diff --git a/BUILDGUIDE.md b/BUILDGUIDE.md
index 464984ef39..75c94576c3 100644
--- a/BUILDGUIDE.md
+++ b/BUILDGUIDE.md
@@ -253,6 +253,45 @@ dotnet build -t:TestSqlClientFunctional -p:TestFramework=net10.0
 
 ### Packaging Projects
 
+#### Consumer family-version check
+
+The Logging package owns `ValidateSqlClientFamilyPackageVersions` and ships it in
+both `build/` and `buildTransitive/`. NuGet imports it into direct consumers and
+transitive PackageReference consumers (unless build assets are excluded).
+Installed Logging, Abstractions, SqlClient, Extensions.Azure, and AKV packages
+must match the resolved Logging version exactly, including prerelease labels.
+Optional family packages are not required; independently versioned
+Microsoft.SqlServer.Server and native SNI packages are excluded. The target uses
+resolved compile/runtime package metadata or the active legacy `packages.config`
+(including `packages.<project-name>.config`), not
+assembly versions or declared version ranges, and skips design-time builds.
+Missing version metadata or a missing Logging anchor is not guessed.
+
+**SQLCLIENT001** means installed family versions differ. Upgrade them together;
+historical extension `1.0.0` versions are not automatically mapped to driver
+`7.0.0`/`7.0.1`. The emergency escape hatch is
+`-p:SqlClientEnforceFamilyVersions=false` (or that property in the consumer
+project). It suppresses this check only, not incompatibilities.
+Ordinary project references do not propagate NuGet buildTransitive assets:
+Project-mode repository builds are not validated by this consumer target.
+
+Run `dotnet tool restore` first to restore the repository's pinned PowerShell tool.
+The regression suite also requires Pester 5.7.1:
+
+```powershell
+dotnet tool run pwsh -NoProfile -Command "Install-Module Pester -RequiredVersion 5.7.1 -Repository PSGallery -Scope CurrentUser -Force -ErrorAction Stop"
+dotnet tool run pwsh -NoProfile -Command 'Import-Module Pester -RequiredVersion 5.7.1; Invoke-Pester -Path ./src/Microsoft.Data.SqlClient.Internal/Logging/test/VersionChecks.Tests.ps1 -CI'
+```
+
+The parameterized Pester suite packs the real Logging project, creates small family-package fixtures
+in a private local feed, and verifies automatic imports for both direct and
+transitive package consumers. It uses a unique directory under Logging/test and
+removes that directory on completion; no SQL Server is required.
+Add `-Tag Synthetic` to `Invoke-Pester` to run only the metadata and legacy manifest
+matrix without packing consumer fixtures.
+The suite is available for local execution only. PR and OneBranch pipelines do not
+install Pester or run these tests.
+
 Just like building and testing the various projects in this repository, packaging the projects into NuGet packages is
 also handled by `build.proj`. From the root of your repository, run `dotnet build` against `build.proj` with a pack target,
 following this pattern:
diff --git a/src/Microsoft.Data.SqlClient.Internal/Logging/build/Microsoft.Data.SqlClient.Internal.Logging.targets b/src/Microsoft.Data.SqlClient.Internal/Logging/build/Microsoft.Data.SqlClient.Internal.Logging.targets
new file mode 100644
index 0000000000..5d372bad64
--- /dev/null
+++ b/src/Microsoft.Data.SqlClient.Internal/Logging/build/Microsoft.Data.SqlClient.Internal.Logging.targets
@@ -0,0 +1,62 @@
+<!--
+  Licensed to the .NET Foundation under one or more agreements. The .NET Foundation licenses this
+  file to you under the MIT license.
+-->
+<Project>
+  <!-- Logging owns the consumer check and ships it in build/ and buildTransitive/.
+       Only installed members of the lockstep family are checked. SqlServer.Server and native
+       SNI are independently versioned. Project references are not package-version evidence. -->
+  <PropertyGroup>
+    <SqlClientEnforceFamilyVersions Condition="'$(SqlClientEnforceFamilyVersions)' == ''">true</SqlClientEnforceFamilyVersions>
+  </PropertyGroup>
+
+  <Target Name="ValidateSqlClientFamilyPackageVersions"
+          AfterTargets="ResolvePackageAssets;ResolveReferences"
+          Condition="'$(SqlClientEnforceFamilyVersions)' == 'true' And '$(DesignTimeBuild)' != 'true'">
+    <ItemGroup>
+      <!-- Collect first, then use qualified metadata so framework/project references without
+           NuGet metadata cannot cause MSB4096. Include RID-specific runtime-only assets. -->
+      <_SqlClientResolvedAsset Include="@(ResolvedCompileFileDefinitions);@(ReferencePath);@(RuntimeCopyLocalItems);@(RuntimeTargetsCopyLocalItems)" />
+      <_SqlClientFamilyAsset Include="@(_SqlClientResolvedAsset)"
+          Condition="'%(_SqlClientResolvedAsset.NuGetPackageId)' == 'Microsoft.Data.SqlClient' Or
+                     '%(_SqlClientResolvedAsset.NuGetPackageId)' == 'Microsoft.Data.SqlClient.Extensions.Abstractions' Or
+                     '%(_SqlClientResolvedAsset.NuGetPackageId)' == 'Microsoft.Data.SqlClient.Extensions.Azure' Or
+                     '%(_SqlClientResolvedAsset.NuGetPackageId)' == 'Microsoft.Data.SqlClient.Internal.Logging' Or
+                     '%(_SqlClientResolvedAsset.NuGetPackageId)' == 'Microsoft.Data.SqlClient.AlwaysEncrypted.AzureKeyVaultProvider'">
+        <FamilyVersion>%(_SqlClientResolvedAsset.NuGetPackageVersion)</FamilyVersion>
+        <FamilyId>%(_SqlClientResolvedAsset.NuGetPackageId)</FamilyId>
+      </_SqlClientFamilyAsset>
+      <_SqlClientLoggingVersion Include="@(_SqlClientFamilyAsset)"
+          Condition="'%(_SqlClientFamilyAsset.FamilyId)' == 'Microsoft.Data.SqlClient.Internal.Logging' And '%(_SqlClientFamilyAsset.FamilyVersion)' != ''" />
+    </ItemGroup>
+    <PropertyGroup>
+      <!-- Compare resolved version strings, including prerelease labels, not ranges or assembly
+           versions. Missing package metadata is not assigned a guessed version. -->
+      <_SqlClientExpectedFamilyVersion>@(_SqlClientLoggingVersion->'%(FamilyVersion)'->Distinct())</_SqlClientExpectedFamilyVersion>
+    </PropertyGroup>
+    <Error Code="SQLCLIENT001"
+           Condition="'%(_SqlClientFamilyAsset.FamilyVersion)' != '' And '$(_SqlClientExpectedFamilyVersion)' != '' And '%(_SqlClientFamilyAsset.FamilyVersion)' != '$(_SqlClientExpectedFamilyVersion)'"
+           Text="SqlClient family version mismatch: %(_SqlClientFamilyAsset.FamilyId) is %(_SqlClientFamilyAsset.FamilyVersion), but Logging is $(_SqlClientExpectedFamilyVersion). Upgrade all installed family packages together, including prerelease labels. Emergency opt-out: SqlClientEnforceFamilyVersions=false." />
+
+    <!-- Legacy packages.config consumers import build/ explicitly through NuGet installation.
+         Read installed versions from the manifest, independently of assembly reference metadata. -->
+    <PropertyGroup>
+      <!-- Match NuGet: prefer the project-specific manifest, replacing spaces with underscores. -->
+      <_SqlClientConfigPath>$(MSBuildProjectDirectory)/packages.$(MSBuildProjectName.Replace(' ', '_')).config</_SqlClientConfigPath>
+      <_SqlClientConfigPath Condition="!Exists('$(_SqlClientConfigPath)')">$(MSBuildProjectDirectory)/packages.config</_SqlClientConfigPath>
+    </PropertyGroup>
+    <XmlPeek XmlInputPath="$(_SqlClientConfigPath)"
+             Query="/packages/package[@id='Microsoft.Data.SqlClient.Internal.Logging']/@version"
+             Condition="Exists('$(_SqlClientConfigPath)')">
+      <Output TaskParameter="Result" PropertyName="_SqlClientConfigExpectedVersion" />
+    </XmlPeek>
+    <XmlPeek XmlInputPath="$(_SqlClientConfigPath)"
+             Query="/packages/package[(@id='Microsoft.Data.SqlClient.Internal.Logging' or @id='Microsoft.Data.SqlClient.Extensions.Abstractions' or @id='Microsoft.Data.SqlClient' or @id='Microsoft.Data.SqlClient.Extensions.Azure' or @id='Microsoft.Data.SqlClient.AlwaysEncrypted.AzureKeyVaultProvider') and @version!='$(_SqlClientConfigExpectedVersion)']"
+             Condition="'$(_SqlClientConfigExpectedVersion)' != ''">
+      <Output TaskParameter="Result" ItemName="_SqlClientConfigMismatch" />
+    </XmlPeek>
+    <Error Code="SQLCLIENT001"
+           Condition="'@(_SqlClientConfigMismatch)' != ''"
+           Text="SqlClient family version mismatch in $(_SqlClientConfigPath): %(_SqlClientConfigMismatch.Identity), but Logging is $(_SqlClientConfigExpectedVersion). Upgrade all installed family packages together, including prerelease labels. Emergency opt-out: SqlClientEnforceFamilyVersions=false." />
+  </Target>
+</Project>
diff --git a/src/Microsoft.Data.SqlClient.Internal/Logging/src/Logging.csproj b/src/Microsoft.Data.SqlClient.Internal/Logging/src/Logging.csproj
index d83b8ae577..af7b725643 100644
--- a/src/Microsoft.Data.SqlClient.Internal/Logging/src/Logging.csproj
+++ b/src/Microsoft.Data.SqlClient.Internal/Logging/src/Logging.csproj
@@ -75,6 +75,8 @@
   <ItemGroup>
     <None Include="$(RepoRoot)/tools/icons/dotnet.png" Pack="true" PackagePath="/" />
     <None Include="PackageReadme.md" Pack="true" PackagePath="README.md" />
+    <None Include="../build/Microsoft.Data.SqlClient.Internal.Logging.targets"
+          Pack="true" PackagePath="build/;buildTransitive/" />
   </ItemGroup>
 
   <!-- CodeGen Targets ================================================= -->
diff --git a/src/Microsoft.Data.SqlClient.Internal/Logging/src/PackageReadme.md b/src/Microsoft.Data.SqlClient.Internal/Logging/src/PackageReadme.md
index 3ae2b2cd55..a561bae028 100644
--- a/src/Microsoft.Data.SqlClient.Internal/Logging/src/PackageReadme.md
+++ b/src/Microsoft.Data.SqlClient.Internal/Logging/src/PackageReadme.md
@@ -22,6 +22,36 @@ This package provides **ETW EventSource tracing and diagnostics** for [Microsoft
 
 ## Supportability
 
+### SqlClient family version validation
+
+Logging ships a consumer MSBuild target in `build/` and `buildTransitive/`.
+NuGet imports it for direct package consumers and transitive PackageReference
+consumers. After package/reference resolution it compares installed
+`Microsoft.Data.SqlClient`, `Microsoft.Data.SqlClient.Extensions.Abstractions`,
+`Microsoft.Data.SqlClient.Extensions.Azure`, and
+`Microsoft.Data.SqlClient.AlwaysEncrypted.AzureKeyVaultProvider` package versions
+against the **resolved Logging package version**. Optional packages are not required.
+`Microsoft.SqlServer.Server` and native SNI packages are excluded.
+
+Versions must match exactly, including prerelease labels; a mismatch fails the
+build with **SQLCLIENT001**. Upgrade all installed family packages together.
+Historical extensions numbered `1.0.0` are not mapped to driver `7.0.0`/`7.0.1`.
+The check uses resolved compile/runtime asset metadata for PackageReference and
+installed versions in the active `packages.config` for legacy consumers. A
+`packages.<project-name>.config` file takes precedence over `packages.config`;
+spaces in the project name are replaced with underscores, matching NuGet.
+It does not check
+assembly versions, restore ranges, or API compatibility. Assets missing version
+metadata and builds without a Logging version anchor are skipped. Design-time
+builds are skipped.
+
+For emergency recovery, set `SqlClientEnforceFamilyVersions=false` in the
+consumer project or pass `-p:SqlClientEnforceFamilyVersions=false`. This disables
+only this build check; it does not make mixed versions compatible. Excluding the
+package's build assets also prevents target import. Ordinary project references
+do not propagate NuGet buildTransitive targets, so this check does not enforce
+in-tree Project-mode versions.
+
 This package supports:
 
 - .NET Standard 2.0 (compatible with .NET Framework 4.6.1+, .NET Core 2.0+, and .NET 5+)
diff --git a/src/Microsoft.Data.SqlClient.Internal/Logging/test/VersionChecks.Tests.ps1 b/src/Microsoft.Data.SqlClient.Internal/Logging/test/VersionChecks.Tests.ps1
new file mode 100644
index 0000000000..cc7691c320
--- /dev/null
+++ b/src/Microsoft.Data.SqlClient.Internal/Logging/test/VersionChecks.Tests.ps1
@@ -0,0 +1,364 @@
+# Licensed to the .NET Foundation under one or more agreements.
+# The .NET Foundation licenses this file to you under the MIT license.
+# See the LICENSE file in the project root for more information.
+
+<#
+.SYNOPSIS
+Checks exact family versions and automatic NuGet imports using the real Logging package.
+.DESCRIPTION
+Synthetic projects cover every asset group and packages.config without a database.
+Isolated SDK consumers restore from a private fixture feed/cache, never manually import
+the target, and prove direct and transitive package imports. Other family packages are
+small test fixtures, not production builds. No ordinary project-reference propagation
+is asserted. All scratch files stay under this test directory and are removed.
+#>
+BeforeDiscovery {
+    # Expand the matrix during discovery so each contract has a named Pester result.
+    $family = @('Microsoft.Data.SqlClient.Extensions.Abstractions', 'Microsoft.Data.SqlClient',
+        'Microsoft.Data.SqlClient.Extensions.Azure', 'Microsoft.Data.SqlClient.AlwaysEncrypted.AzureKeyVaultProvider')
+    $syntheticCases = @(
+        foreach ($kind in @('ResolvedCompileFileDefinitions', 'ReferencePath', 'RuntimeCopyLocalItems',
+                'RuntimeTargetsCopyLocalItems', 'packages.config', 'packages.VersionTest.config')) {
+            foreach ($anchorVersion in @('8.0.0', '8.0.0-preview1')) {
+                foreach ($id in $family) {
+                    foreach ($version in @('8.0.0', '8.0.1', '7.1.1', '8.0.0-preview1', '8.0.0-preview2', '1.0.0')) {
+                        @{
+                            Kind = $kind; AnchorVersion = $anchorVersion; Id = $id; Version = $version
+                            OptOut = $false
+                        }
+                        if ($version -ne $anchorVersion) {
+                            # Reuse each mismatching input to prove the emergency opt-out bypasses it.
+                            @{
+                                Kind = $kind; AnchorVersion = $anchorVersion; Id = $id; Version = $version
+                                OptOut = $true
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    )
+    $assetKinds = @(
+        @{ Kind = 'ResolvedCompileFileDefinitions' }
+        @{ Kind = 'ReferencePath' }
+        @{ Kind = 'RuntimeCopyLocalItems' }
+        @{ Kind = 'RuntimeTargetsCopyLocalItems' }
+        @{ Kind = 'packages.config' }
+        @{ Kind = 'packages.VersionTest.config' }
+    )
+    # Exercise the same contracts with Logging referenced directly and through a wrapper package.
+    $consumerCases = @(
+        foreach ($transitive in @($false, $true)) {
+            $mode = if ($transitive) { 'transitive' } else { 'direct' }
+            @{ Name = "$mode-matching"; Transitive = $transitive; Version = '8.0.0-preview1'; Package = ''; Mismatch = $false; Properties = @(); RuntimeOnly = $false; ExcludeBuild = $false }
+            foreach ($id in $family) {
+                @{ Name = "$mode-mixed-$id"; Transitive = $transitive; Version = '8.0.0-preview2'; Package = $id; Mismatch = $true; Properties = @(); RuntimeOnly = $false; ExcludeBuild = $false }
+            }
+            @{ Name = "$mode-opt-out"; Transitive = $transitive; Version = '8.0.0-preview2'; Package = $family[0]; Mismatch = $false; Properties = @('-p:SqlClientEnforceFamilyVersions=false'); RuntimeOnly = $false; ExcludeBuild = $false }
+            @{ Name = "$mode-runtime-only"; Transitive = $transitive; Version = '8.0.0-preview2'; Package = $family[3]; Mismatch = $true; Properties = @(); RuntimeOnly = $true; ExcludeBuild = $false }
+        }
+        @{ Name = 'direct-excluded-build-assets'; Transitive = $false; Version = '8.0.0-preview2'; Package = $family[0]; Mismatch = $false; Properties = @(); RuntimeOnly = $false; ExcludeBuild = $true }
+    )
+}
+
+BeforeAll {
+    $ErrorActionPreference = 'Stop'
+    $targets = [IO.Path]::GetFullPath((Join-Path $PSScriptRoot '../build/Microsoft.Data.SqlClient.Internal.Logging.targets'))
+    $loggingProject = [IO.Path]::GetFullPath((Join-Path $PSScriptRoot '../src/Logging.csproj'))
+    # Stay inside the repo for the real pack's imports; isolate each run from existing fixtures.
+    $work = Join-Path $PSScriptRoot ("version-checks-" + [guid]::NewGuid())
+    $previousTmp = $env:TMPDIR
+    $previousPackages = $env:NUGET_PACKAGES
+    $family = @('Microsoft.Data.SqlClient.Extensions.Abstractions', 'Microsoft.Data.SqlClient',
+        'Microsoft.Data.SqlClient.Extensions.Azure', 'Microsoft.Data.SqlClient.AlwaysEncrypted.AzureKeyVaultProvider')
+    $logging = 'Microsoft.Data.SqlClient.Internal.Logging'
+    $excluded = @('Microsoft.SqlServer.Server', 'Microsoft.Data.SqlClient.SNI', 'Microsoft.Data.SqlClient.SNI.runtime')
+
+    # Execute one command, checking both the exit code and the expected diagnostic.
+    function Invoke-CheckedDotnet {
+        param([string[]] $Arguments, [bool] $Mismatch = $false, [string] $Evidence = '')
+        # Do not leave reusable build workers writing fixture outputs after cleanup.
+        if ($Arguments[0] -in @('pack', 'build', 'restore')) {
+            $Arguments += '--disable-build-servers'
+        } else {
+            $Arguments += '-nodeReuse:false'
+        }
+        $output = & dotnet @Arguments 2>&1
+        $exitCode = $LASTEXITCODE
+        $text = $output -join "`n"
+        if ($Mismatch) {
+            # A restore/compiler failure must not masquerade as the expected version diagnostic.
+            if ($exitCode -eq 0 -or $text -notmatch 'SQLCLIENT001' -or
+                ($Evidence -and -not $text.Contains($Evidence)) -or
+                $text -match 'MSB4096|error (?!SQLCLIENT001)[A-Z]+\d+') {
+                throw "Expected only SQLCLIENT001: dotnet $($Arguments -join ' ')`n$text"
+            }
+        } elseif ($exitCode -ne 0 -or ($Evidence -and -not $text.Contains($Evidence))) {
+            throw "Command failed or evidence missing: dotnet $($Arguments -join ' ')`n$text"
+        }
+        # Keep warnings visible even when a command succeeds.
+        $output | Where-Object { "$_" -match '\bwarning\b' } | ForEach-Object { Write-Host "$_" }
+    }
+
+    # Exercise the target with no SDK: these inputs isolate metadata/filtering regressions.
+    function Test-Synthetic {
+        param([string] $Directory, [string] $AssetKind, [object[]] $Items,
+            [bool] $Mismatch = $false, [string[]] $Properties = @(), [string] $Evidence = '',
+            [string] $ProjectName = 'VersionTest', [object[]] $FallbackItems = @())
+        # Arrange: a fresh project prevents one manifest or asset group leaking into the next case.
+        $project = Join-Path $Directory "$ProjectName.proj"
+        foreach ($name in @('packages.config', 'packages.VersionTest.config', 'packages.Version_Test.config')) {
+            $config = Join-Path $Directory $name
+            if (Test-Path $config) { Remove-Item -LiteralPath $config }
+        }
+        $assets = ''
+        if ($AssetKind -like 'packages*.config') {
+            $entries = ($Items | ForEach-Object { "<package id='$($_.Id)' version='$($_.Version)' />" }) -join ''
+            Set-Content (Join-Path $Directory $AssetKind) "<packages>$entries</packages>"
+            if ($FallbackItems.Count -gt 0) {
+                $entries = ($FallbackItems | ForEach-Object { "<package id='$($_.Id)' version='$($_.Version)' />" }) -join ''
+                Set-Content (Join-Path $Directory 'packages.config') "<packages>$entries</packages>"
+            }
+        } else {
+            $entries = ($Items | ForEach-Object {
+                    "<$AssetKind Include='$($_.Id).dll'><NuGetPackageId>$($_.Id)</NuGetPackageId><NuGetPackageVersion>$($_.Version)</NuGetPackageVersion></$AssetKind>"
+                }) -join ''
+            # All collected item kinds can include framework/project assets with no package metadata.
+            $bare = (@('ResolvedCompileFileDefinitions', 'ReferencePath', 'RuntimeCopyLocalItems', 'RuntimeTargetsCopyLocalItems') |
+                    ForEach-Object { "<$_ Include='MetadataFree-$_.dll' />" }) -join ''
+            $assets = "<ItemGroup>$bare$entries</ItemGroup>"
+        }
+        Set-Content $project "<Project>$assets<Import Project='$targets' /></Project>"
+        # Act/assert: run the real shipped target and require the expected diagnostic, not just failure.
+        Invoke-CheckedDotnet (@('msbuild', $project, '-t:ValidateSqlClientFamilyPackageVersions', '-v:quiet', '-nologo') + $Properties) $Mismatch $Evidence
+    }
+
+    # Pack a minimal SDK library, optionally depending on Logging, into the private feed.
+    function New-FixturePackage {
+        param([string] $Id, [string] $Version, [bool] $Wrapper = $false)
+        $directory = Join-Path $work "$Id-$Version"
+        New-Item -ItemType Directory $directory | Out-Null
+        # Exact ranges prevent restore from choosing another fixture version to repair a mismatch.
+        $dependency = if ($Wrapper) { "<PackageReference Include='$logging' Version='[$anchor]' />" } else { '' }
+        Set-Content (Join-Path $directory 'Fixture.csproj') @"
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <PackageId>$Id</PackageId><AssemblyName>$Id</AssemblyName><Version>$Version</Version>
+    <Authors>SqlClient tests</Authors><Description>Isolated version-validation test fixture.</Description>
+  </PropertyGroup>
+  <ItemGroup>$dependency</ItemGroup>
+</Project>
+"@
+        Invoke-CheckedDotnet @('pack', (Join-Path $directory 'Fixture.csproj'), '-o', $feed,
+            '--configfile', $configFile, '-v:quiet', '-nologo')
+    }
+
+    # Build without an explicit target import, then verify NuGet's generated import and the version anchor.
+    function Test-Consumer {
+        param([string] $Name, [bool] $Transitive, [string] $FamilyVersion,
+            [string] $Package = '', [bool] $Mismatch = $false, [string[]] $Properties = @(),
+            [bool] $RuntimeOnly = $false, [bool] $ExcludeBuild = $false)
+        $directory = Join-Path $work $Name
+        New-Item -ItemType Directory $directory | Out-Null
+        # Arrange: the wrapper makes Logging transitive without importing the target by hand.
+        $rootId = if ($Transitive) { 'SqlClient.VersionChecks.Wrapper' } else { $logging }
+        $rootVersion = if ($Transitive) { '1.0.0' } else { $anchor }
+        $exclude = if ($ExcludeBuild) { "ExcludeAssets='build;buildTransitive'" } else { '' }
+        $references = "<PackageReference Include='$rootId' Version='[$rootVersion]' $exclude />"
+        $installed = if ($Package) { @($Package) } else { $family }
+        foreach ($id in $installed) {
+            # Excluding compile assets forces validation to find runtime-only package evidence.
+            $runtime = if ($RuntimeOnly) { "ExcludeAssets='compile'" } else { '' }
+            $references += "<PackageReference Include='$id' Version='[$FamilyVersion]' $runtime />"
+        }
+        foreach ($id in $excluded) {
+            $references += "<PackageReference Include='$id' Version='[1.0.0]' />"
+        }
+        $project = Join-Path $directory 'Consumer.csproj'
+        Set-Content $project @"
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup><TargetFramework>net10.0</TargetFramework></PropertyGroup>
+  <ItemGroup>$references</ItemGroup>
+  <Target Name="ReportVersionCheck" AfterTargets="ValidateSqlClientFamilyPackageVersions">
+    <Message Importance="high" Text="VERSION_CHECK_ANCHOR=`$(_SqlClientExpectedFamilyVersion)" />
+  </Target>
+</Project>
+"@
+        # Act: restore normally so NuGet, rather than the test, imports the shipped target.
+        Invoke-CheckedDotnet @('restore', $project, '--configfile', $configFile, '-v:quiet', '-nologo')
+        $import = (Get-Content (Join-Path $directory 'obj/Consumer.csproj.nuget.g.targets') -Raw) -replace '\\', '/'
+        if ($ExcludeBuild) {
+            if ($import.Contains('Microsoft.Data.SqlClient.Internal.Logging.targets')) {
+                throw 'Excluded build assets unexpectedly imported the target.'
+            }
+        } else {
+            if (-not $import.Contains('buildTransitive/Microsoft.Data.SqlClient.Internal.Logging.targets') -and
+                -not $import.Contains('build/Microsoft.Data.SqlClient.Internal.Logging.targets')) {
+                throw "NuGet did not import Logging's packaged target for $Name."
+            }
+            if ($Transitive -and -not $import.Contains('buildTransitive/Microsoft.Data.SqlClient.Internal.Logging.targets')) {
+                throw 'Transitive consumer did not import buildTransitive.'
+            }
+            if ($Transitive) {
+                # Prove the transitive case was not accidentally turned into a direct reference.
+                $assets = Get-Content (Join-Path $directory 'obj/project.assets.json') -Raw | ConvertFrom-Json -AsHashtable
+                if ($assets.project.frameworks['net10.0'].dependencies.ContainsKey($logging)) {
+                    throw 'Transitive test accidentally references Logging directly.'
+                }
+            }
+        }
+        # Assert both automatic import and the resolved anchor; an arbitrary build error is not success.
+        $evidence = if ($Mismatch) { $Package } elseif (-not $ExcludeBuild -and $Properties.Count -eq 0) { "VERSION_CHECK_ANCHOR=$anchor" } else { '' }
+        Invoke-CheckedDotnet (@('build', $project, '--no-restore', '-v:minimal', '-nologo') + $Properties) $Mismatch $evidence
+        Write-Host "PASS: consumer $Name (automatic NuGet import, expected mismatch=$Mismatch)"
+    }
+
+    New-Item -ItemType Directory $work | Out-Null
+    $env:TMPDIR = $work
+    $synthetic = Join-Path $work 'synthetic'
+    New-Item -ItemType Directory $synthetic | Out-Null
+}
+
+AfterAll {
+    # Restore process-wide settings even after failures; delete only this run's unique directory.
+    $env:TMPDIR = $previousTmp
+    $env:NUGET_PACKAGES = $previousPackages
+    if ($work -and (Test-Path -LiteralPath $work)) {
+        Remove-Item -LiteralPath $work -Recurse -Force
+    }
+}
+
+Describe 'Synthetic family-version validation' -Tag 'Synthetic' {
+    It '<Kind>: <Id> <Version> against Logging <AnchorVersion> (opt-out: <OptOut>)' -ForEach $syntheticCases {
+        # Arrange matching/mixed family metadata alongside independently versioned packages.
+        $items = @(@{ Id = $logging; Version = $AnchorVersion }, @{ Id = $Id; Version = $Version })
+        $items += $excluded | ForEach-Object { @{ Id = $_; Version = '1.0.0' } }
+        $mismatch = $Version -ne $AnchorVersion -and -not $OptOut
+        $properties = if ($OptOut) { @('-p:SqlClientEnforceFamilyVersions=false') } else { @() }
+        $evidence = if ($mismatch) { $Id } else { '' }
+        # Act/assert through the shipped target rather than reproducing its comparison logic.
+        Test-Synthetic $synthetic $Kind $items $mismatch $properties $evidence
+    }
+
+    It '<Kind>: does not require optional family packages' -ForEach $assetKinds {
+        Test-Synthetic $synthetic $Kind @(@{ Id = $logging; Version = '8.0.0' })
+    }
+
+    It '<Kind>: does not guess a missing Logging anchor' -ForEach $assetKinds {
+        Test-Synthetic $synthetic $Kind @(@{ Id = $family[0]; Version = '1.0.0' })
+    }
+
+    It '<Kind>: skips design-time builds' -ForEach $assetKinds {
+        Test-Synthetic $synthetic $Kind @(
+            @{ Id = $logging; Version = '8.0.0' }, @{ Id = $family[0]; Version = '1.0.0' }
+        ) $false @('-p:DesignTimeBuild=true')
+    }
+
+    It '<Kind>: does not guess missing asset version metadata' -ForEach @(
+        @{ Kind = 'ResolvedCompileFileDefinitions' }
+        @{ Kind = 'ReferencePath' }
+        @{ Kind = 'RuntimeCopyLocalItems' }
+        @{ Kind = 'RuntimeTargetsCopyLocalItems' }
+    ) {
+        Test-Synthetic $synthetic $Kind @(
+            @{ Id = $logging; Version = '8.0.0' }, @{ Id = $family[0]; Version = '' })
+    }
+
+    # Duplicate Logging assets from compile and runtime resolution must not create a false mismatch.
+    It 'accepts duplicate matching Logging assets' {
+        Test-Synthetic $synthetic 'ResolvedCompileFileDefinitions' @(
+            @{ Id = $logging; Version = '8.0.0' }, @{ Id = $logging; Version = '8.0.0' },
+            @{ Id = $family[0]; Version = '8.0.0' })
+    }
+
+    It 'skips a consumer with neither manifest nor package metadata' {
+        Test-Synthetic $synthetic 'ReferencePath' @()
+    }
+}
+
+Describe 'Project-specific legacy manifests' -Tag 'Synthetic', 'LegacyManifest' {
+    # Conflicting manifests expose incorrect selection; matching files alone cannot prove precedence.
+    It 'detects mismatches without a fallback packages.config' {
+        Test-Synthetic $synthetic 'packages.VersionTest.config' @(
+            @{ Id = $logging; Version = '8.0.0' }, @{ Id = $family[0]; Version = '8.0.1' }
+        ) $true @() $family[0]
+    }
+
+    It 'prefers a mismatching project manifest over a matching fallback' {
+        Test-Synthetic $synthetic 'packages.VersionTest.config' @(
+            @{ Id = $logging; Version = '8.0.0' }, @{ Id = $family[0]; Version = '8.0.1' }
+        ) $true @() $family[0] -FallbackItems @(
+            @{ Id = $logging; Version = '8.0.0' }, @{ Id = $family[0]; Version = '8.0.0' })
+    }
+
+    It 'ignores a mismatching fallback when the project manifest matches' {
+        Test-Synthetic $synthetic 'packages.VersionTest.config' @(
+            @{ Id = $logging; Version = '8.0.0' }, @{ Id = $family[0]; Version = '8.0.0' }
+        ) -FallbackItems @(
+            @{ Id = $logging; Version = '8.0.0' }, @{ Id = $family[0]; Version = '8.0.1' })
+    }
+
+    It 'does not take a Logging anchor from an inactive fallback' {
+        # Selection applies to the anchor as well as mismatches; never merge the two manifests.
+        Test-Synthetic $synthetic 'packages.VersionTest.config' @(
+            @{ Id = $family[0]; Version = '8.0.1' }
+        ) -FallbackItems @(
+            @{ Id = $logging; Version = '8.0.0' }, @{ Id = $family[0]; Version = '8.0.1' })
+    }
+
+    It 'normalizes spaces in the project name to underscores' {
+        Test-Synthetic $synthetic 'packages.Version_Test.config' @(
+            @{ Id = $logging; Version = '8.0.0' }, @{ Id = $family[0]; Version = '8.0.1' }
+        ) $true @() $family[0] -ProjectName 'Version Test'
+    }
+}
+
+Describe 'Packaged direct and transitive consumers' -Tag 'Consumer' {
+    BeforeAll {
+        # Arrange once: package the real Logging project, not a substitute targets fixture.
+        $feed = Join-Path $work 'feed'
+        New-Item -ItemType Directory $feed | Out-Null
+        $anchor = '8.0.0-preview1'
+        # Use the real packaging project, preserving its repository props/targets and versioning.
+        Invoke-CheckedDotnet @('pack', $loggingProject, '-c', 'Release', '-o', $feed,
+            "-p:SqlClientPackageVersion=$anchor", '-v:minimal', '-nologo')
+        $packageFile = Join-Path $feed "$logging.$anchor.nupkg"
+        # Install isolation boundaries only after the real pack has consumed repository settings.
+        # Stop ancestor props/targets/CPM and user package caches/feeds from affecting fixture consumers.
+        Set-Content (Join-Path $work 'Directory.Build.props') '<Project />'
+        Set-Content (Join-Path $work 'Directory.Build.targets') '<Project />'
+        Set-Content (Join-Path $work 'Directory.Packages.props') '<Project />'
+        $env:NUGET_PACKAGES = Join-Path $work 'cache'
+        $configFile = Join-Path $work 'NuGet.Config'
+        $escapedFeed = [Security.SecurityElement]::Escape($feed)
+        Set-Content $configFile "<configuration><packageSources><clear /><add key='fixtures' value='$escapedFeed' /></packageSources></configuration>"
+        foreach ($id in $family) {
+            New-FixturePackage $id $anchor
+            New-FixturePackage $id '8.0.0-preview2'
+        }
+        foreach ($id in $excluded) { New-FixturePackage $id '1.0.0' }
+        New-FixturePackage 'SqlClient.VersionChecks.Wrapper' '1.0.0' $true
+    }
+
+    It 'ships the current targets unchanged in <Folder>' -ForEach @(
+        @{ Folder = 'build' }
+        @{ Folder = 'buildTransitive' }
+    ) {
+        # Assert the archive contents, so a stale or omitted target cannot pass consumer checks.
+        $archive = [IO.Compression.ZipFile]::OpenRead($packageFile)
+        try {
+            $folder = $Folder
+            $entry = $archive.GetEntry("$folder/$logging.targets")
+            if (-not $entry) { throw "Missing $folder target in the real Logging package." }
+            $reader = [IO.StreamReader]::new($entry.Open())
+            try { $packed = $reader.ReadToEnd() } finally { $reader.Dispose() }
+            if ($packed -ne (Get-Content $targets -Raw)) { throw "Stale $folder target packaged." }
+        } finally { $archive.Dispose() }
+    }
+
+    It 'validates <Name>' -ForEach $consumerCases {
+        # Restore and build a fresh consumer so generated imports and resolved assets are real.
+        Test-Consumer $Name $Transitive $Version $Package $Mismatch $Properties $RuntimeOnly $ExcludeBuild
+    }
+}