feat(siteruntime): thread ParentExecutionId into the routed script's ScriptRuntimeContext

src/ScadaLink.Commons/Messages/ScriptExecution/ScriptCallRequest.cs

@@ -1,7 +1,17 @@
 namespace ScadaLink.Commons.Messages.ScriptExecution;
 
+/// <param name="ParentExecutionId">
+/// Audit Log #23 (ParentExecutionId): the spawning execution's <c>ExecutionId</c>.
+/// For an inbound-API-routed call this is the inbound request's per-request
+/// execution id (carried in from <c>RouteToCallRequest.ParentExecutionId</c>);
+/// the routed script execution records it as its <c>ParentExecutionId</c> so a
+/// spawned execution points back at its spawner. Additive trailing member —
+/// null for normal (tag-change / timer-triggered) runs, nested <c>Script.Call</c>
+/// invocations, and any request built before the field existed.
+/// </param>
 public record ScriptCallRequest(
     string ScriptName,
     IReadOnlyDictionary<string, object?>? Parameters,
     int CurrentCallDepth,
-    string CorrelationId);
+    string CorrelationId,
+    Guid? ParentExecutionId = null);

src/ScadaLink.SiteRuntime/Actors/DeploymentManagerActor.cs

@@ -735,9 +735,13 @@ public class DeploymentManagerActor : ReceiveActor, IWithTimers
     {
         if (_instanceActors.TryGetValue(request.InstanceUniqueName, out var instanceActor))
         {
-            // Convert to ScriptCallRequest and Ask the Instance Actor
+            // Convert to ScriptCallRequest and Ask the Instance Actor.
+            // Audit Log #23 (ParentExecutionId): carry the inbound request's
+            // ExecutionId down as ParentExecutionId so the routed script
+            // execution can record its spawner.
             var scriptCall = new ScriptCallRequest(
-                request.ScriptName, request.Parameters, 0, request.CorrelationId);
+                request.ScriptName, request.Parameters, 0, request.CorrelationId,
+                ParentExecutionId: request.ParentExecutionId);
             var sender = Sender;
             instanceActor.Ask<ScriptCallResult>(scriptCall, TimeSpan.FromSeconds(30))
                 .ContinueWith(t =>

src/ScadaLink.SiteRuntime/Actors/InstanceActor.cs

@@ -320,7 +320,10 @@ public class InstanceActor : ReceiveActor
     {
         if (_scriptActors.TryGetValue(request.ScriptName, out var scriptActor))
         {
-            // Forward the request to the Script Actor, preserving the original sender
+            // Forward the request to the Script Actor, preserving the original
+            // sender. The whole record is forwarded unchanged, so any
+            // ParentExecutionId (Audit Log #23) set by an inbound-API-routed
+            // call is carried through to the Script Actor verbatim.
             scriptActor.Forward(request);
         }
         else

src/ScadaLink.SiteRuntime/Actors/ScriptActor.cs

@@ -184,7 +184,13 @@ public class ScriptActor : ReceiveActor, IWithTimers
             return;
         }
 
-        SpawnExecution(request.Parameters, request.CurrentCallDepth, Sender, request.CorrelationId);
+        // Audit Log #23 (ParentExecutionId): carry any inbound-routed
+        // ParentExecutionId through to the ScriptExecutionActor so the routed
+        // script's ScriptRuntimeContext can record its spawner. Null for normal
+        // (tag-change / timer) runs and nested Script.Call invocations.
+        SpawnExecution(
+            request.Parameters, request.CurrentCallDepth, Sender, request.CorrelationId,
+            request.ParentExecutionId);
     }
 
     /// <summary>
@@ -379,7 +385,8 @@ public class ScriptActor : ReceiveActor, IWithTimers
         IReadOnlyDictionary<string, object?>? parameters,
         int callDepth,
         IActorRef replyTo,
-        string correlationId)
+        string correlationId,
+        Guid? parentExecutionId = null)
     {
         var executionId = $"{_scriptName}-exec-{_executionCounter++}";
 
@@ -401,7 +408,10 @@ public class ScriptActor : ReceiveActor, IWithTimers
             _logger,
             _scope,
             _healthCollector,
-            _serviceProvider));
+            _serviceProvider,
+            // Audit Log #23 (ParentExecutionId): null for trigger-driven runs;
+            // an inbound-API-routed call supplies the inbound request's id.
+            parentExecutionId));
 
         Context.ActorOf(props, executionId);
     }

src/ScadaLink.SiteRuntime/Actors/ScriptExecutionActor.cs

@@ -43,7 +43,11 @@ public class ScriptExecutionActor : ReceiveActor
         ILogger logger,
         Commons.Types.Scripts.ScriptScope scope,
         ISiteHealthCollector? healthCollector = null,
-        IServiceProvider? serviceProvider = null)
+        IServiceProvider? serviceProvider = null,
+        // Audit Log #23 (ParentExecutionId): the spawning execution's
+        // ExecutionId for an inbound-API-routed call. Null for normal
+        // (tag-change / timer) runs and nested Script.Call invocations.
+        Guid? parentExecutionId = null)
     {
         // Immediately begin execution
         var self = Self;
@@ -52,7 +56,8 @@ public class ScriptExecutionActor : ReceiveActor
         ExecuteScript(
             scriptName, instanceName, compiledScript, parameters, callDepth,
             instanceActor, sharedScriptLibrary, options, replyTo, correlationId,
-            self, parent, logger, scope, healthCollector, serviceProvider);
+            self, parent, logger, scope, healthCollector, serviceProvider,
+            parentExecutionId);
     }
 
     private static void ExecuteScript(
@@ -71,7 +76,8 @@ public class ScriptExecutionActor : ReceiveActor
         ILogger logger,
         Commons.Types.Scripts.ScriptScope scope,
         ISiteHealthCollector? healthCollector,
-        IServiceProvider? serviceProvider)
+        IServiceProvider? serviceProvider,
+        Guid? parentExecutionId)
     {
         var timeout = TimeSpan.FromSeconds(options.ScriptExecutionTimeoutSeconds);
 
@@ -164,7 +170,12 @@ public class ScriptExecutionActor : ReceiveActor
                     // emission. Best-effort: null degrades the helpers to a
                     // no-emission path; the S&F handoff and TrackedOperationId
                     // return are unaffected.
-                    cachedForwarder: cachedForwarder);
+                    cachedForwarder: cachedForwarder,
+                    // Audit Log #23 (ParentExecutionId): the spawning execution's
+                    // id for an inbound-API-routed call. The routed script still
+                    // mints its own fresh ExecutionId — this records the spawner.
+                    // Null for normal (tag-change / timer) runs.
+                    parentExecutionId: parentExecutionId);
 
                 var globals = new ScriptGlobals
                 {

src/ScadaLink.SiteRuntime/Scripts/ScriptRuntimeContext.cs

@@ -116,6 +116,19 @@ public class ScriptRuntimeContext
     /// </summary>
     private readonly Guid _executionId;
 
+    /// <summary>
+    /// Audit Log #23 (ParentExecutionId): the spawning execution's
+    /// <see cref="_executionId"/> when this script run was spawned by another
+    /// execution — for an inbound-API-routed call this is the inbound request's
+    /// per-request execution id. <c>null</c> for normal (tag-change /
+    /// timer-triggered) runs and nested <c>CallScript</c> invocations. The
+    /// routed script still mints its OWN fresh <see cref="_executionId"/>; this
+    /// field records the spawner so a spawned execution's audit rows can point
+    /// back at the execution that spawned it. (Task 5 wires the emitter that
+    /// stamps this onto <c>AuditEvent.ParentExecutionId</c>.)
+    /// </summary>
+    private readonly Guid? _parentExecutionId;
+
     /// <param name="executionId">
     /// Audit Log #23: the per-execution id for this script run. When omitted
     /// (tag-change / timer-triggered executions) a fresh id is generated; an
@@ -123,6 +136,13 @@ public class ScriptRuntimeContext
     /// request. Stamped into <c>AuditEvent.ExecutionId</c> on every
     /// trust-boundary audit row this execution emits.
     /// </param>
+    /// <param name="parentExecutionId">
+    /// Audit Log #23 (ParentExecutionId): the spawning execution's
+    /// <c>ExecutionId</c> — supplied for an inbound-API-routed call (the
+    /// inbound request's per-request id), <c>null</c> for normal (tag-change /
+    /// timer-triggered) runs. The routed script still generates its own fresh
+    /// <paramref name="executionId"/>; this only records the spawner.
+    /// </param>
     public ScriptRuntimeContext(
         IActorRef instanceActor,
         IActorRef self,
@@ -141,7 +161,8 @@ public class ScriptRuntimeContext
         IAuditWriter? auditWriter = null,
         IOperationTrackingStore? operationTrackingStore = null,
         ICachedCallTelemetryForwarder? cachedForwarder = null,
-        Guid? executionId = null)
+        Guid? executionId = null,
+        Guid? parentExecutionId = null)
     {
         _instanceActor = instanceActor;
         _self = self;
@@ -161,6 +182,9 @@ public class ScriptRuntimeContext
         _operationTrackingStore = operationTrackingStore;
         _cachedForwarder = cachedForwarder;
         _executionId = executionId ?? Guid.NewGuid();
+        // Audit Log #23 (ParentExecutionId): stored verbatim — no `?? NewGuid()`
+        // fallback. A non-routed run legitimately has no parent and stays null.
+        _parentExecutionId = parentExecutionId;
     }
 
     /// <summary>
@@ -264,7 +288,10 @@ public class ScriptRuntimeContext
         _externalSystemClient, _instanceName, _logger, _executionId, _auditWriter, _siteId, _sourceScript,
         // Audit Log #23 (M3 Bundle E — Task E3): emit CachedSubmit telemetry
         // on every ExternalSystem.CachedCall enqueue.
-        _cachedForwarder);
+        _cachedForwarder,
+        // Audit Log #23 (ParentExecutionId): the spawning execution's id,
+        // threaded alongside _executionId. Null for non-routed runs.
+        _parentExecutionId);
 
     /// <summary>
     /// WP-13: Provides access to database operations.
@@ -285,7 +312,10 @@ public class ScriptRuntimeContext
         _sourceScript,
         // Audit Log #23 (M3 Bundle E — Task E6): emit CachedSubmit telemetry on
         // every Database.CachedWrite enqueue.
-        _cachedForwarder);
+        _cachedForwarder,
+        // Audit Log #23 (ParentExecutionId): the spawning execution's id,
+        // threaded alongside _executionId. Null for non-routed runs.
+        _parentExecutionId);
 
     /// <summary>
     /// Provides access to the Notification Outbox API.
@@ -302,7 +332,10 @@ public class ScriptRuntimeContext
     /// </remarks>
     public NotifyHelper Notify => new(
         _storeAndForward, _siteCommunicationActor, _siteId, _instanceName, _sourceScript, _askTimeout, _logger,
-        _executionId, _auditWriter);
+        _executionId, _auditWriter,
+        // Audit Log #23 (ParentExecutionId): the spawning execution's id,
+        // threaded alongside _executionId. Null for non-routed runs.
+        _parentExecutionId);
 
     /// <summary>
     /// Audit Log #23 (M3): site-local tracking-status API for cached operations.
@@ -384,6 +417,15 @@ public class ScriptRuntimeContext
         private readonly string _instanceName;
         private readonly ILogger _logger;
         private readonly Guid _executionId;
+
+        /// <summary>
+        /// Audit Log #23 (ParentExecutionId): the spawning execution's id when
+        /// this run was inbound-API-routed; <c>null</c> for non-routed runs.
+        /// Threaded alongside <see cref="_executionId"/> ready for the Task 5
+        /// emitter — no audit row carries it yet.
+        /// </summary>
+        private readonly Guid? _parentExecutionId;
+
         private readonly IAuditWriter? _auditWriter;
         private readonly string _siteId;
         private readonly string? _sourceScript;
@@ -398,7 +440,9 @@ public class ScriptRuntimeContext
         // DatabaseHelper, AuditingDbConnection, AuditingDbCommand) — a required
         // Guid cannot follow the optional provenance params without a
         // required-after-optional compile error, so the post-logger slot is the
-        // one consistent position that compiles cleanly everywhere.
+        // one consistent position that compiles cleanly everywhere. The nullable
+        // parentExecutionId is a trailing optional param so existing positional
+        // callers stay source-compatible.
         internal ExternalSystemHelper(
             IExternalSystemClient? client,
             string instanceName,
@@ -407,7 +451,8 @@ public class ScriptRuntimeContext
             IAuditWriter? auditWriter = null,
             string siteId = "",
             string? sourceScript = null,
-            ICachedCallTelemetryForwarder? cachedForwarder = null)
+            ICachedCallTelemetryForwarder? cachedForwarder = null,
+            Guid? parentExecutionId = null)
         {
             _client = client;
             _instanceName = instanceName;
@@ -417,6 +462,7 @@ public class ScriptRuntimeContext
             _siteId = siteId;
             _sourceScript = sourceScript;
             _cachedForwarder = cachedForwarder;
+            _parentExecutionId = parentExecutionId;
         }
 
         public async Task<ExternalCallResult> Call(
@@ -1001,6 +1047,15 @@ public class ScriptRuntimeContext
         private readonly string _instanceName;
         private readonly ILogger _logger;
         private readonly Guid _executionId;
+
+        /// <summary>
+        /// Audit Log #23 (ParentExecutionId): the spawning execution's id when
+        /// this run was inbound-API-routed; <c>null</c> for non-routed runs.
+        /// Threaded alongside <see cref="_executionId"/> ready for the Task 5
+        /// emitter — no audit row carries it yet.
+        /// </summary>
+        private readonly Guid? _parentExecutionId;
+
         private readonly string _siteId;
         private readonly string? _sourceScript;
         private readonly ICachedCallTelemetryForwarder? _cachedForwarder;
@@ -1020,7 +1075,7 @@ public class ScriptRuntimeContext
         // Parameter ordering: executionId sits immediately after the
         // ILogger — see the note on ExternalSystemHelper's ctor for why the
         // post-logger slot is the one consistent position across all four
-        // audit-threaded ctors.
+        // audit-threaded ctors. parentExecutionId is a trailing optional param.
         internal DatabaseHelper(
             IDatabaseGateway? gateway,
             string instanceName,
@@ -1029,7 +1084,8 @@ public class ScriptRuntimeContext
             IAuditWriter? auditWriter = null,
             string siteId = "",
             string? sourceScript = null,
-            ICachedCallTelemetryForwarder? cachedForwarder = null)
+            ICachedCallTelemetryForwarder? cachedForwarder = null,
+            Guid? parentExecutionId = null)
         {
             _gateway = gateway;
             _instanceName = instanceName;
@@ -1039,6 +1095,7 @@ public class ScriptRuntimeContext
             _siteId = siteId;
             _sourceScript = sourceScript;
             _cachedForwarder = cachedForwarder;
+            _parentExecutionId = parentExecutionId;
         }
 
         public async Task<System.Data.Common.DbConnection> Connection(
@@ -1213,6 +1270,14 @@ public class ScriptRuntimeContext
         /// </summary>
         private readonly Guid _executionId;
 
+        /// <summary>
+        /// Audit Log #23 (ParentExecutionId): the spawning execution's id when
+        /// this run was inbound-API-routed; <c>null</c> for non-routed runs.
+        /// Threaded alongside <see cref="_executionId"/> ready for the Task 5
+        /// emitter — no audit row carries it yet.
+        /// </summary>
+        private readonly Guid? _parentExecutionId;
+
         /// <summary>
         /// Audit Log #23 (M4 Bundle C): best-effort emitter for the
         /// <c>Notification</c>/<c>NotifySend</c> row produced when the script
@@ -1224,7 +1289,8 @@ public class ScriptRuntimeContext
         private readonly IAuditWriter? _auditWriter;
 
         // Parameter ordering: executionId sits immediately after the ILogger,
-        // consistent with the other audit-threaded ctors.
+        // consistent with the other audit-threaded ctors. parentExecutionId is
+        // a trailing optional param.
         internal NotifyHelper(
             StoreAndForwardService? storeAndForward,
             ICanTell? siteCommunicationActor,
@@ -1234,7 +1300,8 @@ public class ScriptRuntimeContext
             TimeSpan askTimeout,
             ILogger logger,
             Guid executionId,
-            IAuditWriter? auditWriter = null)
+            IAuditWriter? auditWriter = null,
+            Guid? parentExecutionId = null)
         {
             _storeAndForward = storeAndForward;
             _siteCommunicationActor = siteCommunicationActor;
@@ -1245,6 +1312,7 @@ public class ScriptRuntimeContext
             _logger = logger;
             _executionId = executionId;
             _auditWriter = auditWriter;
+            _parentExecutionId = parentExecutionId;
         }
 
         /// <summary>
@@ -1259,7 +1327,10 @@ public class ScriptRuntimeContext
                 _executionId,
                 // Audit Log #23 (M4 Bundle C): forward the writer so Send()
                 // can emit one NotifySend(Submitted) row per accepted submission.
-                _auditWriter);
+                _auditWriter,
+                // Audit Log #23 (ParentExecutionId): the spawning execution's
+                // id, threaded alongside _executionId. Null for non-routed runs.
+                _parentExecutionId);
         }
 
         /// <summary>
@@ -1340,6 +1411,14 @@ public class ScriptRuntimeContext
         /// </summary>
         private readonly Guid _executionId;
 
+        /// <summary>
+        /// Audit Log #23 (ParentExecutionId): the spawning execution's id when
+        /// this run was inbound-API-routed; <c>null</c> for non-routed runs.
+        /// Threaded alongside <see cref="_executionId"/> ready for the Task 5
+        /// emitter — no audit row carries it yet.
+        /// </summary>
+        private readonly Guid? _parentExecutionId;
+
         /// <summary>
         /// Audit Log #23 (M4 Bundle C): best-effort emitter for the
         /// <c>Notification</c>/<c>NotifySend</c> row written immediately after
@@ -1356,7 +1435,8 @@ public class ScriptRuntimeContext
             string? sourceScript,
             ILogger logger,
             Guid executionId,
-            IAuditWriter? auditWriter = null)
+            IAuditWriter? auditWriter = null,
+            Guid? parentExecutionId = null)
         {
             _listName = listName;
             _storeAndForward = storeAndForward;
@@ -1366,6 +1446,7 @@ public class ScriptRuntimeContext
             _logger = logger;
             _executionId = executionId;
             _auditWriter = auditWriter;
+            _parentExecutionId = parentExecutionId;
         }
 
         /// <summary>

tests/ScadaLink.SiteRuntime.Tests/Actors/DeploymentManagerActorTests.cs

@@ -3,6 +3,7 @@ using Akka.TestKit.Xunit2;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
 using ScadaLink.Commons.Messages.Deployment;
+using ScadaLink.Commons.Messages.InboundApi;
 using ScadaLink.Commons.Messages.Lifecycle;
 using ScadaLink.Commons.Types.Enums;
 using ScadaLink.Commons.Types.Flattening;
@@ -68,6 +69,28 @@ public class DeploymentManagerActorTests : TestKit, IDisposable
         return JsonSerializer.Serialize(config);
     }
 
+    /// <summary>
+    /// Builds a config carrying a single callable (no-trigger) script that
+    /// returns a constant — enough for an inbound <see cref="RouteToCallRequest"/>
+    /// to be routed end-to-end through the Instance/Script/ScriptExecution actors.
+    /// </summary>
+    private static string MakeConfigWithScriptJson(string instanceName, string scriptName)
+    {
+        var config = new FlattenedConfiguration
+        {
+            InstanceUniqueName = instanceName,
+            Attributes =
+            [
+                new ResolvedAttribute { CanonicalName = "TestAttr", Value = "42", DataType = "Int32" }
+            ],
+            Scripts =
+            [
+                new ResolvedScript { CanonicalName = scriptName, Code = "return 7;" }
+            ]
+        };
+        return JsonSerializer.Serialize(config);
+    }
+
     [Fact]
     public async Task DeploymentManager_CreatesInstanceActors_FromStoredConfigs()
     {
@@ -240,4 +263,57 @@ public class DeploymentManagerActorTests : TestKit, IDisposable
         var response = ExpectMsg<DeploymentStatusResponse>(TimeSpan.FromSeconds(5));
         Assert.Equal(DeploymentStatus.Success, response.Status);
     }
+
+    // ── Audit Log #23 (ParentExecutionId, Task 4): inbound-API routing ──
+
+    [Fact]
+    public async Task RouteInboundApiCall_WithParentExecutionId_RoutesToScriptSuccessfully()
+    {
+        // A RouteToCallRequest carrying a ParentExecutionId (the inbound
+        // request's ExecutionId) must be mapped to a ScriptCallRequest and
+        // routed end-to-end through the Instance/Script/ScriptExecution actors.
+        // The additive ParentExecutionId field must not break that routing.
+        var actor = CreateDeploymentManager();
+        await Task.Delay(500); // empty startup
+
+        actor.Tell(new DeployInstanceCommand(
+            "dep-route", "RoutedPump", "sha256:route",
+            MakeConfigWithScriptJson("RoutedPump", "DoWork"), "admin", DateTimeOffset.UtcNow));
+        ExpectMsg<DeploymentStatusResponse>(TimeSpan.FromSeconds(5));
+        await Task.Delay(1000); // let the InstanceActor + ScriptActor spin up
+
+        var parentExecutionId = Guid.NewGuid();
+        actor.Tell(new RouteToCallRequest(
+            "route-corr-1", "RoutedPump", "DoWork",
+            Parameters: null, DateTimeOffset.UtcNow, ParentExecutionId: parentExecutionId));
+
+        var response = ExpectMsg<RouteToCallResponse>(TimeSpan.FromSeconds(10));
+        Assert.Equal("route-corr-1", response.CorrelationId);
+        Assert.True(response.Success, $"Routed call failed: {response.ErrorMessage}");
+        Assert.Equal(7, Convert.ToInt32(response.ReturnValue));
+    }
+
+    [Fact]
+    public async Task RouteInboundApiCall_WithoutParentExecutionId_StillRoutes()
+    {
+        // A routed call with no ParentExecutionId (e.g. the Central UI sandbox)
+        // is the additive-default path — it must route exactly as before.
+        var actor = CreateDeploymentManager();
+        await Task.Delay(500);
+
+        actor.Tell(new DeployInstanceCommand(
+            "dep-route2", "RoutedPump2", "sha256:route2",
+            MakeConfigWithScriptJson("RoutedPump2", "DoWork"), "admin", DateTimeOffset.UtcNow));
+        ExpectMsg<DeploymentStatusResponse>(TimeSpan.FromSeconds(5));
+        await Task.Delay(1000);
+
+        // No ParentExecutionId argument — exercises the additive `= null` default.
+        actor.Tell(new RouteToCallRequest(
+            "route-corr-2", "RoutedPump2", "DoWork",
+            Parameters: null, DateTimeOffset.UtcNow));
+
+        var response = ExpectMsg<RouteToCallResponse>(TimeSpan.FromSeconds(10));
+        Assert.Equal("route-corr-2", response.CorrelationId);
+        Assert.True(response.Success, $"Routed call failed: {response.ErrorMessage}");
+    }
 }

tests/ScadaLink.SiteRuntime.Tests/Scripts/ExecutionCorrelationContextTests.cs

@@ -62,7 +62,8 @@ public class ExecutionCorrelationContextTests
         IExternalSystemClient? externalSystemClient,
         IDatabaseGateway? databaseGateway,
         IAuditWriter? auditWriter,
-        Guid? executionId = null)
+        Guid? executionId = null,
+        Guid? parentExecutionId = null)
     {
         var compilationService = new ScriptCompilationService(
             NullLogger<ScriptCompilationService>.Instance);
@@ -87,7 +88,24 @@ public class ExecutionCorrelationContextTests
             auditWriter: auditWriter,
             operationTrackingStore: null,
             cachedForwarder: null,
-            executionId: executionId);
+            executionId: executionId,
+            parentExecutionId: parentExecutionId);
+    }
+
+    /// <summary>
+    /// Reads a private <see cref="Guid"/>/<see cref="Nullable{Guid}"/> field off a
+    /// <see cref="ScriptRuntimeContext"/>. The ParentExecutionId plumbing (Audit
+    /// Log #23, Task 4) only stores the value on the context — no emitter stamps
+    /// it onto an audit row yet (that is Task 5) — so the field is inspected
+    /// directly rather than through an emitted row.
+    /// </summary>
+    private static object? ReadPrivateField(ScriptRuntimeContext context, string fieldName)
+    {
+        var field = typeof(ScriptRuntimeContext).GetField(
+            fieldName,
+            System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
+        Assert.NotNull(field);
+        return field!.GetValue(context);
     }
 
     /// <summary>
@@ -183,4 +201,54 @@ public class ExecutionCorrelationContextTests
         Assert.Null(apiRow.CorrelationId);
         Assert.Null(dbRow.CorrelationId);
     }
+
+    [Fact]
+    public void ParentExecutionIdSupplied_StoredVerbatim_AndOwnExecutionIdIsFreshAndDistinct()
+    {
+        // Audit Log #23 (ParentExecutionId, Task 4): an inbound-API-routed call
+        // supplies the spawning execution's ExecutionId as the routed script's
+        // ParentExecutionId. The context must store that value verbatim AND
+        // still mint its OWN fresh ExecutionId — the routed script is a new
+        // execution, it does not inherit the parent's id.
+        var parentExecutionId = Guid.NewGuid();
+
+        var context = CreateContext(
+            externalSystemClient: null,
+            databaseGateway: null,
+            auditWriter: null,
+            // executionId omitted — the ctor's `?? Guid.NewGuid()` fallback runs.
+            parentExecutionId: parentExecutionId);
+
+        var storedParent = ReadPrivateField(context, "_parentExecutionId");
+        var ownExecutionId = ReadPrivateField(context, "_executionId");
+
+        // The parent id is carried through untouched.
+        Assert.Equal(parentExecutionId, storedParent);
+
+        // The routed script's own ExecutionId is freshly generated, non-empty,
+        // and NOT the parent id — they are separate correlation values.
+        Assert.NotNull(ownExecutionId);
+        var ownId = Assert.IsType<Guid>(ownExecutionId);
+        Assert.NotEqual(Guid.Empty, ownId);
+        Assert.NotEqual(parentExecutionId, ownId);
+    }
+
+    [Fact]
+    public void NoParentExecutionIdSupplied_NonRoutedRun_ParentStaysNull()
+    {
+        // A normal (tag-change / timer) script run is not inbound-API-routed —
+        // no ParentExecutionId is supplied, so _parentExecutionId stays null
+        // while the run still gets its own fresh ExecutionId.
+        var context = CreateContext(
+            externalSystemClient: null,
+            databaseGateway: null,
+            auditWriter: null);
+
+        var storedParent = ReadPrivateField(context, "_parentExecutionId");
+        var ownExecutionId = ReadPrivateField(context, "_executionId");
+
+        Assert.Null(storedParent);
+        var ownId = Assert.IsType<Guid>(ownExecutionId);
+        Assert.NotEqual(Guid.Empty, ownId);
+    }
 }