[DEPRECATION] Removal of Iron Python loader and Refactor loader to enhance C# session orchestration

.github/copilot-instructions.md

@@ -53,7 +53,7 @@ The installer places a `.addin` manifest file in the Revit Addins folder, instru
 
 ### pyRevitLoader.dll
 The loader dll is the C# entry point for pyRevit inside Revit. There are multiple versions to support:
-- Different Revit versions: one for Revit 2025 and newer, another for older versions.
+- Different Revit versions: one for Revit 2025 and newer, another for Revit 2021-2024.
 - Different IronPython versions: 2.7.12 (default) and 3.4.0 (available but not fully tested).
 
 > Since only one IronPython engine can be active at a time, pyRevit updates the `.addin` manifest to point to the correct loader when the user switches engines. If installation issues arise, running `pyrevit attach` usually resolves them by regenerating the manifest correctly.

CLAUDE.md

@@ -27,29 +27,29 @@ pyRevit is a Rapid Application Development (RAD) environment for Autodesk Revit.
 
 ## Build Commands
 
-All build commands use pipenv. Run from the repository root:
+The build is driven by the C# ModularPipelines project under [`build/`](build/). Run from `build/`:
 
-```bash
-# Setup environment
-pipenv install
-pipenv run pyrevit check              # Verify build environment
-
-# Build commands
-pipenv run pyrevit build products     # Build all C# DLLs (Release mode)
-pipenv run pyrevit build products Debug  # Build in Debug mode
-pipenv run pyrevit build labs         # Build main project only
-pipenv run pyrevit build engines      # Build Python engines
-pipenv run pyrevit build installers   # Create Inno Setup installers
-
-# Cleaning
-pipenv run pyrevit clean labs         # Clean build artifacts
-
-# Version management
-pipenv run pyrevit set version <ver>  # Set version number
-pipenv run pyrevit set build wip      # Set as work-in-progress
-pipenv run pyrevit set build release  # Set as release build
+```powershell
+# Default unsigned local build (Channel=none)
+dotnet run -c Release -- ci
+
+# Debug build (attach the Visual Studio debugger to revit.exe)
+dotnet run -c Debug -- ci
+
+# WIP-style stamping + product build (mirrors develop push on the main repo)
+$env:Build__Channel = 'wip'
+dotnet run -c Release -- ci
+
+# Release-style stamping + product build (mirrors master / tag CI on the main repo)
+$env:Build__Channel = 'release'
+$env:DOTNET_ENVIRONMENT = 'Production'
+dotnet run -c Release -- ci
 ```
 
+Other pipeline modes: `pack`, `sign`, `publish`, `winget`, `notify`. See [`build/README.md`](build/README.md) for the full list, `Build__Channel` semantics, and CI gating.
+
+The legacy Python CLI (`pipenv run pyrevit build products`, `set build`, `set products`, …) still works for local/manual workflows and is documented in [`docs/ci-cd.md`](docs/ci-cd.md); CI no longer invokes it.
+
 ## Documentation
 
 - Main website: https://pyrevitlabs.io/
@@ -74,7 +74,7 @@ pyrevit attach dev default --installed
 2. Checkout `develop` branch (active development)
 3. Initialize submodules: `git submodule update --init --recursive`
 4. Install dependencies: `pipenv install`
-5. Build: `pipenv run pyrevit build products Debug`
+5. Build: `cd build && dotnet run -c Debug -- ci && cd ..`
 6. Test in Revit by attaching the clone
 
 For debugging C# code:
@@ -87,9 +87,11 @@ For debugging C# code:
 ### Loading Sequence
 1. Revit reads `.addin` manifest from Addins folder
 2. Manifest points to `pyRevitLoader.dll` (C#)
-3. Loader launches `pyrevitloader.py` in IronPython
-4. Python script calls `pyrevit.loader.sessionmgr.load_session()`
-5. Extensions are discovered and UI is built
+3. `PyRevitLoaderApplication.OnStartup` calls the C# session manager directly (no IronPython bootstrap)
+4. `SessionManagerService.LoadSession` runs `session_preload.py`, builds extension assemblies and UI in C#, then runs `session_postload.py`
+5. The preload/postload scripts drive the residual Python session services (telemetry, routes, output window, hooks framework) through the runtime engine
+
+Reload re-enters the same C# orchestrator via `PyRevitLoaderApplication.LoadSession`. The legacy pure-Python loader has been removed; the C# loader requires Revit 2021+.
 
 ### Key Components
 - **pyRevitLoader** (`dev/pyRevitLoader/`): Revit add-in entry point

dev/Directory.Build.targets

@@ -29,36 +29,12 @@
     </PropertyGroup>
 
     <PropertyGroup>
-        <RevitVersion Condition="'$(RevitVersion)' == '' and '$(TargetFramework)' == 'net48'">2017</RevitVersion>
+        <RevitVersion Condition="'$(RevitVersion)' == '' and '$(TargetFramework)' == 'net48'">2021</RevitVersion>
         <RevitVersion Condition="'$(RevitVersion)' == '' and '$(TargetFramework)' == 'net8.0-windows'">2025</RevitVersion>
         <RevitVersion Condition="'$(RevitVersion)' == '' and '$(TargetFramework)' == 'net10.0-windows'">2027</RevitVersion>
     </PropertyGroup>
 
     <!-- Define REVIT version constants based on RevitVersion (must be in targets, not props, to evaluate after project sets RevitVersion) -->
-    <PropertyGroup Condition="'$(RevitVersion)' == '2013'">
-        <DefineConstants>$(DefineConstants);REVIT2013</DefineConstants>
-    </PropertyGroup>
-    <PropertyGroup Condition="'$(RevitVersion)' == '2014'">
-        <DefineConstants>$(DefineConstants);REVIT2014</DefineConstants>
-    </PropertyGroup>
-    <PropertyGroup Condition="'$(RevitVersion)' == '2015'">
-        <DefineConstants>$(DefineConstants);REVIT2015</DefineConstants>
-    </PropertyGroup>
-    <PropertyGroup Condition="'$(RevitVersion)' == '2016'">
-        <DefineConstants>$(DefineConstants);REVIT2016</DefineConstants>
-    </PropertyGroup>
-    <PropertyGroup Condition="'$(RevitVersion)' == '2017'">
-        <DefineConstants>$(DefineConstants);REVIT2017</DefineConstants>
-    </PropertyGroup>
-    <PropertyGroup Condition="'$(RevitVersion)' == '2018'">
-        <DefineConstants>$(DefineConstants);REVIT2018</DefineConstants>
-    </PropertyGroup>
-    <PropertyGroup Condition="'$(RevitVersion)' == '2019'">
-        <DefineConstants>$(DefineConstants);REVIT2019</DefineConstants>
-    </PropertyGroup>
-    <PropertyGroup Condition="'$(RevitVersion)' == '2020'">
-        <DefineConstants>$(DefineConstants);REVIT2020</DefineConstants>
-    </PropertyGroup>
     <PropertyGroup Condition="'$(RevitVersion)' == '2021'">
         <DefineConstants>$(DefineConstants);REVIT2021;REVIT2021_OR_GREATER</DefineConstants>
     </PropertyGroup>
@@ -89,7 +65,7 @@
     <!-- Xceed.Wpf.AvalonDock reference (must be in targets to use RevitDevDir and RevitVersion) -->
     <ItemGroup Condition="'$(UseRevit)' == 'true'">
         <Reference
-            Condition="'$(RevitVersion)' != '' and $(RevitVersion) &gt;= 2018"
+            Condition="'$(RevitVersion)' != '' and $(RevitVersion) &gt;= 2021"
             Include="Xceed.Wpf.AvalonDock"
             HintPath="$(RevitDevDir)\$(RevitVersion)\Xceed.Wpf.AvalonDock.dll"/>
     </ItemGroup>

dev/pyRevitLabs.PyRevit.Runtime/pyRevitLabs.PyRevit.Runtime.sln

@@ -3,14 +3,6 @@ Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
 VisualStudioVersion = 17.1.32421.90
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "pyRevitLabs.PyRevit.Runtime.2017", "2017\pyRevitLabs.PyRevit.Runtime.2017.csproj", "{1B786F43-6125-42FF-8EA2-C4AEF640AEE4}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "pyRevitLabs.PyRevit.Runtime.2018", "2018\pyRevitLabs.PyRevit.Runtime.2018.csproj", "{8CEA0B80-D74F-411F-A607-DC1599AA934E}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "pyRevitLabs.PyRevit.Runtime.2019", "2019\pyRevitLabs.PyRevit.Runtime.2019.csproj", "{EFBE5B7E-227A-4122-98D7-D1F353AAF157}"
-EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "pyRevitLabs.PyRevit.Runtime.2020", "2020\pyRevitLabs.PyRevit.Runtime.2020.csproj", "{F5A23012-880A-4FE6-89EC-6F9DAB148DEF}"
-EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "pyRevitLabs.PyRevit.Runtime.2021", "2021\pyRevitLabs.PyRevit.Runtime.2021.csproj", "{479435EA-C820-49E4-942F-1274C151EE71}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "pyRevitLabs.PyRevit.Runtime.2022", "2022\pyRevitLabs.PyRevit.Runtime.2022.csproj", "{DB535262-30DA-404D-A32E-F024FF37935C}"
@@ -33,38 +25,6 @@ Global
 		Release IPY342|x64 = Release IPY342|x64
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{1B786F43-6125-42FF-8EA2-C4AEF640AEE4}.Debug IPY2712PR|x64.ActiveCfg = Debug IPY2712PR|x64
-		{1B786F43-6125-42FF-8EA2-C4AEF640AEE4}.Debug IPY2712PR|x64.Build.0 = Debug IPY2712PR|x64
-		{1B786F43-6125-42FF-8EA2-C4AEF640AEE4}.Debug IPY342|x64.ActiveCfg = Debug IPY342|x64
-		{1B786F43-6125-42FF-8EA2-C4AEF640AEE4}.Debug IPY342|x64.Build.0 = Debug IPY342|x64
-		{1B786F43-6125-42FF-8EA2-C4AEF640AEE4}.Release IPY2712PR|x64.ActiveCfg = Release IPY2712PR|x64
-		{1B786F43-6125-42FF-8EA2-C4AEF640AEE4}.Release IPY2712PR|x64.Build.0 = Release IPY2712PR|x64
-		{1B786F43-6125-42FF-8EA2-C4AEF640AEE4}.Release IPY342|x64.ActiveCfg = Release IPY342|x64
-		{1B786F43-6125-42FF-8EA2-C4AEF640AEE4}.Release IPY342|x64.Build.0 = Release IPY342|x64
-		{8CEA0B80-D74F-411F-A607-DC1599AA934E}.Debug IPY2712PR|x64.ActiveCfg = Debug IPY2712PR|x64
-		{8CEA0B80-D74F-411F-A607-DC1599AA934E}.Debug IPY2712PR|x64.Build.0 = Debug IPY2712PR|x64
-		{8CEA0B80-D74F-411F-A607-DC1599AA934E}.Debug IPY342|x64.ActiveCfg = Debug IPY342|x64
-		{8CEA0B80-D74F-411F-A607-DC1599AA934E}.Debug IPY342|x64.Build.0 = Debug IPY342|x64
-		{8CEA0B80-D74F-411F-A607-DC1599AA934E}.Release IPY2712PR|x64.ActiveCfg = Release IPY2712PR|x64
-		{8CEA0B80-D74F-411F-A607-DC1599AA934E}.Release IPY2712PR|x64.Build.0 = Release IPY2712PR|x64
-		{8CEA0B80-D74F-411F-A607-DC1599AA934E}.Release IPY342|x64.ActiveCfg = Release IPY342|x64
-		{8CEA0B80-D74F-411F-A607-DC1599AA934E}.Release IPY342|x64.Build.0 = Release IPY342|x64
-		{EFBE5B7E-227A-4122-98D7-D1F353AAF157}.Debug IPY2712PR|x64.ActiveCfg = Debug IPY2712PR|x64
-		{EFBE5B7E-227A-4122-98D7-D1F353AAF157}.Debug IPY2712PR|x64.Build.0 = Debug IPY2712PR|x64
-		{EFBE5B7E-227A-4122-98D7-D1F353AAF157}.Debug IPY342|x64.ActiveCfg = Debug IPY342|x64
-		{EFBE5B7E-227A-4122-98D7-D1F353AAF157}.Debug IPY342|x64.Build.0 = Debug IPY342|x64
-		{EFBE5B7E-227A-4122-98D7-D1F353AAF157}.Release IPY2712PR|x64.ActiveCfg = Release IPY2712PR|x64
-		{EFBE5B7E-227A-4122-98D7-D1F353AAF157}.Release IPY2712PR|x64.Build.0 = Release IPY2712PR|x64
-		{EFBE5B7E-227A-4122-98D7-D1F353AAF157}.Release IPY342|x64.ActiveCfg = Release IPY342|x64
-		{EFBE5B7E-227A-4122-98D7-D1F353AAF157}.Release IPY342|x64.Build.0 = Release IPY342|x64
-		{F5A23012-880A-4FE6-89EC-6F9DAB148DEF}.Debug IPY2712PR|x64.ActiveCfg = Debug IPY2712PR|x64
-		{F5A23012-880A-4FE6-89EC-6F9DAB148DEF}.Debug IPY2712PR|x64.Build.0 = Debug IPY2712PR|x64
-		{F5A23012-880A-4FE6-89EC-6F9DAB148DEF}.Debug IPY342|x64.ActiveCfg = Debug IPY342|x64
-		{F5A23012-880A-4FE6-89EC-6F9DAB148DEF}.Debug IPY342|x64.Build.0 = Debug IPY342|x64
-		{F5A23012-880A-4FE6-89EC-6F9DAB148DEF}.Release IPY2712PR|x64.ActiveCfg = Release IPY2712PR|x64
-		{F5A23012-880A-4FE6-89EC-6F9DAB148DEF}.Release IPY2712PR|x64.Build.0 = Release IPY2712PR|x64
-		{F5A23012-880A-4FE6-89EC-6F9DAB148DEF}.Release IPY342|x64.ActiveCfg = Release IPY342|x64
-		{F5A23012-880A-4FE6-89EC-6F9DAB148DEF}.Release IPY342|x64.Build.0 = Release IPY342|x64
 		{479435EA-C820-49E4-942F-1274C151EE71}.Debug IPY2712PR|x64.ActiveCfg = Debug IPY2712PR|x64
 		{479435EA-C820-49E4-942F-1274C151EE71}.Debug IPY2712PR|x64.Build.0 = Debug IPY2712PR|x64
 		{479435EA-C820-49E4-942F-1274C151EE71}.Debug IPY342|x64.ActiveCfg = Debug IPY342|x64

dev/pyRevitLabs/pyRevitLabs.PyRevit/PyRevitConsts.cs

@@ -180,8 +180,6 @@ public static class PyRevitConsts {
         public const string BundleScriptRevitFamilyPostfix = ".rfa";
 
         // loader settings
-        public const string ConfigsNewLoaderKey = "new_loader";
-        public const bool ConfigsNewLoaderDefault = true;
         public const string ConfigsReadScriptMetadataKey = "read_script_metadata";
         public const bool ConfigsReadScriptMetadataDefault = true;
 

dev/pyRevitLoader/Source/PyRevitLoaderApplication.cs

@@ -1,3 +1,20 @@
+/*
+   ██▓███▓██   ██▓ ██▀███  ▓█████ ██▒   █▓ ██▓▄▄▄█████▓
+  ▓██░  ██▒██  ██▒▓██ ▒ ██▒▓█   ▀▓██░   █▒▓██▒▓  ██▒ ▓▒
+  ▓██░ ██▓▒▒██ ██░▓██ ░▄█ ▒▒███   ▓██  █▒░▒██▒▒ ▓██░ ▒░
+  ▒██▄█▓▒ ▒░ ▐██▓░▒██▀▀█▄  ▒▓█  ▄  ▒██ █░░░██░░ ▓██▓ ░
+  ▒██▒ ░  ░░ ██▒▓░░██▓ ▒██▒░▒████▒  ▒▀█░  ░██░  ▒██▒ ░
+  ▒▓▒░ ░  ░ ██▒▒▒ ░ ▒▓ ░▒▓░░░ ▒░ ░  ░ ▐░  ░▓    ▒ ░░
+  ░▒ ░    ▓██ ░▒░   ░▒ ░ ▒░ ░ ░  ░  ░ ░░   ▒ ░    ░
+  ░░      ▒ ▒ ░░    ░░   ░    ░       ░░   ▒ ░  ░
+          ░ ░        ░        ░  ░     ░   ░
+          ░ ░                         ░
+
+  This is the entry point for pyRevit. Revit loads the PyRevitLoader.dll addon
+  at startup, and PyRevitLoaderApplication.OnStartup calls into the C# session
+  manager to build the UI and the button commands.
+ */
+
 using Autodesk.Revit.Attributes;
 using Autodesk.Revit.UI;
 using pyRevitAssemblyBuilder.AssemblyMaker;
@@ -49,17 +66,10 @@ Result IExternalApplication.OnStartup(UIControlledApplication application)
 			var commonFolder = Path.GetDirectoryName(Path.GetDirectoryName(LoaderPath));
 			LoadAssembliesInFolder(commonFolder);
 
-			try
-			{
-				var uiApplication = GetUIApplication(application);
-				var result = ExecuteStartupScript(application);
-				return result;
-			}
-			catch (Exception ex)
-			{
-				TaskDialog.Show("Error Loading Startup Script", ex.ToString());
-				return Result.Failed;
-			}
+			// Load the session directly through the C# session manager. The Python
+			// pre/post-load services are driven from within LoadSession, so Revit
+			// startup no longer bootstraps an IronPython engine to reach the loader.
+			return LoadSessionInternal(firstLoad: true);
 		}
 
 		private static void LoadAssembliesInFolder(string folder)
@@ -80,81 +90,44 @@ private static void LoadAssembliesInFolder(string folder)
 			}
 		}
 
-	private static Result ExecuteStartupScript(UIControlledApplication uiControlledApplication)
-		{
-			var uiApplication = GetUIApplication(uiControlledApplication);
-			// execute StartupScript
-			Result result = Result.Succeeded;
-			var startupScript = GetStartupScriptPath();
-			if (startupScript != null)
-			{
-				var executor = new ScriptExecutor(uiApplication);
-				result = executor.ExecuteScript(startupScript);
-				if (result == Result.Failed)
-				{
-					TaskDialog.Show("Error Loading pyRevit", executor.Message);
-				}
-			}
-
-			return result;
-		}
+		// Reload entry invoked by the Python session manager via reflection
+		// (GetMethod("LoadSession")). Must stay the only static method named LoadSession
+		// so that lookup remains unambiguous. A reload is never the first load.
+		public static Result LoadSession() => LoadSessionInternal(firstLoad: false);
 
-		public static Result LoadSession(string buildStrategy = null)
+		// Shared entry for initial startup and reload. The C# SessionManagerService
+		// drives the full load, including the residual Python pre/post-load services.
+		private static Result LoadSessionInternal(bool firstLoad)
 		{
 			try
 			{
-				// Use the stored UIControlledApplication
 				if (_uiControlledApplication == null)
 				{
 					throw new InvalidOperationException("UIControlledApplication not available." +
 						" LoadSession can only be called after OnStartup.");
 				}
 
-				var uiControlledApplication = _uiControlledApplication;
-				var uiApplication = GetUIApplication(uiControlledApplication);
-
-				// Get the current Revit version
-				var revitVersion = uiControlledApplication.ControlledApplication.VersionNumber;
-
-			// Always use Roslyn build strategy
-			AssemblyBuildStrategy strategyEnum = AssemblyBuildStrategy.Roslyn;
+				var uiApplication = GetUIApplication(_uiControlledApplication);
+				var revitVersion = _uiControlledApplication.ControlledApplication.VersionNumber;
 
 				var sessionManager = ServiceFactory.CreateSessionManagerService(
 					revitVersion,
-					strategyEnum,
+					AssemblyBuildStrategy.Roslyn,
 					uiApplication);
 
-				// Load the session using the C# SessionManagerService
-				sessionManager.LoadSession();
+				sessionManager.LoadSession(firstLoad);
 
 				return Result.Succeeded;
 			}
 			catch (Exception ex)
 			{
-				TaskDialog.Show("Error Loading C# Session",
-					$"An error occurred while loading the C# session:\n\n{ex.Message}\n\n" +
+				TaskDialog.Show("Error Loading pyRevit Session",
+					$"An error occurred while loading the pyRevit session:\n\n{ex.Message}\n\n" +
 					$"Check the output window for details.");
 				return Result.Failed;
 			}
 		}
-		private static string GetStartupScriptPath()
-		{
-			var assemblyLocation = Assembly.GetExecutingAssembly().Location;
-			var loaderDir = Path.GetDirectoryName(assemblyLocation);
-			if (string.IsNullOrEmpty(loaderDir))
-			{
-				throw new InvalidOperationException($"Could not determine directory for assembly location: {assemblyLocation}");
-			}
-
-			var dllDir = Path.GetDirectoryName(loaderDir);
-			if (string.IsNullOrEmpty(dllDir))
-			{
-				throw new InvalidOperationException($"Could not determine parent directory for loader directory: {loaderDir}");
-			}
 
-			var assemblyName = Assembly.GetExecutingAssembly().GetName().Name;
-			return Path.Combine(dllDir, $"{assemblyName}.py");
-		}
 		Result IExternalApplication.OnShutdown(UIControlledApplication application)
 		{
 			// FIXME: deallocate the python shell...

dev/pyRevitLoader/pyRevitAssemblyBuilder/SessionManager/Constants.cs

@@ -29,6 +29,16 @@ internal static class Constants
         /// Key for referenced assemblies in environment dictionary.
         /// </summary>
         public const string REFED_ASSMS_KEY = "PYREVIT_REFEDASSMS";
+
+        /// <summary>
+        /// Python entry script that runs pre-load session setup.
+        /// </summary>
+        public const string PRELOAD_SCRIPT = "session_preload.py";
+
+        /// <summary>
+        /// Python entry script that runs post-load session finalization.
+        /// </summary>
+        public const string POSTLOAD_SCRIPT = "session_postload.py";
     }
 
     /// <summary>

dev/pyRevitLoader/pyRevitAssemblyBuilder/SessionManager/ISessionManagerService.cs

@@ -20,6 +20,8 @@ public interface ISessionManagerService
         ///    - Executes startup scripts if present
         ///    - Creates the UI
         /// </remarks>
-        void LoadSession();
+        /// <param name="firstLoad">True on initial Revit startup, false on reload. Gates
+        /// first-load-only work such as removing stale appdata files from closed sessions.</param>
+        void LoadSession(bool firstLoad);
     }
 }