diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e524f79f..a8c57d1f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -39,3 +39,32 @@ jobs:
 
       - name: Test
         run: dotnet test Linq2GraphQL.CI.slnf --no-build --verbosity normal
+
+  generated-clients:
+
+    name: Test clients up to date
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup .NET
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: 10.0.x
+          cache: true
+          cache-dependency-path: '**/packages.lock.json'
+
+      - name: Restore tools
+        run: dotnet tool restore
+
+      - name: Restore
+        run: dotnet restore Linq2GraphQL.CI.slnf --locked-mode
+
+      # Regenerates test/Linq2GraphQL.TestClient* from the test servers' live
+      # schemas and fails if the result differs from what is committed.
+      - name: Check checked-in test clients
+        shell: pwsh
+        run: ./scripts/regenerate-test-clients.ps1 -Check
diff --git a/CLAUDE.md b/CLAUDE.md
index 9eb69778..44033b2e 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -21,6 +21,12 @@ dotnet restore Linq2GraphQL.CI.slnf --locked-mode
 dotnet build   Linq2GraphQL.CI.slnf --no-restore
 dotnet test    Linq2GraphQL.CI.slnf --no-build
 
+# Also CI: verify the checked-in test clients still match the generator
+./scripts/regenerate-test-clients.ps1 -Check
+
+# Refresh them after a template or test-schema change
+./scripts/regenerate-test-clients.ps1
+
 # Single test / class
 dotnet test test/Linq2GraphQL.Tests --filter "FullyQualifiedName~QueryTests.Hello_WithNoName_HelloWorld"
 dotnet test test/Linq2GraphQL.Tests --filter "FullyQualifiedName~ExpressionParserTests"
@@ -63,6 +69,6 @@ Key details that bite:
 
 `Linq2GraphQL.Tests` is xUnit + Shouldly + Moq. It spins up the real GraphQL server in-process with `WebApplicationFactory<Program>` — `Linq2GraphQL.TestServer` is HotChocolate over the POCOs in `TestServer.Shared`, and `TestServerNullable` is the same schema for the nullable client. `SampleClientFixture` / `SampleClientNullableFixture` wire the generated client to that in-memory host (safe mode on, SSE subscriptions), and test classes take them via `IClassFixture<>`. So most tests are end-to-end: an assertion failure can come from the expression parser, the query text, or the server's own resolvers.
 
-`Linq2GraphQL.TestClient` / `TestClientNullable` hold **checked-in generated output**. They are not regenerated by the build — when a template or schema changes, run the generator against a locally running TestServer and commit the result, then verify the round trip still passes.
+`Linq2GraphQL.TestClient` / `TestClientNullable` hold **checked-in generated output**. They are not regenerated by the build — run `./scripts/regenerate-test-clients.ps1` (it boots both test servers over plain HTTP, regenerates both clients with the flags that produced the committed output, and writes them back) and commit the diff. The `generated-clients` CI job runs the same script with `-Check` and fails if the committed output no longer matches the generator, so a template or schema change that you forget to regenerate is caught in CI rather than passing against stale output.
 
 `docs/`, `docs/StarWars.Client` and `StartGG/` are the Blazor documentation site and sample clients; they are outside the CI solution filter and can drift.
diff --git a/REPO_REPORT.md b/REPO_REPORT.md
index b37f9625..fbe33764 100644
--- a/REPO_REPORT.md
+++ b/REPO_REPORT.md
@@ -53,7 +53,7 @@ Three stages, and understanding them is usually the whole job:
 ## 5. Highlights — the risks
 
 - ~~**T4 is the sharpest edge in the repo.**~~ **Fixed.** Templates are now preprocessed at build time by the pinned `dotnet-t4` local tool into gitignored `X.g.cs` files, so a `.tt` edit takes effect on the next `dotnet build` on any platform and stale template logic cannot be built. (Switching it on revealed one already-dormant edit: `ScalarTemplate.tt` referenced a non-existent `GraphqlType.ScalarTypeName` and had never been regenerated.)
-- **Generated test clients are checked in but never regenerated by the build.** `TestClient`/`TestClientNullable` must be re-generated by hand against a locally running TestServer after any template or schema change. Nothing in CI detects the drift — the tests keep passing against stale output.
+- ~~**Generated test clients are checked in but never regenerated by the build.**~~ **Fixed.** `./scripts/regenerate-test-clients.ps1` boots both test servers over plain HTTP and regenerates `TestClient`/`TestClientNullable`, and the `generated-clients` CI job runs it with `-Check` so committed output that no longer matches the generator fails the build. Refreshing the output picked up three pieces of accumulated drift: the newly active template edits, the signed `Byte` scalar mapping (`byte` → `sbyte`), and the `raiseError`/`raiseAuthError` query methods.
 - **Coupling between alias hashing and deserialization.** `Utilities.GetArgumentsId` must produce the *same* hash at write time and read time. Any change to argument hashing breaks reads as well as writes, and the failure mode is a silently missing field rather than an exception.
 - **Ambient static generator state.** `GeneratorSettings.Current` is read from inside templates, so nullable/non-nullable output depends on global mutable state rather than a passed parameter. Fine today; awkward if generation ever needs to run concurrently.
 - **`docs/` and `StartGG/` are outside the CI filter and can drift.** They are in `Linq2GraphQL.sln` but not `Linq2GraphQL.CI.slnf`, so nothing verifies they still compile — roughly 15k lines CI never touches.
@@ -70,7 +70,7 @@ Three stages, and understanding them is usually the whole job:
 ## 7. If I were picking up work here
 
 1. ~~Wire up **CLI T4 regeneration**~~ — done: `dotnet-t4` runs from the generator's csproj on every build, and the preprocessed output is no longer checked in.
-2. Add a **CI job that regenerates the test clients and diffs them** — it closes the stale-generated-output gap for free.
+2. ~~Add a **CI job that regenerates the test clients and diffs them**~~ — done: `scripts/regenerate-test-clients.ps1 -Check`, run by the `generated-clients` job.
 3. Pull `docs/` and `StartGG/` into a **build-only CI job** so they cannot rot unnoticed.
 4. Get the **WebSocket subscription transport under test**, even against a standalone host outside `WebApplicationFactory`.
 5. Delete `nuget.config.backup` and the stray root `StarWars.Client/`.
diff --git a/scripts/regenerate-test-clients.ps1 b/scripts/regenerate-test-clients.ps1
new file mode 100644
index 00000000..439a38d0
--- /dev/null
+++ b/scripts/regenerate-test-clients.ps1
@@ -0,0 +1,148 @@
+#!/usr/bin/env pwsh
+<#
+.SYNOPSIS
+    Regenerates the checked-in test clients from the test servers' live schemas.
+
+.DESCRIPTION
+    test/Linq2GraphQL.TestClient and test/Linq2GraphQL.TestClientNullable hold
+    generated output that the test suite compiles against. Nothing in the normal
+    build refreshes it, so it silently drifts whenever a template or the test
+    schema changes.
+
+    This script boots each test server over plain HTTP, runs the generator
+    against it with the flags that produced the checked-in output, and writes
+    the result back over the Generated folders. CI runs the same script and
+    fails if the result differs from what is committed.
+
+.PARAMETER Check
+    Do not keep the regenerated output: restore the working tree afterwards and
+    exit non-zero if anything differed. Used by CI.
+
+.EXAMPLE
+    ./scripts/regenerate-test-clients.ps1
+    ./scripts/regenerate-test-clients.ps1 -Check
+#>
+[CmdletBinding()]
+param(
+    [switch]$Check
+)
+
+$ErrorActionPreference = 'Stop'
+$repoRoot = Split-Path -Parent $PSScriptRoot
+
+$clients = @(
+    @{
+        Name      = 'SampleClient'
+        Server    = 'test/Linq2GraphQL.TestServer'
+        Output    = 'test/Linq2GraphQL.TestClient/Generated'
+        Namespace = 'Linq2GraphQL.TestClient'
+        Port      = 5180
+        Nullable  = $false
+    }
+    @{
+        Name      = 'SampleNullableClient'
+        Server    = 'test/Linq2GraphQL.TestServerNullable'
+        Output    = 'test/Linq2GraphQL.TestClientNullable/Generated'
+        Namespace = 'Linq2GraphQL.TestClientNullable'
+        Port      = 5181
+        Nullable  = $true
+    }
+)
+
+function Wait-ForServer([string]$url, [System.Diagnostics.Process]$process) {
+    foreach ($attempt in 1..60) {
+        if ($process.HasExited) {
+            throw "Server exited with code $($process.ExitCode) before becoming ready."
+        }
+
+        try {
+            Invoke-WebRequest -Uri $url -Method Get -TimeoutSec 2 -SkipHttpErrorCheck | Out-Null
+            return
+        }
+        catch {
+            Start-Sleep -Milliseconds 500
+        }
+    }
+
+    throw "Server at $url did not become ready in 30 seconds."
+}
+
+Push-Location $repoRoot
+try {
+    Write-Host '==> Building generator and test servers' -ForegroundColor Cyan
+    dotnet build Linq2GraphQL.CI.slnf --nologo
+    if ($LASTEXITCODE -ne 0) { throw 'Build failed.' }
+
+    foreach ($client in $clients) {
+        $endpoint = "http://127.0.0.1:$($client.Port)/graphql/"
+        Write-Host "==> Starting $($client.Server) on $endpoint" -ForegroundColor Cyan
+
+        $server = Start-Process -PassThru -NoNewWindow -FilePath 'dotnet' -ArgumentList @(
+            'run', '--project', $client.Server, '--no-build', '--no-launch-profile'
+        ) -Environment @{
+            ASPNETCORE_URLS        = "http://127.0.0.1:$($client.Port)"
+            ASPNETCORE_ENVIRONMENT = "Development"
+        }
+
+        try {
+            Wait-ForServer -url $endpoint -process $server
+
+            Write-Host "==> Generating $($client.Name) into $($client.Output)" -ForegroundColor Cyan
+            $arguments = @(
+                'run', '--project', 'src/Linq2GraphQL.Generator', '--no-build', '--no-launch-profile', '--'
+                $endpoint
+                "-c=$($client.Name)"
+                "-n=$($client.Namespace)"
+                "-o=$(Join-Path $repoRoot $client.Output)"
+                '-s=true'
+                '-d=true'
+            )
+            if ($client.Nullable) { $arguments += '-nu=true' }
+
+            $sentinel = Join-Path $repoRoot "$($client.Output)/Client/$($client.Name).cs"
+            $generatedAt = Get-Date
+
+            dotnet @arguments
+
+            # The generator reports schema failures on stdout without a non-zero
+            # exit code, so verify it actually wrote fresh output.
+            if (-not (Test-Path $sentinel) -or (Get-Item $sentinel).LastWriteTime -lt $generatedAt) {
+                throw "Generating $($client.Name) failed - $sentinel was not written."
+            }
+        }
+        finally {
+            if (-not $server.HasExited) {
+                $server.Kill($true)
+            }
+            $server.WaitForExit()
+        }
+    }
+
+    if (-not $Check) {
+        Write-Host '==> Done. Review and commit the regenerated output.' -ForegroundColor Green
+        exit 0
+    }
+
+    $paths = $clients | ForEach-Object { $_.Output }
+
+    # git status refreshes the index first, so files rewritten with identical
+    # content are not reported as changed just because their mtime moved.
+    $drifted = @(git status --porcelain -- @paths)
+    $diff = git diff --stat -- @paths
+
+    git checkout -- @paths
+
+    if ($drifted.Count -gt 0) {
+        Write-Host ''
+        Write-Host 'The checked-in test clients do not match the generator output:' -ForegroundColor Red
+        Write-Host ($diff -join [Environment]::NewLine)
+        Write-Host ''
+        Write-Host 'Run ./scripts/regenerate-test-clients.ps1 and commit the result.' -ForegroundColor Red
+        exit 1
+    }
+
+    Write-Host '==> Checked-in test clients match the generator output.' -ForegroundColor Green
+}
+finally {
+    Pop-Location
+}
diff --git a/test/Linq2GraphQL.TestClient/Generated/Client/MutationMethods.cs b/test/Linq2GraphQL.TestClient/Generated/Client/MutationMethods.cs
index 3fb3aceb..97af698e 100644
--- a/test/Linq2GraphQL.TestClient/Generated/Client/MutationMethods.cs
+++ b/test/Linq2GraphQL.TestClient/Generated/Client/MutationMethods.cs
@@ -5,39 +5,56 @@
 // Url: https://linq2graphql.com
 //---------------------------------------------------------------------
 
-using System.Collections.Generic;
 using System;
+using System.Collections.Generic;
 using Linq2GraphQL.Client;
 
 namespace Linq2GraphQL.TestClient;
 
+/// <summary>
+/// Implementation of MutationMethods GraphQL operations
+/// </summary>
 public class MutationMethods : IMutationMethods
 {
     private readonly GraphClient client;
 
+    /// <summary>
+    /// Initializes a new instance of the MutationMethods class
+    /// </summary>
+    /// <param name="client">The GraphQL client instance</param>
     public MutationMethods(GraphClient client)
     {
-        this.client = client;
+        this.client = client ?? throw new ArgumentNullException(nameof(client));
     }
 
+    /// <summary>
+    /// Executes setName GraphQL operation
+    /// </summary>
+    /// <param name="setName">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<string></returns>
     public GraphQuery<string> SetName(string name = null)
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
-    	    new("name","String", name),
+            new("name", "String", name),
         };
 
-        return new GraphQuery<string>(client,  "setName", OperationType.Mutation, arguments); 
+        return new GraphQuery<string>(client, "setName", OperationType.Mutation, arguments);
     }
 
+    /// <summary>
+    /// Executes addCustomer GraphQL operation
+    /// </summary>
+    /// <param name="addCustomer">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<Customer></returns>
     public GraphQuery<Customer> AddCustomer(CustomerInput customer = null)
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
-    	    new("customer","CustomerInput", customer),
+            new("customer", "CustomerInput", customer),
         };
 
-        return new GraphQuery<Customer>(client,  "addCustomer", OperationType.Mutation, arguments); 
+        return new GraphQuery<Customer>(client, "addCustomer", OperationType.Mutation, arguments);
     }
 
-    }
+}
diff --git a/test/Linq2GraphQL.TestClient/Generated/Client/QueryMethods.cs b/test/Linq2GraphQL.TestClient/Generated/Client/QueryMethods.cs
index aef2cb5a..72456615 100644
--- a/test/Linq2GraphQL.TestClient/Generated/Client/QueryMethods.cs
+++ b/test/Linq2GraphQL.TestClient/Generated/Client/QueryMethods.cs
@@ -5,120 +5,196 @@
 // Url: https://linq2graphql.com
 //---------------------------------------------------------------------
 
-using System.Collections.Generic;
 using System;
+using System.Collections.Generic;
 using Linq2GraphQL.Client;
 
 namespace Linq2GraphQL.TestClient;
 
+/// <summary>
+/// Implementation of QueryMethods GraphQL operations
+/// </summary>
 public class QueryMethods : IQueryMethods
 {
     private readonly GraphClient client;
 
+    /// <summary>
+    /// Initializes a new instance of the QueryMethods class
+    /// </summary>
+    /// <param name="client">The GraphQL client instance</param>
     public QueryMethods(GraphClient client)
     {
-        this.client = client;
+        this.client = client ?? throw new ArgumentNullException(nameof(client));
     }
 
+    /// <summary>
+    /// Executes hello GraphQL operation
+    /// </summary>
+    /// <param name="hello">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<string></returns>
     public GraphQuery<string> Hello(string name = null)
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
+        {
+            new("name", "String", name),
+        };
+
+        return new GraphQuery<string>(client, "hello", OperationType.Query, arguments);
+    }
+
+    /// <summary>
+    /// Executes raiseError GraphQL operation
+    /// </summary>
+    /// <param name="raiseError">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<string></returns>
+    public GraphQuery<string> RaiseError(string message = null)
+    {
+        var arguments = new List<ArgumentValue>
         {
-    	    new("name","String", name),
+            new("message", "String", message),
         };
 
-        return new GraphQuery<string>(client,  "hello", OperationType.Query, arguments); 
+        return new GraphQuery<string>(client, "raiseError", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes raiseAuthError GraphQL operation
+    /// </summary>
+    /// <param name="raiseAuthError">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<string></returns>
+    public GraphQuery<string> RaiseAuthError()
+    {
+        var arguments = new List<ArgumentValue>
+        {
+        };
+
+        return new GraphQuery<string>(client, "raiseAuthError", OperationType.Query, arguments);
+    }
+
+    /// <summary>
+    /// Executes customerReturnNull GraphQL operation
+    /// </summary>
+    /// <param name="customerReturnNull">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<Customer></returns>
     public GraphQuery<Customer> CustomerReturnNull()
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
         };
 
-        return new GraphQuery<Customer>(client,  "customerReturnNull", OperationType.Query, arguments); 
+        return new GraphQuery<Customer>(client, "customerReturnNull", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes customers GraphQL operation
+    /// </summary>
+    /// <param name="customers">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<List<Customer>></returns>
     public GraphQuery<List<Customer>> Customers()
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
         };
 
-        return new GraphQuery<List<Customer>>(client,  "customers", OperationType.Query, arguments); 
+        return new GraphQuery<List<Customer>>(client, "customers", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes ordersNoBackwardPagination GraphQL operation
+    /// </summary>
+    /// <param name="ordersNoBackwardPagination">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<OrdersNoBackwardPaginationConnection></returns>
     public GraphQuery<OrdersNoBackwardPaginationConnection> OrdersNoBackwardPagination(int? first = null, string after = null, OrderFilterInput where = null, List<OrderSortInput> order = null)
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
-    	    new("first","Int", first),
-    	    new("after","String", after),
-    	    new("where","OrderFilterInput", where),
-    	    new("order","[OrderSortInput!]", order),
+            new("first", "Int", first),
+            new("after", "String", after),
+            new("where", "OrderFilterInput", where),
+            new("order", "[OrderSortInput!]", order),
         };
 
-        return new GraphQuery<OrdersNoBackwardPaginationConnection>(client,  "ordersNoBackwardPagination", OperationType.Query, arguments); 
+        return new GraphQuery<OrdersNoBackwardPaginationConnection>(client, "ordersNoBackwardPagination", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes ordersNoTotalCount GraphQL operation
+    /// </summary>
+    /// <param name="ordersNoTotalCount">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphCursorQuery<OrdersNoTotalCountConnection></returns>
     public GraphCursorQuery<OrdersNoTotalCountConnection> OrdersNoTotalCount(int? first = null, string after = null, int? last = null, string before = null, OrderFilterInput where = null, List<OrderSortInput> order = null)
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
-    	    new("first","Int", first),
-    	    new("after","String", after),
-    	    new("last","Int", last),
-    	    new("before","String", before),
-    	    new("where","OrderFilterInput", where),
-    	    new("order","[OrderSortInput!]", order),
+            new("first", "Int", first),
+            new("after", "String", after),
+            new("last", "Int", last),
+            new("before", "String", before),
+            new("where", "OrderFilterInput", where),
+            new("order", "[OrderSortInput!]", order),
         };
 
-        return new GraphCursorQuery<OrdersNoTotalCountConnection>(client,  "ordersNoTotalCount", OperationType.Query, arguments); 
+        return new GraphCursorQuery<OrdersNoTotalCountConnection>(client, "ordersNoTotalCount", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes orders GraphQL operation
+    /// </summary>
+    /// <param name="orders">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphCursorQuery<OrdersConnection></returns>
     public GraphCursorQuery<OrdersConnection> Orders(int? first = null, string after = null, int? last = null, string before = null, OrderFilterInput where = null, List<OrderSortInput> order = null)
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
-    	    new("first","Int", first),
-    	    new("after","String", after),
-    	    new("last","Int", last),
-    	    new("before","String", before),
-    	    new("where","OrderFilterInput", where),
-    	    new("order","[OrderSortInput!]", order),
+            new("first", "Int", first),
+            new("after", "String", after),
+            new("last", "Int", last),
+            new("before", "String", before),
+            new("where", "OrderFilterInput", where),
+            new("order", "[OrderSortInput!]", order),
         };
 
-        return new GraphCursorQuery<OrdersConnection>(client,  "orders", OperationType.Query, arguments); 
+        return new GraphCursorQuery<OrdersConnection>(client, "orders", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes animals GraphQL operation
+    /// </summary>
+    /// <param name="animals">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphCursorQuery<AnimalsConnection></returns>
     public GraphCursorQuery<AnimalsConnection> Animals(int? first = null, string after = null, int? last = null, string before = null, IAnimalFilterInput where = null, List<IAnimalSortInput> order = null)
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
-    	    new("first","Int", first),
-    	    new("after","String", after),
-    	    new("last","Int", last),
-    	    new("before","String", before),
-    	    new("where","IAnimalFilterInput", where),
-    	    new("order","[IAnimalSortInput!]", order),
+            new("first", "Int", first),
+            new("after", "String", after),
+            new("last", "Int", last),
+            new("before", "String", before),
+            new("where", "IAnimalFilterInput", where),
+            new("order", "[IAnimalSortInput!]", order),
         };
 
-        return new GraphCursorQuery<AnimalsConnection>(client,  "animals", OperationType.Query, arguments); 
+        return new GraphCursorQuery<AnimalsConnection>(client, "animals", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes ordersOffsetPaging GraphQL operation
+    /// </summary>
+    /// <param name="ordersOffsetPaging">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphCursorQuery<OrdersOffsetPagingConnection></returns>
     public GraphCursorQuery<OrdersOffsetPagingConnection> OrdersOffsetPaging(int? first = null, string after = null, int? last = null, string before = null, OrderFilterInput where = null, List<OrderSortInput> order = null)
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
-    	    new("first","Int", first),
-    	    new("after","String", after),
-    	    new("last","Int", last),
-    	    new("before","String", before),
-    	    new("where","OrderFilterInput", where),
-    	    new("order","[OrderSortInput!]", order),
+            new("first", "Int", first),
+            new("after", "String", after),
+            new("last", "Int", last),
+            new("before", "String", before),
+            new("where", "OrderFilterInput", where),
+            new("order", "[OrderSortInput!]", order),
         };
 
-        return new GraphCursorQuery<OrdersOffsetPagingConnection>(client,  "ordersOffsetPaging", OperationType.Query, arguments); 
+        return new GraphCursorQuery<OrdersOffsetPagingConnection>(client, "ordersOffsetPaging", OperationType.Query, arguments);
     }
 
-    }
+}
diff --git a/test/Linq2GraphQL.TestClient/Generated/Client/SubscriptionMethods.cs b/test/Linq2GraphQL.TestClient/Generated/Client/SubscriptionMethods.cs
index 6d3f0010..d4d9bb59 100644
--- a/test/Linq2GraphQL.TestClient/Generated/Client/SubscriptionMethods.cs
+++ b/test/Linq2GraphQL.TestClient/Generated/Client/SubscriptionMethods.cs
@@ -5,39 +5,56 @@
 // Url: https://linq2graphql.com
 //---------------------------------------------------------------------
 
-using System.Collections.Generic;
 using System;
+using System.Collections.Generic;
 using Linq2GraphQL.Client;
 using Linq2GraphQL.Client.Subscriptions;
 
 namespace Linq2GraphQL.TestClient;
 
+/// <summary>
+/// Implementation of SubscriptionMethods GraphQL operations
+/// </summary>
 public class SubscriptionMethods : ISubscriptionMethods
 {
     private readonly GraphClient client;
 
+    /// <summary>
+    /// Initializes a new instance of the SubscriptionMethods class
+    /// </summary>
+    /// <param name="client">The GraphQL client instance</param>
     public SubscriptionMethods(GraphClient client)
     {
-        this.client = client;
+        this.client = client ?? throw new ArgumentNullException(nameof(client));
     }
 
+    /// <summary>
+    /// Executes customerAdded GraphQL operation
+    /// </summary>
+    /// <param name="customerAdded">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphSubscription<Customer></returns>
     public GraphSubscription<Customer> CustomerAdded()
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
         };
 
-        return new GraphSubscription<Customer>(client,  "customerAdded", OperationType.Subscription, arguments); 
+        return new GraphSubscription<Customer>(client, "customerAdded", OperationType.Subscription, arguments);
     }
 
+    /// <summary>
+    /// Executes customerNameAdded GraphQL operation
+    /// </summary>
+    /// <param name="customerNameAdded">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphSubscription<Customer></returns>
     public GraphSubscription<Customer> CustomerNameAdded(string name = null)
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
-    	    new("name","String", name),
+            new("name", "String", name),
         };
 
-        return new GraphSubscription<Customer>(client,  "customerNameAdded", OperationType.Subscription, arguments); 
+        return new GraphSubscription<Customer>(client, "customerNameAdded", OperationType.Subscription, arguments);
     }
 
-    }
+}
diff --git a/test/Linq2GraphQL.TestClient/Generated/Inputs/ByteOperationFilterInput.cs b/test/Linq2GraphQL.TestClient/Generated/Inputs/ByteOperationFilterInput.cs
index 4f1ef9e9..93c7d9dc 100644
--- a/test/Linq2GraphQL.TestClient/Generated/Inputs/ByteOperationFilterInput.cs
+++ b/test/Linq2GraphQL.TestClient/Generated/Inputs/ByteOperationFilterInput.cs
@@ -17,97 +17,97 @@ public partial class ByteOperationFilterInput : GraphInputBase
 {
 	[GraphQLMember("eq")]
 	[JsonPropertyName("eq")]
-	public byte? Eq 
+	public sbyte? Eq 
 	{
-		get => GetValue<byte?>("eq");
+		get => GetValue<sbyte?>("eq");
     	set => SetValue("eq", value);
 	}
 
 	[GraphQLMember("neq")]
 	[JsonPropertyName("neq")]
-	public byte? Neq 
+	public sbyte? Neq 
 	{
-		get => GetValue<byte?>("neq");
+		get => GetValue<sbyte?>("neq");
     	set => SetValue("neq", value);
 	}
 
 	[GraphQLMember("in")]
 	[JsonPropertyName("in")]
-	public List<byte?> In 
+	public List<sbyte?> In 
 	{
-		get => GetValue<List<byte?>>("in");
+		get => GetValue<List<sbyte?>>("in");
     	set => SetValue("in", value);
 	}
 
 	[GraphQLMember("nin")]
 	[JsonPropertyName("nin")]
-	public List<byte?> Nin 
+	public List<sbyte?> Nin 
 	{
-		get => GetValue<List<byte?>>("nin");
+		get => GetValue<List<sbyte?>>("nin");
     	set => SetValue("nin", value);
 	}
 
 	[GraphQLMember("gt")]
 	[JsonPropertyName("gt")]
-	public byte? Gt 
+	public sbyte? Gt 
 	{
-		get => GetValue<byte?>("gt");
+		get => GetValue<sbyte?>("gt");
     	set => SetValue("gt", value);
 	}
 
 	[GraphQLMember("ngt")]
 	[JsonPropertyName("ngt")]
-	public byte? Ngt 
+	public sbyte? Ngt 
 	{
-		get => GetValue<byte?>("ngt");
+		get => GetValue<sbyte?>("ngt");
     	set => SetValue("ngt", value);
 	}
 
 	[GraphQLMember("gte")]
 	[JsonPropertyName("gte")]
-	public byte? Gte 
+	public sbyte? Gte 
 	{
-		get => GetValue<byte?>("gte");
+		get => GetValue<sbyte?>("gte");
     	set => SetValue("gte", value);
 	}
 
 	[GraphQLMember("ngte")]
 	[JsonPropertyName("ngte")]
-	public byte? Ngte 
+	public sbyte? Ngte 
 	{
-		get => GetValue<byte?>("ngte");
+		get => GetValue<sbyte?>("ngte");
     	set => SetValue("ngte", value);
 	}
 
 	[GraphQLMember("lt")]
 	[JsonPropertyName("lt")]
-	public byte? Lt 
+	public sbyte? Lt 
 	{
-		get => GetValue<byte?>("lt");
+		get => GetValue<sbyte?>("lt");
     	set => SetValue("lt", value);
 	}
 
 	[GraphQLMember("nlt")]
 	[JsonPropertyName("nlt")]
-	public byte? Nlt 
+	public sbyte? Nlt 
 	{
-		get => GetValue<byte?>("nlt");
+		get => GetValue<sbyte?>("nlt");
     	set => SetValue("nlt", value);
 	}
 
 	[GraphQLMember("lte")]
 	[JsonPropertyName("lte")]
-	public byte? Lte 
+	public sbyte? Lte 
 	{
-		get => GetValue<byte?>("lte");
+		get => GetValue<sbyte?>("lte");
     	set => SetValue("lte", value);
 	}
 
 	[GraphQLMember("nlte")]
 	[JsonPropertyName("nlte")]
-	public byte? Nlte 
+	public sbyte? Nlte 
 	{
-		get => GetValue<byte?>("nlte");
+		get => GetValue<sbyte?>("nlte");
     	set => SetValue("nlte", value);
 	}
 
diff --git a/test/Linq2GraphQL.TestClient/Generated/Inputs/InputFactory.cs b/test/Linq2GraphQL.TestClient/Generated/Inputs/InputFactory.cs
index f09339b5..17906a10 100644
--- a/test/Linq2GraphQL.TestClient/Generated/Inputs/InputFactory.cs
+++ b/test/Linq2GraphQL.TestClient/Generated/Inputs/InputFactory.cs
@@ -255,84 +255,84 @@ public static AddressSortInput CreatedDate(this AddressSortInput input, SortEnum
 public static class ByteOperationFilterInputExtensions
 { 
 	
-    public static ByteOperationFilterInput Eq(this ByteOperationFilterInput input, byte? val)
+    public static ByteOperationFilterInput Eq(this ByteOperationFilterInput input, sbyte? val)
     {
          input.Eq = val;
          return input;
     }
 
 
-    public static ByteOperationFilterInput Neq(this ByteOperationFilterInput input, byte? val)
+    public static ByteOperationFilterInput Neq(this ByteOperationFilterInput input, sbyte? val)
     {
          input.Neq = val;
          return input;
     }
 
 
-    public static ByteOperationFilterInput In(this ByteOperationFilterInput input, List<byte?> val)
+    public static ByteOperationFilterInput In(this ByteOperationFilterInput input, List<sbyte?> val)
     {
          input.In = val;
          return input;
     }
 
 
-    public static ByteOperationFilterInput Nin(this ByteOperationFilterInput input, List<byte?> val)
+    public static ByteOperationFilterInput Nin(this ByteOperationFilterInput input, List<sbyte?> val)
     {
          input.Nin = val;
          return input;
     }
 
 
-    public static ByteOperationFilterInput Gt(this ByteOperationFilterInput input, byte? val)
+    public static ByteOperationFilterInput Gt(this ByteOperationFilterInput input, sbyte? val)
     {
          input.Gt = val;
          return input;
     }
 
 
-    public static ByteOperationFilterInput Ngt(this ByteOperationFilterInput input, byte? val)
+    public static ByteOperationFilterInput Ngt(this ByteOperationFilterInput input, sbyte? val)
     {
          input.Ngt = val;
          return input;
     }
 
 
-    public static ByteOperationFilterInput Gte(this ByteOperationFilterInput input, byte? val)
+    public static ByteOperationFilterInput Gte(this ByteOperationFilterInput input, sbyte? val)
     {
          input.Gte = val;
          return input;
     }
 
 
-    public static ByteOperationFilterInput Ngte(this ByteOperationFilterInput input, byte? val)
+    public static ByteOperationFilterInput Ngte(this ByteOperationFilterInput input, sbyte? val)
     {
          input.Ngte = val;
          return input;
     }
 
 
-    public static ByteOperationFilterInput Lt(this ByteOperationFilterInput input, byte? val)
+    public static ByteOperationFilterInput Lt(this ByteOperationFilterInput input, sbyte? val)
     {
          input.Lt = val;
          return input;
     }
 
 
-    public static ByteOperationFilterInput Nlt(this ByteOperationFilterInput input, byte? val)
+    public static ByteOperationFilterInput Nlt(this ByteOperationFilterInput input, sbyte? val)
     {
          input.Nlt = val;
          return input;
     }
 
 
-    public static ByteOperationFilterInput Lte(this ByteOperationFilterInput input, byte? val)
+    public static ByteOperationFilterInput Lte(this ByteOperationFilterInput input, sbyte? val)
     {
          input.Lte = val;
          return input;
     }
 
 
-    public static ByteOperationFilterInput Nlte(this ByteOperationFilterInput input, byte? val)
+    public static ByteOperationFilterInput Nlte(this ByteOperationFilterInput input, sbyte? val)
     {
          input.Nlte = val;
          return input;
@@ -1015,7 +1015,7 @@ public static ItemInput ItemName(this ItemInput input, string val)
     }
 
 
-    public static ItemInput Data(this ItemInput input, List<byte> val)
+    public static ItemInput Data(this ItemInput input, List<sbyte> val)
     {
          input.Data = val;
          return input;
diff --git a/test/Linq2GraphQL.TestClient/Generated/Inputs/ItemInput.cs b/test/Linq2GraphQL.TestClient/Generated/Inputs/ItemInput.cs
index aa030c07..ab73488f 100644
--- a/test/Linq2GraphQL.TestClient/Generated/Inputs/ItemInput.cs
+++ b/test/Linq2GraphQL.TestClient/Generated/Inputs/ItemInput.cs
@@ -33,9 +33,9 @@ public string ItemName
 
 	[GraphQLMember("data")]
 	[JsonPropertyName("data")]
-	public List<byte> Data 
+	public List<sbyte> Data 
 	{
-		get => GetValue<List<byte>>("data");
+		get => GetValue<List<sbyte>>("data");
     	set => SetValue("data", value);
 	}
 
diff --git a/test/Linq2GraphQL.TestClient/Generated/Interfaces/IQueryMethods.cs b/test/Linq2GraphQL.TestClient/Generated/Interfaces/IQueryMethods.cs
index 49d46dee..cd109fd3 100644
--- a/test/Linq2GraphQL.TestClient/Generated/Interfaces/IQueryMethods.cs
+++ b/test/Linq2GraphQL.TestClient/Generated/Interfaces/IQueryMethods.cs
@@ -23,6 +23,20 @@ public interface IQueryMethods
     /// <returns>GraphQL query result of type GraphQuery<string></returns>
     GraphQuery<string> Hello(string name = null);
 
+    /// <summary>
+    /// Executes raiseError GraphQL operation
+    /// </summary>
+    /// <param name="raiseError">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<string></returns>
+    GraphQuery<string> RaiseError(string message = null);
+
+    /// <summary>
+    /// Executes raiseAuthError GraphQL operation
+    /// </summary>
+    /// <param name="raiseAuthError">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<string></returns>
+    GraphQuery<string> RaiseAuthError();
+
     /// <summary>
     /// Executes customerReturnNull GraphQL operation
     /// </summary>
diff --git a/test/Linq2GraphQL.TestClient/Generated/Types/Item.cs b/test/Linq2GraphQL.TestClient/Generated/Types/Item.cs
index 5cc05426..474fe27a 100644
--- a/test/Linq2GraphQL.TestClient/Generated/Types/Item.cs
+++ b/test/Linq2GraphQL.TestClient/Generated/Types/Item.cs
@@ -26,6 +26,6 @@ public partial class Item : GraphQLTypeBase
 
     [GraphQLMember("data")]
     [JsonPropertyName("data")]
-    public List<byte> Data { get; set; }
+    public List<sbyte> Data { get; set; }
 
 }
diff --git a/test/Linq2GraphQL.TestClient/ReadMe.txt b/test/Linq2GraphQL.TestClient/ReadMe.txt
index 332fddad..82dd4504 100644
--- a/test/Linq2GraphQL.TestClient/ReadMe.txt
+++ b/test/Linq2GraphQL.TestClient/ReadMe.txt
@@ -1,10 +1,12 @@
-
-*Upgrade Tool
-dotnet tool update Linq2GraphQL.Generator -g --prerelease
+This folder holds CHECKED-IN GENERATED OUTPUT. Do not edit Generated/ by hand.
 
+To refresh it after a template or test-schema change, run from the repo root:
 
-*Update Schema
-Linq2GraphQL https://localhost:7184/graphql/ -c="SampleClient" -n="Linq2GraphQL.TestClient" -o="Generated" -s=true
+    ./scripts/regenerate-test-clients.ps1
 
-*Generate local
-https://localhost:7184/graphql/ -c="SampleClient" -n="Linq2GraphQL.TestClient" -o="C:\Code\Linq2GraphQL.Client\test\Linq2GraphQL.TestClient\Generated" -s=true -d=true
+The script boots both test servers over plain HTTP, runs the generator against
+them with the flags that produced this output, and writes the result back here.
+Review the diff and commit it.
+
+The "Test clients up to date" CI job runs the same script with -Check and fails
+if the committed output no longer matches what the generator produces.
diff --git a/test/Linq2GraphQL.TestClientNullable/Generated/Client/MutationMethods.cs b/test/Linq2GraphQL.TestClientNullable/Generated/Client/MutationMethods.cs
index 0942a94a..89ac2339 100644
--- a/test/Linq2GraphQL.TestClientNullable/Generated/Client/MutationMethods.cs
+++ b/test/Linq2GraphQL.TestClientNullable/Generated/Client/MutationMethods.cs
@@ -5,39 +5,56 @@
 // Url: https://linq2graphql.com
 //---------------------------------------------------------------------
 
-using System.Collections.Generic;
 using System;
+using System.Collections.Generic;
 using Linq2GraphQL.Client;
 
 namespace Linq2GraphQL.TestClientNullable;
 
+/// <summary>
+/// Implementation of MutationMethods GraphQL operations
+/// </summary>
 public class MutationMethods : IMutationMethods
 {
     private readonly GraphClient client;
 
+    /// <summary>
+    /// Initializes a new instance of the MutationMethods class
+    /// </summary>
+    /// <param name="client">The GraphQL client instance</param>
     public MutationMethods(GraphClient client)
     {
-        this.client = client;
+        this.client = client ?? throw new ArgumentNullException(nameof(client));
     }
 
+    /// <summary>
+    /// Executes updateCustomer GraphQL operation
+    /// </summary>
+    /// <param name="updateCustomer">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<Customer></returns>
     public GraphQuery<Customer> UpdateCustomer(CustomerInput customer)
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
-    	    new("customer","CustomerInput!", customer),
+            new("customer", "CustomerInput!", customer),
         };
 
-        return new GraphQuery<Customer>(client,  "updateCustomer", OperationType.Mutation, arguments); 
+        return new GraphQuery<Customer>(client, "updateCustomer", OperationType.Mutation, arguments);
     }
 
+    /// <summary>
+    /// Executes updatePerson GraphQL operation
+    /// </summary>
+    /// <param name="updatePerson">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<Person></returns>
     public GraphQuery<Person> UpdatePerson(PersonInput person)
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
-    	    new("person","PersonInput!", person),
+            new("person", "PersonInput!", person),
         };
 
-        return new GraphQuery<Person>(client,  "updatePerson", OperationType.Mutation, arguments); 
+        return new GraphQuery<Person>(client, "updatePerson", OperationType.Mutation, arguments);
     }
 
-    }
+}
diff --git a/test/Linq2GraphQL.TestClientNullable/Generated/Client/QueryMethods.cs b/test/Linq2GraphQL.TestClientNullable/Generated/Client/QueryMethods.cs
index 3e264a0b..bbec1f75 100644
--- a/test/Linq2GraphQL.TestClientNullable/Generated/Client/QueryMethods.cs
+++ b/test/Linq2GraphQL.TestClientNullable/Generated/Client/QueryMethods.cs
@@ -5,92 +5,142 @@
 // Url: https://linq2graphql.com
 //---------------------------------------------------------------------
 
-using System.Collections.Generic;
 using System;
+using System.Collections.Generic;
 using Linq2GraphQL.Client;
 
 namespace Linq2GraphQL.TestClientNullable;
 
+/// <summary>
+/// Implementation of QueryMethods GraphQL operations
+/// </summary>
 public class QueryMethods : IQueryMethods
 {
     private readonly GraphClient client;
 
+    /// <summary>
+    /// Initializes a new instance of the QueryMethods class
+    /// </summary>
+    /// <param name="client">The GraphQL client instance</param>
     public QueryMethods(GraphClient client)
     {
-        this.client = client;
+        this.client = client ?? throw new ArgumentNullException(nameof(client));
     }
 
+    /// <summary>
+    /// Executes item GraphQL operation
+    /// </summary>
+    /// <param name="item">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<Item></returns>
     public GraphQuery<Item> Item()
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
         };
 
-        return new GraphQuery<Item>(client,  "item", OperationType.Query, arguments); 
+        return new GraphQuery<Item>(client, "item", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes itemDraft GraphQL operation
+    /// </summary>
+    /// <remarks>
+    /// This operation is deprecated: This is an really old method! please d not use it!!
+    /// </remarks>
     [Obsolete("This is an really old method! please d not use it!!")]
+    /// <param name="itemDraft">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<Item></returns>
     public GraphQuery<Item> ItemDraft()
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
         };
 
-        return new GraphQuery<Item>(client,  "itemDraft", OperationType.Query, arguments); 
+        return new GraphQuery<Item>(client, "itemDraft", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes customerList GraphQL operation
+    /// </summary>
+    /// <param name="customerList">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<List<Customer>></returns>
     public GraphQuery<List<Customer>> CustomerList()
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
         };
 
-        return new GraphQuery<List<Customer>>(client,  "customerList", OperationType.Query, arguments); 
+        return new GraphQuery<List<Customer>>(client, "customerList", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes customerNullable GraphQL operation
+    /// </summary>
+    /// <param name="customerNullable">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<Customer?></returns>
     public GraphQuery<Customer?> CustomerNullable()
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
         };
 
-        return new GraphQuery<Customer?>(client,  "customerNullable", OperationType.Query, arguments); 
+        return new GraphQuery<Customer?>(client, "customerNullable", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes customerListAllNullable GraphQL operation
+    /// </summary>
+    /// <param name="customerListAllNullable">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<List<Customer?>?></returns>
     public GraphQuery<List<Customer?>?> CustomerListAllNullable()
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
         };
 
-        return new GraphQuery<List<Customer?>?>(client,  "customerListAllNullable", OperationType.Query, arguments); 
+        return new GraphQuery<List<Customer?>?>(client, "customerListAllNullable", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes customerListNullable GraphQL operation
+    /// </summary>
+    /// <param name="customerListNullable">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<List<Customer>?></returns>
     public GraphQuery<List<Customer>?> CustomerListNullable()
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
         };
 
-        return new GraphQuery<List<Customer>?>(client,  "customerListNullable", OperationType.Query, arguments); 
+        return new GraphQuery<List<Customer>?>(client, "customerListNullable", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes customerListInList GraphQL operation
+    /// </summary>
+    /// <param name="customerListInList">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<List<List<Customer>>></returns>
     public GraphQuery<List<List<Customer>>> CustomerListInList()
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
         };
 
-        return new GraphQuery<List<List<Customer>>>(client,  "customerListInList", OperationType.Query, arguments); 
+        return new GraphQuery<List<List<Customer>>>(client, "customerListInList", OperationType.Query, arguments);
     }
 
+    /// <summary>
+    /// Executes person GraphQL operation
+    /// </summary>
+    /// <param name="person">The operation parameters</param>
+    /// <returns>GraphQL query result of type GraphQuery<Person></returns>
     public GraphQuery<Person> Person()
     {
-	    var arguments = new List<ArgumentValue>
+        var arguments = new List<ArgumentValue>
         {
         };
 
-        return new GraphQuery<Person>(client,  "person", OperationType.Query, arguments); 
+        return new GraphQuery<Person>(client, "person", OperationType.Query, arguments);
     }
 
-    }
+}
diff --git a/test/Linq2GraphQL.TestClientNullable/Generated/Inputs/ItemInput.cs b/test/Linq2GraphQL.TestClientNullable/Generated/Inputs/ItemInput.cs
index 51d98fcf..cf19b908 100644
--- a/test/Linq2GraphQL.TestClientNullable/Generated/Inputs/ItemInput.cs
+++ b/test/Linq2GraphQL.TestClientNullable/Generated/Inputs/ItemInput.cs
@@ -33,9 +33,9 @@ public required string ItemName
 
 	[GraphQLMember("data")]
 	[JsonPropertyName("data")]
-	public List<byte>? Data 
+	public List<sbyte>? Data 
 	{
-		get => GetValue<List<byte>?>("data");
+		get => GetValue<List<sbyte>?>("data");
     	set => SetValue("data", value);
 	}
 
diff --git a/test/Linq2GraphQL.TestClientNullable/Generated/Types/Item.cs b/test/Linq2GraphQL.TestClientNullable/Generated/Types/Item.cs
index f1b1dfcc..7e6a55cd 100644
--- a/test/Linq2GraphQL.TestClientNullable/Generated/Types/Item.cs
+++ b/test/Linq2GraphQL.TestClientNullable/Generated/Types/Item.cs
@@ -27,6 +27,6 @@ public partial class Item : GraphQLTypeBase
 
     [GraphQLMember("data")]
     [JsonPropertyName("data")]
-    public List<byte>? Data { get; set; }
+    public List<sbyte>? Data { get; set; }
 
 }
diff --git a/test/Linq2GraphQL.TestClientNullable/ReadMe.txt b/test/Linq2GraphQL.TestClientNullable/ReadMe.txt
index 90e7d896..82dd4504 100644
--- a/test/Linq2GraphQL.TestClientNullable/ReadMe.txt
+++ b/test/Linq2GraphQL.TestClientNullable/ReadMe.txt
@@ -1,11 +1,12 @@
-
-*Upgrade Tool
-dotnet tool update Linq2GraphQL.Generator -g --prerelease
+This folder holds CHECKED-IN GENERATED OUTPUT. Do not edit Generated/ by hand.
 
+To refresh it after a template or test-schema change, run from the repo root:
 
-*Update Schema
-Linq2GraphQL https://localhost:50741/graphql/ -c="SampleNullableClient" -n="Linq2GraphQL.TestClientNullable" -o="Generated" 
+    ./scripts/regenerate-test-clients.ps1
 
-*Generate local
-https://localhost:50741/graphql/ -c="SampleNullableClient" -n="Linq2GraphQL.TestClientNullable" -o="C:\Code\Github\Linq2GraphQL.Client\test\Linq2GraphQL.TestClientNullable\Generated" -s=true -nu=true
+The script boots both test servers over plain HTTP, runs the generator against
+them with the flags that produced this output, and writes the result back here.
+Review the diff and commit it.
 
+The "Test clients up to date" CI job runs the same script with -Check and fails
+if the committed output no longer matches what the generator produces.
diff --git a/test/Linq2GraphQL.Tests/QueryNullableTests.cs b/test/Linq2GraphQL.Tests/QueryNullableTests.cs
index d023d028..c0366a7a 100644
--- a/test/Linq2GraphQL.Tests/QueryNullableTests.cs
+++ b/test/Linq2GraphQL.Tests/QueryNullableTests.cs
@@ -34,7 +34,8 @@ public async Task GetItemData()
             .Select()
             .ExecuteAsync();
 
-        var data = Encoding.UTF8.GetString(result.Data!.ToArray());
+        // The GraphQL Byte scalar is signed (HotChocolate), so Data is List<sbyte>.
+        var data = Encoding.UTF8.GetString(result.Data!.Select(e => (byte)e).ToArray());
 
         Assert.Equal(result.ItemName, data);
     }