Move IBootstrapperApplication and IBootstrapperEngine into balutil.

17 files changed, 1770 insertions, 18 deletions

diff --git a/src/WixToolset.Mba.Core/BaseBootstrapperApplicationFactory.cs b/src/WixToolset.Mba.Core/BaseBootstrapperApplicationFactory.cs
index 08d2c4d8..20151b71 100644
--- a/src/WixToolset.Mba.Core/BaseBootstrapperApplicationFactory.cs
+++ b/src/WixToolset.Mba.Core/BaseBootstrapperApplicationFactory.cs
@@ -2,8 +2,6 @@
 
 namespace WixToolset.Mba.Core
 {
-    using WixToolset.BootstrapperCore;
-
     public abstract class BaseBootstrapperApplicationFactory : IBootstrapperApplicationFactory
     {
         public IBootstrapperApplication Create(IBootstrapperEngine pEngine, ref Command command)
diff --git a/src/WixToolset.Mba.Core/BootstrapperApplication.cs b/src/WixToolset.Mba.Core/BootstrapperApplication.cs
index 52667923..f8ac2a1e 100644
--- a/src/WixToolset.Mba.Core/BootstrapperApplication.cs
+++ b/src/WixToolset.Mba.Core/BootstrapperApplication.cs
@@ -5,7 +5,6 @@ namespace WixToolset.Mba.Core
     using System;
     using System.Runtime.InteropServices;
     using System.Threading;
-    using WixToolset.BootstrapperCore;
 
     /// <summary>
     /// The default bootstrapper application.
@@ -1574,7 +1573,7 @@ namespace WixToolset.Mba.Core
             return args.HResult;
         }
 
-        int IBootstrapperApplication.BAProc(BOOTSTRAPPER_APPLICATION_MESSAGE message, IntPtr pvArgs, IntPtr pvResults, IntPtr pvContext)
+        int IBootstrapperApplication.BAProc(int message, IntPtr pvArgs, IntPtr pvResults, IntPtr pvContext)
         {
             switch (message)
             {
@@ -1583,7 +1582,7 @@ namespace WixToolset.Mba.Core
             }
         }
 
-        void IBootstrapperApplication.BAProcFallback(BOOTSTRAPPER_APPLICATION_MESSAGE message, IntPtr pvArgs, IntPtr pvResults, ref int phr, IntPtr pvContext)
+        void IBootstrapperApplication.BAProcFallback(int message, IntPtr pvArgs, IntPtr pvResults, ref int phr, IntPtr pvContext)
         {
         }
 
diff --git a/src/WixToolset.Mba.Core/BootstrapperApplicationFactory.cs b/src/WixToolset.Mba.Core/BootstrapperApplicationFactory.cs
index de12ca17..968c6336 100644
--- a/src/WixToolset.Mba.Core/BootstrapperApplicationFactory.cs
+++ b/src/WixToolset.Mba.Core/BootstrapperApplicationFactory.cs
@@ -6,7 +6,6 @@ namespace WixToolset.Mba.Core
     using System.Configuration;
     using System.Reflection;
     using System.Runtime.InteropServices;
-    using WixToolset.BootstrapperCore;
 
     /// <summary>
     /// Entry point for the MBA host to create and return the IBootstrapperApplication implementation to the engine.
diff --git a/src/WixToolset.Mba.Core/BootstrapperCommand.cs b/src/WixToolset.Mba.Core/BootstrapperCommand.cs
index 1ca64924..6854e9ae 100644
--- a/src/WixToolset.Mba.Core/BootstrapperCommand.cs
+++ b/src/WixToolset.Mba.Core/BootstrapperCommand.cs
@@ -5,7 +5,6 @@ namespace WixToolset.Mba.Core
     using System;
     using System.ComponentModel;
     using System.Runtime.InteropServices;
-    using WixToolset.BootstrapperCore;
 
     public sealed class BootstrapperCommand : IBootstrapperCommand
     {
diff --git a/src/WixToolset.Mba.Core/Engine.cs b/src/WixToolset.Mba.Core/Engine.cs
index 2e094bb9..f2cc3947 100644
--- a/src/WixToolset.Mba.Core/Engine.cs
+++ b/src/WixToolset.Mba.Core/Engine.cs
@@ -7,7 +7,6 @@ namespace WixToolset.Mba.Core
     using System.Runtime.InteropServices;
     using System.Security;
     using System.Text;
-    using WixToolset.BootstrapperCore;
 
     /// <summary>
     /// Container class for the <see cref="IBootstrapperEngine"/> interface.
diff --git a/src/WixToolset.Mba.Core/EventArgs.cs b/src/WixToolset.Mba.Core/EventArgs.cs
index 26a3b573..83c0c96a 100644
--- a/src/WixToolset.Mba.Core/EventArgs.cs
+++ b/src/WixToolset.Mba.Core/EventArgs.cs
@@ -5,7 +5,6 @@ namespace WixToolset.Mba.Core
     using System;
     using System.Collections.Generic;
     using System.Collections.ObjectModel;
-    using WixToolset.BootstrapperCore;
 
     /// <summary>
     /// Base class for BA <see cref="EventArgs"/> classes.
diff --git a/src/WixToolset.Mba.Core/IBootstrapperApplication.cs b/src/WixToolset.Mba.Core/IBootstrapperApplication.cs
new file mode 100644
index 00000000..8e5d2aeb
--- /dev/null
+++ b/src/WixToolset.Mba.Core/IBootstrapperApplication.cs
@@ -0,0 +1,834 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Mba.Core
+{
+    using System;
+    using System.CodeDom.Compiler;
+    using System.Runtime.InteropServices;
+
+    /// <summary>
+    /// Allows customization of the bootstrapper application.
+    /// </summary>
+    [ComImport]
+    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    [Guid("53C31D56-49C0-426B-AB06-099D717C67FE")]
+    [GeneratedCodeAttribute("WixToolset.Bootstrapper.InteropCodeGenerator", "1.0.0.0")]
+    public interface IBootstrapperApplication
+    {
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnStartup();
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnShutdown(ref BOOTSTRAPPER_SHUTDOWN_ACTION action);
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnSystemShutdown(
+            [MarshalAs(UnmanagedType.U4)] EndSessionReasons dwEndSession,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectBegin(
+            [MarshalAs(UnmanagedType.Bool)] bool fInstalled,
+            [MarshalAs(UnmanagedType.U4)] int cPackages,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectForwardCompatibleBundle(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzBundleId,
+            [MarshalAs(UnmanagedType.U4)] RelationType relationType,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzBundleTag,
+            [MarshalAs(UnmanagedType.Bool)] bool fPerMachine,
+            [MarshalAs(UnmanagedType.U8)] long dw64Version,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fIgnoreBundle
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectUpdateBegin(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzUpdateLocation,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fSkip
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectUpdate(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzUpdateLocation,
+            [MarshalAs(UnmanagedType.U8)] long dw64Size,
+            [MarshalAs(UnmanagedType.U8)] long dw64Version,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzTitle,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzSummary,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzContentType,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzContent,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fStopProcessingUpdates
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectUpdateComplete(
+            int hrStatus,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fIgnoreError
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectRelatedBundle(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzBundleId,
+            [MarshalAs(UnmanagedType.U4)] RelationType relationType,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzBundleTag,
+            [MarshalAs(UnmanagedType.Bool)] bool fPerMachine,
+            [MarshalAs(UnmanagedType.U8)] long dw64Version,
+            [MarshalAs(UnmanagedType.U4)] RelatedOperation operation,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectPackageBegin(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectCompatibleMsiPackage(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzCompatiblePackageId,
+            [MarshalAs(UnmanagedType.U8)] long dw64CompatiblePackageVersion,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectRelatedMsiPackage(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzUpgradeCode,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzProductCode,
+            [MarshalAs(UnmanagedType.Bool)] bool fPerMachine,
+            [MarshalAs(UnmanagedType.U8)] long dw64Version,
+            [MarshalAs(UnmanagedType.U4)] RelatedOperation operation,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectTargetMsiPackage(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzProductCode,
+            [MarshalAs(UnmanagedType.U4)] PackageState patchState,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectMsiFeature(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzFeatureId,
+            [MarshalAs(UnmanagedType.U4)] FeatureState state,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectPackageComplete(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            int hrStatus,
+            [MarshalAs(UnmanagedType.U4)] PackageState state
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnDetectComplete(
+            int hrStatus
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnPlanBegin(
+            [MarshalAs(UnmanagedType.U4)] int cPackages,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnPlanRelatedBundle(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzBundleId,
+            [MarshalAs(UnmanagedType.U4)] RequestState recommendedState,
+            [MarshalAs(UnmanagedType.U4)] ref RequestState pRequestedState,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnPlanPackageBegin(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.U4)] RequestState recommendedState,
+            [MarshalAs(UnmanagedType.U4)] ref RequestState pRequestedState,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnPlanCompatibleMsiPackageBegin(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzCompatiblePackageId,
+            [MarshalAs(UnmanagedType.U8)] long dw64CompatiblePackageVersion,
+            [MarshalAs(UnmanagedType.U4)] RequestState recommendedState,
+            [MarshalAs(UnmanagedType.U4)] ref RequestState pRequestedState,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnPlanCompatibleMsiPackageComplete(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzCompatiblePackageId,
+            int hrStatus,
+            [MarshalAs(UnmanagedType.U4)] PackageState state,
+            [MarshalAs(UnmanagedType.U4)] RequestState requested,
+            [MarshalAs(UnmanagedType.U4)] ActionState execute,
+            [MarshalAs(UnmanagedType.U4)] ActionState rollback
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnPlanTargetMsiPackage(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzProductCode,
+            [MarshalAs(UnmanagedType.U4)] RequestState recommendedState,
+            [MarshalAs(UnmanagedType.U4)] ref RequestState pRequestedState,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnPlanMsiFeature(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzFeatureId,
+            [MarshalAs(UnmanagedType.U4)] FeatureState recommendedState,
+            [MarshalAs(UnmanagedType.U4)] ref FeatureState pRequestedState,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnPlanPackageComplete(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            int hrStatus,
+            [MarshalAs(UnmanagedType.U4)] PackageState state,
+            [MarshalAs(UnmanagedType.U4)] RequestState requested,
+            [MarshalAs(UnmanagedType.U4)] ActionState execute,
+            [MarshalAs(UnmanagedType.U4)] ActionState rollback
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnPlanComplete(
+            int hrStatus
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnApplyBegin(
+            [MarshalAs(UnmanagedType.U4)] int dwPhaseCount,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnElevateBegin(
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnElevateComplete(
+            int hrStatus
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnProgress(
+            [MarshalAs(UnmanagedType.U4)] int dwProgressPercentage,
+            [MarshalAs(UnmanagedType.U4)] int dwOverallPercentage,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnError(
+            [MarshalAs(UnmanagedType.U4)] ErrorType errorType,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.U4)] int dwCode,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzError,
+            [MarshalAs(UnmanagedType.I4)] int dwUIHint,
+            [MarshalAs(UnmanagedType.U4)] int cData,
+            [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 5, ArraySubType = UnmanagedType.LPWStr), In] string[] rgwzData,
+            [MarshalAs(UnmanagedType.I4)] Result nRecommendation,
+            [MarshalAs(UnmanagedType.I4)] ref Result pResult
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnRegisterBegin(
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnRegisterComplete(
+            int hrStatus
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnCacheBegin(
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnCachePackageBegin(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.U4)] int cCachePayloads,
+            [MarshalAs(UnmanagedType.U8)] long dw64PackageCacheSize,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnCacheAcquireBegin(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageOrContainerId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPayloadId,
+            [MarshalAs(UnmanagedType.U4)] CacheOperation operation,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzSource,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnCacheAcquireProgress(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageOrContainerId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPayloadId,
+            [MarshalAs(UnmanagedType.U8)] long dw64Progress,
+            [MarshalAs(UnmanagedType.U8)] long dw64Total,
+            [MarshalAs(UnmanagedType.U4)] int dwOverallPercentage,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnResolveSource(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageOrContainerId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPayloadId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzLocalSource,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzDownloadSource,
+            BOOTSTRAPPER_RESOLVESOURCE_ACTION recommendation,
+            ref BOOTSTRAPPER_RESOLVESOURCE_ACTION action,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnCacheAcquireComplete(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageOrContainerId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPayloadId,
+            int hrStatus,
+            BOOTSTRAPPER_CACHEACQUIRECOMPLETE_ACTION recommendation,
+            ref BOOTSTRAPPER_CACHEACQUIRECOMPLETE_ACTION pAction
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnCacheVerifyBegin(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPayloadId,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnCacheVerifyComplete(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPayloadId,
+            int hrStatus,
+            BOOTSTRAPPER_CACHEVERIFYCOMPLETE_ACTION recommendation,
+            ref BOOTSTRAPPER_CACHEVERIFYCOMPLETE_ACTION action
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnCachePackageComplete(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            int hrStatus,
+            BOOTSTRAPPER_CACHEPACKAGECOMPLETE_ACTION recommendation,
+            ref BOOTSTRAPPER_CACHEPACKAGECOMPLETE_ACTION action
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnCacheComplete(
+            int hrStatus
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnExecuteBegin(
+            [MarshalAs(UnmanagedType.U4)] int cExecutingPackages,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnExecutePackageBegin(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.Bool)] bool fExecute,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnExecutePatchTarget(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzTargetProductCode,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnExecuteProgress(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.U4)] int dwProgressPercentage,
+            [MarshalAs(UnmanagedType.U4)] int dwOverallPercentage,
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnExecuteMsiMessage(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.U4)] InstallMessage messageType,
+            [MarshalAs(UnmanagedType.I4)] int dwUIHint,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzMessage,
+            [MarshalAs(UnmanagedType.U4)] int cData,
+            [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 4, ArraySubType = UnmanagedType.LPWStr), In] string[] rgwzData,
+            [MarshalAs(UnmanagedType.I4)] Result nRecommendation,
+            [MarshalAs(UnmanagedType.I4)] ref Result pResult
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnExecuteFilesInUse(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            [MarshalAs(UnmanagedType.U4)] int cFiles,
+            [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 1, ArraySubType = UnmanagedType.LPWStr), In] string[] rgwzFiles,
+            [MarshalAs(UnmanagedType.I4)] Result nRecommendation,
+            [MarshalAs(UnmanagedType.I4)] ref Result pResult
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnExecutePackageComplete(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageId,
+            int hrStatus,
+            [MarshalAs(UnmanagedType.U4)] ApplyRestart restart,
+            [MarshalAs(UnmanagedType.I4)] BOOTSTRAPPER_EXECUTEPACKAGECOMPLETE_ACTION recommendation,
+            [MarshalAs(UnmanagedType.I4)] ref BOOTSTRAPPER_EXECUTEPACKAGECOMPLETE_ACTION pAction
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnExecuteComplete(
+            int hrStatus
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnUnregisterBegin(
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnUnregisterComplete(
+            int hrStatus
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnApplyComplete(
+            int hrStatus,
+            [MarshalAs(UnmanagedType.U4)] ApplyRestart restart,
+            [MarshalAs(UnmanagedType.I4)] BOOTSTRAPPER_APPLYCOMPLETE_ACTION recommendation,
+            [MarshalAs(UnmanagedType.I4)] ref BOOTSTRAPPER_APPLYCOMPLETE_ACTION pAction
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnLaunchApprovedExeBegin(
+            [MarshalAs(UnmanagedType.Bool)] ref bool fCancel
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int OnLaunchApprovedExeComplete(
+            int hrStatus,
+            int processId
+            );
+
+        [PreserveSig]
+        [return: MarshalAs(UnmanagedType.I4)]
+        int BAProc(
+            int message,
+            IntPtr pvArgs,
+            IntPtr pvResults,
+            IntPtr pvContext
+            );
+
+        void BAProcFallback(
+            int message,
+            IntPtr pvArgs,
+            IntPtr pvResults,
+            ref int phr,
+            IntPtr pvContext
+            );
+    }
+
+    /// <summary>
+    /// The display level for the BA.
+    /// </summary>
+    public enum Display
+    {
+        Unknown,
+        Embedded,
+        None,
+        Passive,
+        Full,
+    }
+
+    /// <summary>
+    /// Messages from Windows Installer.
+    /// </summary>
+    public enum InstallMessage
+    {
+        FatalExit,
+        Error = 0x01000000,
+        Warning = 0x02000000,
+        User = 0x03000000,
+        Info = 0x04000000,
+        FilesInUse = 0x05000000,
+        ResolveSource = 0x06000000,
+        OutOfDiskSpace = 0x07000000,
+        ActionStart = 0x08000000,
+        ActionData = 0x09000000,
+        Progress = 0x0a000000,
+        CommonData = 0x0b000000,
+        Initialize = 0x0c000000,
+        Terminate = 0x0d000000,
+        ShowDialog = 0x0e000000,
+        RMFilesInUse = 0x19000000,
+    }
+
+    /// <summary>
+    /// The action to perform when a reboot is necessary.
+    /// </summary>
+    public enum Restart
+    {
+        Unknown,
+        Never,
+        Prompt,
+        Automatic,
+        Always,
+    }
+
+    /// <summary>
+    /// Result codes.
+    /// </summary>
+    public enum Result
+    {
+        Error = -1,
+        None,
+        Ok,
+        Cancel,
+        Abort,
+        Retry,
+        Ignore,
+        Yes,
+        No,
+        Close,
+        Help,
+        TryAgain,
+        Continue,
+    }
+
+    /// <summary>
+    /// Describes why a bundle or packaged is being resumed.
+    /// </summary>
+    public enum ResumeType
+    {
+        None,
+
+        /// <summary>
+        /// Resume information exists but is invalid.
+        /// </summary>
+        Invalid,
+
+        /// <summary>
+        /// The bundle was re-launched after an unexpected interruption.
+        /// </summary>
+        Interrupted,
+
+        /// <summary>
+        /// A reboot is pending.
+        /// </summary>
+        RebootPending,
+
+        /// <summary>
+        /// The bundle was re-launched after a reboot.
+        /// </summary>
+        Reboot,
+
+        /// <summary>
+        /// The bundle was re-launched after being suspended.
+        /// </summary>
+        Suspend,
+
+        /// <summary>
+        /// The bundle was launched from Add/Remove Programs.
+        /// </summary>
+        Arp,
+    }
+
+    /// <summary>
+    /// Indicates what caused the error.
+    /// </summary>
+    public enum ErrorType
+    {
+        /// <summary>
+        /// The error occurred trying to elevate.
+        /// </summary>
+        Elevate,
+
+        /// <summary>
+        /// The error came from the Windows Installer.
+        /// </summary>
+        WindowsInstaller,
+
+        /// <summary>
+        /// The error came from an EXE Package.
+        /// </summary>
+        ExePackage,
+
+        /// <summary>
+        /// The error came while trying to authenticate with an HTTP server.
+        /// </summary>
+        HttpServerAuthentication,
+
+        /// <summary>
+        /// The error came while trying to authenticate with an HTTP proxy.
+        /// </summary>
+        HttpProxyAuthentication,
+
+        /// <summary>
+        /// The error occurred during apply.
+        /// </summary>
+        Apply,
+    };
+
+    public enum RelatedOperation
+    {
+        None,
+
+        /// <summary>
+        /// The related bundle or package will be downgraded.
+        /// </summary>
+        Downgrade,
+
+        /// <summary>
+        /// The related package will be upgraded as a minor revision.
+        /// </summary>
+        MinorUpdate,
+
+        /// <summary>
+        /// The related bundle or package will be upgraded as a major revision.
+        /// </summary>
+        MajorUpgrade,
+
+        /// <summary>
+        /// The related bundle will be removed.
+        /// </summary>
+        Remove,
+
+        /// <summary>
+        /// The related bundle will be installed.
+        /// </summary>
+        Install,
+
+        /// <summary>
+        /// The related bundle will be repaired.
+        /// </summary>
+        Repair,
+    };
+
+    /// <summary>
+    /// The cache operation used to acquire a container or payload.
+    /// </summary>
+    public enum CacheOperation
+    {
+        /// <summary>
+        /// Container or payload is being copied.
+        /// </summary>
+        Copy,
+
+        /// <summary>
+        /// Container or payload is being downloaded.
+        /// </summary>
+        Download,
+
+        /// <summary>
+        /// Container or payload is being extracted.
+        /// </summary>
+        Extract
+    }
+
+    /// <summary>
+    /// The restart state after a package or all packages were applied.
+    /// </summary>
+    public enum ApplyRestart
+    {
+        /// <summary>
+        /// Package or chain does not require a restart.
+        /// </summary>
+        None,
+
+        /// <summary>
+        /// Package or chain requires a restart but it has not been initiated yet.
+        /// </summary>
+        RestartRequired,
+
+        /// <summary>
+        /// Package or chain has already initiated the restart.
+        /// </summary>
+        RestartInitiated
+    }
+
+    /// <summary>
+    /// The relation type for related bundles.
+    /// </summary>
+    public enum RelationType
+    {
+        None,
+        Detect,
+        Upgrade,
+        Addon,
+        Patch,
+        Dependent,
+        Update,
+    }
+
+    /// <summary>
+    /// One or more reasons why the application is requested to be closed or is being closed.
+    /// </summary>
+    [Flags]
+    public enum EndSessionReasons
+    {
+        /// <summary>
+        /// The system is shutting down or restarting (it is not possible to determine which event is occurring).
+        /// </summary>
+        Unknown,
+
+        /// <summary>
+        /// The application is using a file that must be replaced, the system is being serviced, or system resources are exhausted.
+        /// </summary>
+        CloseApplication,
+
+        /// <summary>
+        /// The application is forced to shut down.
+        /// </summary>
+        Critical = 0x40000000,
+
+        /// <summary>
+        /// The user is logging off.
+        /// </summary>
+        Logoff = unchecked((int)0x80000000)
+    }
+
+    /// <summary>
+    /// The available actions for OnApplyComplete.
+    /// </summary>
+    public enum BOOTSTRAPPER_APPLYCOMPLETE_ACTION
+    {
+        None,
+        Restart,
+    }
+
+    /// <summary>
+    /// The available actions for OnCacheAcquireComplete.
+    /// </summary>
+    public enum BOOTSTRAPPER_CACHEACQUIRECOMPLETE_ACTION
+    {
+        None,
+        Retry,
+    }
+
+    /// <summary>
+    /// The available actions for OnCachePackageComplete.
+    /// </summary>
+    public enum BOOTSTRAPPER_CACHEPACKAGECOMPLETE_ACTION
+    {
+        None,
+        Ignore,
+        Retry,
+    }
+
+    /// <summary>
+    /// The available actions for OnCacheVerifyComplete.
+    /// </summary>
+    public enum BOOTSTRAPPER_CACHEVERIFYCOMPLETE_ACTION
+    {
+        None,
+        RetryVerification,
+        RetryAcquisition,
+    }
+
+    /// <summary>
+    /// The available actions for OnExecutePackageComplete.
+    /// </summary>
+    public enum BOOTSTRAPPER_EXECUTEPACKAGECOMPLETE_ACTION
+    {
+        None,
+        Ignore,
+        Retry,
+        Restart,
+        Suspend,
+    }
+
+    /// <summary>
+    /// The available actions for OnResolveSource.
+    /// </summary>
+    public enum BOOTSTRAPPER_RESOLVESOURCE_ACTION
+    {
+        None,
+        Retry,
+        Download,
+    }
+
+    /// <summary>
+    /// The available actions for OnShutdown.
+    /// </summary>
+    public enum BOOTSTRAPPER_SHUTDOWN_ACTION
+    {
+        None,
+        Restart,
+        ReloadBootstrapper,
+    }
+}
diff --git a/src/WixToolset.Mba.Core/IBootstrapperApplicationFactory.cs b/src/WixToolset.Mba.Core/IBootstrapperApplicationFactory.cs
index 6dd4af72..f5d4c705 100644
--- a/src/WixToolset.Mba.Core/IBootstrapperApplicationFactory.cs
+++ b/src/WixToolset.Mba.Core/IBootstrapperApplicationFactory.cs
@@ -5,7 +5,6 @@ namespace WixToolset.Mba.Core
     using System;
     using System.CodeDom.Compiler;
     using System.Runtime.InteropServices;
-    using WixToolset.BootstrapperCore;
 
     [ComVisible(true)]
     [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
diff --git a/src/WixToolset.Mba.Core/IBootstrapperCommand.cs b/src/WixToolset.Mba.Core/IBootstrapperCommand.cs
index fc7d1fc2..675abdf9 100644
--- a/src/WixToolset.Mba.Core/IBootstrapperCommand.cs
+++ b/src/WixToolset.Mba.Core/IBootstrapperCommand.cs
@@ -3,7 +3,6 @@
 namespace WixToolset.Mba.Core
 {
     using System;
-    using WixToolset.BootstrapperCore;
 
     /// <summary>
     /// Command information passed from the engine for the BA to perform.
diff --git a/src/WixToolset.Mba.Core/IBootstrapperEngine.cs b/src/WixToolset.Mba.Core/IBootstrapperEngine.cs
new file mode 100644
index 00000000..d070998e
--- /dev/null
+++ b/src/WixToolset.Mba.Core/IBootstrapperEngine.cs
@@ -0,0 +1,279 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+namespace WixToolset.Mba.Core
+{
+    using System;
+    using System.CodeDom.Compiler;
+    using System.Runtime.InteropServices;
+    using System.Text;
+
+    /// <summary>
+    /// Allows calls into the bootstrapper engine.
+    /// </summary>
+    [ComImport]
+    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
+    [Guid("6480D616-27A0-44D7-905B-81512C29C2FB")]
+    [GeneratedCodeAttribute("WixToolset.Bootstrapper.InteropCodeGenerator", "1.0.0.0")]
+    public interface IBootstrapperEngine
+    {
+        void GetPackageCount(
+            [MarshalAs(UnmanagedType.U4)] out int pcPackages
+            );
+
+        [PreserveSig]
+        int GetVariableNumeric(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzVariable,
+            out long pllValue
+            );
+
+        [PreserveSig]
+        int GetVariableString(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzVariable,
+                                              IntPtr wzValue,
+            [MarshalAs(UnmanagedType.U4)] ref int pcchValue
+            );
+
+        [PreserveSig]
+        int GetVariableVersion(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzVariable,
+            [MarshalAs(UnmanagedType.U8)] out long pqwValue
+            );
+
+        [PreserveSig]
+        int FormatString(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzIn,
+            [MarshalAs(UnmanagedType.LPWStr), Out] StringBuilder wzOut,
+            [MarshalAs(UnmanagedType.U4)] ref int pcchOut
+            );
+
+        [PreserveSig]
+        int EscapeString(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzIn,
+            [MarshalAs(UnmanagedType.LPWStr), Out] StringBuilder wzOut,
+            [MarshalAs(UnmanagedType.U4)] ref int pcchOut
+            );
+
+        void EvaluateCondition(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzCondition,
+            [MarshalAs(UnmanagedType.Bool)] out bool pf
+            );
+
+        void Log(
+            [MarshalAs(UnmanagedType.U4)] LogLevel level,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzMessage
+            );
+
+        void SendEmbeddedError(
+            [MarshalAs(UnmanagedType.U4)] int dwErrorCode,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzMessage,
+            [MarshalAs(UnmanagedType.U4)] int dwUIHint,
+            [MarshalAs(UnmanagedType.I4)] out int pnResult
+            );
+
+        void SendEmbeddedProgress(
+            [MarshalAs(UnmanagedType.U4)] int dwProgressPercentage,
+            [MarshalAs(UnmanagedType.U4)] int dwOverallProgressPercentage,
+            [MarshalAs(UnmanagedType.I4)] out int pnResult
+            );
+
+        void SetUpdate(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzLocalSource,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzDownloadSource,
+            [MarshalAs(UnmanagedType.U8)] long qwValue,
+            [MarshalAs(UnmanagedType.U4)] UpdateHashType hashType,
+            [MarshalAs(UnmanagedType.LPArray, SizeParamIndex=4)] byte[] rgbHash,
+            [MarshalAs(UnmanagedType.U4)] int cbHash
+            );
+
+        void SetLocalSource(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageOrContainerId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPayloadId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPath
+            );
+
+        void SetDownloadSource(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPackageOrContainerId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPayloadId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzUrl,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzUser,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzPassword
+            );
+
+        void SetVariableNumeric(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzVariable,
+            long llValue
+            );
+
+        void SetVariableString(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzVariable,
+                                              IntPtr wzValue
+            );
+
+        void SetVariableVersion(
+            [MarshalAs(UnmanagedType.LPWStr)] string wzVariable,
+            [MarshalAs(UnmanagedType.U8)] long qwValue
+            );
+
+        void CloseSplashScreen();
+
+        void Detect(
+            IntPtr hwndParent
+            );
+
+        void Plan(
+            [MarshalAs(UnmanagedType.U4)] LaunchAction action
+            );
+
+        [PreserveSig]
+        int Elevate(
+            IntPtr hwndParent
+            );
+
+        void Apply(
+            IntPtr hwndParent
+            );
+
+        void Quit(
+            [MarshalAs(UnmanagedType.U4)] int dwExitCode
+            );
+
+        void LaunchApprovedExe(
+            IntPtr hwndParent,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzApprovedExeForElevationId,
+            [MarshalAs(UnmanagedType.LPWStr)] string wzArguments,
+            [MarshalAs(UnmanagedType.U4)] int dwWaitForInputIdleTimeout
+            );
+    }
+
+    /// <summary>
+    /// The installation action for the bundle or current package.
+    /// </summary>
+    public enum ActionState
+    {
+        None,
+        Uninstall,
+        Install,
+        AdminInstall,
+        Modify,
+        Repair,
+        MinorUpgrade,
+        MajorUpgrade,
+        Patch,
+    }
+
+    /// <summary>
+    /// The action for the BA to perform.
+    /// </summary>
+    public enum LaunchAction
+    {
+        Unknown,
+        Help,
+        Layout,
+        Uninstall,
+        Cache,
+        Install,
+        Modify,
+        Repair,
+        UpdateReplace,
+        UpdateReplaceEmbedded,
+    }
+
+    /// <summary>
+    /// The message log level.
+    /// </summary>
+    public enum LogLevel
+    {
+        /// <summary>
+        /// No logging level (generic).
+        /// </summary>
+        None,
+
+        /// <summary>
+        /// User messages.
+        /// </summary>
+        Standard,
+
+        /// <summary>
+        /// Verbose messages.
+        /// </summary>
+        Verbose,
+
+        /// <summary>
+        /// Messages for debugging.
+        /// </summary>
+        Debug,
+
+        /// <summary>
+        /// Error messages.
+        /// </summary>
+        Error,
+    }
+
+    /// <summary>
+    /// Type of hash used for update bundle.
+    /// </summary>
+    public enum UpdateHashType
+    {
+        /// <summary>
+        /// No hash provided.
+        /// </summary>
+        None,
+
+        /// <summary>
+        /// SHA-1 based hash provided.
+        /// </summary>
+        Sha1,
+    }
+
+    /// <summary>
+    /// Describes the state of an installation package.
+    /// </summary>
+    public enum PackageState
+    {
+        Unknown,
+        Obsolete,
+        Absent,
+        Cached,
+        Present,
+        Superseded,
+    }
+
+    /// <summary>
+    /// Indicates the state desired for an installation package.
+    /// </summary>
+    public enum RequestState
+    {
+        None,
+        ForceAbsent,
+        Absent,
+        Cache,
+        Present,
+        Repair,
+    }
+
+    /// <summary>
+    /// Indicates the state of a feature.
+    /// </summary>
+    public enum FeatureState
+    {
+        Unknown,
+        Absent,
+        Advertised,
+        Local,
+        Source,
+    }
+
+    /// <summary>
+    /// Indicates the action for a feature.
+    /// </summary>
+    public enum FeatureAction
+    {
+        None,
+        AddLocal,
+        AddSource,
+        AddDefault,
+        Reinstall,
+        Advertise,
+        Remove,
+    }
+}
diff --git a/src/WixToolset.Mba.Core/IDefaultBootstrapperApplication.cs b/src/WixToolset.Mba.Core/IDefaultBootstrapperApplication.cs
index ee290865..9bea6418 100644
--- a/src/WixToolset.Mba.Core/IDefaultBootstrapperApplication.cs
+++ b/src/WixToolset.Mba.Core/IDefaultBootstrapperApplication.cs
@@ -3,7 +3,6 @@
 namespace WixToolset.Mba.Core
 {
     using System;
-    using WixToolset.BootstrapperCore;
 
     public interface IDefaultBootstrapperApplication : IBootstrapperApplication
     {
diff --git a/src/WixToolset.Mba.Core/IEngine.cs b/src/WixToolset.Mba.Core/IEngine.cs
index 6aef50b3..5ddc4176 100644
--- a/src/WixToolset.Mba.Core/IEngine.cs
+++ b/src/WixToolset.Mba.Core/IEngine.cs
@@ -5,7 +5,6 @@ namespace WixToolset.Mba.Core
     using System;
     using System.ComponentModel;
     using System.Security;
-    using WixToolset.BootstrapperCore;
 
     public interface IEngine
     {
diff --git a/src/WixToolset.Mba.Core/PackageInfo.cs b/src/WixToolset.Mba.Core/PackageInfo.cs
index 9bc21923..46894d2e 100644
--- a/src/WixToolset.Mba.Core/PackageInfo.cs
+++ b/src/WixToolset.Mba.Core/PackageInfo.cs
@@ -6,7 +6,6 @@ namespace WixToolset.Mba.Core
     using System.Collections.Generic;
     using System.Xml;
     using System.Xml.XPath;
-    using WixToolset.BootstrapperCore;
 
     public enum CacheType
     {
diff --git a/src/WixToolset.Mba.Core/WixToolset.Mba.Core.csproj b/src/WixToolset.Mba.Core/WixToolset.Mba.Core.csproj
index 16d278b0..05d042c3 100644
--- a/src/WixToolset.Mba.Core/WixToolset.Mba.Core.csproj
+++ b/src/WixToolset.Mba.Core/WixToolset.Mba.Core.csproj
@@ -35,9 +35,11 @@
     <Compile Include="EventArgs.cs" />
     <Compile Include="Exceptions.cs" />
     <Compile Include="HostSection.cs" />
+    <Compile Include="IBootstrapperApplication.cs" />
     <Compile Include="IBootstrapperApplicationData.cs" />
     <Compile Include="IBootstrapperApplicationFactory.cs" />
     <Compile Include="IBootstrapperCommand.cs" />
+    <Compile Include="IBootstrapperEngine.cs" />
     <Compile Include="IBundleInfo.cs" />
     <Compile Include="IDefaultBootstrapperApplication.cs" />
     <Compile Include="IEngine.cs" />
@@ -62,9 +64,6 @@
     <Reference Include="System.Configuration" />
     <Reference Include="System.Data" />
     <Reference Include="System.Xml" />
-    <Reference Include="WixToolset.BootstrapperCore">
-      <HintPath>..\..\packages\WixToolset.BootstrapperCore.4.0.8\lib\net20\WixToolset.BootstrapperCore.dll</HintPath>
-    </Reference>
   </ItemGroup>
   <ItemGroup>
     <HeaderPath Include="$(BaseOutputPath)$(Configuration)\$(AssemblyName).h">
diff --git a/src/WixToolset.Mba.Core/packages.config b/src/WixToolset.Mba.Core/packages.config
index 3702a604..03e866cf 100644
--- a/src/WixToolset.Mba.Core/packages.config
+++ b/src/WixToolset.Mba.Core/packages.config
@@ -1,5 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Nerdbank.GitVersioning" version="2.1.65" targetFramework="net20" developmentDependency="true" />
-  <package id="WixToolset.BootstrapperCore" version="4.0.8" targetFramework="net20" />
 </packages>
\ No newline at end of file
diff --git a/src/balutil/inc/IBootstrapperApplication.h b/src/balutil/inc/IBootstrapperApplication.h
new file mode 100644
index 00000000..6ab7ed20
--- /dev/null
+++ b/src/balutil/inc/IBootstrapperApplication.h
@@ -0,0 +1,525 @@
+#pragma once
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+
+DECLARE_INTERFACE_IID_(IBootstrapperApplication, IUnknown, "53C31D56-49C0-426B-AB06-099D717C67FE")
+{
+    // OnStartup - called when the engine is ready for the bootstrapper application to start.
+    //
+    STDMETHOD(OnStartup)() = 0;
+
+    // OnShutdown - called after the bootstrapper application quits the engine.
+    STDMETHOD(OnShutdown)(
+        __inout BOOTSTRAPPER_SHUTDOWN_ACTION* pAction
+        ) = 0;
+
+    // OnSystemShutdown - called when the operating system is instructed to shutdown the machine.
+    STDMETHOD(OnSystemShutdown)(
+        __in DWORD dwEndSession,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnDetectBegin - called when the engine begins detection.
+    STDMETHOD(OnDetectBegin)(
+        __in BOOL fInstalled,
+        __in DWORD cPackages,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnDetectForwardCompatibleBundle - called when the engine detects a forward compatible bundle.
+    STDMETHOD(OnDetectForwardCompatibleBundle)(
+        __in_z LPCWSTR wzBundleId,
+        __in BOOTSTRAPPER_RELATION_TYPE relationType,
+        __in_z LPCWSTR wzBundleTag,
+        __in BOOL fPerMachine,
+        __in DWORD64 dw64Version,
+        __inout BOOL* pfCancel,
+        __inout BOOL* pfIgnoreBundle
+        ) = 0;
+
+    // OnDetectUpdateBegin - called when the engine begins detection for bundle update.
+    STDMETHOD(OnDetectUpdateBegin)(
+        __in_z LPCWSTR wzUpdateLocation,
+        __inout BOOL* pfCancel,
+        __inout BOOL* pfSkip
+        ) = 0;
+
+    // OnDetectUpdate - called when the engine has an update candidate for bundle update.
+    STDMETHOD(OnDetectUpdate)(
+        __in_z_opt LPCWSTR wzUpdateLocation,
+        __in DWORD64 dw64Size,
+        __in DWORD64 dw64Version,
+        __in_z_opt LPCWSTR wzTitle,
+        __in_z_opt LPCWSTR wzSummary,
+        __in_z_opt LPCWSTR wzContentType,
+        __in_z_opt LPCWSTR wzContent,
+        __inout BOOL* pfCancel,
+        __inout BOOL* pfStopProcessingUpdates
+        ) = 0;
+
+    // OnDetectUpdateComplete - called when the engine completes detection for bundle update.
+    STDMETHOD(OnDetectUpdateComplete)(
+        __in HRESULT hrStatus,
+        __inout BOOL* pfIgnoreError
+        ) = 0;
+
+    // OnDetectRelatedBundle - called when the engine detects a related bundle.
+    STDMETHOD(OnDetectRelatedBundle)(
+        __in_z LPCWSTR wzBundleId,
+        __in BOOTSTRAPPER_RELATION_TYPE relationType,
+        __in_z LPCWSTR wzBundleTag,
+        __in BOOL fPerMachine,
+        __in DWORD64 dw64Version,
+        __in BOOTSTRAPPER_RELATED_OPERATION operation,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnDetectPackageBegin - called when the engine begins detecting a package.
+    STDMETHOD(OnDetectPackageBegin)(
+        __in_z LPCWSTR wzPackageId,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnDetectCompatibleMsiPackage - called when the engine detects that a package is not installed but a newer package using the same provider key is.
+    STDMETHOD(OnDetectCompatibleMsiPackage)(
+        __in_z LPCWSTR wzPackageId,
+        __in_z LPCWSTR wzCompatiblePackageId,
+        __in DWORD64 dw64CompatiblePackageVersion,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnDetectRelatedMsiPackage - called when the engine begins detects a related package.
+    STDMETHOD(OnDetectRelatedMsiPackage)(
+        __in_z LPCWSTR wzPackageId,
+        __in_z LPCWSTR wzUpgradeCode,
+        __in_z LPCWSTR wzProductCode,
+        __in BOOL fPerMachine,
+        __in DWORD64 dw64Version,
+        __in BOOTSTRAPPER_RELATED_OPERATION operation,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnDetectTargetMsiPackage - called when the engine detects a target MSI package for
+    //                            an MSP package.
+    STDMETHOD(OnDetectTargetMsiPackage)(
+        __in_z LPCWSTR wzPackageId,
+        __in_z LPCWSTR wzProductCode,
+        __in BOOTSTRAPPER_PACKAGE_STATE patchState,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnDetectMsiFeature - called when the engine detects a feature in an MSI package.
+    STDMETHOD(OnDetectMsiFeature)(
+        __in_z LPCWSTR wzPackageId,
+        __in_z LPCWSTR wzFeatureId,
+        __in BOOTSTRAPPER_FEATURE_STATE state,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnDetectPackageComplete - called after the engine detects a package.
+    //
+    STDMETHOD(OnDetectPackageComplete)(
+        __in_z LPCWSTR wzPackageId,
+        __in HRESULT hrStatus,
+        __in BOOTSTRAPPER_PACKAGE_STATE state
+        ) = 0;
+
+    // OnDetectPackageComplete - called after the engine completes detection.
+    //
+    STDMETHOD(OnDetectComplete)(
+        __in HRESULT hrStatus
+        ) = 0;
+
+    // OnPlanBegin - called when the engine begins planning.
+    STDMETHOD(OnPlanBegin)(
+        __in DWORD cPackages,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnPlanRelatedBundle - called when the engine begins planning a related bundle.
+    STDMETHOD(OnPlanRelatedBundle)(
+        __in_z LPCWSTR wzBundleId,
+        __in BOOTSTRAPPER_REQUEST_STATE recommendedState,
+        __inout BOOTSTRAPPER_REQUEST_STATE* pRequestedState,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnPlanPackageBegin - called when the engine begins planning a package.
+    STDMETHOD(OnPlanPackageBegin)(
+        __in_z LPCWSTR wzPackageId,
+        __in BOOTSTRAPPER_REQUEST_STATE recommendedState,
+        __inout BOOTSTRAPPER_REQUEST_STATE* pRequestedState,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnPlanCompatibleMsiPackageBegin - called when the engine plans a newer, compatible package using the same provider key.
+    STDMETHOD(OnPlanCompatibleMsiPackageBegin)(
+        __in_z LPCWSTR wzPackageId,
+        __in_z LPCWSTR wzCompatiblePackageId,
+        __in DWORD64 dw64CompatiblePackageVersion,
+        __in BOOTSTRAPPER_REQUEST_STATE recommendedState,
+        __inout BOOTSTRAPPER_REQUEST_STATE* pRequestedState,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnPlanCompatibleMsiPackageComplete - called after the engine plans the package.
+    //
+    STDMETHOD(OnPlanCompatibleMsiPackageComplete)(
+        __in_z LPCWSTR wzPackageId,
+        __in_z LPCWSTR wzCompatiblePackageId,
+        __in HRESULT hrStatus,
+        __in BOOTSTRAPPER_PACKAGE_STATE state,
+        __in BOOTSTRAPPER_REQUEST_STATE requested,
+        __in BOOTSTRAPPER_ACTION_STATE execute,
+        __in BOOTSTRAPPER_ACTION_STATE rollback
+        ) = 0;
+
+    // OnPlanTargetMsiPackage - called when the engine plans an MSP package
+    //                          to apply to an MSI package.
+    STDMETHOD(OnPlanTargetMsiPackage)(
+        __in_z LPCWSTR wzPackageId,
+        __in_z LPCWSTR wzProductCode,
+        __in BOOTSTRAPPER_REQUEST_STATE recommendedState,
+        __inout BOOTSTRAPPER_REQUEST_STATE* pRequestedState,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnPlanMsiFeature - called when the engine plans a feature in an
+    //                    MSI package.
+    STDMETHOD(OnPlanMsiFeature)(
+        __in_z LPCWSTR wzPackageId,
+        __in_z LPCWSTR wzFeatureId,
+        __in BOOTSTRAPPER_FEATURE_STATE recommendedState,
+        __inout BOOTSTRAPPER_FEATURE_STATE* pRequestedState,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnPlanPackageComplete - called after the engine plans a package.
+    //
+    STDMETHOD(OnPlanPackageComplete)(
+        __in_z LPCWSTR wzPackageId,
+        __in HRESULT hrStatus,
+        __in BOOTSTRAPPER_PACKAGE_STATE state,
+        __in BOOTSTRAPPER_REQUEST_STATE requested,
+        __in BOOTSTRAPPER_ACTION_STATE execute,
+        __in BOOTSTRAPPER_ACTION_STATE rollback
+        ) = 0;
+
+    // OnPlanComplete - called when the engine completes planning.
+    //
+    STDMETHOD(OnPlanComplete)(
+        __in HRESULT hrStatus
+        ) = 0;
+
+    // OnApplyBegin - called when the engine begins applying the plan.
+    //
+    STDMETHOD(OnApplyBegin)(
+        __in DWORD dwPhaseCount,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnElevateBegin - called before the engine displays an elevation prompt.
+    //                  Will only happen once per execution of the engine,
+    //                  assuming the elevation was successful.
+    STDMETHOD(OnElevateBegin)(
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnElevateComplete - called after the engine attempted to elevate.
+    //
+    STDMETHOD(OnElevateComplete)(
+        __in HRESULT hrStatus
+        ) = 0;
+
+    // OnProgress - called when the engine makes progress.
+    //
+    STDMETHOD(OnProgress)(
+        __in DWORD dwProgressPercentage,
+        __in DWORD dwOverallPercentage,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnError - called when the engine encounters an error.
+    //
+    // nResult:
+    //  uiFlags is a combination of valid ID* return values appropriate for
+    //          the error.
+    //
+    //  IDNOACTION instructs the engine to pass the error through to default
+    //             handling which usually results in the apply failing.
+    STDMETHOD(OnError)(
+        __in BOOTSTRAPPER_ERROR_TYPE errorType,
+        __in_z_opt LPCWSTR wzPackageId,
+        __in DWORD dwCode,
+        __in_z_opt LPCWSTR wzError,
+        __in DWORD dwUIHint,
+        __in DWORD cData,
+        __in_ecount_z_opt(cData) LPCWSTR* rgwzData,
+        __in int nRecommendation,
+        __inout int* pResult
+        ) = 0;
+
+    // OnRegisterBegin - called when the engine registers the bundle.
+    //
+    STDMETHOD(OnRegisterBegin)(
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnRegisterComplete - called when the engine registration is
+    //                      complete.
+    //
+    STDMETHOD(OnRegisterComplete)(
+        __in HRESULT hrStatus
+        ) = 0;
+
+    // OnCacheBegin - called when the engine begins caching.
+    //
+    STDMETHOD(OnCacheBegin)(
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnCachePackageBegin - called when the engine begins caching
+    //                       a package.
+    //
+    STDMETHOD(OnCachePackageBegin)(
+        __in_z LPCWSTR wzPackageId,
+        __in DWORD cCachePayloads,
+        __in DWORD64 dw64PackageCacheSize,
+        __inout BOOL* pfCancel
+        )  = 0;
+
+    // OnCacheAcquireBegin - called when the engine begins copying or
+    //                       downloading a payload to the working folder.
+    //
+    STDMETHOD(OnCacheAcquireBegin)(
+        __in_z_opt LPCWSTR wzPackageOrContainerId,
+        __in_z_opt LPCWSTR wzPayloadId,
+        __in BOOTSTRAPPER_CACHE_OPERATION operation,
+        __in_z LPCWSTR wzSource,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnCacheAcquireProgress - called when the engine makes progresss copying
+    //                          or downloading a payload to the working folder.
+    //
+    STDMETHOD(OnCacheAcquireProgress)(
+        __in_z_opt LPCWSTR wzPackageOrContainerId,
+        __in_z_opt LPCWSTR wzPayloadId,
+        __in DWORD64 dw64Progress,
+        __in DWORD64 dw64Total,
+        __in DWORD dwOverallPercentage,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnResolveSource - called when a payload or container cannot be found locally.
+    //
+    // Parameters:
+    //  wzPayloadId will be NULL when resolving a container.
+    //  wzDownloadSource will be NULL if the container or payload does not provide a DownloadURL.
+    //
+    // Notes:
+    //  It is expected the BA may call IBootstrapperEngine::SetLocalSource() or IBootstrapperEngine::SetDownloadSource()
+    //  to update the source location before returning BOOTSTRAPPER_RESOLVESOURCE_ACTION_RETRY or BOOTSTRAPPER_RESOLVESOURCE_ACTION_DOWNLOAD.
+    STDMETHOD(OnResolveSource)(
+        __in_z LPCWSTR wzPackageOrContainerId,
+        __in_z_opt LPCWSTR wzPayloadId,
+        __in_z LPCWSTR wzLocalSource,
+        __in_z_opt LPCWSTR wzDownloadSource,
+        __in BOOTSTRAPPER_RESOLVESOURCE_ACTION recommendation,
+        __inout BOOTSTRAPPER_RESOLVESOURCE_ACTION* pAction,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnCacheAcquireComplete - called after the engine copied or downloaded
+    //                          a payload to the working folder.
+    //
+    STDMETHOD(OnCacheAcquireComplete)(
+        __in_z_opt LPCWSTR wzPackageOrContainerId,
+        __in_z_opt LPCWSTR wzPayloadId,
+        __in HRESULT hrStatus,
+        __in BOOTSTRAPPER_CACHEACQUIRECOMPLETE_ACTION recommendation,
+        __inout BOOTSTRAPPER_CACHEACQUIRECOMPLETE_ACTION* pAction
+        ) = 0;
+
+    // OnCacheVerifyBegin - called when the engine begins to verify then copy
+    //                      a payload or container to the package cache folder.
+    //
+    STDMETHOD(OnCacheVerifyBegin)(
+        __in_z_opt LPCWSTR wzPackageOrContainerId,
+        __in_z_opt LPCWSTR wzPayloadId,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnCacheVerifyComplete - called after the engine verifies and copies
+    //                         a payload or container to the package cache folder.
+    //
+    STDMETHOD(OnCacheVerifyComplete)(
+        __in_z_opt LPCWSTR wzPackageOrContainerId,
+        __in_z_opt LPCWSTR wzPayloadId,
+        __in HRESULT hrStatus,
+        __in BOOTSTRAPPER_CACHEVERIFYCOMPLETE_ACTION recommendation,
+        __inout BOOTSTRAPPER_CACHEVERIFYCOMPLETE_ACTION* pAction
+        ) = 0;
+
+    // OnCachePackageComplete - called after the engine attempts to copy or download all
+    //                          payloads of a package into the package cache folder.
+    //
+    STDMETHOD(OnCachePackageComplete)(
+        __in_z LPCWSTR wzPackageId,
+        __in HRESULT hrStatus,
+        __in BOOTSTRAPPER_CACHEPACKAGECOMPLETE_ACTION recommendation,
+        __inout BOOTSTRAPPER_CACHEPACKAGECOMPLETE_ACTION* pAction
+        )  = 0;
+
+    // OnCacheComplete - called when the engine caching is complete.
+    //
+    STDMETHOD(OnCacheComplete)(
+        __in HRESULT hrStatus
+        ) = 0;
+
+    // OnExecuteBegin - called when the engine begins executing the plan.
+    //
+    STDMETHOD(OnExecuteBegin)(
+        __in DWORD cExecutingPackages,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnExecuteBegin - called when the engine begins executing a package.
+    //
+    STDMETHOD(OnExecutePackageBegin)(
+        __in_z LPCWSTR wzPackageId,
+        __in BOOL fExecute,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnExecutePatchTarget - called for each patch in an MspPackage targeting the product
+    //                        when the engine begins executing the MspPackage.
+    //
+    STDMETHOD(OnExecutePatchTarget)(
+        __in_z LPCWSTR wzPackageId,
+        __in_z LPCWSTR wzTargetProductCode,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnExecuteProgress - called when the engine makes progress executing a package.
+    //
+    STDMETHOD(OnExecuteProgress)(
+        __in_z LPCWSTR wzPackageId,
+        __in DWORD dwProgressPercentage,
+        __in DWORD dwOverallPercentage,
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnExecuteMsiMessage - called when the engine receives an MSI package message.
+    //
+    // Return:
+    //  uiFlags is a combination of valid ID* return values appropriate for
+    //          the message.
+    //
+    //  IDNOACTION instructs the engine to pass the message through to default
+    //             handling which usually results in the execution continuing.
+    STDMETHOD(OnExecuteMsiMessage)(
+        __in_z LPCWSTR wzPackageId,
+        __in INSTALLMESSAGE messageType,
+        __in DWORD dwUIHint,
+        __in_z LPCWSTR wzMessage,
+        __in DWORD cData,
+        __in_ecount_z_opt(cData) LPCWSTR* rgwzData,
+        __in int nRecommendation,
+        __inout int* pResult
+        ) = 0;
+
+    // OnExecuteFilesInUse - called when the engine encounters files in use while
+    //                       executing a package.
+    //
+    // Return:
+    //  IDOK instructs the engine to let the Restart Manager attempt to close the
+    //       applications to avoid a restart.
+    //
+    //  IDCANCEL instructs the engine to abort the execution and start rollback.
+    //
+    //  IDIGNORE instructs the engine to ignore the running applications. A restart will be
+    //           required.
+    //
+    //  IDRETRY instructs the engine to check if the applications are still running again.
+    //
+    //  IDNOACTION is equivalent to ignoring the running applications. A restart will be
+    //             required.
+    STDMETHOD(OnExecuteFilesInUse)(
+        __in_z LPCWSTR wzPackageId,
+        __in DWORD cFiles,
+        __in_ecount_z(cFiles) LPCWSTR* rgwzFiles,
+        __in int nRecommendation,
+        __inout int* pResult
+        ) = 0;
+
+    // OnExecutePackageComplete - called when a package execution is complete.
+    //
+    STDMETHOD(OnExecutePackageComplete)(
+        __in_z LPCWSTR wzPackageId,
+        __in HRESULT hrStatus,
+        __in BOOTSTRAPPER_APPLY_RESTART restart,
+        __in BOOTSTRAPPER_EXECUTEPACKAGECOMPLETE_ACTION recommendation,
+        __inout BOOTSTRAPPER_EXECUTEPACKAGECOMPLETE_ACTION* pAction
+        ) = 0;
+
+    // OnExecuteComplete - called when the engine execution is complete.
+    //
+    STDMETHOD(OnExecuteComplete)(
+        __in HRESULT hrStatus
+        ) = 0;
+
+    // OnUnregisterBegin - called when the engine unregisters the bundle.
+    //
+    STDMETHOD(OnUnregisterBegin)(
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnUnregisterComplete - called when the engine unregistration is complete.
+    //
+    STDMETHOD(OnUnregisterComplete)(
+        __in HRESULT hrStatus
+        ) = 0;
+
+    // OnApplyComplete - called after the plan has been applied.
+    //
+    STDMETHOD(OnApplyComplete)(
+        __in HRESULT hrStatus,
+        __in BOOTSTRAPPER_APPLY_RESTART restart,
+        __in BOOTSTRAPPER_APPLYCOMPLETE_ACTION recommendation,
+        __inout BOOTSTRAPPER_APPLYCOMPLETE_ACTION* pAction
+        ) = 0;
+
+    // OnLaunchApprovedExeBegin - called before trying to launch the preapproved executable.
+    // 
+    STDMETHOD(OnLaunchApprovedExeBegin)(
+        __inout BOOL* pfCancel
+        ) = 0;
+
+    // OnLaunchApprovedExeComplete - called after trying to launch the preapproved executable.
+    //
+    STDMETHOD(OnLaunchApprovedExeComplete)(
+        __in HRESULT hrStatus,
+        __in DWORD dwProcessId
+        ) = 0;
+
+    // BAProc - The PFN_BOOTSTRAPPER_APPLICATION_PROC can call this method to give the BA raw access to the callback from the engine.
+    //          This might be used to help the BA support more than one version of the engine.
+    STDMETHOD(BAProc)(
+        __in BOOTSTRAPPER_APPLICATION_MESSAGE message,
+        __in const LPVOID pvArgs,
+        __inout LPVOID pvResults,
+        __in_opt LPVOID pvContext
+        ) = 0;
+
+    // BAProcFallback - The PFN_BOOTSTRAPPER_APPLICATION_PROC can call this method
+    //                  to give the BA the ability to use default behavior
+    //                  and then forward the message to extensions.
+    STDMETHOD_(void, BAProcFallback)(
+        __in BOOTSTRAPPER_APPLICATION_MESSAGE message,
+        __in const LPVOID pvArgs,
+        __inout LPVOID pvResults,
+        __inout HRESULT* phr,
+        __in_opt LPVOID pvContext
+        ) = 0;
+};
diff --git a/src/balutil/inc/IBootstrapperEngine.h b/src/balutil/inc/IBootstrapperEngine.h
new file mode 100644
index 00000000..3fe3d401
--- /dev/null
+++ b/src/balutil/inc/IBootstrapperEngine.h
@@ -0,0 +1,128 @@
+#pragma once
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+
+DECLARE_INTERFACE_IID_(IBootstrapperEngine, IUnknown, "6480D616-27A0-44D7-905B-81512C29C2FB")
+{
+    STDMETHOD(GetPackageCount)(
+        __out DWORD* pcPackages
+        ) = 0;
+
+    STDMETHOD(GetVariableNumeric)(
+        __in_z LPCWSTR wzVariable,
+        __out LONGLONG* pllValue
+        ) = 0;
+
+    STDMETHOD(GetVariableString)(
+        __in_z LPCWSTR wzVariable,
+        __out_ecount_opt(*pcchValue) LPWSTR wzValue,
+        __inout DWORD* pcchValue
+        ) = 0;
+
+    STDMETHOD(GetVariableVersion)(
+        __in_z LPCWSTR wzVariable,
+        __out DWORD64* pqwValue
+        ) = 0;
+
+    STDMETHOD(FormatString)(
+        __in_z LPCWSTR wzIn,
+        __out_ecount_opt(*pcchOut) LPWSTR wzOut,
+        __inout DWORD* pcchOut
+        ) = 0;
+
+    STDMETHOD(EscapeString)(
+        __in_z LPCWSTR wzIn,
+        __out_ecount_opt(*pcchOut) LPWSTR wzOut,
+        __inout DWORD* pcchOut
+        ) = 0;
+
+    STDMETHOD(EvaluateCondition)(
+        __in_z LPCWSTR wzCondition,
+        __out BOOL* pf
+        ) = 0;
+
+    STDMETHOD(Log)(
+        __in BOOTSTRAPPER_LOG_LEVEL level,
+        __in_z LPCWSTR wzMessage
+        ) = 0;
+
+    STDMETHOD(SendEmbeddedError)(
+        __in DWORD dwErrorCode,
+        __in_z_opt LPCWSTR wzMessage,
+        __in DWORD dwUIHint,
+        __out int* pnResult
+        ) = 0;
+
+    STDMETHOD(SendEmbeddedProgress)(
+        __in DWORD dwProgressPercentage,
+        __in DWORD dwOverallProgressPercentage,
+        __out int* pnResult
+        ) = 0;
+
+    STDMETHOD(SetUpdate)(
+        __in_z_opt LPCWSTR wzLocalSource,
+        __in_z_opt LPCWSTR wzDownloadSource,
+        __in DWORD64 qwSize,
+        __in BOOTSTRAPPER_UPDATE_HASH_TYPE hashType,
+        __in_bcount_opt(cbHash) BYTE* rgbHash,
+        __in DWORD cbHash
+        ) = 0;
+
+    STDMETHOD(SetLocalSource)(
+        __in_z LPCWSTR wzPackageOrContainerId,
+        __in_z_opt LPCWSTR wzPayloadId,
+        __in_z LPCWSTR wzPath
+        ) = 0;
+
+    STDMETHOD(SetDownloadSource)(
+        __in_z LPCWSTR wzPackageOrContainerId,
+        __in_z_opt LPCWSTR wzPayloadId,
+        __in_z LPCWSTR wzUrl,
+        __in_z_opt LPCWSTR wzUser,
+        __in_z_opt LPCWSTR wzPassword
+        ) = 0;
+
+    STDMETHOD(SetVariableNumeric)(
+        __in_z LPCWSTR wzVariable,
+        __in LONGLONG llValue
+        ) = 0;
+
+    STDMETHOD(SetVariableString)(
+        __in_z LPCWSTR wzVariable,
+        __in_z_opt LPCWSTR wzValue
+        ) = 0;
+
+    STDMETHOD(SetVariableVersion)(
+        __in_z LPCWSTR wzVariable,
+        __in DWORD64 qwValue
+        ) = 0;
+
+    STDMETHOD(CloseSplashScreen)() = 0;
+
+    STDMETHOD(Detect)(
+        __in_opt HWND hwndParent = NULL
+        ) = 0;
+
+    STDMETHOD(Plan)(
+        __in BOOTSTRAPPER_ACTION action
+        ) = 0;
+
+    STDMETHOD(Elevate)(
+        __in_opt HWND hwndParent
+        ) = 0;
+
+    STDMETHOD(Apply)(
+        __in_opt HWND hwndParent
+        ) = 0;
+
+    STDMETHOD(Quit)(
+        __in DWORD dwExitCode
+        ) = 0;
+
+    STDMETHOD(LaunchApprovedExe)(
+        __in_opt HWND hwndParent,
+        __in_z LPCWSTR wzApprovedExeForElevationId,
+        __in_z_opt LPCWSTR wzArguments,
+        __in DWORD dwWaitForInputIdleTimeout
+        ) = 0;
+};