Initial plan

---
updated-dependencies:
- dependency-name: System.ServiceProcess.ServiceController
  dependency-version: 10.0.3
  dependency-type: direct:production
  update-type: version-update:semver-major
- dependency-name: System.ServiceProcess.ServiceController
  dependency-version: 10.0.3
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.devcontainer/devcontainer.json

@@ -4,7 +4,7 @@
   "features": {
     "ghcr.io/devcontainers/features/docker-in-docker:1": {},
     "ghcr.io/devcontainers/features/dotnet": {
-      "version": "8.0.417"
+      "version": "8.0.418"
     },
     "ghcr.io/devcontainers/features/node:1": {
       "version": "20"

README.md

@@ -32,7 +32,7 @@ We are taking the following steps to better direct requests related to GitHub Ac
 
 2. High Priority bugs can be reported through Community Discussions or you can report these to our support team https://support.github.com/contact/bug-report.
 
-3. Security Issues should be handled as per our [security.md](security.md)
+3. Security Issues should be handled as per our [SECURITY.md](https://github.com/actions/runner?tab=security-ov-file)
 
 We will still provide security updates for this project and fix major breaking changes during this time.
 

docs/start/envlinux.md

@@ -28,8 +28,8 @@ Debian based OS (Debian, Ubuntu, Linux Mint)
 - liblttng-ust1 or liblttng-ust0
 - libkrb5-3
 - zlib1g
-- libssl1.1, libssl1.0.2 or libssl1.0.0
-- libicu63, libicu60, libicu57 or libicu55
+- libssl3t64, libssl3, libssl1.1, libssl1.0.2 or libssl1.0.0
+- libicu76, libicu75, ..., libicu66, libicu65, libicu63, libicu60, libicu57, libicu55, or libicu52
 
 Fedora based OS (Fedora, Red Hat Enterprise Linux, CentOS, Oracle Linux 7)
 

images/Dockerfile

@@ -21,7 +21,7 @@ RUN curl -f -L -o runner-container-hooks.zip https://github.com/actions/runner-c
     && unzip ./runner-container-hooks.zip -d ./k8s \
     && rm runner-container-hooks.zip
 
-RUN curl -f -L -o runner-container-hooks.zip https://github.com/actions/runner-container-hooks/releases/download/v0.8.0/actions-runner-hooks-k8s-0.8.0.zip \
+RUN curl -f -L -o runner-container-hooks.zip https://github.com/actions/runner-container-hooks/releases/download/v0.8.1/actions-runner-hooks-k8s-0.8.1.zip \
     && unzip ./runner-container-hooks.zip -d ./k8s-novolume \
     && rm runner-container-hooks.zip
 

src/Misc/externals.sh

@@ -7,7 +7,7 @@ NODE_ALPINE_URL=https://github.com/actions/alpine_nodejs/releases/download
 # When you update Node versions you must also create a new release of alpine_nodejs at that updated version.
 # Follow the instructions here: https://github.com/actions/alpine_nodejs?tab=readme-ov-file#getting-started
 NODE20_VERSION="20.20.0"
-NODE24_VERSION="24.13.0"
+NODE24_VERSION="24.13.1"
 
 get_abs_path() {
   # exploits the fact that pwd will print abs path when no args

src/Misc/layoutbin/installdependencies.sh

@@ -102,7 +102,7 @@ then
             exit 1
         fi
 
-        apt_get_with_fallbacks libssl1.1$ libssl1.0.2$ libssl1.0.0$
+        apt_get_with_fallbacks libssl3t64$ libssl3$ libssl1.1$ libssl1.0.2$ libssl1.0.0$
         if [ $? -ne 0 ]
         then
             echo "'$apt_get' failed with exit code '$?'"

src/Runner.Common/ActionCommand.cs

@@ -204,6 +204,26 @@ namespace GitHub.Runner.Common
             return unescaped;
         }
 
+        /// <summary>
+        /// Escapes special characters in a value using the standard action command escape mappings.
+        /// Iterates in reverse so that '%' is escaped first to avoid double-encoding.
+        /// </summary>
+        public static string EscapeValue(string value)
+        {
+            if (string.IsNullOrEmpty(value))
+            {
+                return value;
+            }
+
+            string escaped = value;
+            for (int i = _escapeMappings.Length - 1; i >= 0; i--)
+            {
+                escaped = escaped.Replace(_escapeMappings[i].Token, _escapeMappings[i].Replacement);
+            }
+
+            return escaped;
+        }
+
         private static string UnescapeProperty(string escaped)
         {
             if (string.IsNullOrEmpty(escaped))

src/Runner.Common/ConfigurationStore.cs

@@ -75,6 +75,41 @@ namespace GitHub.Runner.Common
                 {
                     return UrlUtil.IsHostedServer(new UriBuilder(GitHubUrl));
                 }
+                else
+                {
+                    // feature flag env in case the new logic is wrong.
+                    if (StringUtil.ConvertToBoolean(Environment.GetEnvironmentVariable("GITHUB_ACTIONS_RUNNER_FORCE_EMPTY_GITHUB_URL_IS_HOSTED")))
+                    {
+                        return true;
+                    }
+
+                    // GitHubUrl will be empty for jit configured runner
+                    // We will try to infer it from the ServerUrl/ServerUrlV2
+                    if (StringUtil.ConvertToBoolean(Environment.GetEnvironmentVariable("GITHUB_ACTIONS_RUNNER_FORCE_GHES")))
+                    {
+                        // Allow env to override and force GHES in case the inference logic is wrong.
+                        return false;
+                    }
+
+                    if (!string.IsNullOrEmpty(ServerUrl))
+                    {
+                        // pipelines services
+                        var serverUrl = new UriBuilder(ServerUrl);
+                        return serverUrl.Host.EndsWith(".actions.githubusercontent.com", StringComparison.OrdinalIgnoreCase)
+                                || serverUrl.Host.EndsWith(".codedev.ms", StringComparison.OrdinalIgnoreCase);
+                    }
+
+                    if (!string.IsNullOrEmpty(ServerUrlV2))
+                    {
+                        // broker-listener
+                        var serverUrlV2 = new UriBuilder(ServerUrlV2);
+                        return serverUrlV2.Host.EndsWith(".actions.githubusercontent.com", StringComparison.OrdinalIgnoreCase)
+                                || serverUrlV2.Host.EndsWith(".githubapp.com", StringComparison.OrdinalIgnoreCase)
+                                || serverUrlV2.Host.EndsWith(".ghe.com", StringComparison.OrdinalIgnoreCase)
+                                || serverUrlV2.Host.EndsWith(".actions.localhost", StringComparison.OrdinalIgnoreCase)
+                                || serverUrlV2.Host.EndsWith(".ghe.localhost", StringComparison.OrdinalIgnoreCase);
+                    }
+                }
 
                 // Default to true since Hosted runners likely don't have this property set.
                 return true;

src/Runner.Common/Constants.cs

@@ -172,9 +172,9 @@ namespace GitHub.Runner.Common
                 public static readonly string SnapshotPreflightHostedRunnerCheck = "actions_snapshot_preflight_hosted_runner_check";
                 public static readonly string SnapshotPreflightImageGenPoolCheck = "actions_snapshot_preflight_image_gen_pool_check";
                 public static readonly string CompareWorkflowParser = "actions_runner_compare_workflow_parser";
-                public static readonly string CutoverWorkflowParser = "actions_runner_cutover_workflow_parser";
                 public static readonly string SetOrchestrationIdEnvForActions = "actions_set_orchestration_id_env_for_actions";
                 public static readonly string SendJobLevelAnnotations = "actions_send_job_level_annotations";
+                public static readonly string EmitCompositeMarkers = "actions_runner_emit_composite_markers";
             }
 
             // Node version migration related constants
@@ -191,6 +191,10 @@ namespace GitHub.Runner.Common
                 // Feature flags for controlling the migration phases
                 public static readonly string UseNode24ByDefaultFlag = "actions.runner.usenode24bydefault";
                 public static readonly string RequireNode24Flag = "actions.runner.requirenode24";
+                public static readonly string WarnOnNode20Flag = "actions.runner.warnonnode20";
+
+                // Blog post URL for Node 20 deprecation
+                public static readonly string Node20DeprecationUrl = "https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/";
             }
 
             public static readonly string InternalTelemetryIssueDataKey = "_internal_telemetry";
@@ -285,6 +289,8 @@ namespace GitHub.Runner.Common
                 public static readonly string ForcedActionsNodeVersion = "ACTIONS_RUNNER_FORCE_ACTIONS_NODE_VERSION";
                 public static readonly string PrintLogToStdout = "ACTIONS_RUNNER_PRINT_LOG_TO_STDOUT";
                 public static readonly string ActionArchiveCacheDirectory = "ACTIONS_RUNNER_ACTION_ARCHIVE_CACHE";
+                public static readonly string SymlinkCachedActions = "ACTIONS_RUNNER_SYMLINK_CACHED_ACTIONS";
+                public static readonly string EmitCompositeMarkers = "ACTIONS_RUNNER_EMIT_COMPOSITE_MARKERS";
             }
 
             public static class System

src/Runner.Listener/Configuration/ConfigurationManager.cs

@@ -178,8 +178,12 @@ namespace GitHub.Runner.Listener.Configuration
                         }
                     }
 
-                    // Validate can connect.
-                    await _runnerServer.ConnectAsync(new Uri(runnerSettings.ServerUrl), creds);
+                    // Validate can connect using the obtained vss credentials.
+                    // In Runner Admin flow there's nothing new to test connection to at this point as registerToken is already validated via GetTenantCredential.
+                    if (!runnerSettings.UseRunnerAdminFlow)
+                    {
+                        await _runnerServer.ConnectAsync(new Uri(runnerSettings.ServerUrl), creds);
+                    }
 
                     _term.WriteLine();
                     _term.WriteSuccessMessage("Connected to GitHub");

src/Runner.Listener/JobDispatcher.cs

@@ -24,7 +24,7 @@ namespace GitHub.Runner.Listener
     public interface IJobDispatcher : IRunnerService
     {
         bool Busy { get; }
-        TaskCompletionSource<bool> RunOnceJobCompleted { get; }
+        TaskCompletionSource<TaskResult> RunOnceJobCompleted { get; }
         void Run(Pipelines.AgentJobRequestMessage message, bool runOnce = false);
         bool Cancel(JobCancelMessage message);
         Task WaitAsync(CancellationToken token);
@@ -56,7 +56,7 @@ namespace GitHub.Runner.Listener
         // timeout limit can be overwritten by environment GITHUB_ACTIONS_RUNNER_CHANNEL_TIMEOUT
         private TimeSpan _channelTimeout;
 
-        private TaskCompletionSource<bool> _runOnceJobCompleted = new();
+        private TaskCompletionSource<TaskResult> _runOnceJobCompleted = new();
 
         public event EventHandler<JobStatusEventArgs> JobStatus;
 
@@ -82,7 +82,7 @@ namespace GitHub.Runner.Listener
             Trace.Info($"Set runner/worker IPC timeout to {_channelTimeout.TotalSeconds} seconds.");
         }
 
-        public TaskCompletionSource<bool> RunOnceJobCompleted => _runOnceJobCompleted;
+        public TaskCompletionSource<TaskResult> RunOnceJobCompleted => _runOnceJobCompleted;
 
         public bool Busy { get; private set; }
 
@@ -340,18 +340,19 @@ namespace GitHub.Runner.Listener
 
         private async Task RunOnceAsync(Pipelines.AgentJobRequestMessage message, string orchestrationId, WorkerDispatcher previousJobDispatch, CancellationToken jobRequestCancellationToken, CancellationToken workerCancelTimeoutKillToken)
         {
+            var jobResult = TaskResult.Succeeded;
             try
             {
-                await RunAsync(message, orchestrationId, previousJobDispatch, jobRequestCancellationToken, workerCancelTimeoutKillToken);
+                jobResult = await RunAsync(message, orchestrationId, previousJobDispatch, jobRequestCancellationToken, workerCancelTimeoutKillToken);
             }
             finally
             {
                 Trace.Info("Fire signal for one time used runner.");
-                _runOnceJobCompleted.TrySetResult(true);
+                _runOnceJobCompleted.TrySetResult(jobResult);
             }
         }
 
-        private async Task RunAsync(Pipelines.AgentJobRequestMessage message, string orchestrationId, WorkerDispatcher previousJobDispatch, CancellationToken jobRequestCancellationToken, CancellationToken workerCancelTimeoutKillToken)
+        private async Task<TaskResult> RunAsync(Pipelines.AgentJobRequestMessage message, string orchestrationId, WorkerDispatcher previousJobDispatch, CancellationToken jobRequestCancellationToken, CancellationToken workerCancelTimeoutKillToken)
         {
             Busy = true;
             try
@@ -399,7 +400,7 @@ namespace GitHub.Runner.Listener
                     {
                         // renew job request task complete means we run out of retry for the first job request renew.
                         Trace.Info($"Unable to renew job request for job {message.JobId} for the first time, stop dispatching job to worker.");
-                        return;
+                        return TaskResult.Abandoned;
                     }
 
                     if (jobRequestCancellationToken.IsCancellationRequested)
@@ -412,7 +413,7 @@ namespace GitHub.Runner.Listener
 
                         // complete job request with result Cancelled
                         await CompleteJobRequestAsync(_poolId, message, systemConnection, lockToken, TaskResult.Canceled);
-                        return;
+                        return TaskResult.Canceled;
                     }
 
                     HostContext.WritePerfCounter($"JobRequestRenewed_{requestId.ToString()}");
@@ -523,7 +524,7 @@ namespace GitHub.Runner.Listener
                             await renewJobRequest;
 
                             // not finish the job request since the job haven't run on worker at all, we will not going to set a result to server.
-                            return;
+                            return TaskResult.Failed;
                         }
 
                         // we get first jobrequest renew succeed and start the worker process with the job message.
@@ -604,7 +605,7 @@ namespace GitHub.Runner.Listener
                                     Trace.Error(detailInfo);
                                 }
 
-                                return;
+                                return TaskResultUtil.TranslateFromReturnCode(returnCode);
                             }
                             else if (completedTask == renewJobRequest)
                             {
@@ -706,6 +707,8 @@ namespace GitHub.Runner.Listener
 
                             // complete job request
                             await CompleteJobRequestAsync(_poolId, message, systemConnection, lockToken, resultOnAbandonOrCancel);
+
+                            return resultOnAbandonOrCancel;
                         }
                         finally
                         {

src/Runner.Listener/Runner.Listener.csproj

@@ -23,7 +23,7 @@
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
     <PackageReference Include="System.IO.FileSystem.AccessControl" Version="5.0.0" />
     <PackageReference Include="System.Security.Cryptography.ProtectedData" Version="8.0.0" />
-    <PackageReference Include="System.ServiceProcess.ServiceController" Version="8.0.1" />
+    <PackageReference Include="System.ServiceProcess.ServiceController" Version="10.0.3" />
   </ItemGroup>
 
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">

src/Runner.Listener/Runner.cs

@@ -5,8 +5,8 @@ using System.IO;
 using System.Linq;
 using System.Reflection;
 using System.Runtime.CompilerServices;
-using System.Security.Cryptography;
 using System.Security.Claims;
+using System.Security.Cryptography;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
@@ -324,8 +324,11 @@ namespace GitHub.Runner.Listener
                         HostContext.EnableAuthMigration("EnableAuthMigrationByDefault");
                     }
 
+                    // hosted runner only run one job and would like to know the result of the job for telemetry and alerting on failure spike.
+                    var returnJobResultForHosted = StringUtil.ConvertToBoolean(Environment.GetEnvironmentVariable("ACTIONS_RUNNER_RETURN_JOB_RESULT_FOR_HOSTED"));
+
                     // Run the runner interactively or as service
-                    return await ExecuteRunnerAsync(settings, command.RunOnce || settings.Ephemeral);
+                    return await ExecuteRunnerAsync(settings, command.RunOnce || settings.Ephemeral || returnJobResultForHosted, returnJobResultForHosted);
                 }
                 else
                 {
@@ -401,17 +404,32 @@ namespace GitHub.Runner.Listener
         }
 
         //create worker manager, create message listener and start listening to the queue
-        private async Task<int> RunAsync(RunnerSettings settings, bool runOnce = false)
+        private async Task<int> RunAsync(RunnerSettings settings, bool runOnce = false, bool returnRunOnceJobResult = false)
         {
             try
             {
                 Trace.Info(nameof(RunAsync));
-                
+
+                // Validate directory permissions.
+                string workDirectory = HostContext.GetDirectory(WellKnownDirectory.Work);
+                Trace.Info($"Validating directory permissions for: '{workDirectory}'");
+                try
+                {
+                    Directory.CreateDirectory(workDirectory);
+                    IOUtil.ValidateExecutePermission(workDirectory);
+                }
+                catch (Exception ex)
+                {
+                    Trace.Error(ex);
+                    _term.WriteError($"Fail to create and validate runner's work directory '{workDirectory}'.");
+                    return Constants.Runner.ReturnCode.TerminatedError;
+                }
+
                 // First try using migrated settings if available
                 var configManager = HostContext.GetService<IConfigurationManager>();
                 RunnerSettings migratedSettings = null;
-                
-                try 
+
+                try
                 {
                     migratedSettings = configManager.LoadMigratedSettings();
                     Trace.Info("Loaded migrated settings from .runner_migrated file");
@@ -422,15 +440,15 @@ namespace GitHub.Runner.Listener
                     // If migrated settings file doesn't exist or can't be loaded, we'll use the provided settings
                     Trace.Info($"Failed to load migrated settings: {ex.Message}");
                 }
-                
+
                 bool usedMigratedSettings = false;
-                
+
                 if (migratedSettings != null)
                 {
                     // Try to create session with migrated settings first
                     Trace.Info("Attempting to create session using migrated settings");
                     _listener = GetMessageListener(migratedSettings, isMigratedSettings: true);
-                    
+
                     try
                     {
                         CreateSessionResult createSessionResult = await _listener.CreateSessionAsync(HostContext.RunnerShutdownToken);
@@ -450,7 +468,7 @@ namespace GitHub.Runner.Listener
                         Trace.Error($"Exception when creating session with migrated settings: {ex}");
                     }
                 }
-                
+
                 // If migrated settings weren't used or session creation failed, use original settings
                 if (!usedMigratedSettings)
                 {
@@ -503,7 +521,7 @@ namespace GitHub.Runner.Listener
                             restartSession = true;
                             break;
                         }
-                        
+
                         TaskAgentMessage message = null;
                         bool skipMessageDeletion = false;
                         try
@@ -565,6 +583,21 @@ namespace GitHub.Runner.Listener
                                         Trace.Info($"Ignore any exception after cancel message loop. {ex}");
                                     }
 
+                                    if (returnRunOnceJobResult)
+                                    {
+                                        try
+                                        {
+                                            var jobResult = await jobDispatcher.RunOnceJobCompleted.Task;
+                                            return TaskResultUtil.TranslateToReturnCode(jobResult);
+                                        }
+                                        catch (Exception ex)
+                                        {
+                                            Trace.Error("run once job finished with error.");
+                                            Trace.Error(ex);
+                                            return Constants.Runner.ReturnCode.TerminatedError;
+                                        }
+                                    }
+
                                     return Constants.Runner.ReturnCode.Success;
                                 }
                             }
@@ -851,15 +884,15 @@ namespace GitHub.Runner.Listener
             return Constants.Runner.ReturnCode.Success;
         }
 
-        private async Task<int> ExecuteRunnerAsync(RunnerSettings settings, bool runOnce)
+        private async Task<int> ExecuteRunnerAsync(RunnerSettings settings, bool runOnce, bool returnRunOnceJobResult)
         {
             int returnCode = Constants.Runner.ReturnCode.Success;
             bool restart = false;
             do
             {
                 restart = false;
-                returnCode = await RunAsync(settings, runOnce);
-                
+                returnCode = await RunAsync(settings, runOnce, returnRunOnceJobResult);
+
                 if (returnCode == Constants.Runner.ReturnCode.RunnerConfigurationRefreshed)
                 {
                     Trace.Info("Runner configuration was refreshed, restarting session...");

src/Runner.Sdk/Util/IOUtil.cs

@@ -93,6 +93,16 @@ namespace GitHub.Runner.Sdk
             }
         }
 
+        public static FileSystemInfo CreateSymbolicLink(string destDirectory, string srcDirectory)
+        {
+            // ensure directory chain exists
+            Directory.CreateDirectory(destDirectory);
+            // delete leaf directory
+            Directory.Delete(destDirectory);
+            // create symlink for the leaf directory
+            return Directory.CreateSymbolicLink(destDirectory, srcDirectory);
+        }
+
         public static void Delete(string path, CancellationToken cancellationToken)
         {
             DeleteDirectory(path, cancellationToken);

src/Runner.Worker/ActionCommandManager.cs

@@ -318,6 +318,17 @@ namespace GitHub.Runner.Worker
                 context.AddIssue(issue, ExecutionContextLogOptions.Default);
             }
 
+            if (!context.Global.HasDeprecatedSetOutput)
+            {
+                context.Global.HasDeprecatedSetOutput = true;
+                var telemetry = new JobTelemetry
+                {
+                    Type = JobTelemetryType.ActionCommand,
+                    Message = "DeprecatedCommand: set-output"
+                };
+                context.Global.JobTelemetry.Add(telemetry);
+            }
+
             if (!command.Properties.TryGetValue(SetOutputCommandProperties.Name, out string outputName) || string.IsNullOrEmpty(outputName))
             {
                 throw new Exception("Required field 'name' is missing in ##[set-output] command.");
@@ -353,6 +364,17 @@ namespace GitHub.Runner.Worker
                 context.AddIssue(issue, ExecutionContextLogOptions.Default);
             }
 
+            if (!context.Global.HasDeprecatedSaveState)
+            {
+                context.Global.HasDeprecatedSaveState = true;
+                var telemetry = new JobTelemetry
+                {
+                    Type = JobTelemetryType.ActionCommand,
+                    Message = "DeprecatedCommand: save-state"
+                };
+                context.Global.JobTelemetry.Add(telemetry);
+            }
+
             if (!command.Properties.TryGetValue(SaveStateCommandProperties.Name, out string stateName) || string.IsNullOrEmpty(stateName))
             {
                 throw new Exception("Required field 'name' is missing in ##[save-state] command.");

src/Runner.Worker/ActionManager.cs

@@ -773,10 +773,6 @@ namespace GitHub.Runner.Worker
             }
             else
             {
-                // make sure we get a clean folder ready to use.
-                IOUtil.DeleteDirectory(destDirectory, executionContext.CancellationToken);
-                Directory.CreateDirectory(destDirectory);
-
                 if (downloadInfo.PackageDetails != null)
                 {
                     executionContext.Output($"##[group]Download immutable action package '{downloadInfo.NameWithOwner}@{downloadInfo.Ref}'");
@@ -811,6 +807,50 @@ namespace GitHub.Runner.Worker
                 if (!string.IsNullOrEmpty(actionArchiveCacheDir) &&
                     Directory.Exists(actionArchiveCacheDir))
                 {
+                    var symlinkCachedActions = StringUtil.ConvertToBoolean(Environment.GetEnvironmentVariable(Constants.Variables.Agent.SymlinkCachedActions));
+                    if (symlinkCachedActions)
+                    {
+                        Trace.Info($"Checking if can symlink '{downloadInfo.ResolvedNameWithOwner}@{downloadInfo.ResolvedSha}'");
+
+                        var cacheDirectory = Path.Combine(actionArchiveCacheDir, downloadInfo.ResolvedNameWithOwner.Replace(Path.DirectorySeparatorChar, '_').Replace(Path.AltDirectorySeparatorChar, '_'), downloadInfo.ResolvedSha);
+                        if (Directory.Exists(cacheDirectory))
+                        {
+                            try
+                            {
+                                Trace.Info($"Found unpacked action directory '{cacheDirectory}' in cache directory '{actionArchiveCacheDir}'");
+                                                        
+                                // repository archive from github always contains a nested folder
+                                var nestedDirectories = new DirectoryInfo(cacheDirectory).GetDirectories();
+                                if (nestedDirectories.Length != 1)
+                                {
+                                    throw new InvalidOperationException($"'{cacheDirectory}' contains '{nestedDirectories.Length}' directories");
+                                }
+                                else
+                                {
+                                    executionContext.Debug($"Symlink '{nestedDirectories[0].Name}' to '{destDirectory}'");
+                                    // make sure we get a clean folder ready to use.
+                                    IOUtil.DeleteDirectory(destDirectory, executionContext.CancellationToken);
+                                    IOUtil.CreateSymbolicLink(destDirectory, nestedDirectories[0].FullName);
+                                }
+                                                        
+                                executionContext.Debug($"Created symlink from cached directory '{cacheDirectory}' to '{destDirectory}'");
+                                executionContext.Global.JobTelemetry.Add(new JobTelemetry()
+                                {
+                                    Type = JobTelemetryType.General,
+                                    Message = $"Action archive cache usage: {downloadInfo.ResolvedNameWithOwner}@{downloadInfo.ResolvedSha} use cache {useActionArchiveCache} has cache {hasActionArchiveCache} via symlink"
+                                });
+                                
+                                Trace.Info("Finished getting action repository.");
+                                return;
+                            }
+                            catch (Exception ex)
+                            {
+                                Trace.Error($"Failed to create symlink from cached directory '{cacheDirectory}' to '{destDirectory}'. Error: {ex}");
+                                // Fall through to normal download logic
+                            }
+                        }
+                    }
+
                     hasActionArchiveCache = true;
                     Trace.Info($"Check if action archive '{downloadInfo.ResolvedNameWithOwner}@{downloadInfo.ResolvedSha}' already exists in cache directory '{actionArchiveCacheDir}'");
 #if OS_WINDOWS
@@ -892,6 +932,10 @@ namespace GitHub.Runner.Worker
                 }
 #endif
 
+                // make sure we get a clean folder ready to use.
+                IOUtil.DeleteDirectory(destDirectory, executionContext.CancellationToken);
+                Directory.CreateDirectory(destDirectory);
+
                 // repository archive from github always contains a nested folder
                 var subDirectories = new DirectoryInfo(stagingDirectory).GetDirectories();
                 if (subDirectories.Length != 1)

src/Runner.Worker/ActionManifestManagerWrapper.cs

@@ -40,7 +40,7 @@ namespace GitHub.Runner.Worker
 
         public ActionDefinitionData Load(IExecutionContext executionContext, string manifestFile)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 executionContext,
                 "Load",
                 () => _legacyManager.Load(executionContext, manifestFile),
@@ -53,7 +53,7 @@ namespace GitHub.Runner.Worker
             TemplateToken token,
             IDictionary<string, PipelineContextData> extraExpressionValues)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 executionContext,
                 "EvaluateCompositeOutputs",
                 () => _legacyManager.EvaluateCompositeOutputs(executionContext, token, extraExpressionValues),
@@ -66,7 +66,7 @@ namespace GitHub.Runner.Worker
             SequenceToken token,
             IDictionary<string, PipelineContextData> extraExpressionValues)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 executionContext,
                 "EvaluateContainerArguments",
                 () => _legacyManager.EvaluateContainerArguments(executionContext, token, extraExpressionValues),
@@ -79,7 +79,7 @@ namespace GitHub.Runner.Worker
             MappingToken token,
             IDictionary<string, PipelineContextData> extraExpressionValues)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 executionContext,
                 "EvaluateContainerEnvironment",
                 () => _legacyManager.EvaluateContainerEnvironment(executionContext, token, extraExpressionValues),
@@ -96,7 +96,7 @@ namespace GitHub.Runner.Worker
             string inputName,
             TemplateToken token)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 executionContext,
                 "EvaluateDefaultInput",
                 () => _legacyManager.EvaluateDefaultInput(executionContext, inputName, token),
@@ -166,9 +166,150 @@ namespace GitHub.Runner.Worker
                 return null;
             }
 
-            // Serialize new steps and deserialize to old steps
-            var json = StringUtil.ConvertToJson(newSteps, Newtonsoft.Json.Formatting.None);
-            return StringUtil.ConvertFromJson<List<GitHub.DistributedTask.Pipelines.ActionStep>>(json);
+            var result = new List<GitHub.DistributedTask.Pipelines.ActionStep>();
+            foreach (var step in newSteps)
+            {
+                var actionStep = new GitHub.DistributedTask.Pipelines.ActionStep
+                {
+                    ContextName = step.Id,
+                };
+
+                if (step is GitHub.Actions.WorkflowParser.RunStep runStep)
+                {
+                    actionStep.Condition = ExtractConditionString(runStep.If);
+                    actionStep.DisplayNameToken = ConvertToLegacyToken<TemplateToken>(runStep.Name);
+                    actionStep.ContinueOnError = ConvertToLegacyToken<TemplateToken>(runStep.ContinueOnError);
+                    actionStep.TimeoutInMinutes = ConvertToLegacyToken<TemplateToken>(runStep.TimeoutMinutes);
+                    actionStep.Environment = ConvertToLegacyToken<TemplateToken>(runStep.Env);
+                    actionStep.Reference = new GitHub.DistributedTask.Pipelines.ScriptReference();
+                    actionStep.Inputs = BuildRunStepInputs(runStep);
+                }
+                else if (step is GitHub.Actions.WorkflowParser.ActionStep usesStep)
+                {
+                    actionStep.Condition = ExtractConditionString(usesStep.If);
+                    actionStep.DisplayNameToken = ConvertToLegacyToken<TemplateToken>(usesStep.Name);
+                    actionStep.ContinueOnError = ConvertToLegacyToken<TemplateToken>(usesStep.ContinueOnError);
+                    actionStep.TimeoutInMinutes = ConvertToLegacyToken<TemplateToken>(usesStep.TimeoutMinutes);
+                    actionStep.Environment = ConvertToLegacyToken<TemplateToken>(usesStep.Env);
+                    actionStep.Reference = ParseActionReference(usesStep.Uses?.Value);
+                    actionStep.Inputs = ConvertToLegacyToken<MappingToken>(usesStep.With);
+                }
+
+                result.Add(actionStep);
+            }
+            return result;
+        }
+
+        private string ExtractConditionString(GitHub.Actions.WorkflowParser.ObjectTemplating.Tokens.BasicExpressionToken ifToken)
+        {
+            if (ifToken == null)
+            {
+                return null;
+            }
+
+            // The Expression property is internal, so we use ToString() which formats as "${{ expr }}"
+            // Then strip the delimiters to get just the expression
+            var str = ifToken.ToString();
+            if (str.StartsWith("${{") && str.EndsWith("}}"))
+            {
+                return str.Substring(3, str.Length - 5).Trim();
+            }
+            return str;
+        }
+
+        private MappingToken BuildRunStepInputs(GitHub.Actions.WorkflowParser.RunStep runStep)
+        {
+            var inputs = new MappingToken(null, null, null);
+
+            // script (from run)
+            if (runStep.Run != null)
+            {
+                inputs.Add(
+                    new StringToken(null, null, null, "script"),
+                    ConvertToLegacyToken<TemplateToken>(runStep.Run));
+            }
+
+            // shell
+            if (runStep.Shell != null)
+            {
+                inputs.Add(
+                    new StringToken(null, null, null, "shell"),
+                    ConvertToLegacyToken<TemplateToken>(runStep.Shell));
+            }
+
+            // working-directory
+            if (runStep.WorkingDirectory != null)
+            {
+                inputs.Add(
+                    new StringToken(null, null, null, "workingDirectory"),
+                    ConvertToLegacyToken<TemplateToken>(runStep.WorkingDirectory));
+            }
+
+            return inputs.Count > 0 ? inputs : null;
+        }
+
+        private GitHub.DistributedTask.Pipelines.ActionStepDefinitionReference ParseActionReference(string uses)
+        {
+            if (string.IsNullOrEmpty(uses))
+            {
+                return null;
+            }
+
+            // Docker reference: docker://image:tag
+            if (uses.StartsWith("docker://", StringComparison.OrdinalIgnoreCase))
+            {
+                return new GitHub.DistributedTask.Pipelines.ContainerRegistryReference
+                {
+                    Image = uses.Substring("docker://".Length)
+                };
+            }
+
+            // Local path reference: ./path/to/action
+            if (uses.StartsWith("./") || uses.StartsWith(".\\"))
+            {
+                return new GitHub.DistributedTask.Pipelines.RepositoryPathReference
+                {
+                    RepositoryType = "self",
+                    Path = uses
+                };
+            }
+
+            // Repository reference: owner/repo@ref or owner/repo/path@ref
+            var atIndex = uses.LastIndexOf('@');
+            string refPart = null;
+            string repoPart = uses;
+
+            if (atIndex > 0)
+            {
+                refPart = uses.Substring(atIndex + 1);
+                repoPart = uses.Substring(0, atIndex);
+            }
+
+            // Split by / to get owner/repo and optional path
+            var parts = repoPart.Split('/');
+            string name;
+            string path = null;
+
+            if (parts.Length >= 2)
+            {
+                name = $"{parts[0]}/{parts[1]}";
+                if (parts.Length > 2)
+                {
+                    path = string.Join("/", parts, 2, parts.Length - 2);
+                }
+            }
+            else
+            {
+                name = repoPart;
+            }
+
+            return new GitHub.DistributedTask.Pipelines.RepositoryPathReference
+            {
+                RepositoryType = "GitHub",
+                Name = name,
+                Ref = refPart,
+                Path = path
+            };
         }
 
         private T ConvertToLegacyToken<T>(GitHub.Actions.WorkflowParser.ObjectTemplating.Tokens.TemplateToken newToken) where T : TemplateToken
@@ -217,27 +358,13 @@ namespace GitHub.Runner.Worker
         }
 
         // Comparison helper methods
-        private TLegacy EvaluateWrapper<TLegacy, TNew>(
+        private TLegacy EvaluateAndCompare<TLegacy, TNew>(
             IExecutionContext context,
             string methodName,
             Func<TLegacy> legacyEvaluator,
             Func<TNew> newEvaluator,
             Func<TLegacy, TNew, bool> resultComparer)
         {
-            // Cutover: use only the new evaluator, convert result to legacy type
-            if ((context.Global.Variables.GetBoolean(Constants.Runner.Features.CutoverWorkflowParser) ?? false)
-                || StringUtil.ConvertToBoolean(Environment.GetEnvironmentVariable("ACTIONS_RUNNER_CUTOVER_WORKFLOW_PARSER")))
-            {
-                var newResult = newEvaluator();
-                if (typeof(TLegacy) == typeof(TNew))
-                {
-                    return (TLegacy)(object)newResult;
-                }
-
-                var json = StringUtil.ConvertToJson(newResult, Newtonsoft.Json.Formatting.None);
-                return StringUtil.ConvertFromJson<TLegacy>(json);
-            }
-
             // Legacy only?
             if (!((context.Global.Variables.GetBoolean(Constants.Runner.Features.CompareWorkflowParser) ?? false)
                 || StringUtil.ConvertToBoolean(Environment.GetEnvironmentVariable("ACTIONS_RUNNER_COMPARE_WORKFLOW_PARSER"))))
@@ -648,6 +775,14 @@ namespace GitHub.Runner.Worker
                 return false;
             }
 
+            // Check for known equivalent error patterns (e.g., JSON parse errors)
+            // where both parsers correctly reject invalid input but with different wording
+            if (PipelineTemplateEvaluatorWrapper.HasJsonExceptionType(legacyException) && PipelineTemplateEvaluatorWrapper.HasJsonExceptionType(newException))
+            {
+                trace.Info("CompareExceptions - both exceptions are JSON parse errors, treating as matched");
+                return true;
+            }
+
             // Compare exception messages recursively (including inner exceptions)
             var legacyMessages = GetExceptionMessages(legacyException);
             var newMessages = GetExceptionMessages(newException);
@@ -712,5 +847,6 @@ namespace GitHub.Runner.Worker
 
             return messages;
         }
+
     }
 }

src/Runner.Worker/ExecutionContext.cs

@@ -856,6 +856,9 @@ namespace GitHub.Runner.Worker
             // Job level annotations
             Global.JobAnnotations = new List<Annotation>();
 
+            // Track Node.js 20 actions for deprecation warning
+            Global.DeprecatedNode20Actions = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
             // Job Outputs
             JobOutputs = new Dictionary<string, VariableValue>(StringComparer.OrdinalIgnoreCase);
 
@@ -1416,8 +1419,7 @@ namespace GitHub.Runner.Worker
         public static IPipelineTemplateEvaluator ToPipelineTemplateEvaluator(this IExecutionContext context, ObjectTemplating.ITraceWriter traceWriter = null)
         {
             // Create wrapper?
-            if ((context.Global.Variables.GetBoolean(Constants.Runner.Features.CompareWorkflowParser) ?? false) || StringUtil.ConvertToBoolean(Environment.GetEnvironmentVariable("ACTIONS_RUNNER_COMPARE_WORKFLOW_PARSER"))
-                || (context.Global.Variables.GetBoolean(Constants.Runner.Features.CutoverWorkflowParser) ?? false) || StringUtil.ConvertToBoolean(Environment.GetEnvironmentVariable("ACTIONS_RUNNER_CUTOVER_WORKFLOW_PARSER")))
+            if ((context.Global.Variables.GetBoolean(Constants.Runner.Features.CompareWorkflowParser) ?? false) || StringUtil.ConvertToBoolean(Environment.GetEnvironmentVariable("ACTIONS_RUNNER_COMPARE_WORKFLOW_PARSER")))
             {
                 return (context as ExecutionContext).ToPipelineTemplateEvaluatorInternal(traceWriter);
             }

src/Runner.Worker/GlobalContext.cs

@@ -31,5 +31,8 @@ namespace GitHub.Runner.Worker
         public JObject ContainerHookState { get; set; }
         public bool HasTemplateEvaluatorMismatch { get; set; }
         public bool HasActionManifestMismatch { get; set; }
+        public bool HasDeprecatedSetOutput { get; set; }
+        public bool HasDeprecatedSaveState { get; set; }
+        public HashSet<string> DeprecatedNode20Actions { get; set; }
     }
 }

src/Runner.Worker/Handlers/CompositeActionHandler.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -226,6 +227,11 @@ namespace GitHub.Runner.Worker.Handlers
         {
             ArgUtil.NotNull(embeddedSteps, nameof(embeddedSteps));
 
+            bool emitCompositeMarkers =
+                (ExecutionContext.Global.Variables.GetBoolean(Constants.Runner.Features.EmitCompositeMarkers) ?? false)
+                || StringUtil.ConvertToBoolean(
+                    System.Environment.GetEnvironmentVariable(Constants.Variables.Agent.EmitCompositeMarkers));
+
             foreach (IStep step in embeddedSteps)
             {
                 Trace.Info($"Processing embedded step: DisplayName='{step.DisplayName}'");
@@ -297,6 +303,20 @@ namespace GitHub.Runner.Worker.Handlers
                     SetStepConclusion(step, TaskResult.Failed);
                 }
 
+                // Marker ID uses the step's fully qualified context name (ScopeName.ContextName),
+                // which encodes the full composite nesting chain at any depth.
+                var markerId = emitCompositeMarkers ? step.ExecutionContext.GetFullyQualifiedContextName() : null;
+                var stepStopwatch = default(Stopwatch);
+                var endMarkerEmitted = false;
+
+                // Emit start marker after full context setup so display name expressions resolve correctly
+                if (emitCompositeMarkers)
+                {
+                    step.TryUpdateDisplayName(out _);
+                    ExecutionContext.Output($"##[start-action display={EscapeProperty(SanitizeDisplayName(step.DisplayName))};id={EscapeProperty(markerId)}]");
+                    stepStopwatch = Stopwatch.StartNew();
+                }
+
                 // Register Callback
                 CancellationTokenRegistration? jobCancelRegister = null;
                 try
@@ -381,6 +401,14 @@ namespace GitHub.Runner.Worker.Handlers
                         // Condition is false
                         Trace.Info("Skipping step due to condition evaluation.");
                         SetStepConclusion(step, TaskResult.Skipped);
+
+                        if (emitCompositeMarkers)
+                        {
+                            stepStopwatch.Stop();
+                            ExecutionContext.Output($"##[end-action id={EscapeProperty(markerId)};outcome=skipped;conclusion=skipped;duration_ms=0]");
+                            endMarkerEmitted = true;
+                        }
+
                         continue;
                     }
                     else if (conditionEvaluateError != null)
@@ -389,13 +417,31 @@ namespace GitHub.Runner.Worker.Handlers
                         step.ExecutionContext.Error(conditionEvaluateError);
                         SetStepConclusion(step, TaskResult.Failed);
                         ExecutionContext.Result = TaskResult.Failed;
+
+                        if (emitCompositeMarkers)
+                        {
+                            stepStopwatch.Stop();
+                            ExecutionContext.Output($"##[end-action id={EscapeProperty(markerId)};outcome=failure;conclusion=failure;duration_ms={stepStopwatch.ElapsedMilliseconds}]");
+                            endMarkerEmitted = true;
+                        }
+
                         break;
                     }
                     else
                     {
                         await RunStepAsync(step);
-                    }
 
+                        if (emitCompositeMarkers)
+                        {
+                            stepStopwatch.Stop();
+                            // Outcome = raw result before continue-on-error (null when continue-on-error didn't fire)
+                            // Result = final result after continue-on-error
+                            var outcome = (step.ExecutionContext.Outcome ?? step.ExecutionContext.Result ?? TaskResult.Succeeded).ToActionResult().ToString().ToLowerInvariant();
+                            var conclusion = (step.ExecutionContext.Result ?? TaskResult.Succeeded).ToActionResult().ToString().ToLowerInvariant();
+                            ExecutionContext.Output($"##[end-action id={EscapeProperty(markerId)};outcome={outcome};conclusion={conclusion};duration_ms={stepStopwatch.ElapsedMilliseconds}]");
+                            endMarkerEmitted = true;
+                        }
+                    }
                 }
                 finally
                 {
@@ -404,6 +450,14 @@ namespace GitHub.Runner.Worker.Handlers
                         jobCancelRegister?.Dispose();
                         jobCancelRegister = null;
                     }
+
+                    if (emitCompositeMarkers && !endMarkerEmitted)
+                    {
+                        stepStopwatch.Stop();
+                        var outcome = (step.ExecutionContext.Outcome ?? step.ExecutionContext.Result ?? TaskResult.Failed).ToActionResult().ToString().ToLowerInvariant();
+                        var conclusion = (step.ExecutionContext.Result ?? TaskResult.Failed).ToActionResult().ToString().ToLowerInvariant();
+                        ExecutionContext.Output($"##[end-action id={EscapeProperty(markerId)};outcome={outcome};conclusion={conclusion};duration_ms={stepStopwatch.ElapsedMilliseconds}]");
+                    }
                 }
                 // Check failed or cancelled
                 if (step.ExecutionContext.Result == TaskResult.Failed || step.ExecutionContext.Result == TaskResult.Canceled)
@@ -470,5 +524,44 @@ namespace GitHub.Runner.Worker.Handlers
             step.ExecutionContext.Result = result;
             step.ExecutionContext.UpdateGlobalStepsContext();
         }
+
+        /// <summary>
+        /// Escapes marker property values so they cannot break the ##[command key=value] format.
+        /// Delegates to ActionCommand.EscapeValue which escapes `;`, `]`, `\r`, `\n`, and `%`.
+        /// </summary>
+        internal static string EscapeProperty(string value)
+        {
+            return ActionCommand.EscapeValue(value);
+        }
+
+        /// <summary>Maximum character length for display names in markers to prevent log bloat.</summary>
+        internal const int MaxDisplayNameLength = 1000;
+
+        /// <summary>
+        /// Normalizes a step display name for safe embedding in a marker property.
+        /// Trims leading whitespace, drops everything after the first newline, and
+        /// truncates to <see cref="MaxDisplayNameLength"/> characters.
+        /// </summary>
+        internal static string SanitizeDisplayName(string displayName)
+        {
+            if (string.IsNullOrEmpty(displayName)) return displayName;
+
+            // Take first line only (FormatStepName in ActionRunner.cs already does this
+            // for most cases, but be defensive for any code path that skips it)
+            var result = displayName.TrimStart(' ', '\t', '\r', '\n');
+            var firstNewLine = result.IndexOfAny(new[] { '\r', '\n' });
+            if (firstNewLine >= 0)
+            {
+                result = result.Substring(0, firstNewLine);
+            }
+
+            // Truncate excessively long names
+            if (result.Length > MaxDisplayNameLength)
+            {
+                result = result.Substring(0, MaxDisplayNameLength);
+            }
+
+            return result;
+        }
     }
 }

src/Runner.Worker/Handlers/HandlerFactory.cs

@@ -65,6 +65,20 @@ namespace GitHub.Runner.Worker.Handlers
                     nodeData.NodeVersion = Common.Constants.Runner.NodeMigration.Node20;
                 }
 
+                // Track Node.js 20 actions for deprecation annotation
+                if (string.Equals(nodeData.NodeVersion, Constants.Runner.NodeMigration.Node20, StringComparison.InvariantCultureIgnoreCase))
+                {
+                    bool warnOnNode20 = executionContext.Global.Variables?.GetBoolean(Constants.Runner.NodeMigration.WarnOnNode20Flag) ?? false;
+                    if (warnOnNode20)
+                    {
+                        string actionName = GetActionName(action);
+                        if (!string.IsNullOrEmpty(actionName))
+                        {
+                            executionContext.Global.DeprecatedNode20Actions?.Add(actionName);
+                        }
+                    }
+                }
+
                 // Check if node20 was explicitly specified in the action
                 // We don't modify if node24 was explicitly specified
                 if (string.Equals(nodeData.NodeVersion, Constants.Runner.NodeMigration.Node20, StringComparison.InvariantCultureIgnoreCase))
@@ -90,7 +104,8 @@ namespace GitHub.Runner.Worker.Handlers
                     if (useNode24ByDefault && !requireNode24 && string.Equals(finalNodeVersion, Constants.Runner.NodeMigration.Node24, StringComparison.OrdinalIgnoreCase))
                     {
                         string infoMessage = "Node 20 is being deprecated. This workflow is running with Node 24 by default. " +
-                                             "If you need to temporarily use Node 20, you can set the ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION=true environment variable.";
+                                             "If you need to temporarily use Node 20, you can set the ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION=true environment variable. " +
+                                             $"For more information see: {Constants.Runner.NodeMigration.Node20DeprecationUrl}";
                         executionContext.Output(infoMessage);
                     }
                 }
@@ -129,5 +144,25 @@ namespace GitHub.Runner.Worker.Handlers
             handler.LocalActionContainerSetupSteps = localActionContainerSetupSteps;
             return handler;
         }
+
+        private static string GetActionName(Pipelines.ActionStepDefinitionReference action)
+        {
+            if (action is Pipelines.RepositoryPathReference repoRef)
+            {
+                var pathString = string.Empty;
+                if (!string.IsNullOrEmpty(repoRef.Path))
+                {
+                    pathString = string.IsNullOrEmpty(repoRef.Name)
+                        ? repoRef.Path
+                        : $"/{repoRef.Path}";
+                }
+                var repoString = string.IsNullOrEmpty(repoRef.Ref)
+                    ? $"{repoRef.Name}{pathString}"
+                    : $"{repoRef.Name}{pathString}@{repoRef.Ref}";
+                return string.IsNullOrEmpty(repoString) ? null : repoString;
+            }
+
+            return null;
+        }
     }
 }

src/Runner.Worker/Handlers/OutputManager.cs

@@ -90,6 +90,14 @@ namespace GitHub.Runner.Worker.Handlers
                 }
             }
 
+            // Strip runner-controlled markers from user output to prevent injection
+            if (!String.IsNullOrEmpty(line) &&
+                (line.Contains("##[start-action") || line.Contains("##[end-action")))
+            {
+                line = line.Replace("##[start-action", @"##[\start-action")
+                           .Replace("##[end-action", @"##[\end-action");
+            }
+
             // Problem matchers
             if (_matchers.Length > 0)
             {

src/Runner.Worker/JobExtension.cs

@@ -735,6 +735,15 @@ namespace GitHub.Runner.Worker
                             context.Global.JobTelemetry.Add(new JobTelemetry() { Type = JobTelemetryType.ConnectivityCheck, Message = $"Fail to check service connectivity. {ex.Message}" });
                         }
                     }
+
+                    // Add deprecation warning annotation for Node.js 20 actions
+                    if (context.Global.DeprecatedNode20Actions?.Count > 0)
+                    {
+                        var sortedActions = context.Global.DeprecatedNode20Actions.OrderBy(a => a, StringComparer.OrdinalIgnoreCase);
+                        var actionsList = string.Join(", ", sortedActions);
+                        var deprecationMessage = $"Node.js 20 actions are deprecated. The following actions are running on Node.js 20 and may not work as expected: {actionsList}. Actions will be forced to run with Node.js 24 by default starting June 2nd, 2026. Please check if updated versions of these actions are available that support Node.js 24. To opt into Node.js 24 now, set the FORCE_JAVASCRIPT_ACTIONS_TO_NODE24=true environment variable on the runner or in your workflow file. Once Node.js 24 becomes the default, you can temporarily opt out by setting ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION=true. For more information see: {Constants.Runner.NodeMigration.Node20DeprecationUrl}";
+                        context.Warning(deprecationMessage);
+                    }
                 }
                 catch (Exception ex)
                 {

src/Runner.Worker/PipelineTemplateEvaluatorWrapper.cs

@@ -19,7 +19,6 @@ namespace GitHub.Runner.Worker
         private WorkflowTemplateEvaluator _newEvaluator;
         private IExecutionContext _context;
         private Tracing _trace;
-        private bool _cutover;
 
         public PipelineTemplateEvaluatorWrapper(
             IHostContext hostContext,
@@ -30,8 +29,6 @@ namespace GitHub.Runner.Worker
             ArgUtil.NotNull(context, nameof(context));
             _context = context;
             _trace = hostContext.GetTrace(nameof(PipelineTemplateEvaluatorWrapper));
-            _cutover = (context.Global.Variables.GetBoolean(Constants.Runner.Features.CutoverWorkflowParser) ?? false)
-                || StringUtil.ConvertToBoolean(Environment.GetEnvironmentVariable("ACTIONS_RUNNER_CUTOVER_WORKFLOW_PARSER"));
 
             if (traceWriter == null)
             {
@@ -58,7 +55,7 @@ namespace GitHub.Runner.Worker
             DictionaryContextData contextData,
             IList<IFunctionInfo> expressionFunctions)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 "EvaluateStepContinueOnError",
                 () => _legacyEvaluator.EvaluateStepContinueOnError(token, contextData, expressionFunctions),
                 () => _newEvaluator.EvaluateStepContinueOnError(ConvertToken(token), ConvertData(contextData), ConvertFunctions(expressionFunctions)),
@@ -70,7 +67,7 @@ namespace GitHub.Runner.Worker
             DictionaryContextData contextData,
             IList<IFunctionInfo> expressionFunctions)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 "EvaluateStepDisplayName",
                 () => _legacyEvaluator.EvaluateStepDisplayName(token, contextData, expressionFunctions),
                 () => _newEvaluator.EvaluateStepName(ConvertToken(token), ConvertData(contextData), ConvertFunctions(expressionFunctions)),
@@ -83,7 +80,7 @@ namespace GitHub.Runner.Worker
             IList<IFunctionInfo> expressionFunctions,
             StringComparer keyComparer)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 "EvaluateStepEnvironment",
                 () => _legacyEvaluator.EvaluateStepEnvironment(token, contextData, expressionFunctions, keyComparer),
                 () => _newEvaluator.EvaluateStepEnvironment(ConvertToken(token), ConvertData(contextData), ConvertFunctions(expressionFunctions), keyComparer),
@@ -96,7 +93,7 @@ namespace GitHub.Runner.Worker
             IList<IFunctionInfo> expressionFunctions,
             IEnumerable<KeyValuePair<string, object>> expressionState)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 "EvaluateStepIf",
                 () => _legacyEvaluator.EvaluateStepIf(token, contextData, expressionFunctions, expressionState),
                 () => _newEvaluator.EvaluateStepIf(ConvertToken(token), ConvertData(contextData), ConvertFunctions(expressionFunctions), expressionState),
@@ -108,7 +105,7 @@ namespace GitHub.Runner.Worker
             DictionaryContextData contextData,
             IList<IFunctionInfo> expressionFunctions)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 "EvaluateStepInputs",
                 () => _legacyEvaluator.EvaluateStepInputs(token, contextData, expressionFunctions),
                 () => _newEvaluator.EvaluateStepInputs(ConvertToken(token), ConvertData(contextData), ConvertFunctions(expressionFunctions)),
@@ -120,7 +117,7 @@ namespace GitHub.Runner.Worker
             DictionaryContextData contextData,
             IList<IFunctionInfo> expressionFunctions)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 "EvaluateStepTimeout",
                 () => _legacyEvaluator.EvaluateStepTimeout(token, contextData, expressionFunctions),
                 () => _newEvaluator.EvaluateStepTimeout(ConvertToken(token), ConvertData(contextData), ConvertFunctions(expressionFunctions)),
@@ -132,7 +129,7 @@ namespace GitHub.Runner.Worker
             DictionaryContextData contextData,
             IList<IFunctionInfo> expressionFunctions)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 "EvaluateJobContainer",
                 () => _legacyEvaluator.EvaluateJobContainer(token, contextData, expressionFunctions),
                 () => _newEvaluator.EvaluateJobContainer(ConvertToken(token), ConvertData(contextData), ConvertFunctions(expressionFunctions)),
@@ -144,7 +141,7 @@ namespace GitHub.Runner.Worker
             DictionaryContextData contextData,
             IList<IFunctionInfo> expressionFunctions)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 "EvaluateJobOutput",
                 () => _legacyEvaluator.EvaluateJobOutput(token, contextData, expressionFunctions),
                 () => _newEvaluator.EvaluateJobOutputs(ConvertToken(token), ConvertData(contextData), ConvertFunctions(expressionFunctions)),
@@ -156,7 +153,7 @@ namespace GitHub.Runner.Worker
             DictionaryContextData contextData,
             IList<IFunctionInfo> expressionFunctions)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 "EvaluateEnvironmentUrl",
                 () => _legacyEvaluator.EvaluateEnvironmentUrl(token, contextData, expressionFunctions),
                 () => _newEvaluator.EvaluateJobEnvironmentUrl(ConvertToken(token), ConvertData(contextData), ConvertFunctions(expressionFunctions)),
@@ -168,7 +165,7 @@ namespace GitHub.Runner.Worker
             DictionaryContextData contextData,
             IList<IFunctionInfo> expressionFunctions)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 "EvaluateJobDefaultsRun",
                 () => _legacyEvaluator.EvaluateJobDefaultsRun(token, contextData, expressionFunctions),
                 () => _newEvaluator.EvaluateJobDefaultsRun(ConvertToken(token), ConvertData(contextData), ConvertFunctions(expressionFunctions)),
@@ -180,7 +177,7 @@ namespace GitHub.Runner.Worker
             DictionaryContextData contextData,
             IList<IFunctionInfo> expressionFunctions)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 "EvaluateJobServiceContainers",
                 () => _legacyEvaluator.EvaluateJobServiceContainers(token, contextData, expressionFunctions),
                 () => _newEvaluator.EvaluateJobServiceContainers(ConvertToken(token), ConvertData(contextData), ConvertFunctions(expressionFunctions)),
@@ -192,7 +189,7 @@ namespace GitHub.Runner.Worker
             DictionaryContextData contextData,
             IList<IFunctionInfo> expressionFunctions)
         {
-            return EvaluateWrapper(
+            return EvaluateAndCompare(
                 "EvaluateJobSnapshotRequest",
                 () => _legacyEvaluator.EvaluateJobSnapshotRequest(token, contextData, expressionFunctions),
                 () => _newEvaluator.EvaluateSnapshot(string.Empty, ConvertToken(token), ConvertData(contextData), ConvertFunctions(expressionFunctions)),
@@ -219,24 +216,14 @@ namespace GitHub.Runner.Worker
             }
         }
 
-        private TLegacy EvaluateWrapper<TLegacy, TNew>(
+        internal TLegacy EvaluateAndCompare<TLegacy, TNew>(
             string methodName,
             Func<TLegacy> legacyEvaluator,
             Func<TNew> newEvaluator,
             Func<TLegacy, TNew, bool> resultComparer)
         {
-            // Cutover: use only the new evaluator, convert result to legacy type
-            if (_cutover)
-            {
-                var newResult = newEvaluator();
-                if (typeof(TLegacy) == typeof(TNew))
-                {
-                    return (TLegacy)(object)newResult;
-                }
-
-                var json = StringUtil.ConvertToJson(newResult, Newtonsoft.Json.Formatting.None);
-                return StringUtil.ConvertFromJson<TLegacy>(json);
-            }
+            // Capture cancellation state before evaluation
+            var cancellationRequestedBefore = _context.CancellationToken.IsCancellationRequested;
 
             // Legacy evaluator
             var legacyException = default(Exception);
@@ -269,14 +256,18 @@ namespace GitHub.Runner.Worker
                     newException = ex;
                 }
 
+                // Capture cancellation state after evaluation
+                var cancellationRequestedAfter = _context.CancellationToken.IsCancellationRequested;
+
                 // Compare results or exceptions
+                bool hasMismatch = false;
                 if (legacyException != null || newException != null)
                 {
                     // Either one or both threw exceptions - compare them
                     if (!CompareExceptions(legacyException, newException))
                     {
                         _trace.Info($"{methodName} exception mismatch");
-                        RecordMismatch($"{methodName}");
+                        hasMismatch = true;
                     }
                 }
                 else
@@ -285,6 +276,20 @@ namespace GitHub.Runner.Worker
                     if (!resultComparer(legacyResult, newResult))
                     {
                         _trace.Info($"{methodName} mismatch");
+                        hasMismatch = true;
+                    }
+                }
+
+                // Only record mismatch if it wasn't caused by a cancellation race condition
+                if (hasMismatch)
+                {
+                    if (!cancellationRequestedBefore && cancellationRequestedAfter)
+                    {
+                        // Cancellation state changed during evaluation window - skip recording
+                        _trace.Info($"{methodName} mismatch skipped due to cancellation race condition");
+                    }
+                    else
+                    {
                         RecordMismatch($"{methodName}");
                     }
                 }
@@ -628,6 +633,13 @@ namespace GitHub.Runner.Worker
                 return false;
             }
 
+            // Check for known equivalent error patterns (e.g., JSON parse errors)
+            // where both parsers correctly reject invalid input but with different wording
+            if (IsKnownEquivalentErrorPattern(legacyException, newException))
+            {
+                return true;
+            }
+
             // Compare exception messages recursively (including inner exceptions)
             var legacyMessages = GetExceptionMessages(legacyException);
             var newMessages = GetExceptionMessages(newException);
@@ -650,6 +662,67 @@ namespace GitHub.Runner.Worker
             return true;
         }
 
+        /// <summary>
+        /// Checks if two exceptions match a known pattern where both parsers correctly reject
+        /// invalid input but with different error messages (e.g., JSON parse errors from fromJSON).
+        /// </summary>
+        private bool IsKnownEquivalentErrorPattern(Exception legacyException, Exception newException)
+        {
+            // fromJSON('') - both parsers fail when parsing empty string as JSON
+            // The error messages differ but both indicate JSON parsing failure.
+            // Legacy throws raw JsonReaderException: "Error reading JToken from JsonReader..."
+            // New wraps it: "Error parsing fromJson" with inner JsonReaderException
+            // Both may be wrapped in TemplateValidationException: "The template is not valid..."
+            if (HasJsonExceptionType(legacyException) && HasJsonExceptionType(newException))
+            {
+                _trace.Info("CompareExceptions - both exceptions are JSON parse errors, treating as matched");
+                return true;
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Checks if the exception chain contains a JSON-related exception type.
+        /// </summary>
+        internal static bool HasJsonExceptionType(Exception ex)
+        {
+            var toProcess = new Queue<Exception>();
+            toProcess.Enqueue(ex);
+            int count = 0;
+
+            while (toProcess.Count > 0 && count < 50)
+            {
+                var current = toProcess.Dequeue();
+                if (current == null) continue;
+
+                count++;
+
+                if (current is Newtonsoft.Json.JsonReaderException ||
+                    current is System.Text.Json.JsonException)
+                {
+                    return true;
+                }
+
+                if (current is AggregateException aggregateEx)
+                {
+                    foreach (var innerEx in aggregateEx.InnerExceptions)
+                    {
+                        if (innerEx != null && count < 50)
+                        {
+                            toProcess.Enqueue(innerEx);
+                        }
+                    }
+                }
+                else if (current.InnerException != null)
+                {
+                    toProcess.Enqueue(current.InnerException);
+                }
+            }
+
+            return false;
+        }
+
         private IList<string> GetExceptionMessages(Exception ex)
         {
             var messages = new List<string>();

src/Sdk/WorkflowParser/Conversion/WorkflowTemplateConverter.cs

@@ -1,4 +1,4 @@
-#nullable disable // Consider removing in the future to minimize likelihood of NullReferenceException; refer https://learn.microsoft.com/en-us/dotnet/csharp/nullable-references
+#nullable disable // Consider removing in the future to minimize likelihood of NullReferenceException; refer https://learn.microsoft.com/en-us/dotnet/csharp/nullable-references
 
 using System;
 using System.Collections.Generic;
@@ -43,7 +43,7 @@ namespace GitHub.Actions.WorkflowParser.Conversion
                     {
                         case WorkflowTemplateConstants.On:
                             var inputTypes = ConvertToOnWorkflowDispatchInputTypes(workflowPair.Value);
-                            foreach(var item in inputTypes)
+                            foreach (var item in inputTypes)
                             {
                                 result.InputTypes.TryAdd(item.Key, item.Value);
                             }
@@ -432,7 +432,7 @@ namespace GitHub.Actions.WorkflowParser.Conversion
                 context.Error(snapshotToken, $"job {WorkflowTemplateConstants.Snapshot} {WorkflowTemplateConstants.ImageName} is required.");
                 return null;
             }
-            
+
             return new Snapshot
             {
                 ImageName = imageName,
@@ -445,7 +445,7 @@ namespace GitHub.Actions.WorkflowParser.Conversion
         {
             var versionSegments = versionString.Split(".");
 
-            if (versionSegments.Length != 2 || 
+            if (versionSegments.Length != 2 ||
                 !versionSegments[1].Equals("*") ||
                 !Int32.TryParse(versionSegments[0], NumberStyles.None, CultureInfo.InvariantCulture, result: out int parsedMajor) ||
                 parsedMajor < 0)
@@ -1154,7 +1154,12 @@ namespace GitHub.Actions.WorkflowParser.Conversion
 
             if (String.IsNullOrEmpty(result.Image))
             {
-                context.Error(value, "Container image cannot be empty");
+                // Only error during early validation (parse time)
+                // At runtime (expression evaluation), empty image = no container
+                if (isEarlyValidation)
+                {
+                    context.Error(value, "Container image cannot be empty");
+                }
                 return null;
             }
 
@@ -1838,9 +1843,9 @@ namespace GitHub.Actions.WorkflowParser.Conversion
                     case "actions":
                         permissions.Actions = permissionLevel;
                         break;
-					case "artifact-metadata":
-						permissions.ArtifactMetadata = permissionLevel;
-						break;
+                    case "artifact-metadata":
+                        permissions.ArtifactMetadata = permissionLevel;
+                        break;
                     case "attestations":
                         permissions.Attestations = permissionLevel;
                         break;

src/Test/L0/Listener/JobDispatcherL0.cs

@@ -739,7 +739,8 @@ namespace GitHub.Runner.Common.Tests.Listener
                 Assert.True(jobDispatcher.RunOnceJobCompleted.Task.IsCompleted, "JobDispatcher should set task complete token for one time agent.");
                 if (jobDispatcher.RunOnceJobCompleted.Task.IsCompleted)
                 {
-                    Assert.True(await jobDispatcher.RunOnceJobCompleted.Task, "JobDispatcher should set task complete token to 'TRUE' for one time agent.");
+                    var result = await jobDispatcher.RunOnceJobCompleted.Task;
+                    Assert.Equal(TaskResult.Succeeded, result);
                 }
             }
         }

src/Test/L0/Listener/RunnerL0.cs

@@ -295,13 +295,13 @@ namespace GitHub.Runner.Common.Tests.Listener
                 _messageListener.Setup(x => x.DeleteMessageAsync(It.IsAny<TaskAgentMessage>()))
                     .Returns(Task.CompletedTask);
 
-                var runOnceJobCompleted = new TaskCompletionSource<bool>();
+                var runOnceJobCompleted = new TaskCompletionSource<TaskResult>();
                 _jobDispatcher.Setup(x => x.RunOnceJobCompleted)
                     .Returns(runOnceJobCompleted);
                 _jobDispatcher.Setup(x => x.Run(It.IsAny<Pipelines.AgentJobRequestMessage>(), It.IsAny<bool>()))
                     .Callback(() =>
                     {
-                        runOnceJobCompleted.TrySetResult(true);
+                        runOnceJobCompleted.TrySetResult(TaskResult.Succeeded);
                     });
                 _jobNotification.Setup(x => x.StartClient(It.IsAny<String>()))
                     .Callback(() =>
@@ -399,13 +399,13 @@ namespace GitHub.Runner.Common.Tests.Listener
                 _messageListener.Setup(x => x.DeleteMessageAsync(It.IsAny<TaskAgentMessage>()))
                     .Returns(Task.CompletedTask);
 
-                var runOnceJobCompleted = new TaskCompletionSource<bool>();
+                var runOnceJobCompleted = new TaskCompletionSource<TaskResult>();
                 _jobDispatcher.Setup(x => x.RunOnceJobCompleted)
                     .Returns(runOnceJobCompleted);
                 _jobDispatcher.Setup(x => x.Run(It.IsAny<Pipelines.AgentJobRequestMessage>(), It.IsAny<bool>()))
                     .Callback(() =>
                     {
-                        runOnceJobCompleted.TrySetResult(true);
+                        runOnceJobCompleted.TrySetResult(TaskResult.Succeeded);
                     });
                 _jobNotification.Setup(x => x.StartClient(It.IsAny<String>()))
                     .Callback(() =>
@@ -733,8 +733,8 @@ namespace GitHub.Runner.Common.Tests.Listener
 
                 _configStore.Setup(x => x.IsServiceConfigured()).Returns(false);
 
-                var completedTask = new TaskCompletionSource<bool>();
-                completedTask.SetResult(true);
+                var completedTask = new TaskCompletionSource<TaskResult>();
+                completedTask.SetResult(TaskResult.Succeeded);
                 _jobDispatcher.Setup(x => x.RunOnceJobCompleted).Returns(completedTask);
 
                 //Act
@@ -834,8 +834,8 @@ namespace GitHub.Runner.Common.Tests.Listener
 
                 _configStore.Setup(x => x.IsServiceConfigured()).Returns(false);
 
-                var completedTask = new TaskCompletionSource<bool>();
-                completedTask.SetResult(true);
+                var completedTask = new TaskCompletionSource<TaskResult>();
+                completedTask.SetResult(TaskResult.Succeeded);
                 _jobDispatcher.Setup(x => x.RunOnceJobCompleted).Returns(completedTask);
 
                 //Act
@@ -954,8 +954,8 @@ namespace GitHub.Runner.Common.Tests.Listener
 
                 _configStore.Setup(x => x.IsServiceConfigured()).Returns(false);
 
-                var completedTask = new TaskCompletionSource<bool>();
-                completedTask.SetResult(true);
+                var completedTask = new TaskCompletionSource<TaskResult>();
+                completedTask.SetResult(TaskResult.Succeeded);
                 _jobDispatcher.Setup(x => x.RunOnceJobCompleted).Returns(completedTask);
 
                 //Act

src/Test/L0/Worker/ActionCommandManagerL0.cs

@@ -457,6 +457,8 @@ namespace GitHub.Runner.Common.Tests.Worker
                 new SetEnvCommandExtension(),
                 new WarningCommandExtension(),
                 new AddMaskCommandExtension(),
+                new SetOutputCommandExtension(),
+                new SaveStateCommandExtension(),
             };
             foreach (var command in commands)
             {
@@ -499,5 +501,53 @@ namespace GitHub.Runner.Common.Tests.Worker
             };
         }
 
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SetOutputCommand_EmitsTelemetryOnce()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                _ec.Object.Global.JobTelemetry = new List<JobTelemetry>();
+                var reference = string.Empty;
+                _ec.Setup(x => x.SetOutput(It.IsAny<string>(), It.IsAny<string>(), out reference));
+
+                // First set-output should add telemetry
+                Assert.True(_commandManager.TryProcessCommand(_ec.Object, "::set-output name=foo::bar", null));
+                Assert.Single(_ec.Object.Global.JobTelemetry);
+                Assert.Equal(JobTelemetryType.ActionCommand, _ec.Object.Global.JobTelemetry[0].Type);
+                Assert.Equal("DeprecatedCommand: set-output", _ec.Object.Global.JobTelemetry[0].Message);
+                Assert.True(_ec.Object.Global.HasDeprecatedSetOutput);
+
+                // Second set-output should not add another telemetry entry
+                Assert.True(_commandManager.TryProcessCommand(_ec.Object, "::set-output name=foo2::bar2", null));
+                Assert.Single(_ec.Object.Global.JobTelemetry);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SaveStateCommand_EmitsTelemetryOnce()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                _ec.Object.Global.JobTelemetry = new List<JobTelemetry>();
+                _ec.Setup(x => x.IsEmbedded).Returns(false);
+                _ec.Setup(x => x.IntraActionState).Returns(new Dictionary<string, string>());
+
+                // First save-state should add telemetry
+                Assert.True(_commandManager.TryProcessCommand(_ec.Object, "::save-state name=foo::bar", null));
+                Assert.Single(_ec.Object.Global.JobTelemetry);
+                Assert.Equal(JobTelemetryType.ActionCommand, _ec.Object.Global.JobTelemetry[0].Type);
+                Assert.Equal("DeprecatedCommand: save-state", _ec.Object.Global.JobTelemetry[0].Message);
+                Assert.True(_ec.Object.Global.HasDeprecatedSaveState);
+
+                // Second save-state should not add another telemetry entry
+                Assert.True(_commandManager.TryProcessCommand(_ec.Object, "::save-state name=foo2::bar2", null));
+                Assert.Single(_ec.Object.Global.JobTelemetry);
+            }
+        }
+
     }
 }

src/Test/L0/Worker/ActionManagerL0.cs

@@ -468,6 +468,73 @@ runs:
             }
         }
 
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public async void PrepareActions_SymlinkCacheIsReentrant()
+        {
+            try
+            {
+                //Arrange
+                Environment.SetEnvironmentVariable(Constants.Variables.Agent.SymlinkCachedActions, "true");
+                Setup();
+                var actionId = Guid.NewGuid();
+                var actions = new List<Pipelines.ActionStep>
+                {
+                    new Pipelines.ActionStep()
+                    {
+                        Name = "action",
+                        Id = actionId,
+                        Reference = new Pipelines.RepositoryPathReference()
+                        {
+                            Name = "actions/checkout",
+                            Ref = "master",
+                            RepositoryType = "GitHub"
+                        }
+                    },
+                    new Pipelines.ActionStep()
+                    {
+                        Name = "action",
+                        Id = actionId,
+                        Reference = new Pipelines.RepositoryPathReference()
+                        {
+                            Name = "actions/checkout",
+                            Ref = "master",
+                            RepositoryType = "GitHub"
+                        }
+                    }
+                };
+
+                const string Content = @"
+name: 'Test'
+runs:
+  using: 'node20'
+  main: 'dist/index.js'
+";
+
+                string actionsArchive = Path.Combine(_hc.GetDirectory(WellKnownDirectory.Temp), "actions_archive", "action_checkout");
+                Directory.CreateDirectory(actionsArchive);
+                Directory.CreateDirectory(Path.Combine(actionsArchive, "actions_checkout", "master-sha"));
+                Directory.CreateDirectory(Path.Combine(actionsArchive, "actions_checkout", "master-sha", "content"));
+                await File.WriteAllTextAsync(Path.Combine(actionsArchive, "actions_checkout", "master-sha", "content", "action.yml"), Content);
+                Environment.SetEnvironmentVariable(Constants.Variables.Agent.ActionArchiveCacheDirectory, actionsArchive);
+
+                //Act
+                await _actionManager.PrepareActionsAsync(_ec.Object, actions);
+
+                //Assert
+                string destDirectory = Path.Combine(_hc.GetDirectory(WellKnownDirectory.Actions), "actions", "checkout", "master");
+                Assert.True(Directory.Exists(destDirectory), "Destination directory does not exist");  
+                var di = new DirectoryInfo(destDirectory);   
+                Assert.NotNull(di.LinkTarget); 
+            }
+            finally
+            {
+                Environment.SetEnvironmentVariable(Constants.Variables.Agent.SymlinkCachedActions, null);
+                Teardown();
+            }
+        }
+
 #if OS_LINUX
         [Fact]
         [Trait("Level", "L0")]

src/Test/L0/Worker/ActionManifestParserComparisonL0.cs

@@ -222,132 +222,13 @@ namespace GitHub.Runner.Common.Tests.Worker
         [Fact]
         [Trait("Level", "L0")]
         [Trait("Category", "Worker")]
-        public void EvaluateWrapper_SkipsMismatchRecording_WhenCancellationOccursDuringEvaluation()
+        public void EvaluateDefaultInput_BothParsersAgree()
         {
             try
             {
-                // Arrange - Test that mismatches are not recorded when cancellation state changes during evaluation
                 Setup();
-
-                // Enable comparison feature
                 _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
 
-                // Create the wrapper
-                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
-
-                // Create a simple token for evaluation
-                var token = new StringToken(null, null, null, "test-value");
-                var contextData = new DictionaryContextData();
-                var expressionFunctions = new List<LegacyExpressions.IFunctionInfo>();
-
-                // First evaluation without cancellation - should work normally
-                var result1 = wrapper.EvaluateStepDisplayName(token, contextData, expressionFunctions);
-                Assert.Equal("test-value", result1);
-                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
-
-                // Now simulate a scenario where cancellation occurs during evaluation
-                // Cancel the token before next evaluation
-                _ecTokenSource.Cancel();
-
-                // Evaluate again - even if there were a mismatch, it should be skipped due to cancellation
-                var result2 = wrapper.EvaluateStepDisplayName(token, contextData, expressionFunctions);
-                Assert.Equal("test-value", result2);
-
-                // Verify no mismatch was recorded (cancellation race detection should have prevented it)
-                // Note: In this test, both parsers return the same result, so there's no actual mismatch.
-                // The cancellation race detection is a safeguard for when results differ due to timing.
-                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
-            }
-            finally
-            {
-                Teardown();
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public void EvaluateWrapper_DoesNotRecordMismatch_WhenResultsMatch()
-        {
-            try
-            {
-                // Arrange - Test that no mismatch is recorded when both parsers return matching results
-                Setup();
-
-                // Enable comparison feature
-                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
-
-                // Create the wrapper
-                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
-
-                // Create a simple token for evaluation
-                var token = new StringToken(null, null, null, "test-value");
-                var contextData = new DictionaryContextData();
-                var expressionFunctions = new List<LegacyExpressions.IFunctionInfo>();
-
-                // Evaluation without cancellation - should work normally and not record mismatch for matching results
-                var result = wrapper.EvaluateStepDisplayName(token, contextData, expressionFunctions);
-                Assert.Equal("test-value", result);
-
-                // Since both parsers return the same result, no mismatch should be recorded
-                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
-            }
-            finally
-            {
-                Teardown();
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public void CutoverFlag_UsesNewEvaluator_ForPipelineTemplateEvaluator()
-        {
-            try
-            {
-                // Arrange - Test that cutover flag causes the wrapper to use only the new evaluator
-                Setup();
-
-                // Enable cutover feature (not comparison)
-                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CutoverWorkflowParser, "true");
-
-                // Create the wrapper
-                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
-
-                // Create a simple token for evaluation
-                var token = new StringToken(null, null, null, "test-value");
-                var contextData = new DictionaryContextData();
-                var expressionFunctions = new List<LegacyExpressions.IFunctionInfo>();
-
-                // Act - Evaluate in cutover mode
-                var result = wrapper.EvaluateStepDisplayName(token, contextData, expressionFunctions);
-
-                // Assert - Should get the correct result from the new evaluator
-                Assert.Equal("test-value", result);
-
-                // No mismatch should be recorded (comparison is skipped entirely in cutover mode)
-                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
-            }
-            finally
-            {
-                Teardown();
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public void CutoverFlag_UsesNewManager_ForActionManifestLoad()
-        {
-            try
-            {
-                // Arrange - Test that cutover flag causes the manifest wrapper to use only the new manager
-                Setup();
-
-                // Enable cutover feature (not comparison)
-                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CutoverWorkflowParser, "true");
-
-                // Register required services
                 var legacyManager = new ActionManifestManagerLegacy();
                 legacyManager.Initialize(_hc);
                 _hc.SetSingleton<IActionManifestManagerLegacy>(legacyManager);
@@ -359,16 +240,18 @@ namespace GitHub.Runner.Common.Tests.Worker
                 var wrapper = new ActionManifestManagerWrapper();
                 wrapper.Initialize(_hc);
 
-                var manifestPath = Path.Combine(TestUtil.GetTestDataPath(), "conditional_composite_action.yml");
+                _ec.Object.ExpressionValues["github"] = new LegacyContextData.DictionaryContextData();
+                _ec.Object.ExpressionValues["strategy"] = new LegacyContextData.DictionaryContextData();
+                _ec.Object.ExpressionValues["matrix"] = new LegacyContextData.DictionaryContextData();
+                _ec.Object.ExpressionValues["steps"] = new LegacyContextData.DictionaryContextData();
+                _ec.Object.ExpressionValues["job"] = new LegacyContextData.DictionaryContextData();
+                _ec.Object.ExpressionValues["runner"] = new LegacyContextData.DictionaryContextData();
+                _ec.Object.ExpressionValues["env"] = new LegacyContextData.DictionaryContextData();
+                _ec.Object.ExpressionFunctions.Add(new LegacyExpressions.FunctionInfo<GitHub.Runner.Worker.Expressions.HashFilesFunction>("hashFiles", 1, 255));
 
-                // Act - Load through the wrapper in cutover mode
-                var result = wrapper.Load(_ec.Object, manifestPath);
+                var result = wrapper.EvaluateDefaultInput(_ec.Object, "testInput", new StringToken(null, null, null, "defaultValue"));
 
-                // Assert - Should get the correct result from the new manager
-                Assert.NotNull(result);
-                Assert.Equal(ActionExecutionType.Composite, result.Execution.ExecutionType);
-
-                // No mismatch should be recorded (comparison is skipped in cutover mode)
+                Assert.Equal("defaultValue", result);
                 Assert.False(_ec.Object.Global.HasActionManifestMismatch);
             }
             finally
@@ -380,30 +263,115 @@ namespace GitHub.Runner.Common.Tests.Worker
         [Fact]
         [Trait("Level", "L0")]
         [Trait("Category", "Worker")]
-        public void CutoverFlag_TakesPrecedence_OverCompareFlag()
+        public void EvaluateContainerArguments_BothParsersAgree()
         {
             try
             {
-                // Arrange - Test that cutover flag takes precedence over compare flag
                 Setup();
-
-                // Enable both flags
                 _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
-                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CutoverWorkflowParser, "true");
 
-                // Create the wrapper
-                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+                var legacyManager = new ActionManifestManagerLegacy();
+                legacyManager.Initialize(_hc);
+                _hc.SetSingleton<IActionManifestManagerLegacy>(legacyManager);
 
-                var token = new StringToken(null, null, null, "test-value");
-                var contextData = new DictionaryContextData();
-                var expressionFunctions = new List<LegacyExpressions.IFunctionInfo>();
+                var newManager = new ActionManifestManager();
+                newManager.Initialize(_hc);
+                _hc.SetSingleton<IActionManifestManager>(newManager);
 
-                // Act - Evaluate (cutover should take precedence, skipping comparison entirely)
-                var result = wrapper.EvaluateStepDisplayName(token, contextData, expressionFunctions);
+                var wrapper = new ActionManifestManagerWrapper();
+                wrapper.Initialize(_hc);
 
-                // Assert - Should get correct result, no comparison mismatch recorded
-                Assert.Equal("test-value", result);
-                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+                var arguments = new SequenceToken(null, null, null);
+                arguments.Add(new StringToken(null, null, null, "arg1"));
+                arguments.Add(new StringToken(null, null, null, "arg2"));
+
+                var evaluateContext = new Dictionary<string, LegacyContextData.PipelineContextData>(StringComparer.OrdinalIgnoreCase);
+
+                var result = wrapper.EvaluateContainerArguments(_ec.Object, arguments, evaluateContext);
+
+                Assert.Equal(2, result.Count);
+                Assert.Equal("arg1", result[0]);
+                Assert.Equal("arg2", result[1]);
+                Assert.False(_ec.Object.Global.HasActionManifestMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateContainerEnvironment_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var legacyManager = new ActionManifestManagerLegacy();
+                legacyManager.Initialize(_hc);
+                _hc.SetSingleton<IActionManifestManagerLegacy>(legacyManager);
+
+                var newManager = new ActionManifestManager();
+                newManager.Initialize(_hc);
+                _hc.SetSingleton<IActionManifestManager>(newManager);
+
+                var wrapper = new ActionManifestManagerWrapper();
+                wrapper.Initialize(_hc);
+
+                var environment = new MappingToken(null, null, null);
+                environment.Add(new StringToken(null, null, null, "hello"), new StringToken(null, null, null, "world"));
+
+                var evaluateContext = new Dictionary<string, LegacyContextData.PipelineContextData>(StringComparer.OrdinalIgnoreCase);
+
+                var result = wrapper.EvaluateContainerEnvironment(_ec.Object, environment, evaluateContext);
+
+                Assert.Equal(1, result.Count);
+                Assert.Equal("world", result["hello"]);
+                Assert.False(_ec.Object.Global.HasActionManifestMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateCompositeOutputs_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var legacyManager = new ActionManifestManagerLegacy();
+                legacyManager.Initialize(_hc);
+                _hc.SetSingleton<IActionManifestManagerLegacy>(legacyManager);
+
+                var newManager = new ActionManifestManager();
+                newManager.Initialize(_hc);
+                _hc.SetSingleton<IActionManifestManager>(newManager);
+
+                var wrapper = new ActionManifestManagerWrapper();
+                wrapper.Initialize(_hc);
+
+                var outputDef = new MappingToken(null, null, null);
+                outputDef.Add(new StringToken(null, null, null, "description"), new StringToken(null, null, null, "test output"));
+                outputDef.Add(new StringToken(null, null, null, "value"), new StringToken(null, null, null, "value1"));
+
+                var token = new MappingToken(null, null, null);
+                token.Add(new StringToken(null, null, null, "output1"), outputDef);
+
+                var evaluateContext = new Dictionary<string, LegacyContextData.PipelineContextData>(StringComparer.OrdinalIgnoreCase);
+
+                var result = wrapper.EvaluateCompositeOutputs(_ec.Object, token, evaluateContext);
+
+                Assert.NotNull(result);
+                Assert.False(_ec.Object.Global.HasActionManifestMismatch);
             }
             finally
             {

src/Test/L0/Worker/HandlerFactoryL0.cs

@@ -74,7 +74,7 @@ namespace GitHub.Runner.Common.Tests.Worker
             }
         }
 
-      
+
 
         [Fact]
         [Trait("Level", "L0")]
@@ -116,5 +116,259 @@ namespace GitHub.Runner.Common.Tests.Worker
                 Assert.Equal("node24", handler.Data.NodeVersion);
             }
         }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void Node20Action_TrackedWhenWarnFlagEnabled()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                // Arrange.
+                var hf = new HandlerFactory();
+                hf.Initialize(hc);
+
+                var variables = new Dictionary<string, VariableValue>
+                {
+                    { Constants.Runner.NodeMigration.WarnOnNode20Flag, new VariableValue("true") }
+                };
+                Variables serverVariables = new(hc, variables);
+                var deprecatedActions = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+                _ec.Setup(x => x.Global).Returns(new GlobalContext()
+                {
+                    Variables = serverVariables,
+                    EnvironmentVariables = new Dictionary<string, string>(),
+                    DeprecatedNode20Actions = deprecatedActions
+                });
+
+                var actionRef = new RepositoryPathReference
+                {
+                    Name = "actions/checkout",
+                    Ref = "v4"
+                };
+
+                // Act.
+                var data = new NodeJSActionExecutionData();
+                data.NodeVersion = "node20";
+                hf.Create(
+                    _ec.Object,
+                    actionRef,
+                    new Mock<IStepHost>().Object,
+                    data,
+                    new Dictionary<string, string>(),
+                    new Dictionary<string, string>(),
+                    new Variables(hc, new Dictionary<string, VariableValue>()),
+                    "",
+                    new List<JobExtensionRunner>()
+                );
+
+                // Assert.
+                Assert.Contains("actions/checkout@v4", deprecatedActions);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void Node20Action_NotTrackedWhenWarnFlagDisabled()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                // Arrange.
+                var hf = new HandlerFactory();
+                hf.Initialize(hc);
+
+                var variables = new Dictionary<string, VariableValue>();
+                Variables serverVariables = new(hc, variables);
+                var deprecatedActions = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+                _ec.Setup(x => x.Global).Returns(new GlobalContext()
+                {
+                    Variables = serverVariables,
+                    EnvironmentVariables = new Dictionary<string, string>(),
+                    DeprecatedNode20Actions = deprecatedActions
+                });
+
+                var actionRef = new RepositoryPathReference
+                {
+                    Name = "actions/checkout",
+                    Ref = "v4"
+                };
+
+                // Act.
+                var data = new NodeJSActionExecutionData();
+                data.NodeVersion = "node20";
+                hf.Create(
+                    _ec.Object,
+                    actionRef,
+                    new Mock<IStepHost>().Object,
+                    data,
+                    new Dictionary<string, string>(),
+                    new Dictionary<string, string>(),
+                    new Variables(hc, new Dictionary<string, VariableValue>()),
+                    "",
+                    new List<JobExtensionRunner>()
+                );
+
+                // Assert - should not track when flag is disabled
+                Assert.Empty(deprecatedActions);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void Node24Action_NotTrackedEvenWhenWarnFlagEnabled()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                // Arrange.
+                var hf = new HandlerFactory();
+                hf.Initialize(hc);
+
+                var variables = new Dictionary<string, VariableValue>
+                {
+                    { Constants.Runner.NodeMigration.WarnOnNode20Flag, new VariableValue("true") }
+                };
+                Variables serverVariables = new(hc, variables);
+                var deprecatedActions = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+                _ec.Setup(x => x.Global).Returns(new GlobalContext()
+                {
+                    Variables = serverVariables,
+                    EnvironmentVariables = new Dictionary<string, string>(),
+                    DeprecatedNode20Actions = deprecatedActions
+                });
+
+                var actionRef = new RepositoryPathReference
+                {
+                    Name = "actions/checkout",
+                    Ref = "v5"
+                };
+
+                // Act.
+                var data = new NodeJSActionExecutionData();
+                data.NodeVersion = "node24";
+                hf.Create(
+                    _ec.Object,
+                    actionRef,
+                    new Mock<IStepHost>().Object,
+                    data,
+                    new Dictionary<string, string>(),
+                    new Dictionary<string, string>(),
+                    new Variables(hc, new Dictionary<string, VariableValue>()),
+                    "",
+                    new List<JobExtensionRunner>()
+                );
+
+                // Assert - node24 actions should not be tracked
+                Assert.Empty(deprecatedActions);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void Node12Action_TrackedAsDeprecatedWhenWarnFlagEnabled()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                // Arrange.
+                var hf = new HandlerFactory();
+                hf.Initialize(hc);
+
+                var variables = new Dictionary<string, VariableValue>
+                {
+                    { Constants.Runner.NodeMigration.WarnOnNode20Flag, new VariableValue("true") }
+                };
+                Variables serverVariables = new(hc, variables);
+                var deprecatedActions = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+                _ec.Setup(x => x.Global).Returns(new GlobalContext()
+                {
+                    Variables = serverVariables,
+                    EnvironmentVariables = new Dictionary<string, string>(),
+                    DeprecatedNode20Actions = deprecatedActions
+                });
+
+                var actionRef = new RepositoryPathReference
+                {
+                    Name = "some-org/old-action",
+                    Ref = "v1"
+                };
+
+                // Act - node12 gets migrated to node20, then should be tracked
+                var data = new NodeJSActionExecutionData();
+                data.NodeVersion = "node12";
+                hf.Create(
+                    _ec.Object,
+                    actionRef,
+                    new Mock<IStepHost>().Object,
+                    data,
+                    new Dictionary<string, string>(),
+                    new Dictionary<string, string>(),
+                    new Variables(hc, new Dictionary<string, VariableValue>()),
+                    "",
+                    new List<JobExtensionRunner>()
+                );
+
+                // Assert - node12 gets migrated to node20 and should be tracked
+                Assert.Contains("some-org/old-action@v1", deprecatedActions);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void LocalNode20Action_TrackedWhenWarnFlagEnabled()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                // Arrange.
+                var hf = new HandlerFactory();
+                hf.Initialize(hc);
+
+                var variables = new Dictionary<string, VariableValue>
+                {
+                    { Constants.Runner.NodeMigration.WarnOnNode20Flag, new VariableValue("true") }
+                };
+                Variables serverVariables = new(hc, variables);
+                var deprecatedActions = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+                _ec.Setup(x => x.Global).Returns(new GlobalContext()
+                {
+                    Variables = serverVariables,
+                    EnvironmentVariables = new Dictionary<string, string>(),
+                    DeprecatedNode20Actions = deprecatedActions
+                });
+
+                // Local action: Name is empty, Path is the local path
+                var actionRef = new RepositoryPathReference
+                {
+                    Name = "",
+                    Path = "./.github/actions/my-action",
+                    RepositoryType = "self"
+                };
+
+                // Act.
+                var data = new NodeJSActionExecutionData();
+                data.NodeVersion = "node20";
+                hf.Create(
+                    _ec.Object,
+                    actionRef,
+                    new Mock<IStepHost>().Object,
+                    data,
+                    new Dictionary<string, string>(),
+                    new Dictionary<string, string>(),
+                    new Variables(hc, new Dictionary<string, VariableValue>()),
+                    "",
+                    new List<JobExtensionRunner>()
+                );
+
+                // Assert - local action should be tracked with its path
+                Assert.Contains("./.github/actions/my-action", deprecatedActions);
+            }
+        }
     }
 }

src/Test/L0/Worker/Handlers/CompositeActionHandlerL0.cs

@@ -0,0 +1,271 @@
+using System;
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+using GitHub.DistributedTask.WebApi;
+using GitHub.Runner.Common.Util;
+using GitHub.Runner.Sdk;
+using GitHub.Runner.Worker;
+using GitHub.Runner.Worker.Handlers;
+using Moq;
+using Xunit;
+using DTWebApi = GitHub.DistributedTask.WebApi;
+
+namespace GitHub.Runner.Common.Tests.Worker.Handlers
+{
+    public sealed class CompositeActionHandlerL0
+    {
+        // Test EscapeProperty helper logic via reflection or by testing the markers output
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EscapeProperty_EscapesSpecialCharacters()
+        {
+            // Test the escaping logic that would be applied
+            var input = "value;with%special\r\n]chars";
+            var escaped = EscapeProperty(input);
+            Assert.Equal("value%3Bwith%25special%0D%0A%5Dchars", escaped);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EscapeProperty_HandlesNullAndEmpty()
+        {
+            Assert.Null(EscapeProperty(null));
+            Assert.Equal("", EscapeProperty(""));
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SanitizeDisplayName_TruncatesLongNames()
+        {
+            var longName = new string('a', 1500);
+            var sanitized = SanitizeDisplayName(longName);
+            Assert.Equal(CompositeActionHandler.MaxDisplayNameLength, sanitized.Length);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SanitizeDisplayName_TakesFirstLineOnly()
+        {
+            var multiline = "First line\nSecond line\nThird line";
+            var sanitized = SanitizeDisplayName(multiline);
+            Assert.Equal("First line", sanitized);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SanitizeDisplayName_TrimsLeadingWhitespace()
+        {
+            var withLeading = "   \n  \t  Actual name\nSecond line";
+            var sanitized = SanitizeDisplayName(withLeading);
+            Assert.Equal("Actual name", sanitized);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SanitizeDisplayName_HandlesCarriageReturn()
+        {
+            var withCR = "First line\r\nSecond line";
+            var sanitized = SanitizeDisplayName(withCR);
+            Assert.Equal("First line", sanitized);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void SanitizeDisplayName_HandlesNullAndEmpty()
+        {
+            Assert.Null(SanitizeDisplayName(null));
+            Assert.Equal("", SanitizeDisplayName(""));
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EmitMarkers_DisplayNameEscaping()
+        {
+            // Verify that special characters in display names get escaped properly
+            var displayName = "Step with semicolons; and more; here";
+            var escaped = EscapeProperty(SanitizeDisplayName(displayName));
+            Assert.Equal("Step with semicolons%3B and more%3B here", escaped);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EmitMarkers_DisplayNameWithBrackets()
+        {
+            var displayName = "Step with [brackets] inside";
+            var escaped = EscapeProperty(SanitizeDisplayName(displayName));
+            Assert.Equal("Step with [brackets%5D inside", escaped);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void StripUserEmittedMarkers_StartAction()
+        {
+            // Simulate what OutputManager does to strip markers
+            var userLine = "##[start-action display=Fake;id=fake]";
+            var stripped = StripMarkers(userLine);
+            Assert.Equal(@"##[\start-action display=Fake;id=fake]", stripped);
+            Assert.DoesNotContain("##[start-action", stripped);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void StripUserEmittedMarkers_EndAction()
+        {
+            var userLine = "##[end-action id=fake;outcome=success;conclusion=success;duration_ms=100]";
+            var stripped = StripMarkers(userLine);
+            Assert.Equal(@"##[\end-action id=fake;outcome=success;conclusion=success;duration_ms=100]", stripped);
+            Assert.DoesNotContain("##[end-action", stripped);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void StripUserEmittedMarkers_PreservesOtherCommands()
+        {
+            var userLine = "##[group]My Group";
+            var stripped = StripMarkers(userLine);
+            Assert.Equal("##[group]My Group", stripped);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void StripUserEmittedMarkers_HandlesEmbeddedMarkers()
+        {
+            var userLine = "Some text ##[start-action display=fake;id=fake] more text";
+            var stripped = StripMarkers(userLine);
+            Assert.Equal(@"Some text ##[\start-action display=fake;id=fake] more text", stripped);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void TaskResultToActionResult_Success()
+        {
+            var result = GitHub.DistributedTask.WebApi.TaskResult.Succeeded;
+            var actionResult = result.ToActionResult();
+            Assert.Equal(ActionResult.Success, actionResult);
+            Assert.Equal("success", actionResult.ToString().ToLowerInvariant());
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void TaskResultToActionResult_Failure()
+        {
+            var result = GitHub.DistributedTask.WebApi.TaskResult.Failed;
+            var actionResult = result.ToActionResult();
+            Assert.Equal(ActionResult.Failure, actionResult);
+            Assert.Equal("failure", actionResult.ToString().ToLowerInvariant());
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void TaskResultToActionResult_Cancelled()
+        {
+            var result = GitHub.DistributedTask.WebApi.TaskResult.Canceled;
+            var actionResult = result.ToActionResult();
+            Assert.Equal(ActionResult.Cancelled, actionResult);
+            Assert.Equal("cancelled", actionResult.ToString().ToLowerInvariant());
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void TaskResultToActionResult_Skipped()
+        {
+            var result = GitHub.DistributedTask.WebApi.TaskResult.Skipped;
+            var actionResult = result.ToActionResult();
+            Assert.Equal(ActionResult.Skipped, actionResult);
+            Assert.Equal("skipped", actionResult.ToString().ToLowerInvariant());
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void MarkerFormat_StartAction()
+        {
+            var display = "My Step";
+            var id = "my-step";
+            var marker = $"##[start-action display={EscapeProperty(display)};id={EscapeProperty(id)}]";
+            Assert.Equal("##[start-action display=My Step;id=my-step]", marker);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void MarkerFormat_EndAction()
+        {
+            var id = "my-step";
+            var outcome = "success";
+            var conclusion = "success";
+            var durationMs = 1234;
+            var marker = $"##[end-action id={EscapeProperty(id)};outcome={outcome};conclusion={conclusion};duration_ms={durationMs}]";
+            Assert.Equal("##[end-action id=my-step;outcome=success;conclusion=success;duration_ms=1234]", marker);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void MarkerFormat_NestedId()
+        {
+            var prefix = "outer-composite";
+            var contextName = "inner-step";
+            var stepId = $"{prefix}.{contextName}";
+            Assert.Equal("outer-composite.inner-step", stepId);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void MarkerFormat_SkippedStep()
+        {
+            var id = "skipped-step";
+            var marker = $"##[end-action id={EscapeProperty(id)};outcome=skipped;conclusion=skipped;duration_ms=0]";
+            Assert.Equal("##[end-action id=skipped-step;outcome=skipped;conclusion=skipped;duration_ms=0]", marker);
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void MarkerFormat_ContinueOnError()
+        {
+            // When continue-on-error is true and step fails:
+            // outcome = failure (raw result)
+            // conclusion = success (after continue-on-error applied)
+            var id = "failing-step";
+            var marker = $"##[end-action id={EscapeProperty(id)};outcome=failure;conclusion=success;duration_ms=500]";
+            Assert.Equal("##[end-action id=failing-step;outcome=failure;conclusion=success;duration_ms=500]", marker);
+        }
+
+        // Helper methods that call the real production code
+        private static string EscapeProperty(string value) =>
+            CompositeActionHandler.EscapeProperty(value);
+
+        private static string SanitizeDisplayName(string displayName) =>
+            CompositeActionHandler.SanitizeDisplayName(displayName);
+
+        private static string StripMarkers(string line)
+        {
+            if (!string.IsNullOrEmpty(line) &&
+                (line.Contains("##[start-action") || line.Contains("##[end-action")))
+            {
+                line = line.Replace("##[start-action", @"##[\start-action")
+                           .Replace("##[end-action", @"##[\end-action");
+            }
+            return line;
+        }
+    }
+}

src/Test/L0/Worker/OutputManagerL0.cs

@@ -1006,6 +1006,66 @@ namespace GitHub.Runner.Common.Tests.Worker
             }
         }
 
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void StripCompositeMarkers_StartAction()
+        {
+            using (Setup())
+            using (_outputManager)
+            {
+                Process("##[start-action display=Fake;id=fake]");
+                Assert.Single(_messages);
+                Assert.Contains(@"##[\start-action", _messages[0]);
+                Assert.DoesNotContain("##[start-action", _messages[0]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void StripCompositeMarkers_EndAction()
+        {
+            using (Setup())
+            using (_outputManager)
+            {
+                Process("##[end-action id=fake;outcome=success;conclusion=success;duration_ms=100]");
+                Assert.Single(_messages);
+                Assert.Contains(@"##[\end-action", _messages[0]);
+                Assert.DoesNotContain("##[end-action", _messages[0]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void StripCompositeMarkers_PreservesOtherCommands()
+        {
+            using (Setup())
+            using (_outputManager)
+            {
+                Process("##[group]My Group");
+                // Should not be stripped (not a composite marker)
+                Assert.Single(_messages);
+                Assert.Equal("##[group]My Group", _messages[0]);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void StripCompositeMarkers_EmbeddedInLine()
+        {
+            using (Setup())
+            using (_outputManager)
+            {
+                Process("Some text ##[start-action display=fake;id=fake] more text");
+                Assert.Single(_messages);
+                Assert.Contains(@"##[\start-action", _messages[0]);
+                Assert.DoesNotContain("##[start-action", _messages[0]);
+            }
+        }
+
         private TestHostContext Setup(
             [CallerMemberName] string name = "",
             IssueMatchersConfig matchers = null,

src/Test/L0/Worker/PipelineTemplateEvaluatorWrapperL0.cs

@@ -0,0 +1,550 @@
+using GitHub.DistributedTask.ObjectTemplating.Tokens;
+using GitHub.DistributedTask.Pipelines.ContextData;
+using GitHub.DistributedTask.Pipelines.ObjectTemplating;
+using GitHub.DistributedTask.WebApi;
+using GitHub.Runner.Common;
+using GitHub.Runner.Sdk;
+using GitHub.Runner.Worker;
+using LegacyContextData = GitHub.DistributedTask.Pipelines.ContextData;
+using LegacyExpressions = GitHub.DistributedTask.Expressions2;
+using Moq;
+using System;
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+using System.Threading;
+using Xunit;
+
+namespace GitHub.Runner.Common.Tests.Worker
+{
+    public sealed class PipelineTemplateEvaluatorWrapperL0
+    {
+        private CancellationTokenSource _ecTokenSource;
+        private Mock<IExecutionContext> _ec;
+        private TestHostContext _hc;
+
+        // -------------------------------------------------------------------
+        // EvaluateAndCompare core behavior
+        // -------------------------------------------------------------------
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateAndCompare_DoesNotRecordMismatch_WhenResultsMatch()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+
+                var token = new StringToken(null, null, null, "test-value");
+                var contextData = new DictionaryContextData();
+                var expressionFunctions = new List<LegacyExpressions.IFunctionInfo>();
+
+                var result = wrapper.EvaluateStepDisplayName(token, contextData, expressionFunctions);
+
+                Assert.Equal("test-value", result);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateAndCompare_SkipsMismatchRecording_WhenCancellationOccursDuringEvaluation()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+
+                // Call EvaluateAndCompare directly: the new evaluator cancels the token
+                // and returns a different value, forcing hasMismatch = true.
+                // Because cancellation flipped during the evaluation window, the
+                // mismatch should be skipped.
+                var result = wrapper.EvaluateAndCompare<string, string>(
+                    "TestCancellationSkip",
+                    () => "legacy-value",
+                    () =>
+                    {
+                        _ecTokenSource.Cancel();
+                        return "different-value";
+                    },
+                    (legacy, @new) => string.Equals(legacy, @new, StringComparison.Ordinal));
+
+                Assert.Equal("legacy-value", result);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateAndCompare_RecordsMismatch_WhenResultsDifferWithoutCancellation()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+
+                // Different results without cancellation — mismatch SHOULD be recorded.
+                var result = wrapper.EvaluateAndCompare<string, string>(
+                    "TestMismatchRecorded",
+                    () => "legacy-value",
+                    () => "different-value",
+                    (legacy, @new) => string.Equals(legacy, @new, StringComparison.Ordinal));
+
+                Assert.Equal("legacy-value", result);
+                Assert.True(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        // -------------------------------------------------------------------
+        // Smoke tests — both parsers agree, no mismatch recorded
+        // -------------------------------------------------------------------
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateStepContinueOnError_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+                var token = new BooleanToken(null, null, null, true);
+                var contextData = new DictionaryContextData();
+                var functions = new List<LegacyExpressions.IFunctionInfo>();
+
+                var result = wrapper.EvaluateStepContinueOnError(token, contextData, functions);
+
+                Assert.True(result);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateStepEnvironment_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+                var token = new MappingToken(null, null, null);
+                token.Add(new StringToken(null, null, null, "FOO"), new StringToken(null, null, null, "bar"));
+                var contextData = new DictionaryContextData();
+                var functions = new List<LegacyExpressions.IFunctionInfo>();
+
+                var result = wrapper.EvaluateStepEnvironment(token, contextData, functions, StringComparer.OrdinalIgnoreCase);
+
+                Assert.NotNull(result);
+                Assert.Equal("bar", result["FOO"]);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateStepIf_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+                var token = new BasicExpressionToken(null, null, null, "true");
+                var contextData = new DictionaryContextData();
+                var functions = new List<LegacyExpressions.IFunctionInfo>();
+                var expressionState = new List<KeyValuePair<string, object>>();
+
+                var result = wrapper.EvaluateStepIf(token, contextData, functions, expressionState);
+
+                Assert.True(result);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateStepInputs_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+                var token = new MappingToken(null, null, null);
+                token.Add(new StringToken(null, null, null, "input1"), new StringToken(null, null, null, "val1"));
+                var contextData = new DictionaryContextData();
+                var functions = new List<LegacyExpressions.IFunctionInfo>();
+
+                var result = wrapper.EvaluateStepInputs(token, contextData, functions);
+
+                Assert.NotNull(result);
+                Assert.Equal("val1", result["input1"]);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateStepTimeout_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+                var token = new NumberToken(null, null, null, 10);
+                var contextData = new DictionaryContextData();
+                var functions = new List<LegacyExpressions.IFunctionInfo>();
+
+                var result = wrapper.EvaluateStepTimeout(token, contextData, functions);
+
+                Assert.Equal(10, result);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateJobContainer_EmptyImage_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+                var token = new StringToken(null, null, null, "");
+                var contextData = new DictionaryContextData();
+                var functions = new List<LegacyExpressions.IFunctionInfo>();
+
+                var result = wrapper.EvaluateJobContainer(token, contextData, functions);
+
+                Assert.Null(result);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateJobOutput_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+                var token = new MappingToken(null, null, null);
+                token.Add(new StringToken(null, null, null, "out1"), new StringToken(null, null, null, "val1"));
+                var contextData = new DictionaryContextData();
+                var functions = new List<LegacyExpressions.IFunctionInfo>();
+
+                var result = wrapper.EvaluateJobOutput(token, contextData, functions);
+
+                Assert.NotNull(result);
+                Assert.Equal("val1", result["out1"]);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateEnvironmentUrl_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+                var token = new StringToken(null, null, null, "https://example.com");
+                var contextData = new DictionaryContextData();
+                var functions = new List<LegacyExpressions.IFunctionInfo>();
+
+                var result = wrapper.EvaluateEnvironmentUrl(token, contextData, functions);
+
+                Assert.NotNull(result);
+                var stringResult = result as StringToken;
+                Assert.NotNull(stringResult);
+                Assert.Equal("https://example.com", stringResult.Value);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateJobDefaultsRun_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+                var token = new MappingToken(null, null, null);
+                token.Add(new StringToken(null, null, null, "shell"), new StringToken(null, null, null, "bash"));
+                var contextData = new DictionaryContextData();
+                var functions = new List<LegacyExpressions.IFunctionInfo>();
+
+                var result = wrapper.EvaluateJobDefaultsRun(token, contextData, functions);
+
+                Assert.NotNull(result);
+                Assert.Equal("bash", result["shell"]);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateJobServiceContainers_Null_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+                var contextData = new DictionaryContextData();
+                var functions = new List<LegacyExpressions.IFunctionInfo>();
+
+                var result = wrapper.EvaluateJobServiceContainers(null, contextData, functions);
+
+                Assert.Null(result);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateJobSnapshotRequest_Null_BothParsersAgree()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+                var contextData = new DictionaryContextData();
+                var functions = new List<LegacyExpressions.IFunctionInfo>();
+
+                var result = wrapper.EvaluateJobSnapshotRequest(null, contextData, functions);
+
+                Assert.Null(result);
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        // -------------------------------------------------------------------
+        // JSON parse error equivalence via EvaluateAndCompare
+        // -------------------------------------------------------------------
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateAndCompare_JsonReaderExceptions_TreatedAsEquivalent()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+
+                // Both throw JsonReaderException with different messages — should be treated as equivalent
+                var legacyEx = new Newtonsoft.Json.JsonReaderException("Error reading JToken from JsonReader. Path '', line 0, position 0.");
+                var newEx = new Newtonsoft.Json.JsonReaderException("Error parsing fromJson", new Newtonsoft.Json.JsonReaderException("Unexpected end"));
+
+                Assert.Throws<Newtonsoft.Json.JsonReaderException>(() =>
+                    wrapper.EvaluateAndCompare<string, string>(
+                        "TestJsonEquivalence",
+                        () => throw legacyEx,
+                        () => throw newEx,
+                        (a, b) => string.Equals(a, b, StringComparison.Ordinal)));
+
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateAndCompare_MixedJsonExceptionTypes_TreatedAsEquivalent()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+
+                // Legacy throws Newtonsoft JsonReaderException, new throws System.Text.Json.JsonException
+                var legacyEx = new Newtonsoft.Json.JsonReaderException("Error reading JToken");
+                var newEx = new System.Text.Json.JsonException("Error parsing fromJson");
+
+                Assert.Throws<Newtonsoft.Json.JsonReaderException>(() =>
+                    wrapper.EvaluateAndCompare<string, string>(
+                        "TestMixedJsonTypes",
+                        () => throw legacyEx,
+                        () => throw newEx,
+                        (a, b) => string.Equals(a, b, StringComparison.Ordinal)));
+
+                Assert.False(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void EvaluateAndCompare_NonJsonExceptions_RecordsMismatch()
+        {
+            try
+            {
+                Setup();
+                _ec.Object.Global.Variables.Set(Constants.Runner.Features.CompareWorkflowParser, "true");
+
+                var wrapper = new PipelineTemplateEvaluatorWrapper(_hc, _ec.Object);
+
+                // Both throw non-JSON exceptions with different messages — should record mismatch
+                var legacyEx = new InvalidOperationException("some error");
+                var newEx = new InvalidOperationException("different error");
+
+                Assert.Throws<InvalidOperationException>(() =>
+                    wrapper.EvaluateAndCompare<string, string>(
+                        "TestNonJsonMismatch",
+                        () => throw legacyEx,
+                        () => throw newEx,
+                        (a, b) => string.Equals(a, b, StringComparison.Ordinal)));
+
+                Assert.True(_ec.Object.Global.HasTemplateEvaluatorMismatch);
+            }
+            finally
+            {
+                Teardown();
+            }
+        }
+
+        // -------------------------------------------------------------------
+        // Helpers
+        // -------------------------------------------------------------------
+
+        private void Setup([CallerMemberName] string name = "")
+        {
+            _ecTokenSource?.Dispose();
+            _ecTokenSource = new CancellationTokenSource();
+
+            _hc = new TestHostContext(this, name);
+
+            var expressionValues = new LegacyContextData.DictionaryContextData();
+            var expressionFunctions = new List<LegacyExpressions.IFunctionInfo>();
+
+            _ec = new Mock<IExecutionContext>();
+            _ec.Setup(x => x.Global)
+                .Returns(new GlobalContext
+                {
+                    FileTable = new List<String>(),
+                    Variables = new Variables(_hc, new Dictionary<string, VariableValue>()),
+                    WriteDebug = true,
+                });
+            _ec.Setup(x => x.CancellationToken).Returns(_ecTokenSource.Token);
+            _ec.Setup(x => x.ExpressionValues).Returns(expressionValues);
+            _ec.Setup(x => x.ExpressionFunctions).Returns(expressionFunctions);
+            _ec.Setup(x => x.Write(It.IsAny<string>(), It.IsAny<string>())).Callback((string tag, string message) => { _hc.GetTrace().Info($"{tag}{message}"); });
+            _ec.Setup(x => x.AddIssue(It.IsAny<Issue>(), It.IsAny<ExecutionContextLogOptions>())).Callback((Issue issue, ExecutionContextLogOptions logOptions) => { _hc.GetTrace().Info($"[{issue.Type}]{logOptions.LogMessageOverride ?? issue.Message}"); });
+        }
+
+        private void Teardown()
+        {
+            _hc?.Dispose();
+        }
+    }
+}

src/dev.sh

@@ -17,7 +17,7 @@ LAYOUT_DIR="$SCRIPT_DIR/../_layout"
 DOWNLOAD_DIR="$SCRIPT_DIR/../_downloads/netcore2x"
 PACKAGE_DIR="$SCRIPT_DIR/../_package"
 DOTNETSDK_ROOT="$SCRIPT_DIR/../_dotnetsdk"
-DOTNETSDK_VERSION="8.0.417"
+DOTNETSDK_VERSION="8.0.418"
 DOTNETSDK_INSTALLDIR="$DOTNETSDK_ROOT/$DOTNETSDK_VERSION"
 RUNNER_VERSION=$(cat runnerversion)
 

src/global.json

@@ -1,5 +1,5 @@
 {
   "sdk": {
-    "version": "8.0.417"
+    "version": "8.0.418"
   }
 }