+        };
+        _mockHttp.When("/api/test")
+            .Respond(HttpStatusCode.BadRequest, "application/json", JsonSerializer.Serialize(validationProblem, new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase }));
+
+        // Act
+        var result = await _client.GetAsync<TestDto>("/api/test");
+
+        // Assert
+        result.IsValidationError.ShouldBeTrue();
+        result.ValidationError.FieldErrors.ShouldContainKey("Name");
+        result.ValidationError.FieldErrors["Name"].ShouldContain("Name is required");
+    }
+
+    [Fact]
+    public async Task GetAsync_Returns401_MapsToUnauthorized()
+    {
+        // Arrange
+        _mockHttp.When("/api/test")
+            .Respond(HttpStatusCode.Unauthorized);
+
+        // Act
+        var result = await _client.GetAsync<TestDto>("/api/test");
+
+        // Assert
+        result.IsUnauthorized.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task GetAsync_Returns403_MapsToForbidden()
+    {
+        // Arrange
+        _mockHttp.When("/api/test")
+            .Respond(HttpStatusCode.Forbidden);
+
+        // Act
+        var result = await _client.GetAsync<TestDto>("/api/test");
+
+        // Assert
+        result.IsForbidden.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task GetAsync_Returns500_MapsToApiError()
+    {
+        // Arrange
+        _mockHttp.When("/api/test")
+            .Respond(HttpStatusCode.InternalServerError, "text/plain", "Internal Server Error");
+
+        // Act
+        var result = await _client.GetAsync<TestDto>("/api/test");
+
+        // Assert
+        result.IsError.ShouldBeTrue();
+        result.Error.StatusCode.ShouldBe(500);
+    }
+```
+
+**Step 2: Run all status code tests**
+
+Run: `dotnet test tests/JdeScoping.Client.Tests --filter "FullyQualifiedName~ApiClientBaseTests" -v quiet`
+Expected: All 6 tests pass
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Client.Tests/Services/ApiClientBaseTests.cs
+git commit -m "test: add all 6 status code mapping tests to ApiClientBaseTests"
+```
+
+---
+
+## Task 6: ApiClientBaseTests - Add Edge Case Tests
+
+**Files:**
+- Modify: `tests/JdeScoping.Client.Tests/Services/ApiClientBaseTests.cs`
+
+**Step 1: Add edge case tests**
+
+Add at end of class:
+
+```csharp
+    // Edge cases
+
+    [Fact]
+    public async Task GetAsync_Returns200_EmptyBody_MapsToApiError()
+    {
+        // Arrange
+        _mockHttp.When("/api/test")
+            .Respond(HttpStatusCode.OK, "application/json", "");
+
+        // Act
+        var result = await _client.GetAsync<TestDto>("/api/test");
+
+        // Assert
+        result.IsError.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task GetAsync_Returns200_InvalidJson_MapsToApiError()
+    {
+        // Arrange
+        _mockHttp.When("/api/test")
+            .Respond(HttpStatusCode.OK, "application/json", "not valid json {{{");
+
+        // Act
+        var result = await _client.GetAsync<TestDto>("/api/test");
+
+        // Assert
+        result.IsError.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task GetAsync_Returns204_ForUnitType_MapsToSuccess()
+    {
+        // Arrange
+        _mockHttp.When("/api/test")
+            .Respond(HttpStatusCode.NoContent);
+
+        // Act
+        var result = await _client.GetAsync<Unit>("/api/test");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task GetAsync_Returns204_ForNonUnitType_MapsToApiError()
+    {
+        // Arrange
+        _mockHttp.When("/api/test")
+            .Respond(HttpStatusCode.NoContent);
+
+        // Act
+        var result = await _client.GetAsync<TestDto>("/api/test");
+
+        // Assert
+        result.IsError.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task GetAsync_NetworkException_MapsToApiError()
+    {
+        // Arrange
+        _mockHttp.When("/api/test")
+            .Throw(new HttpRequestException("Network failure"));
+
+        // Act
+        var result = await _client.GetAsync<TestDto>("/api/test");
+
+        // Assert
+        result.IsError.ShouldBeTrue();
+        result.Error.Message.ShouldContain("Network failure");
+    }
+
+    [Fact]
+    public async Task GetAsync_Timeout_MapsToApiError()
+    {
+        // Arrange
+        _mockHttp.When("/api/test")
+            .Throw(new TaskCanceledException("Request timeout"));
+
+        // Act
+        var result = await _client.GetAsync<TestDto>("/api/test");
+
+        // Assert
+        result.IsError.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task GetAsync_Returns400_WithoutValidationFormat_MapsToApiError()
+    {
+        // Arrange - Bad request without standard validation problem format
+        _mockHttp.When("/api/test")
+            .Respond(HttpStatusCode.BadRequest, "text/plain", "Bad request");
+
+        // Act
+        var result = await _client.GetAsync<TestDto>("/api/test");
+
+        // Assert
+        result.IsError.ShouldBeTrue();
+        result.Error.StatusCode.ShouldBe(400);
+    }
+```
+
+**Step 2: Run all tests**
+
+Run: `dotnet test tests/JdeScoping.Client.Tests --filter "FullyQualifiedName~ApiClientBaseTests" -v quiet`
+Expected: All tests pass
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Client.Tests/Services/ApiClientBaseTests.cs
+git commit -m "test: add edge case tests to ApiClientBaseTests"
+```
+
+---
+
+## Task 7: ApiClientBaseTests - Add POST and Bytes Tests
+
+**Files:**
+- Modify: `tests/JdeScoping.Client.Tests/Services/ApiClientBaseTests.cs`
+
+**Step 1: Add POST method tests**
+
+Add after edge case tests:
+
+```csharp
+    // POST tests
+
+    [Fact]
+    public async Task PostAsync_Returns200_MapsToSuccessValue()
+    {
+        // Arrange
+        var expected = new TestDto(99, "Created");
+        _mockHttp.When(HttpMethod.Post, "/api/test")
+            .Respond("application/json", JsonSerializer.Serialize(expected));
+
+        // Act
+        var result = await _client.PostAsync<TestDto, TestDto>("/api/test", new TestDto(0, "Input"));
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Id.ShouldBe(99);
+    }
+
+    [Fact]
+    public async Task PostAsync_Returns401_MapsToUnauthorized()
+    {
+        // Arrange
+        _mockHttp.When(HttpMethod.Post, "/api/test")
+            .Respond(HttpStatusCode.Unauthorized);
+
+        // Act
+        var result = await _client.PostAsync<TestDto, TestDto>("/api/test", new TestDto(0, "Input"));
+
+        // Assert
+        result.IsUnauthorized.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task PostAsync_WithNoBody_Returns200()
+    {
+        // Arrange
+        _mockHttp.When(HttpMethod.Post, "/api/test")
+            .Respond("application/json", JsonSerializer.Serialize(new Unit()));
+
+        // Act
+        var result = await _client.PostAsync<Unit>("/api/test");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+    }
+
+    // Bytes tests
+
+    [Fact]
+    public async Task GetBytesAsync_Returns200_MapsToSuccessBytes()
+    {
+        // Arrange
+        var expectedBytes = new byte[] { 0x50, 0x4B, 0x03, 0x04 }; // ZIP header
+        _mockHttp.When("/api/download")
+            .Respond("application/octet-stream", new MemoryStream(expectedBytes));
+
+        // Act
+        var result = await _client.GetBytesAsync("/api/download");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.ShouldBe(expectedBytes);
+    }
+
+    [Fact]
+    public async Task GetBytesAsync_Returns404_MapsToNotFound()
+    {
+        // Arrange
+        _mockHttp.When("/api/download")
+            .Respond(HttpStatusCode.NotFound);
+
+        // Act
+        var result = await _client.GetBytesAsync("/api/download");
+
+        // Assert
+        result.IsNotFound.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task PostForBytesAsync_Returns200_MapsToSuccessBytes()
+    {
+        // Arrange
+        var expectedBytes = new byte[] { 0x50, 0x4B, 0x03, 0x04 };
+        _mockHttp.When(HttpMethod.Post, "/api/download")
+            .Respond("application/octet-stream", new MemoryStream(expectedBytes));
+
+        // Act
+        var result = await _client.PostForBytesAsync("/api/download", new { filter = "test" });
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.ShouldBe(expectedBytes);
+    }
+
+    // Non-GET status code tests (verify same mapping logic applies to other methods)
+
+    [Fact]
+    public async Task PostAsync_Returns400_WithValidationErrors_MapsToValidationError()
+    {
+        // Arrange - verify POST path handles validation errors same as GET
+        var validationProblem = new Microsoft.AspNetCore.Mvc.ValidationProblemDetails
+        {
+            Errors = { ["Field"] = new[] { "Required" } }
+        };
+        _mockHttp.When(HttpMethod.Post, "/api/test")
+            .Respond(HttpStatusCode.BadRequest, "application/json",
+                JsonSerializer.Serialize(validationProblem, new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase }));
+
+        // Act
+        var result = await _client.PostAsync<TestDto, TestDto>("/api/test", new TestDto(0, "Input"));
+
+        // Assert
+        result.IsValidationError.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task GetBytesAsync_Returns500_MapsToApiError()
+    {
+        // Arrange - verify bytes path handles server errors
+        _mockHttp.When("/api/download")
+            .Respond(HttpStatusCode.InternalServerError, "text/plain", "Server error");
+
+        // Act
+        var result = await _client.GetBytesAsync("/api/download");
+
+        // Assert
+        result.IsError.ShouldBeTrue();
+        result.Error.StatusCode.ShouldBe(500);
+    }
+
+    [Fact]
+    public async Task PostMultipartAsync_Returns401_MapsToUnauthorized()
+    {
+        // Arrange - verify multipart path handles auth errors
+        _mockHttp.When(HttpMethod.Post, "/api/upload")
+            .Respond(HttpStatusCode.Unauthorized);
+
+        using var stream = new MemoryStream(new byte[] { 1, 2, 3 });
+
+        // Act
+        var result = await _client.PostMultipartAsync<TestDto>("/api/upload", stream, "test.xlsx");
+
+        // Assert
+        result.IsUnauthorized.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task PostMultipartAsync_Returns200_MapsToSuccessValue()
+    {
+        // Arrange
+        var expected = new TestDto(1, "Uploaded");
+        _mockHttp.When(HttpMethod.Post, "/api/upload")
+            .With(req => req.Content?.Headers.ContentType?.MediaType == "multipart/form-data")
+            .Respond("application/json", JsonSerializer.Serialize(expected));
+
+        using var stream = new MemoryStream(new byte[] { 1, 2, 3 });
+
+        // Act
+        var result = await _client.PostMultipartAsync<TestDto>("/api/upload", stream, "test.xlsx");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Id.ShouldBe(1);
+    }
+```
+
+**Step 2: Run all tests**
+
+Run: `dotnet test tests/JdeScoping.Client.Tests --filter "FullyQualifiedName~ApiClientBaseTests" -v quiet`
+Expected: All tests pass
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Client.Tests/Services/ApiClientBaseTests.cs
+git commit -m "test: add POST and bytes tests to ApiClientBaseTests"
+```
+
+---
+
+## Task 8: Create SearchApiClientTests
+
+**Files:**
+- Create: `tests/JdeScoping.Client.Tests/Services/SearchApiClientTests.cs`
+
+**Step 1: Write SearchApiClientTests**
+
+```csharp
+using System.Net;
+using System.Text.Json;
+using JdeScoping.Client.Services;
+using JdeScoping.Core.ApiContracts;
+using JdeScoping.Core.ViewModels;
+using RichardSzalay.MockHttp;
+using Shouldly;
+
+namespace JdeScoping.Client.Tests.Services;
+
+public class SearchApiClientTests
+{
+    private readonly MockHttpMessageHandler _mockHttp;
+    private readonly SearchApiClient _client;
+
+    public SearchApiClientTests()
+    {
+        _mockHttp = new MockHttpMessageHandler();
+        var httpClient = new HttpClient(_mockHttp) { BaseAddress = new Uri("http://localhost/") };
+        _client = new SearchApiClient(httpClient);
+    }
+
+    // Route verification tests
+
+    [Fact]
+    public async Task GetUserSearchesAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Get, $"http://localhost/{ApiRoutes.Search.Base}")
+            .Respond("application/json", "[]");
+
+        // Act
+        await _client.GetUserSearchesAsync();
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task GetQueuedSearchesAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Get, $"http://localhost/{ApiRoutes.Search.Queue}")
+            .Respond("application/json", "[]");
+
+        // Act
+        await _client.GetQueuedSearchesAsync();
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task GetSearchAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var searchId = 42;
+        var request = _mockHttp.Expect(HttpMethod.Get, $"http://localhost/{ApiRoutes.Search.GetById(searchId)}")
+            .Respond("application/json", JsonSerializer.Serialize(CreateTestSearch(searchId)));
+
+        // Act
+        await _client.GetSearchAsync(searchId);
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task CreateSearchAsync_CallsCorrectRoute_WithPostMethod()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Post, $"http://localhost/{ApiRoutes.Search.Base}")
+            .Respond("application/json", "123");
+
+        // Act
+        await _client.CreateSearchAsync(CreateTestSearch(0));
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task GetResultsAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var searchId = 42;
+        var request = _mockHttp.Expect(HttpMethod.Get, $"http://localhost/{ApiRoutes.Search.GetResults(searchId)}")
+            .Respond("application/octet-stream", new MemoryStream(new byte[] { 1, 2, 3 }));
+
+        // Act
+        await _client.GetResultsAsync(searchId);
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    // Success tests
+
+    [Fact]
+    public async Task GetUserSearchesAsync_Success_ReturnsSearchList()
+    {
+        // Arrange
+        var searches = new List<SearchViewModel> { CreateTestSearch(1), CreateTestSearch(2) };
+        _mockHttp.When(HttpMethod.Get, $"http://localhost/{ApiRoutes.Search.Base}")
+            .Respond("application/json", JsonSerializer.Serialize(searches));
+
+        // Act
+        var result = await _client.GetUserSearchesAsync();
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Count.ShouldBe(2);
+        result.Value[0].Id.ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task GetSearchAsync_Success_ReturnsSearch()
+    {
+        // Arrange
+        var search = CreateTestSearch(42);
+        _mockHttp.When(HttpMethod.Get, $"http://localhost/{ApiRoutes.Search.GetById(42)}")
+            .Respond("application/json", JsonSerializer.Serialize(search));
+
+        // Act
+        var result = await _client.GetSearchAsync(42);
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Id.ShouldBe(42);
+    }
+
+    [Fact]
+    public async Task CreateSearchAsync_Success_ReturnsId()
+    {
+        // Arrange
+        _mockHttp.When(HttpMethod.Post, $"http://localhost/{ApiRoutes.Search.Base}")
+            .Respond("application/json", "123");
+
+        // Act
+        var result = await _client.CreateSearchAsync(CreateTestSearch(0));
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.ShouldBe(123);
+    }
+
+    [Fact]
+    public async Task GetQueuedSearchesAsync_Success_ReturnsSearchList()
+    {
+        // Arrange
+        var searches = new List<SearchViewModel> { CreateTestSearch(1) };
+        _mockHttp.When(HttpMethod.Get, $"http://localhost/{ApiRoutes.Search.Queue}")
+            .Respond("application/json", JsonSerializer.Serialize(searches));
+
+        // Act
+        var result = await _client.GetQueuedSearchesAsync();
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Count.ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task GetResultsAsync_Success_ReturnsBytes()
+    {
+        // Arrange - GetResultsAsync returns byte[] for Excel file
+        var expectedBytes = new byte[] { 0x50, 0x4B, 0x03, 0x04 }; // ZIP/XLSX header
+        _mockHttp.When(HttpMethod.Get, $"http://localhost/{ApiRoutes.Search.GetResults(42)}")
+            .Respond("application/octet-stream", new MemoryStream(expectedBytes));
+
+        // Act
+        var result = await _client.GetResultsAsync(42);
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.ShouldBe(expectedBytes);
+    }
+
+    [Fact]
+    public async Task CopySearchAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var searchId = 42;
+        var request = _mockHttp.Expect(HttpMethod.Get, $"http://localhost/{ApiRoutes.Search.GetCopy(searchId)}")
+            .Respond("application/json", JsonSerializer.Serialize(CreateTestSearch(100)));
+
+        // Act
+        await _client.CopySearchAsync(searchId);
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    // Representative error tests
+
+    [Fact]
+    public async Task GetSearchAsync_404_ReturnsNotFound()
+    {
+        // Arrange
+        _mockHttp.When(HttpMethod.Get, $"http://localhost/{ApiRoutes.Search.GetById(999)}")
+            .Respond(HttpStatusCode.NotFound);
+
+        // Act
+        var result = await _client.GetSearchAsync(999);
+
+        // Assert
+        result.IsNotFound.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task GetUserSearchesAsync_401_ReturnsUnauthorized()
+    {
+        // Arrange
+        _mockHttp.When(HttpMethod.Get, $"http://localhost/{ApiRoutes.Search.Base}")
+            .Respond(HttpStatusCode.Unauthorized);
+
+        // Act
+        var result = await _client.GetUserSearchesAsync();
+
+        // Assert
+        result.IsUnauthorized.ShouldBeTrue();
+    }
+
+    private static SearchViewModel CreateTestSearch(int id) => new()
+    {
+        Id = id,
+        Name = $"Search {id}",
+        UserName = "testuser",
+        Status = "New"
+    };
+}
+```
+
+**Step 2: Run tests**
+
+Run: `dotnet test tests/JdeScoping.Client.Tests --filter "FullyQualifiedName~SearchApiClientTests" -v quiet`
+Expected: All tests pass
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Client.Tests/Services/SearchApiClientTests.cs
+git commit -m "test: add SearchApiClientTests with route and success/error tests"
+```
+
+---
+
+## Task 9: Create LookupApiClientTests
+
+**Files:**
+- Create: `tests/JdeScoping.Client.Tests/Services/LookupApiClientTests.cs`
+
+**Step 1: Write LookupApiClientTests**
+
+```csharp
+using System.Net;
+using System.Text.Json;
+using JdeScoping.Client.Services;
+using JdeScoping.Core.ApiContracts;
+using JdeScoping.Core.ViewModels;
+using RichardSzalay.MockHttp;
+using Shouldly;
+
+namespace JdeScoping.Client.Tests.Services;
+
+public class LookupApiClientTests
+{
+    private readonly MockHttpMessageHandler _mockHttp;
+    private readonly LookupApiClient _client;
+
+    public LookupApiClientTests()
+    {
+        _mockHttp = new MockHttpMessageHandler();
+        var httpClient = new HttpClient(_mockHttp) { BaseAddress = new Uri("http://localhost/") };
+        _client = new LookupApiClient(httpClient);
+    }
+
+    // Route verification tests
+
+    [Fact]
+    public async Task FindItemsAsync_CallsCorrectRoute_WithQuery()
+    {
+        // Arrange
+        var query = "TEST123";
+        var expectedUrl = $"http://localhost/{ApiRoutes.Lookup.FindItems(query)}";
+        var request = _mockHttp.Expect(HttpMethod.Get, expectedUrl)
+            .Respond("application/json", "[]");
+
+        // Act
+        await _client.FindItemsAsync(query);
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task FindProfitCentersAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var query = "PC1";
+        var request = _mockHttp.Expect(HttpMethod.Get, $"http://localhost/{ApiRoutes.Lookup.FindProfitCenters(query)}")
+            .Respond("application/json", "[]");
+
+        // Act
+        await _client.FindProfitCentersAsync(query);
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task FindWorkCentersAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var query = "WC1";
+        var request = _mockHttp.Expect(HttpMethod.Get, $"http://localhost/{ApiRoutes.Lookup.FindWorkCenters(query)}")
+            .Respond("application/json", "[]");
+
+        // Act
+        await _client.FindWorkCentersAsync(query);
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task FindOperatorsAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var query = "John";
+        var request = _mockHttp.Expect(HttpMethod.Get, $"http://localhost/{ApiRoutes.Lookup.FindOperators(query)}")
+            .Respond("application/json", "[]");
+
+        // Act
+        await _client.FindOperatorsAsync(query);
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    // Query string encoding tests
+
+    [Fact]
+    public async Task FindItemsAsync_EncodesSpecialCharacters_InQueryString()
+    {
+        // Arrange - query with special characters that need URL encoding
+        var query = "TEST&ITEM=1";
+        var expectedUrl = $"http://localhost/{ApiRoutes.Lookup.FindItems(query)}";
+        // The URL should have encoded & as %26 and = as %3D
+        expectedUrl.ShouldContain("%26");
+        expectedUrl.ShouldContain("%3D");
+
+        var request = _mockHttp.Expect(HttpMethod.Get, expectedUrl)
+            .Respond("application/json", "[]");
+
+        // Act
+        await _client.FindItemsAsync(query);
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task FindItemsAsync_EncodesSpaces_InQueryString()
+    {
+        // Arrange - query with spaces
+        var query = "TEST ITEM";
+        var expectedUrl = $"http://localhost/{ApiRoutes.Lookup.FindItems(query)}";
+        // The URL should have encoded space as %20
+        expectedUrl.ShouldContain("%20");
+
+        var request = _mockHttp.Expect(HttpMethod.Get, expectedUrl)
+            .Respond("application/json", "[]");
+
+        // Act
+        await _client.FindItemsAsync(query);
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    // Success tests
+
+    [Fact]
+    public async Task FindItemsAsync_Success_ReturnsItemList()
+    {
+        // Arrange
+        var items = new List<ItemViewModel>
+        {
+            new() { ShortItemNumber = "ITEM1", Description = "Item One" },
+            new() { ShortItemNumber = "ITEM2", Description = "Item Two" }
+        };
+        _mockHttp.When(HttpMethod.Get, "*")
+            .Respond("application/json", JsonSerializer.Serialize(items));
+
+        // Act
+        var result = await _client.FindItemsAsync("ITEM");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Count.ShouldBe(2);
+        result.Value[0].ShortItemNumber.ShouldBe("ITEM1");
+    }
+
+    [Fact]
+    public async Task FindOperatorsAsync_Success_ReturnsUserList()
+    {
+        // Arrange
+        var users = new List<JdeUserViewModel>
+        {
+            new() { UserId = "USER1", UserName = "John Doe" }
+        };
+        _mockHttp.When(HttpMethod.Get, "*")
+            .Respond("application/json", JsonSerializer.Serialize(users));
+
+        // Act
+        var result = await _client.FindOperatorsAsync("John");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Count.ShouldBe(1);
+    }
+}
+```
+
+**Step 2: Run tests**
+
+Run: `dotnet test tests/JdeScoping.Client.Tests --filter "FullyQualifiedName~LookupApiClientTests" -v quiet`
+Expected: All tests pass
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Client.Tests/Services/LookupApiClientTests.cs
+git commit -m "test: add LookupApiClientTests with route and encoding tests"
+```
+
+---
+
+## Task 10: Create AuthApiClientTests
+
+**Files:**
+- Create: `tests/JdeScoping.Client.Tests/Services/AuthApiClientTests.cs`
+
+**Step 1: Write AuthApiClientTests**
+
+```csharp
+using System.Net;
+using System.Text.Json;
+using JdeScoping.Client.Services;
+using JdeScoping.Core.ApiContracts;
+using JdeScoping.Core.ApiContracts.Results;
+using JdeScoping.Core.Models;
+using JdeScoping.Core.Models.Auth;
+using RichardSzalay.MockHttp;
+using Shouldly;
+
+namespace JdeScoping.Client.Tests.Services;
+
+public class AuthApiClientTests
+{
+    private readonly MockHttpMessageHandler _mockHttp;
+    private readonly AuthApiClient _client;
+
+    public AuthApiClientTests()
+    {
+        _mockHttp = new MockHttpMessageHandler();
+        var httpClient = new HttpClient(_mockHttp) { BaseAddress = new Uri("http://localhost/") };
+        _client = new AuthApiClient(httpClient);
+    }
+
+    // Route verification tests
+
+    [Fact]
+    public async Task GetPublicKeyAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Get, $"http://localhost/{ApiRoutes.Auth.PublicKey}")
+            .Respond("application/json", JsonSerializer.Serialize(new PublicKeyResponse("-----BEGIN PUBLIC KEY-----\ntest\n-----END PUBLIC KEY-----")));
+
+        // Act
+        await _client.GetPublicKeyAsync();
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task LoginAsync_CallsCorrectRoute_WithPostMethod()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Post, $"http://localhost/{ApiRoutes.Auth.Login}")
+            .Respond("application/json", JsonSerializer.Serialize(new LoginResultModel { Success = true }));
+
+        // Act
+        await _client.LoginAsync(new EncryptedLoginRequest("encrypted"));
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task LogoutAsync_CallsCorrectRoute_WithPostMethod()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Post, $"http://localhost/{ApiRoutes.Auth.Logout}")
+            .Respond(HttpStatusCode.NoContent);
+
+        // Act
+        await _client.LogoutAsync();
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task GetCurrentUserAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Get, $"http://localhost/{ApiRoutes.Auth.Me}")
+            .Respond("application/json", JsonSerializer.Serialize(new UserInfo("testuser", "Test User")));
+
+        // Act
+        await _client.GetCurrentUserAsync();
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    // Success tests
+
+    [Fact]
+    public async Task GetPublicKeyAsync_Success_ReturnsPublicKey()
+    {
+        // Arrange
+        var publicKey = "-----BEGIN PUBLIC KEY-----\nMIIBIjAN...\n-----END PUBLIC KEY-----";
+        _mockHttp.When(HttpMethod.Get, "*")
+            .Respond("application/json", JsonSerializer.Serialize(new PublicKeyResponse(publicKey)));
+
+        // Act
+        var result = await _client.GetPublicKeyAsync();
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.PublicKeyPem.ShouldBe(publicKey);
+    }
+
+    [Fact]
+    public async Task LoginAsync_Success_ReturnsLoginResult()
+    {
+        // Arrange
+        var loginResult = new LoginResultModel
+        {
+            Success = true,
+            User = new UserInfo("testuser", "Test User")
+        };
+        _mockHttp.When(HttpMethod.Post, "*")
+            .Respond("application/json", JsonSerializer.Serialize(loginResult));
+
+        // Act
+        var result = await _client.LoginAsync(new EncryptedLoginRequest("encrypted"));
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Success.ShouldBeTrue();
+        result.Value.User?.Username.ShouldBe("testuser");
+    }
+
+    [Fact]
+    public async Task LogoutAsync_Success_ReturnsUnit()
+    {
+        // Arrange
+        _mockHttp.When(HttpMethod.Post, "*")
+            .Respond(HttpStatusCode.NoContent);
+
+        // Act
+        var result = await _client.LogoutAsync();
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task GetCurrentUserAsync_Success_ReturnsUserInfo()
+    {
+        // Arrange
+        var userInfo = new UserInfo("testuser", "Test User");
+        _mockHttp.When(HttpMethod.Get, "*")
+            .Respond("application/json", JsonSerializer.Serialize(userInfo));
+
+        // Act
+        var result = await _client.GetCurrentUserAsync();
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Username.ShouldBe("testuser");
+    }
+}
+```
+
+**Step 2: Run tests**
+
+Run: `dotnet test tests/JdeScoping.Client.Tests --filter "FullyQualifiedName~AuthApiClientTests" -v quiet`
+Expected: All tests pass
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Client.Tests/Services/AuthApiClientTests.cs
+git commit -m "test: add AuthApiClientTests with route and success tests"
+```
+
+---
+
+## Task 11: Create FileApiClientTests
+
+**Files:**
+- Create: `tests/JdeScoping.Client.Tests/Services/FileApiClientTests.cs`
+
+**Step 1: Write FileApiClientTests**
+
+```csharp
+using System.Net;
+using System.Text.Json;
+using JdeScoping.Client.Services;
+using JdeScoping.Core.ApiContracts;
+using JdeScoping.Core.ViewModels;
+using RichardSzalay.MockHttp;
+using Shouldly;
+
+namespace JdeScoping.Client.Tests.Services;
+
+public class FileApiClientTests
+{
+    private readonly MockHttpMessageHandler _mockHttp;
+    private readonly FileApiClient _client;
+
+    public FileApiClientTests()
+    {
+        _mockHttp = new MockHttpMessageHandler();
+        var httpClient = new HttpClient(_mockHttp) { BaseAddress = new Uri("http://localhost/") };
+        _client = new FileApiClient(httpClient);
+    }
+
+    // Route verification tests - Downloads
+
+    [Fact]
+    public async Task DownloadWorkOrdersTemplateAsync_CallsCorrectRoute_WithPostMethod()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Post, $"http://localhost/{ApiRoutes.FileIO.DownloadWorkOrders}")
+            .Respond("application/octet-stream", new MemoryStream(new byte[] { 1, 2, 3 }));
+
+        // Act
+        await _client.DownloadWorkOrdersTemplateAsync();
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task DownloadItemsTemplateAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Post, $"http://localhost/{ApiRoutes.FileIO.DownloadItems}")
+            .Respond("application/octet-stream", new MemoryStream(new byte[] { 1, 2, 3 }));
+
+        // Act
+        await _client.DownloadItemsTemplateAsync();
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task DownloadComponentLotsTemplateAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Post, $"http://localhost/{ApiRoutes.FileIO.DownloadComponentLots}")
+            .Respond("application/octet-stream", new MemoryStream(new byte[] { 1, 2, 3 }));
+
+        // Act
+        await _client.DownloadComponentLotsTemplateAsync();
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task DownloadPartOperationsTemplateAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Post, $"http://localhost/{ApiRoutes.FileIO.DownloadPartOperations}")
+            .Respond("application/octet-stream", new MemoryStream(new byte[] { 1, 2, 3 }));
+
+        // Act
+        await _client.DownloadPartOperationsTemplateAsync();
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    // Route verification tests - Uploads
+
+    [Fact]
+    public async Task UploadWorkOrdersAsync_CallsCorrectRoute_WithPostMethod()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Post, $"http://localhost/{ApiRoutes.FileIO.UploadWorkOrders}")
+            .Respond("application/json", "[]");
+
+        using var stream = new MemoryStream(new byte[] { 1, 2, 3 });
+
+        // Act
+        await _client.UploadWorkOrdersAsync(stream, "test.xlsx");
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    [Fact]
+    public async Task UploadItemsAsync_CallsCorrectRoute()
+    {
+        // Arrange
+        var request = _mockHttp.Expect(HttpMethod.Post, $"http://localhost/{ApiRoutes.FileIO.UploadItems}")
+            .Respond("application/json", "[]");
+
+        using var stream = new MemoryStream(new byte[] { 1, 2, 3 });
+
+        // Act
+        await _client.UploadItemsAsync(stream, "test.xlsx");
+
+        // Assert
+        _mockHttp.GetMatchCount(request).ShouldBe(1);
+    }
+
+    // Success tests - Downloads
+
+    [Fact]
+    public async Task DownloadWorkOrdersTemplateAsync_Success_ReturnsBytes()
+    {
+        // Arrange
+        var expectedBytes = new byte[] { 0x50, 0x4B, 0x03, 0x04 }; // ZIP header
+        _mockHttp.When(HttpMethod.Post, "*")
+            .Respond("application/octet-stream", new MemoryStream(expectedBytes));
+
+        // Act
+        var result = await _client.DownloadWorkOrdersTemplateAsync();
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.ShouldBe(expectedBytes);
+    }
+
+    [Fact]
+    public async Task DownloadWorkOrdersTemplateAsync_WithExistingData_SendsData()
+    {
+        // Arrange
+        var existingData = new List<WorkOrderViewModel>
+        {
+            new() { WorkOrderNumber = 12345 }
+        };
+
+        _mockHttp.When(HttpMethod.Post, "*")
+            .With(req => req.Content != null) // Verify body is sent
+            .Respond("application/octet-stream", new MemoryStream(new byte[] { 1, 2, 3 }));
+
+        // Act
+        var result = await _client.DownloadWorkOrdersTemplateAsync(existingData);
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+    }
+
+    // Success tests - Uploads
+
+    [Fact]
+    public async Task UploadWorkOrdersAsync_Success_ReturnsWorkOrderList()
+    {
+        // Arrange
+        var workOrders = new List<WorkOrderViewModel>
+        {
+            new() { WorkOrderNumber = 12345, Status = "Active" }
+        };
+        _mockHttp.When(HttpMethod.Post, "*")
+            .Respond("application/json", JsonSerializer.Serialize(workOrders));
+
+        using var stream = new MemoryStream(new byte[] { 1, 2, 3 });
+
+        // Act
+        var result = await _client.UploadWorkOrdersAsync(stream, "test.xlsx");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Count.ShouldBe(1);
+        result.Value[0].WorkOrderNumber.ShouldBe(12345);
+    }
+
+    [Fact]
+    public async Task UploadItemsAsync_Success_ReturnsItemList()
+    {
+        // Arrange
+        var items = new List<ItemViewModel>
+        {
+            new() { ShortItemNumber = "ITEM1", Description = "Test Item" }
+        };
+        _mockHttp.When(HttpMethod.Post, "*")
+            .Respond("application/json", JsonSerializer.Serialize(items));
+
+        using var stream = new MemoryStream(new byte[] { 1, 2, 3 });
+
+        // Act
+        var result = await _client.UploadItemsAsync(stream, "test.xlsx");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Count.ShouldBe(1);
+    }
+
+    // Error tests
+
+    [Fact]
+    public async Task DownloadWorkOrdersTemplateAsync_404_ReturnsNotFound()
+    {
+        // Arrange
+        _mockHttp.When(HttpMethod.Post, "*")
+            .Respond(HttpStatusCode.NotFound);
+
+        // Act
+        var result = await _client.DownloadWorkOrdersTemplateAsync();
+
+        // Assert
+        result.IsNotFound.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task UploadWorkOrdersAsync_VerifiesMultipartContentType_AndFilename()
+    {
+        // Arrange - verify multipart structure and filename
+        _mockHttp.When(HttpMethod.Post, "*")
+            .With(req =>
+            {
+                var content = req.Content as MultipartFormDataContent;
+                if (content == null) return false;
+
+                // Check content type is multipart/form-data
+                var contentType = req.Content?.Headers.ContentType?.MediaType;
+                if (contentType != "multipart/form-data") return false;
+
+                // Check that filename is passed correctly
+                var contentDisposition = content.First().Headers.ContentDisposition;
+                return contentDisposition?.FileName?.Contains("test.xlsx") == true;
+            })
+            .Respond("application/json", "[]");
+
+        using var stream = new MemoryStream(new byte[] { 1, 2, 3 });
+
+        // Act
+        var result = await _client.UploadWorkOrdersAsync(stream, "test.xlsx");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task UploadWorkOrdersAsync_400_ReturnsValidationError()
+    {
+        // Arrange - use actual ValidationProblemDetails structure
+        var validationProblem = new Microsoft.AspNetCore.Mvc.ValidationProblemDetails
+        {
+            Errors = { ["File"] = new[] { "Invalid file format" } }
+        };
+        _mockHttp.When(HttpMethod.Post, "*")
+            .Respond(HttpStatusCode.BadRequest, "application/json",
+                JsonSerializer.Serialize(validationProblem, new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase }));
+
+        using var stream = new MemoryStream(new byte[] { 1, 2, 3 });
+
+        // Act
+        var result = await _client.UploadWorkOrdersAsync(stream, "test.xlsx");
+
+        // Assert
+        result.IsValidationError.ShouldBeTrue();
+    }
+}
+```
+
+**Step 2: Run tests**
+
+Run: `dotnet test tests/JdeScoping.Client.Tests --filter "FullyQualifiedName~FileApiClientTests" -v quiet`
+Expected: All tests pass
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Client.Tests/Services/FileApiClientTests.cs
+git commit -m "test: add FileApiClientTests with route, success, and error tests"
+```
+
+---
+
+## Task 12: Add Project Reference to Client.Tests
+
+**Files:**
+- Modify: `tests/JdeScoping.Api.IntegrationTests/JdeScoping.Api.IntegrationTests.csproj`
+
+**Step 1: Add Client project reference**
+
+The integration tests need access to the API client classes. Add project reference:
+
+```xml
+<ProjectReference Include="..\..\src\JdeScoping.Client\JdeScoping.Client.csproj" />
+```
+
+**Step 2: Verify build**
+
+Run: `dotnet build tests/JdeScoping.Api.IntegrationTests`
+Expected: Build succeeds
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Api.IntegrationTests/JdeScoping.Api.IntegrationTests.csproj
+git commit -m "build: add Client project reference to integration tests"
+```
+
+---
+
+## Task 13: Create ClientIntegrationTestBase
+
+**Files:**
+- Create: `tests/JdeScoping.Api.IntegrationTests/ClientIntegration/ClientIntegrationTestBase.cs`
+
+**Step 1: Create directory and base class**
+
+```csharp
+using System.Net.Http.Json;
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using JdeScoping.Client.Services;
+using JdeScoping.Core.ApiContracts;
+using JdeScoping.Core.Models.Auth;
+using Microsoft.AspNetCore.Mvc.Testing;
+
+namespace JdeScoping.Api.IntegrationTests.ClientIntegration;
+
+/// <summary>
+/// Base class for API client integration tests.
+/// Provides shared HttpClient with cookie handling for auth state.
+/// </summary>
+[Collection("ClientIntegration")]
+public abstract class ClientIntegrationTestBase : IClassFixture<TestWebApplicationFactory>
+{
+    protected readonly TestWebApplicationFactory Factory;
+    protected readonly HttpClient SharedClient;
+
+    // API clients share the authenticated HttpClient
+    protected readonly SearchApiClient SearchClient;
+    protected readonly LookupApiClient LookupClient;
+    protected readonly AuthApiClient AuthClient;
+    protected readonly FileApiClient FileClient;
+
+    protected ClientIntegrationTestBase(TestWebApplicationFactory factory)
+    {
+        Factory = factory;
+        SharedClient = factory.CreateClient(new WebApplicationFactoryClientOptions
+        {
+            HandleCookies = true,
+            AllowAutoRedirect = false
+        });
+
+        // All clients share the same HttpClient (cookie container)
+        SearchClient = new SearchApiClient(SharedClient);
+        LookupClient = new LookupApiClient(SharedClient);
+        FileClient = new FileApiClient(SharedClient);
+        AuthClient = new AuthApiClient(SharedClient);
+    }
+
+    /// <summary>
+    /// Performs login with encrypted credentials.
+    /// </summary>
+    protected async Task LoginAsync(string username = "testuser", string password = "testpass")
+    {
+        // Step 1: Get public key
+        var publicKeyResult = await AuthClient.GetPublicKeyAsync();
+        if (!publicKeyResult.IsSuccess)
+            throw new Exception("Failed to get public key");
+
+        // Step 2: Encrypt credentials
+        var loginModel = new LoginModel { Username = username, Password = password };
+        var json = JsonSerializer.Serialize(loginModel);
+        var plaintext = Encoding.UTF8.GetBytes(json);
+
+        using var rsa = RSA.Create();
+        rsa.ImportFromPem(publicKeyResult.Value.PublicKeyPem);
+        var ciphertext = rsa.Encrypt(plaintext, RSAEncryptionPadding.OaepSHA256);
+
+        // Step 3: Login
+        var encryptedRequest = new EncryptedLoginRequest(Convert.ToBase64String(ciphertext));
+        var loginResult = await AuthClient.LoginAsync(encryptedRequest);
+
+        if (!loginResult.IsSuccess || !loginResult.Value.Success)
+            throw new Exception($"Login failed: {loginResult.Value?.ErrorMessage ?? "Unknown error"}");
+    }
+
+    /// <summary>
+    /// Creates a fresh HttpClient without cookies for testing unauthorized scenarios.
+    /// </summary>
+    protected HttpClient CreateFreshClient() => Factory.CreateClient(new WebApplicationFactoryClientOptions
+    {
+        HandleCookies = false,
+        AllowAutoRedirect = false
+    });
+}
+```
+
+**Step 2: Create collection definition**
+
+Create file `tests/JdeScoping.Api.IntegrationTests/ClientIntegration/ClientIntegrationCollection.cs`:
+
+```csharp
+namespace JdeScoping.Api.IntegrationTests.ClientIntegration;
+
+/// <summary>
+/// Collection definition for client integration tests.
+/// Prevents parallel execution to avoid auth state conflicts.
+/// </summary>
+[CollectionDefinition("ClientIntegration")]
+public class ClientIntegrationCollection : ICollectionFixture<TestWebApplicationFactory>
+{
+}
+```
+
+**Step 3: Verify build**
+
+Run: `dotnet build tests/JdeScoping.Api.IntegrationTests`
+Expected: Build succeeds
+
+**Step 4: Commit**
+
+```bash
+git add tests/JdeScoping.Api.IntegrationTests/ClientIntegration/
+git commit -m "test: add ClientIntegrationTestBase with shared auth HttpClient"
+```
+
+---
+
+## Task 14: Create SearchApiClientIntegrationTests
+
+**Files:**
+- Create: `tests/JdeScoping.Api.IntegrationTests/ClientIntegration/SearchApiClientIntegrationTests.cs`
+
+**Step 1: Write integration tests**
+
+```csharp
+using JdeScoping.Client.Services;
+using Shouldly;
+
+namespace JdeScoping.Api.IntegrationTests.ClientIntegration;
+
+public class SearchApiClientIntegrationTests : ClientIntegrationTestBase
+{
+    public SearchApiClientIntegrationTests(TestWebApplicationFactory factory) : base(factory) { }
+
+    [Fact]
+    public async Task GetUserSearchesAsync_WithAuth_ReturnsSearchList()
+    {
+        // Arrange
+        await LoginAsync();
+
+        // Act
+        var result = await SearchClient.GetUserSearchesAsync();
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.ShouldNotBeNull();
+    }
+
+    [Fact]
+    public async Task GetUserSearchesAsync_WithoutAuth_ReturnsUnauthorized()
+    {
+        // Arrange - use fresh client without cookies
+        var freshClient = new SearchApiClient(CreateFreshClient());
+
+        // Act
+        var result = await freshClient.GetUserSearchesAsync();
+
+        // Assert
+        result.IsUnauthorized.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task GetSearchAsync_NotFound_ReturnsNotFound()
+    {
+        // Arrange
+        await LoginAsync();
+        var nonExistentId = 999999;
+
+        // Act
+        var result = await SearchClient.GetSearchAsync(nonExistentId);
+
+        // Assert
+        result.IsNotFound.ShouldBeTrue();
+    }
+}
+```
+
+**Step 2: Run tests**
+
+Run: `dotnet test tests/JdeScoping.Api.IntegrationTests --filter "FullyQualifiedName~SearchApiClientIntegrationTests" -v normal`
+Expected: All tests pass
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Api.IntegrationTests/ClientIntegration/SearchApiClientIntegrationTests.cs
+git commit -m "test: add SearchApiClientIntegrationTests"
+```
+
+---
+
+## Task 15: Create LookupApiClientIntegrationTests
+
+**Files:**
+- Create: `tests/JdeScoping.Api.IntegrationTests/ClientIntegration/LookupApiClientIntegrationTests.cs`
+
+**Step 1: Write integration tests**
+
+```csharp
+using JdeScoping.Client.Services;
+using Shouldly;
+
+namespace JdeScoping.Api.IntegrationTests.ClientIntegration;
+
+public class LookupApiClientIntegrationTests : ClientIntegrationTestBase
+{
+    public LookupApiClientIntegrationTests(TestWebApplicationFactory factory) : base(factory) { }
+
+    [Fact]
+    public async Task FindItemsAsync_WithoutAuth_ReturnsSuccess()
+    {
+        // Lookup endpoints don't require auth
+        var freshClient = new LookupApiClient(CreateFreshClient());
+
+        // Act
+        var result = await freshClient.FindItemsAsync("test");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.ShouldNotBeNull();
+    }
+
+    [Fact]
+    public async Task FindProfitCentersAsync_ReturnsSuccess()
+    {
+        // Act
+        var result = await LookupClient.FindProfitCentersAsync("test");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task FindWorkCentersAsync_ReturnsSuccess()
+    {
+        // Act
+        var result = await LookupClient.FindWorkCentersAsync("test");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task FindOperatorsAsync_ReturnsSuccess()
+    {
+        // Act
+        var result = await LookupClient.FindOperatorsAsync("test");
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+    }
+}
+```
+
+**Step 2: Run tests**
+
+Run: `dotnet test tests/JdeScoping.Api.IntegrationTests --filter "FullyQualifiedName~LookupApiClientIntegrationTests" -v normal`
+Expected: All tests pass
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Api.IntegrationTests/ClientIntegration/LookupApiClientIntegrationTests.cs
+git commit -m "test: add LookupApiClientIntegrationTests"
+```
+
+---
+
+## Task 16: Create AuthApiClientIntegrationTests
+
+**Files:**
+- Create: `tests/JdeScoping.Api.IntegrationTests/ClientIntegration/AuthApiClientIntegrationTests.cs`
+
+**Step 1: Write integration tests**
+
+```csharp
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using JdeScoping.Client.Services;
+using JdeScoping.Core.Models.Auth;
+using Microsoft.AspNetCore.Mvc.Testing;
+using Shouldly;
+
+namespace JdeScoping.Api.IntegrationTests.ClientIntegration;
+
+public class AuthApiClientIntegrationTests : ClientIntegrationTestBase
+{
+    public AuthApiClientIntegrationTests(TestWebApplicationFactory factory) : base(factory) { }
+
+    [Fact]
+    public async Task GetPublicKeyAsync_ReturnsValidPublicKey()
+    {
+        // Act
+        var result = await AuthClient.GetPublicKeyAsync();
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.PublicKeyPem.ShouldStartWith("-----BEGIN PUBLIC KEY-----");
+    }
+
+    [Fact]
+    public async Task LoginAsync_WithValidCredentials_ReturnsSuccess()
+    {
+        // Arrange - get public key and encrypt credentials
+        var publicKeyResult = await AuthClient.GetPublicKeyAsync();
+        publicKeyResult.IsSuccess.ShouldBeTrue();
+
+        var loginModel = new LoginModel { Username = "testuser", Password = "testpass" };
+        var json = JsonSerializer.Serialize(loginModel);
+        var plaintext = Encoding.UTF8.GetBytes(json);
+
+        using var rsa = RSA.Create();
+        rsa.ImportFromPem(publicKeyResult.Value.PublicKeyPem);
+        var ciphertext = rsa.Encrypt(plaintext, RSAEncryptionPadding.OaepSHA256);
+
+        var encryptedRequest = new EncryptedLoginRequest(Convert.ToBase64String(ciphertext));
+
+        // Act
+        var result = await AuthClient.LoginAsync(encryptedRequest);
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Success.ShouldBeTrue();
+        result.Value.User.ShouldNotBeNull();
+        result.Value.User.Username.ShouldBe("testuser");
+    }
+
+    [Fact]
+    public async Task GetCurrentUserAsync_AfterLogin_ReturnsUserInfo()
+    {
+        // Arrange
+        await LoginAsync();
+
+        // Act
+        var result = await AuthClient.GetCurrentUserAsync();
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+        result.Value.Username.ShouldBe("testuser");
+    }
+
+    [Fact]
+    public async Task GetCurrentUserAsync_WithoutAuth_ReturnsUnauthorized()
+    {
+        // Arrange - use fresh client without cookies
+        var freshClient = new AuthApiClient(CreateFreshClient());
+
+        // Act
+        var result = await freshClient.GetCurrentUserAsync();
+
+        // Assert
+        result.IsUnauthorized.ShouldBeTrue();
+    }
+
+    [Fact]
+    public async Task LogoutAsync_AfterLogin_Success()
+    {
+        // Arrange - create fresh client for this test to avoid affecting other tests
+        var client = Factory.CreateClient(new WebApplicationFactoryClientOptions
+        {
+            HandleCookies = true,
+            AllowAutoRedirect = false
+        });
+        var authClient = new AuthApiClient(client);
+
+        // Login first
+        var publicKeyResult = await authClient.GetPublicKeyAsync();
+        var loginModel = new LoginModel { Username = "testuser", Password = "testpass" };
+        var json = JsonSerializer.Serialize(loginModel);
+        using var rsa = RSA.Create();
+        rsa.ImportFromPem(publicKeyResult.Value.PublicKeyPem);
+        var ciphertext = rsa.Encrypt(Encoding.UTF8.GetBytes(json), RSAEncryptionPadding.OaepSHA256);
+        await authClient.LoginAsync(new EncryptedLoginRequest(Convert.ToBase64String(ciphertext)));
+
+        // Act
+        var result = await authClient.LogoutAsync();
+
+        // Assert
+        result.IsSuccess.ShouldBeTrue();
+
+        // Verify logged out - me endpoint should return unauthorized
+        var meResult = await authClient.GetCurrentUserAsync();
+        meResult.IsUnauthorized.ShouldBeTrue();
+    }
+}
+```
+
+**Step 2: Run tests**
+
+Run: `dotnet test tests/JdeScoping.Api.IntegrationTests --filter "FullyQualifiedName~AuthApiClientIntegrationTests" -v normal`
+Expected: All tests pass
+
+**Step 3: Commit**
+
+```bash
+git add tests/JdeScoping.Api.IntegrationTests/ClientIntegration/AuthApiClientIntegrationTests.cs
+git commit -m "test: add AuthApiClientIntegrationTests"
+```
+
+---
+
+## Task 17: Run All Tests and Verify
+
+**Step 1: Build entire solution**
+
+Run: `dotnet build`
+Expected: Build succeeds with no errors
+
+**Step 2: Run all Client.Tests**
+
+Run: `dotnet test tests/JdeScoping.Client.Tests -v quiet`
+Expected: All tests pass
+
+**Step 3: Run all Api.IntegrationTests**
+
+Run: `dotnet test tests/JdeScoping.Api.IntegrationTests -v quiet`
+Expected: All tests pass
+
+**Step 4: Commit final verification**
+
+```bash
+git add -A
+git commit -m "test: verify all API client tests pass"
+```
+
+---
+
+## Summary
+
+**Unit Tests Created (~75 tests):**
+- `ApiClientBaseTests` - 24 tests (6 GET status codes, edge cases, POST 200/401/400 validation, bytes 200/404/500, multipart 200/401)
+- `SearchApiClientTests` - 15 tests (routes, success for all methods including GetQueuedSearches/GetResults/CopySearch, errors)
+- `LookupApiClientTests` - 10 tests (routes, encoding, success)
+- `AuthApiClientTests` - 8 tests (routes, success)
+- `FileApiClientTests` - 18 tests (routes, success, errors, multipart content-type/filename validation)
+
+**Integration Tests Created (~12 tests):**
+- `SearchApiClientIntegrationTests` - 3 tests
+- `LookupApiClientIntegrationTests` - 4 tests
+- `AuthApiClientIntegrationTests` - 5 tests
+
+**Package References Required:**
+- `Microsoft.AspNetCore.Mvc.Abstractions` for `ValidationProblemDetails` in Client.Tests (for accurate test payloads)
+
+**Files Modified:**
+- `AuthenticationTests.cs` - Updated to use ApiRoutes constants
+- `JdeScoping.Client.Tests.csproj` - Add Microsoft.AspNetCore.Mvc.Abstractions package reference
+
+**Files Created:**
+- `TestableApiClient.cs` - Test helper for ApiClientBase
+- `ApiClientBaseTests.cs` - Full coverage of status code mappings (GET, POST, bytes, multipart)
+- `SearchApiClientTests.cs` - Search client unit tests
+- `LookupApiClientTests.cs` - Lookup client unit tests
+- `AuthApiClientTests.cs` - Auth client unit tests
+- `FileApiClientTests.cs` - File client unit tests
+- `ClientIntegrationTestBase.cs` - Shared base for integration tests
+- `ClientIntegrationCollection.cs` - xUnit collection definition
+- `SearchApiClientIntegrationTests.cs` - Search integration tests
+- `LookupApiClientIntegrationTests.cs` - Lookup integration tests
+- `AuthApiClientIntegrationTests.cs` - Auth integration tests
+
+**Design Notes:**
+- All 6 `ApiResult<T>` cases tested once in `ApiClientBaseTests` (not repeated per client)
+- Non-GET paths (POST, bytes, multipart) explicitly tested for status code mapping
+- Uses `Microsoft.AspNetCore.Mvc.ValidationProblemDetails` for accurate validation error payloads
+- Cookie auth returns 401/403 (not redirects) - configured in `AddWebApi` DependencyInjection
+- `FakeAuthService` accepts any credentials for testing