fix(auditlog): evolve existing site auditlog.db schema for ExecutionId

The store-and-forward retry loop emits the per-attempt and terminal cached
audit rows (ApiCallCached/DbWriteCached Attempted, CachedResolve) via
CachedCallLifecycleBridge from a CachedCallAttemptContext, not from the
script context. ExecutionId (and SourceScript) were not threaded through the
S&F buffer, so those rows had ExecutionId = null and SourceScript = null.

Thread both, additively, from the cached-call enqueue path:

- StoreAndForwardMessage gains ExecutionId (Guid?) / SourceScript (string?).
- StoreAndForwardStorage adds nullable execution_id / source_script columns
  via an idempotent PRAGMA-probed ALTER TABLE migration; rows persisted by
  an older build read back null (back-compat).
- StoreAndForwardService.EnqueueAsync gains optional executionId /
  sourceScript params, stamped onto the buffered message and surfaced on the
  CachedCallAttemptContext built in the retry loop.
- CachedCallAttemptContext gains ExecutionId / SourceScript.
- CachedCallLifecycleBridge.BuildPacket sets AuditEvent.ExecutionId and
  AuditEvent.SourceScript from the context (replacing the hard-coded
  SourceScript = null and its now-stale comment).
- IExternalSystemClient.CachedCallAsync / IDatabaseGateway.CachedWriteAsync
  gain optional executionId / sourceScript params; ScriptRuntimeContext's
  CachedCall / CachedWrite helpers pass _executionId / _sourceScript.

Script-side cached rows (CachedSubmit, immediate Attempted+Resolve) are
unchanged. All threading is additive — old buffered S&F rows still
deserialize and process with the new fields null.

CLAUDE.md

@@ -132,6 +132,7 @@ This project contains design documentation for a distributed SCADA system built
 - Layered design — append-only `AuditLog` (#23) sits alongside operational `Notifications` (#21) and `SiteCalls` (#22), not replacing them.
 - Scope = script trust boundary: outbound API (sync + cached), outbound DB (sync + cached), notifications, inbound API. Framework/internal traffic is explicitly excluded.
 - One row per lifecycle event; cached calls produce 4+ rows per operation (`Submitted`, `Forwarded`, `Attempted`, `Delivered`/`Parked`/`Discarded`).
+- `ExecutionId` (`uniqueidentifier NULL`) is the universal per-run correlation value — every audit row emitted by one script execution / inbound request shares it; `CorrelationId` remains the per-operation lifecycle id (NULL for sync one-shots).
 - Site SQLite hot-path first, then gRPC telemetry to central; ingest is idempotent on `EventId`; periodic reconciliation pull as fallback when telemetry is lost.
 - Cached operations: site emits a single additively-extended `CachedCallTelemetry` packet carrying both audit events and operational state; central writes `AuditLog` + `SiteCalls` in one transaction.
 - Payload cap 8 KB by default / 64 KB on error rows; auth headers redacted by default; SQL parameter values captured by default; per-target redaction opt-in.

docs/requirements/Component-AuditLog.md

@@ -83,6 +83,7 @@ row per lifecycle event across all channels.
 | `Channel` | `varchar(32)` | `ApiOutbound` \| `DbOutbound` \| `Notification` \| `ApiInbound`. |
 | `Kind` | `varchar(32)` | Event kind discriminator (see kinds list below). |
 | `CorrelationId` | `uniqueidentifier` NULL | Ties multi-event operations together. `TrackedOperationId` for cached calls, `NotificationId` for notifications, request-id for inbound API. NULL for sync one-shot calls. |
+| `ExecutionId` | `uniqueidentifier` NULL | The originating script execution / inbound request — the universal per-run correlation value; distinct from `CorrelationId`, which is the per-operation lifecycle id. Stamped on *every* audit row emitted by one execution. |
 | `SourceSiteId` | `varchar(64)` NULL | NULL for central-originated events. |
 | `SourceInstanceId` | `varchar(128)` NULL | Instance whose script initiated the action (when applicable). |
 | `SourceScript` | `varchar(128)` NULL | Script name within the instance. |
@@ -102,7 +103,8 @@ row per lifecycle event across all channels.
 
 - `IX_AuditLog_OccurredAtUtc` — primary time-range index for global scans.
 - `IX_AuditLog_Site_Occurred (SourceSiteId, OccurredAtUtc)` — per-site filters.
-- `IX_AuditLog_Correlation (CorrelationId)` — drilldown from a single operation.
+- `IX_AuditLog_CorrelationId (CorrelationId)` — drilldown from a single operation.
+- `IX_AuditLog_Execution (ExecutionId)` — drilldown to every action of one script execution / inbound request.
 - `IX_AuditLog_Channel_Status_Occurred (Channel, Status, OccurredAtUtc)` — KPI / dashboard tiles.
 - `IX_AuditLog_Target_Occurred (Target, OccurredAtUtc)` — "what did we send to system X".
 - Monthly partitioning on `OccurredAtUtc` from day one; purge is a partition switch (see Retention & Purge).
@@ -126,6 +128,27 @@ Inbound API is intentionally collapsed to a single `InboundRequest` (or
 `InboundAuthFailure` for auth rejections) row per request rather than a
 multi-event lifecycle.
 
+### `ExecutionId` vs `CorrelationId`
+
+The table carries two correlation columns at different granularities:
+
+- **`ExecutionId`** is the *universal per-run* value: one id per script
+  execution (tag-change / timer-triggered or otherwise) or per inbound API
+  request. It is stamped on **every** audit row that run produces — the sync
+  `ApiCall` and `DbWrite` rows, the full cached-call lifecycle, the
+  `NotifySend` / `NotifyDeliver` rows, and the inbound row alike. A run that
+  performs no trust-boundary action emits no rows, but any run that emits
+  multiple rows ties them all together under one `ExecutionId`. This lets an
+  audit reader pull the complete trust-boundary footprint of a single script
+  run with one `ExecutionId` filter.
+- **`CorrelationId`** is the *per-operation lifecycle* id — it groups the
+  multiple events of one long-running operation (`TrackedOperationId` for a
+  cached call, `NotificationId` for a notification, request-id for inbound
+  API) and is NULL for sync one-shot calls that have no operation lifecycle.
+
+The two are orthogonal: one execution may touch several operations (each with
+its own `CorrelationId`) yet every resulting row shares the one `ExecutionId`.
+
 ## The Site-Local `AuditLog` (SQLite)
 
 A SQLite database file on each site node, alongside the Store-and-Forward

src/ScadaLink.AuditLog/Site/SqliteAuditWriter.cs

@@ -121,6 +121,46 @@ public class SqliteAuditWriter : IAuditWriter, ISiteAuditQueue, IAsyncDisposable
                 ON AuditLog (ForwardState, OccurredAtUtc);
             """;
         cmd.ExecuteNonQuery();
+
+        // Audit Log #23 (ExecutionId): additively add the ExecutionId column.
+        // CREATE TABLE IF NOT EXISTS above does NOT add columns to an AuditLog
+        // table that already exists from a pre-ExecutionId build, so an
+        // auditlog.db created by an older build needs the column ALTER-ed in.
+        // The file is durable across restart/failover by design (7-day
+        // retention), so without this step every WriteAsync on an upgraded
+        // deployment would bind $ExecutionId against a missing column and the
+        // best-effort write path would silently drop every site audit row.
+        // SQLite has no "ADD COLUMN IF NOT EXISTS"; the column presence is
+        // probed first and the ALTER skipped when already there. The column is
+        // nullable with no default, so any row written before this migration
+        // reads back ExecutionId = null (back-compat).
+        AddColumnIfMissing("ExecutionId", "TEXT NULL");
+    }
+
+    /// <summary>
+    /// Audit Log #23 (ExecutionId): adds a column to <c>AuditLog</c> only when
+    /// it is not already present. SQLite lacks <c>ADD COLUMN IF NOT EXISTS</c>,
+    /// so the schema is probed via <c>PRAGMA table_info</c> first. Idempotent —
+    /// safe to run on every <see cref="InitializeSchema"/>. Mirrors
+    /// <c>StoreAndForwardStorage.AddColumnIfMissingAsync</c>; kept synchronous
+    /// here to match the rest of this writer's bootstrap DDL.
+    /// </summary>
+    private void AddColumnIfMissing(string columnName, string columnDefinition)
+    {
+        using var probe = _connection.CreateCommand();
+        probe.CommandText = "SELECT COUNT(*) FROM pragma_table_info('AuditLog') WHERE name = $name";
+        probe.Parameters.AddWithValue("$name", columnName);
+        var exists = Convert.ToInt32(probe.ExecuteScalar()) > 0;
+        if (exists)
+        {
+            return;
+        }
+
+        using var alter = _connection.CreateCommand();
+        // Column name + definition are caller-controlled constants, never user
+        // input — safe to interpolate (parameters are not permitted in DDL).
+        alter.CommandText = $"ALTER TABLE AuditLog ADD COLUMN {columnName} {columnDefinition}";
+        alter.ExecuteNonQuery();
     }
 
     /// <summary>

src/ScadaLink.AuditLog/Site/Telemetry/CachedCallLifecycleBridge.cs

@@ -133,9 +133,17 @@ public sealed class CachedCallLifecycleBridge : ICachedCallLifecycleObserver
                 Channel = channel,
                 Kind = kind,
                 CorrelationId = context.TrackedOperationId.Value,
+                // Audit Log #23 (ExecutionId Task 4): the originating script
+                // execution's per-run correlation id, threaded through the S&F
+                // buffer; null on rows buffered before Task 4 (back-compat).
+                ExecutionId = context.ExecutionId,
                 SourceSiteId = string.IsNullOrEmpty(context.SourceSite) ? null : context.SourceSite,
                 SourceInstanceId = context.SourceInstanceId,
-                SourceScript = null, // Not threaded through S&F; left null on retry-loop rows.
+                // Audit Log #23 (ExecutionId Task 4): SourceScript is now
+                // threaded through the S&F buffer alongside ExecutionId — the
+                // retry-loop cached rows carry the same provenance the
+                // script-side cached rows do. Null on pre-Task-4 buffered rows.
+                SourceScript = context.SourceScript,
                 Target = context.Target,
                 Status = status,
                 HttpStatus = httpStatus,

src/ScadaLink.CLI/Commands/AuditCommands.cs

@@ -59,6 +59,7 @@ public static class AuditCommands
         var targetOption = new Option<string?>("--target") { Description = "Filter by target (external system, DB connection, notification list)" };
         var actorOption = new Option<string?>("--actor") { Description = "Filter by actor" };
         var correlationIdOption = new Option<string?>("--correlation-id") { Description = "Filter by correlation ID" };
+        var executionIdOption = new Option<string?>("--execution-id") { Description = "Filter by execution ID" };
         var errorsOnlyOption = new Option<bool>("--errors-only") { Description = "Show only failed events (status=Failed; overrides --status)" };
         var pageSizeOption = new Option<int>("--page-size") { Description = "Events per page (1-1000)" };
         pageSizeOption.DefaultValueFactory = _ => 100;
@@ -74,6 +75,7 @@ public static class AuditCommands
         cmd.Add(targetOption);
         cmd.Add(actorOption);
         cmd.Add(correlationIdOption);
+        cmd.Add(executionIdOption);
         cmd.Add(errorsOnlyOption);
         cmd.Add(pageSizeOption);
         cmd.Add(allOption);
@@ -101,6 +103,7 @@ public static class AuditCommands
                 Target = result.GetValue(targetOption),
                 Actor = result.GetValue(actorOption),
                 CorrelationId = result.GetValue(correlationIdOption),
+                ExecutionId = result.GetValue(executionIdOption),
                 ErrorsOnly = result.GetValue(errorsOnlyOption),
                 PageSize = result.GetValue(pageSizeOption),
             };

src/ScadaLink.CLI/Commands/AuditQueryHelpers.cs

@@ -24,6 +24,7 @@ public sealed class AuditQueryArgs
     public string? Target { get; set; }
     public string? Actor { get; set; }
     public string? CorrelationId { get; set; }
+    public string? ExecutionId { get; set; }
     public bool ErrorsOnly { get; set; }
     public int PageSize { get; set; } = 100;
 }
@@ -125,6 +126,7 @@ public static class AuditQueryHelpers
         Add("target", args.Target);
         Add("actor", args.Actor);
         Add("correlationId", args.CorrelationId);
+        Add("executionId", args.ExecutionId);
         Add("pageSize", args.PageSize.ToString(CultureInfo.InvariantCulture));
 
         if (afterOccurredAtUtc.HasValue)

src/ScadaLink.CentralUI/Audit/AuditExportEndpoints.cs

@@ -105,6 +105,13 @@ public static class AuditExportEndpoints
             correlationId = parsedCorr;
         }
 
+        Guid? executionId = null;
+        if (query.TryGetValue("executionId", out var execValues)
+            && Guid.TryParse(execValues.ToString(), out var parsedExec))
+        {
+            executionId = parsedExec;
+        }
+
         DateTime? fromUtc = ParseUtcDate(query, "from");
         DateTime? toUtc = ParseUtcDate(query, "to");
 
@@ -116,6 +123,7 @@ public static class AuditExportEndpoints
             Target: target,
             Actor: actor,
             CorrelationId: correlationId,
+            ExecutionId: executionId,
             FromUtc: fromUtc,
             ToUtc: toUtc);
     }

src/ScadaLink.CentralUI/Components/Audit/AuditDrilldownDrawer.razor

@@ -55,6 +55,9 @@
                 <dt class="col-4 text-muted fw-normal">CorrelationId</dt>
                 <dd class="col-8 font-monospace" data-test="field-CorrelationId">@(Event.CorrelationId?.ToString() ?? "—")</dd>
 
+                <dt class="col-4 text-muted fw-normal">ExecutionId</dt>
+                <dd class="col-8 font-monospace" data-test="field-ExecutionId">@(Event.ExecutionId?.ToString() ?? "—")</dd>
+
                 <dt class="col-4 text-muted fw-normal">OccurredAtUtc</dt>
                 <dd class="col-8 font-monospace" data-test="field-OccurredAtUtc">@FormatTimestamp(Event.OccurredAtUtc)</dd>
 
@@ -151,6 +154,14 @@
                     Show all events for this operation
                 </button>
             }
+            @if (Event.ExecutionId is not null)
+            {
+                <button class="btn btn-outline-secondary btn-sm"
+                        data-test="view-this-execution"
+                        @onclick="ViewThisExecution">
+                    View this execution
+                </button>
+            }
             <button class="btn btn-primary btn-sm ms-auto"
                     data-test="drawer-close-footer"
                     @onclick="HandleClose">

src/ScadaLink.CentralUI/Components/Audit/AuditDrilldownDrawer.razor.cs

@@ -47,9 +47,10 @@ namespace ScadaLink.CentralUI.Components.Audit;
 /// <para>
 /// <b>Drill-back.</b> When <see cref="AuditEvent.CorrelationId"/> is set,
 /// the "Show all events" button navigates to
-/// <c>/audit/log?correlationId={id}</c>. The parent page does not
-/// auto-apply that filter today — it is a deep link the page can use
-/// when Bundle D wires up query-string deserialization.
+/// <c>/audit/log?correlationId={id}</c>. Likewise, when
+/// <see cref="AuditEvent.ExecutionId"/> is set the "View this execution"
+/// button navigates to <c>/audit/log?executionId={id}</c>. Both are deep
+/// links the Audit Log page deserializes on init (Bundle D) and auto-loads.
 /// </para>
 /// </summary>
 public partial class AuditDrilldownDrawer
@@ -276,6 +277,20 @@ public partial class AuditDrilldownDrawer
         Navigation.NavigateTo(uri);
     }
 
+    /// <summary>
+    /// Drill-in to every audit row sharing this row's <see cref="AuditEvent.ExecutionId"/>
+    /// — the universal per-run correlation value, distinct from the per-operation
+    /// CorrelationId drill-back above. Navigates to <c>/audit/log?executionId={id}</c>,
+    /// which the page parses on init and auto-loads. The button is only rendered
+    /// when <see cref="AuditEvent.ExecutionId"/> is non-null, so this is total.
+    /// </summary>
+    private void ViewThisExecution()
+    {
+        if (Event?.ExecutionId is not { } exec) return;
+        var uri = $"/audit/log?executionId={exec}";
+        Navigation.NavigateTo(uri);
+    }
+
     /// <summary>
     /// Build a cURL command from an audit event. The URL comes from
     /// <c>Target</c>; when the RequestSummary parses as

src/ScadaLink.CentralUI/Components/Audit/AuditFilterBar.razor

@@ -117,6 +117,16 @@
                        placeholder="contains…" @bind="_model.ActorSearch" />
             </div>
 
+            @* ExecutionId is an exact-match Guid filter — the operator pastes the
+               universal per-run correlation value. Lax-parsed in ToFilter so a
+               blank/malformed paste simply drops the constraint. *@
+            <div class="col-auto" data-test="filter-execution-id">
+                <label class="form-label small mb-1" for="audit-execution-id">Execution ID</label>
+                <input id="audit-execution-id" type="text"
+                       class="form-control form-control-sm font-monospace"
+                       placeholder="paste GUID…" @bind="_model.ExecutionId" />
+            </div>
+
             <div class="col-auto" data-test="filter-errors-only">
                 <div class="form-check mb-1">
                     <input class="form-check-input" type="checkbox" id="audit-errors-only"

src/ScadaLink.CentralUI/Components/Audit/AuditFilterBar.razor.cs

@@ -135,6 +135,7 @@ public partial class AuditFilterBar
         _model.ScriptSearch = string.Empty;
         _model.TargetSearch = string.Empty;
         _model.ActorSearch = string.Empty;
+        _model.ExecutionId = string.Empty;
         _model.ErrorsOnly = false;
     }
 

src/ScadaLink.CentralUI/Components/Audit/AuditQueryModel.cs

@@ -47,6 +47,14 @@ public sealed class AuditQueryModel
     public string TargetSearch { get; set; } = string.Empty;
     public string ActorSearch { get; set; } = string.Empty;
 
+    /// <summary>
+    /// Paste-in ExecutionId filter — the operator pastes the universal per-run
+    /// correlation Guid. Stored as free text; <see cref="ToFilter"/> lax-parses it
+    /// through <see cref="Guid.TryParse(string?, out Guid)"/> so a blank or
+    /// unparseable value simply yields no constraint.
+    /// </summary>
+    public string ExecutionId { get; set; } = string.Empty;
+
     public bool ErrorsOnly { get; set; }
 
     /// <summary>
@@ -114,6 +122,12 @@ public sealed class AuditQueryModel
 
         var (fromUtc, toUtc) = ResolveTimeWindow(utcNow);
 
+        // Lax-parse the pasted ExecutionId — blank or malformed text yields no
+        // constraint rather than an error, mirroring the optional-filter contract.
+        Guid? executionId = Guid.TryParse(ExecutionId, out var parsedExecutionId)
+            ? parsedExecutionId
+            : null;
+
         return new AuditLogQueryFilter(
             Channels: Channels.Count > 0 ? Channels.ToArray() : null,
             Kinds: Kinds.Count > 0 ? Kinds.ToArray() : null,
@@ -122,6 +136,7 @@ public sealed class AuditQueryModel
             Target: string.IsNullOrWhiteSpace(TargetSearch) ? null : TargetSearch.Trim(),
             Actor: string.IsNullOrWhiteSpace(ActorSearch) ? null : ActorSearch.Trim(),
             CorrelationId: null,
+            ExecutionId: executionId,
             FromUtc: fromUtc,
             ToUtc: toUtc);
     }

src/ScadaLink.CentralUI/Components/Audit/AuditResultsGrid.razor

@@ -83,6 +83,15 @@
 </div>
 
 @code {
+    // Compact display for Guid id columns: the first 8 hex digits, mirroring
+    // the drilldown drawer's ShortEventId presentation. The full value is kept
+    // in the cell's title attribute so it stays copy-paste accessible.
+    private static string ShortGuid(Guid value)
+    {
+        var n = value.ToString("N");
+        return n.Length >= 8 ? n[..8] : n;
+    }
+
     private RenderFragment RenderCell(string key, AuditEvent row) => __builder =>
     {
         switch (key)
@@ -111,6 +120,18 @@
             case "Actor":
                 <span class="small">@(row.Actor ?? "—")</span>
                 break;
+            case "ExecutionId":
+                @if (row.ExecutionId is { } executionId)
+                {
+                    <span class="small font-monospace"
+                          data-test="execution-id-@row.EventId"
+                          title="@executionId">@ShortGuid(executionId)</span>
+                }
+                else
+                {
+                    <span class="small text-muted">—</span>
+                }
+                break;
             case "DurationMs":
                 <span class="small font-monospace">@(row.DurationMs?.ToString() ?? "—")</span>
                 break;

src/ScadaLink.CentralUI/Components/Audit/AuditResultsGrid.razor.cs

@@ -9,9 +9,10 @@ namespace ScadaLink.CentralUI.Components.Audit;
 
 /// <summary>
 /// Keyset-paged results grid for the central Audit Log page (#23 M7-T3).
-/// Renders the 10 columns named in Component-AuditLog.md §10:
-/// OccurredAtUtc, Site, Channel, Kind, Status, Target, Actor, DurationMs,
-/// HttpStatus, ErrorMessage. Talks to <see cref="Services.IAuditLogQueryService"/>
+/// Renders the columns named in Component-AuditLog.md §10 — OccurredAtUtc,
+/// Site, Channel, Kind, Status, Target, Actor, DurationMs, HttpStatus,
+/// ErrorMessage — plus the ExecutionId per-run correlation column. Talks to
+/// <see cref="Services.IAuditLogQueryService"/>
 /// — never to <c>IAuditLogRepository</c> directly — so tests can stub the data
 /// source without standing up EF Core.
 ///
@@ -121,6 +122,7 @@ public partial class AuditResultsGrid : IAsyncDisposable
         ("Status", "Status"),
         ("Target", "Target"),
         ("Actor", "Actor"),
+        ("ExecutionId", "ExecutionId"),
         ("DurationMs", "DurationMs"),
         ("HttpStatus", "HttpStatus"),
         ("ErrorMessage", "ErrorMessage"),

src/ScadaLink.CentralUI/Components/Pages/Audit/AuditLogPage.razor.cs

@@ -22,7 +22,8 @@ namespace ScadaLink.CentralUI.Components.Pages.Audit;
 /// <c>?actor=</c>, <c>?site=</c>, <c>?channel=</c>, <c>?kind=</c>, and the UI-only
 /// <c>?instance=</c> are read on initialization. Bundle E (M7-T13) extends
 /// this with <c>?status=</c> so the Health-dashboard Audit error-rate tile can
-/// drill in to <c>?status=Failed</c>. When any param is present we allocate a
+/// drill in to <c>?status=Failed</c>. The ExecutionId follow-up adds
+/// <c>?executionId=</c> for the "View this execution" drill-in. When any param is present we allocate a
 /// fresh <see cref="AuditLogQueryFilter"/> and assign it to
 /// <see cref="_currentFilter"/>, which kicks the results grid into auto-load
 /// without the user clicking Apply. Unknown values (e.g. an invalid enum name)
@@ -60,6 +61,16 @@ public partial class AuditLogPage
             correlationId = parsedCorr;
         }
 
+        // ?executionId= is the "View this execution" drill-in target — the
+        // universal per-run correlation value. Lax-parsed like ?correlationId=:
+        // an unparseable value is silently dropped (no constraint).
+        Guid? executionId = null;
+        if (query.TryGetValue("executionId", out var execValues)
+            && Guid.TryParse(execValues.ToString(), out var parsedExec))
+        {
+            executionId = parsedExec;
+        }
+
         string? target = null;
         if (query.TryGetValue("target", out var targetValues))
         {
@@ -117,7 +128,7 @@ public partial class AuditLogPage
         // auto-loads. Pure ?instance= deep links (UI-only) do not trigger auto-load
         // because the filter contract has no instance column — the user still needs
         // to refine + Apply for those.
-        if (correlationId is null && target is null && actor is null
+        if (correlationId is null && executionId is null && target is null && actor is null
             && sites is null && channels is null && kinds is null && statuses is null)
         {
             return;
@@ -130,7 +141,8 @@ public partial class AuditLogPage
             SourceSiteIds: sites,
             Target: target,
             Actor: actor,
-            CorrelationId: correlationId);
+            CorrelationId: correlationId,
+            ExecutionId: executionId);
     }
 
     /// <summary>
@@ -236,6 +248,10 @@ public partial class AuditLogPage
         {
             parts.Add(new("correlationId", corr.ToString()));
         }
+        if (filter.ExecutionId is { } exec)
+        {
+            parts.Add(new("executionId", exec.ToString()));
+        }
         if (filter.FromUtc is { } from)
         {
             parts.Add(new("from", from.ToString("O", CultureInfo.InvariantCulture)));

src/ScadaLink.Commons/Entities/Notifications/Notification.cs

@@ -27,6 +27,15 @@ public class Notification
     public string SourceSiteId { get; set; }
     public string? SourceInstanceId { get; set; }
     public string? SourceScript { get; set; }
+
+    /// <summary>
+    /// The originating script execution's <c>ExecutionId</c> (Audit Log #23). Carried from
+    /// the site on the <see cref="Commons.Messages.Notification.NotificationSubmit"/> so the
+    /// central dispatcher can stamp the same id onto its <c>NotifyDeliver</c> audit rows,
+    /// correlating them with the site-emitted <c>NotifySend</c> row. Null for notifications
+    /// submitted before the column existed, or raised outside a script-execution context.
+    /// </summary>
+    public Guid? OriginExecutionId { get; set; }
     public DateTimeOffset SiteEnqueuedAt { get; set; }
 
     /// <summary>Central ingest time.</summary>

src/ScadaLink.Commons/Interfaces/Services/ICachedCallLifecycleObserver.cs

@@ -57,6 +57,20 @@ public interface ICachedCallLifecycleObserver
 /// <param name="OccurredAtUtc">When this attempt completed.</param>
 /// <param name="DurationMs">Duration of the attempt in milliseconds (null when not measured).</param>
 /// <param name="SourceInstanceId">Originating instance, when known.</param>
+/// <param name="ExecutionId">
+/// Audit Log #23 (ExecutionId Task 4): the originating script execution's
+/// per-run correlation id, threaded through the store-and-forward buffer from
+/// the cached-call enqueue path. The audit bridge stamps it onto the
+/// retry-loop <c>ApiCallCached</c>/<c>DbWriteCached</c> Attempted and
+/// <c>CachedResolve</c> rows so they correlate with the rest of the run.
+/// <c>null</c> for rows buffered before Task 4 (back-compat).
+/// </param>
+/// <param name="SourceScript">
+/// Audit Log #23 (ExecutionId Task 4): the originating script identifier,
+/// threaded alongside <paramref name="ExecutionId"/> so the retry-loop audit
+/// rows carry the same <c>SourceScript</c> provenance the script-side cached
+/// rows already do. <c>null</c> when not known.
+/// </param>
 public sealed record CachedCallAttemptContext(
     TrackedOperationId TrackedOperationId,
     string Channel,
@@ -69,7 +83,9 @@ public sealed record CachedCallAttemptContext(
     DateTime CreatedAtUtc,
     DateTime OccurredAtUtc,
     int? DurationMs,
-    string? SourceInstanceId);
+    string? SourceInstanceId,
+    Guid? ExecutionId = null,
+    string? SourceScript = null);
 
 /// <summary>
 /// Coarse outcome of one cached-call delivery attempt, observed from inside

src/ScadaLink.Commons/Interfaces/Services/IDatabaseGateway.cs

@@ -29,11 +29,24 @@ public interface IDatabaseGateway
     /// <c>null</c> — when omitted the S&amp;F engine mints a fresh GUID and no
     /// M3 telemetry is correlated (pre-M3 caller behaviour).
     /// </param>
+    /// <param name="executionId">
+    /// Audit Log #23 (ExecutionId Task 4): the originating script execution's
+    /// per-run correlation id. When the write is buffered on a transient
+    /// failure this is threaded onto the S&amp;F message so the retry-loop
+    /// cached-write audit rows carry it. <c>null</c> when not threaded.
+    /// </param>
+    /// <param name="sourceScript">
+    /// Audit Log #23 (ExecutionId Task 4): the originating script identifier,
+    /// threaded onto the buffered S&amp;F message alongside
+    /// <paramref name="executionId"/>. <c>null</c> when not known.
+    /// </param>
     Task CachedWriteAsync(
         string connectionName,
         string sql,
         IReadOnlyDictionary<string, object?>? parameters = null,
         string? originInstanceName = null,
         CancellationToken cancellationToken = default,
-        TrackedOperationId? trackedOperationId = null);
+        TrackedOperationId? trackedOperationId = null,
+        Guid? executionId = null,
+        string? sourceScript = null);
 }

src/ScadaLink.Commons/Interfaces/Services/IExternalSystemClient.cs

@@ -30,13 +30,26 @@ public interface IExternalSystemClient
     /// M3 telemetry is correlated (the legacy behaviour pre-M3 callers rely
     /// on).
     /// </param>
+    /// <param name="executionId">
+    /// Audit Log #23 (ExecutionId Task 4): the originating script execution's
+    /// per-run correlation id. When the call is buffered on a transient
+    /// failure this is threaded onto the S&amp;F message so the retry-loop
+    /// cached-call audit rows carry it. <c>null</c> when not threaded.
+    /// </param>
+    /// <param name="sourceScript">
+    /// Audit Log #23 (ExecutionId Task 4): the originating script identifier,
+    /// threaded onto the buffered S&amp;F message alongside
+    /// <paramref name="executionId"/>. <c>null</c> when not known.
+    /// </param>
     Task<ExternalCallResult> CachedCallAsync(
         string systemName,
         string methodName,
         IReadOnlyDictionary<string, object?>? parameters = null,
         string? originInstanceName = null,
         CancellationToken cancellationToken = default,
-        TrackedOperationId? trackedOperationId = null);
+        TrackedOperationId? trackedOperationId = null,
+        Guid? executionId = null,
+        string? sourceScript = null);
 }
 
 /// <summary>

src/ScadaLink.Commons/Messages/Notification/NotificationMessages.cs

@@ -4,6 +4,13 @@ namespace ScadaLink.Commons.Messages.Notification;
 /// Site -> Central: submit a notification for central delivery.
 /// Fire-and-forget with ack; the site retries until a <see cref="NotificationSubmitAck"/> is received.
 /// </summary>
+/// <param name="OriginExecutionId">
+/// The originating script execution's <c>ExecutionId</c> (Audit Log #23). Stamped at
+/// <c>Notify.Send</c> time and carried, inside the serialized payload, through the site
+/// store-and-forward buffer so the central dispatcher can echo it onto the
+/// <c>NotifyDeliver</c> audit rows. Additive trailing member — null for messages built
+/// before the field existed, or for notifications raised outside a script execution.
+/// </param>
 public record NotificationSubmit(
     string NotificationId,
     string ListName,
@@ -12,7 +19,8 @@ public record NotificationSubmit(
     string SourceSiteId,
     string? SourceInstanceId,
     string? SourceScript,
-    DateTimeOffset SiteEnqueuedAt);
+    DateTimeOffset SiteEnqueuedAt,
+    Guid? OriginExecutionId = null);
 
 /// <summary>
 /// Central -> Site: ack sent after the notification row is persisted.

src/ScadaLink.ConfigurationDatabase/Configurations/NotificationOutboxConfiguration.cs

@@ -47,6 +47,10 @@ public class NotificationOutboxConfiguration : IEntityTypeConfiguration<Notifica
 
         builder.Property(n => n.SourceScript).HasMaxLength(200);
 
+        // OriginExecutionId (Audit Log #23): nullable uniqueidentifier carried from the
+        // site so the dispatcher can echo it onto NotifyDeliver audit rows. No index —
+        // it is never a query predicate on this table, only copied onto audit events.
+
         builder.HasIndex(n => new { n.Status, n.NextAttemptAt });
 
         builder.HasIndex(n => new { n.SourceSiteId, n.CreatedAt });

src/ScadaLink.ConfigurationDatabase/Migrations/20260521193048_AddNotificationOriginExecutionId.cs

@@ -0,0 +1,41 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ScadaLink.ConfigurationDatabase.Migrations
+{
+    /// <summary>
+    /// Adds the <c>OriginExecutionId</c> correlation column to the central
+    /// <c>Notifications</c> table (#21). It carries the originating script execution's
+    /// <c>ExecutionId</c> from the site so the dispatcher can echo it onto the
+    /// <c>NotifyDeliver</c> audit rows (#23), linking them to the site's <c>NotifySend</c>
+    /// row for the same run.
+    ///
+    /// The change is purely additive: <c>OriginExecutionId uniqueidentifier NULL</c> is
+    /// added with no default, so the operation is a metadata-only <c>ALTER TABLE … ADD</c>.
+    /// Unlike <c>AuditLog</c>, the <c>Notifications</c> table is NOT partitioned, so a
+    /// plain <c>ADD</c> is fine. No index is created — the column is never a query
+    /// predicate, only copied onto audit events. Historical rows stay <c>NULL</c>.
+    /// </summary>
+    public partial class AddNotificationOriginExecutionId : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<Guid>(
+                name: "OriginExecutionId",
+                table: "Notifications",
+                type: "uniqueidentifier",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "OriginExecutionId",
+                table: "Notifications");
+        }
+    }
+}

src/ScadaLink.ConfigurationDatabase/Migrations/ScadaLinkDbContextModelSnapshot.cs

@@ -787,6 +787,9 @@ namespace ScadaLink.ConfigurationDatabase.Migrations
                     b.Property<DateTimeOffset?>("NextAttemptAt")
                         .HasColumnType("datetimeoffset");
 
+                    b.Property<Guid?>("OriginExecutionId")
+                        .HasColumnType("uniqueidentifier");
+
                     b.Property<string>("ResolvedTargets")
                         .HasColumnType("nvarchar(max)");
 

src/ScadaLink.ExternalSystemGateway/DatabaseGateway.cs

@@ -84,7 +84,9 @@ public class DatabaseGateway : IDatabaseGateway
         IReadOnlyDictionary<string, object?>? parameters = null,
         string? originInstanceName = null,
         CancellationToken cancellationToken = default,
-        TrackedOperationId? trackedOperationId = null)
+        TrackedOperationId? trackedOperationId = null,
+        Guid? executionId = null,
+        string? sourceScript = null)
     {
         var definition = await ResolveConnectionAsync(connectionName, cancellationToken);
         if (definition == null)
@@ -124,7 +126,13 @@ public class DatabaseGateway : IDatabaseGateway
             // read it back via StoreAndForwardMessage.Id and emit per-attempt +
             // terminal cached-write telemetry. Null -> S&F mints its own GUID
             // (legacy pre-M3 behaviour).
-            messageId: trackedOperationId?.ToString());
+            messageId: trackedOperationId?.ToString(),
+            // Audit Log #23 (ExecutionId Task 4): thread the originating script
+            // execution's ExecutionId + SourceScript onto the buffered row so
+            // the retry-loop cached-write audit rows carry the same provenance
+            // the script-side cached rows do.
+            executionId: executionId,
+            sourceScript: sourceScript);
     }
 
     /// <summary>

src/ScadaLink.ExternalSystemGateway/ExternalSystemClient.cs

@@ -86,7 +86,9 @@ public class ExternalSystemClient : IExternalSystemClient
         IReadOnlyDictionary<string, object?>? parameters = null,
         string? originInstanceName = null,
         CancellationToken cancellationToken = default,
-        TrackedOperationId? trackedOperationId = null)
+        TrackedOperationId? trackedOperationId = null,
+        Guid? executionId = null,
+        string? sourceScript = null)
     {
         var (system, method) = await ResolveSystemAndMethodAsync(systemName, methodName, cancellationToken);
         if (system == null || method == null)
@@ -144,7 +146,13 @@ public class ExternalSystemClient : IExternalSystemClient
                 // StoreAndForwardMessage.Id and emit per-attempt + terminal
                 // cached-call telemetry (Bundle E Tasks E4/E5). Null -> S&F
                 // mints its own GUID (legacy pre-M3 behaviour).
-                messageId: trackedOperationId?.ToString());
+                messageId: trackedOperationId?.ToString(),
+                // Audit Log #23 (ExecutionId Task 4): thread the originating
+                // script execution's ExecutionId + SourceScript onto the
+                // buffered row so the retry-loop cached-call audit rows carry
+                // the same provenance the script-side cached rows do.
+                executionId: executionId,
+                sourceScript: sourceScript);
 
             return new ExternalCallResult(true, null, null, WasBuffered: true);
         }

src/ScadaLink.InboundAPI/Middleware/AuditWriteMiddleware.cs

@@ -145,17 +145,21 @@ public sealed class AuditWriteMiddleware
                 OccurredAtUtc = DateTime.UtcNow,
                 Channel = AuditChannel.ApiInbound,
                 Kind = kind,
-                // Audit Log #23: a fresh per-request correlation id so the
+                // Audit Log #23: a fresh per-request execution id so the
                 // inbound row carries a request identifier (closes the design
                 // gap that inbound rows should be correlatable).
                 //
                 // This id is intentionally request-local: it is NOT bridged to
                 // RouteHelper's routed-call correlation id or to
                 // HttpContext.TraceIdentifier. Threading an inbound request's
-                // correlation id through to the routed script execution (so an
+                // execution id through to the routed script execution (so an
                 // inbound call and the outbound API/DB rows it triggers share
                 // one id) is a deliberate future follow-up, out of scope here.
-                CorrelationId = Guid.NewGuid(),
+                ExecutionId = Guid.NewGuid(),
+                // CorrelationId is purely the per-operation-lifecycle id; an
+                // inbound request is a one-shot from the audit row's
+                // perspective with no multi-row operation to correlate.
+                CorrelationId = null,
                 Actor = actor,
                 Target = methodName,
                 Status = status,

src/ScadaLink.ManagementService/AuditEndpoints.cs

@@ -395,6 +395,13 @@ public static class AuditEndpoints
             correlationId = parsedCorr;
         }
 
+        Guid? executionId = null;
+        if (query.TryGetValue("executionId", out var execValues)
+            && Guid.TryParse(execValues.ToString(), out var parsedExec))
+        {
+            executionId = parsedExec;
+        }
+
         return new AuditLogQueryFilter(
             Channels: channels,
             Kinds: kinds,
@@ -403,6 +410,7 @@ public static class AuditEndpoints
             Target: TrimToNullable(query, "target"),
             Actor: TrimToNullable(query, "actor"),
             CorrelationId: correlationId,
+            ExecutionId: executionId,
             FromUtc: ParseUtcDate(query, "fromUtc"),
             ToUtc: ParseUtcDate(query, "toUtc"));
     }

src/ScadaLink.NotificationOutbox/NotificationOutboxActor.cs

@@ -489,6 +489,10 @@ public class NotificationOutboxActor : ReceiveActor, IWithTimers
     /// parses the notification's id as a Guid; sites generate the id with
     /// <c>Guid.NewGuid().ToString("N")</c> so the parse always succeeds, but
     /// a non-Guid id is recorded as null rather than crashing the dispatcher.
+    /// <see cref="AuditEvent.ExecutionId"/> is copied straight from
+    /// <see cref="Notification.OriginExecutionId"/> so the dispatcher's
+    /// <c>NotifyDeliver</c> rows carry the same per-run id as the site's
+    /// <c>NotifySend</c> row (Audit Log #23).
     /// </summary>
     private static AuditEvent BuildNotifyDeliverEvent(
         Notification notification,
@@ -515,6 +519,12 @@ public class NotificationOutboxActor : ReceiveActor, IWithTimers
             SourceSiteId = notification.SourceSiteId,
             SourceInstanceId = notification.SourceInstanceId,
             SourceScript = notification.SourceScript,
+            // ExecutionId (Audit Log #23): the originating script execution's id,
+            // carried from the site on NotificationSubmit and persisted on the
+            // Notification row. Echoing it here links the central NotifyDeliver
+            // rows to the site-emitted NotifySend row for the same run. Null when
+            // the notification was raised outside a script execution.
+            ExecutionId = notification.OriginExecutionId,
             Target = notification.ListName,
             Status = status,
             ErrorMessage = errorMessage,
@@ -941,6 +951,9 @@ public class NotificationOutboxActor : ReceiveActor, IWithTimers
         {
             SourceInstanceId = msg.SourceInstanceId,
             SourceScript = msg.SourceScript,
+            // OriginExecutionId (Audit Log #23): the originating script execution's id,
+            // carried from the site so the dispatcher can echo it onto NotifyDeliver rows.
+            OriginExecutionId = msg.OriginExecutionId,
             SiteEnqueuedAt = msg.SiteEnqueuedAt,
             CreatedAt = DateTimeOffset.UtcNow,
             // Status stays at its Pending default for the dispatch sweep to claim.

src/ScadaLink.SiteRuntime/Scripts/AuditingDbCommand.cs

@@ -37,11 +37,11 @@ internal sealed class AuditingDbCommand : DbCommand
     private readonly string _siteId;
     private readonly string _instanceName;
     private readonly string? _sourceScript;
-    private readonly Guid _auditCorrelationId;
+    private readonly Guid _executionId;
     private readonly ILogger _logger;
     private DbConnection? _wrappingConnection;
 
-    // Parameter ordering: auditCorrelationId sits immediately after the ILogger,
+    // Parameter ordering: executionId sits immediately after the ILogger,
     // consistent with the other three audit-threaded ctors (ExternalSystemHelper,
     // DatabaseHelper, AuditingDbConnection).
     public AuditingDbCommand(
@@ -52,7 +52,7 @@ internal sealed class AuditingDbCommand : DbCommand
         string instanceName,
         string? sourceScript,
         ILogger logger,
-        Guid auditCorrelationId)
+        Guid executionId)
     {
         _inner = inner ?? throw new ArgumentNullException(nameof(inner));
         _auditWriter = auditWriter ?? throw new ArgumentNullException(nameof(auditWriter));
@@ -61,7 +61,7 @@ internal sealed class AuditingDbCommand : DbCommand
         _instanceName = instanceName ?? string.Empty;
         _sourceScript = sourceScript;
         _logger = logger ?? throw new ArgumentNullException(nameof(logger));
-        _auditCorrelationId = auditCorrelationId;
+        _executionId = executionId;
     }
 
     // -- Forwarded surface ------------------------------------------------
@@ -432,10 +432,12 @@ internal sealed class AuditingDbCommand : DbCommand
             OccurredAtUtc = DateTime.SpecifyKind(occurredAtUtc, DateTimeKind.Utc),
             Channel = AuditChannel.DbOutbound,
             Kind = AuditKind.DbWrite,
-            // Audit Log #23: the execution-wide correlation id, so this sync
-            // DbWrite row shares an id with the other sync trust-boundary rows
-            // from the same script run.
-            CorrelationId = _auditCorrelationId,
+            // Audit Log #23: a sync one-shot DB write has no operation
+            // lifecycle, so CorrelationId is null. ExecutionId carries the
+            // per-execution id so this row shares an id with the other sync
+            // trust-boundary rows from the same script run.
+            CorrelationId = null,
+            ExecutionId = _executionId,
             SourceSiteId = string.IsNullOrEmpty(_siteId) ? null : _siteId,
             SourceInstanceId = _instanceName,
             SourceScript = _sourceScript,

src/ScadaLink.SiteRuntime/Scripts/AuditingDbConnection.cs

@@ -36,10 +36,10 @@ internal sealed class AuditingDbConnection : DbConnection
     private readonly string _siteId;
     private readonly string _instanceName;
     private readonly string? _sourceScript;
-    private readonly Guid _auditCorrelationId;
+    private readonly Guid _executionId;
     private readonly ILogger _logger;
 
-    // Parameter ordering: auditCorrelationId sits immediately after the ILogger,
+    // Parameter ordering: executionId sits immediately after the ILogger,
     // consistent with the other three audit-threaded ctors (ExternalSystemHelper,
     // DatabaseHelper, AuditingDbCommand).
     public AuditingDbConnection(
@@ -50,7 +50,7 @@ internal sealed class AuditingDbConnection : DbConnection
         string instanceName,
         string? sourceScript,
         ILogger logger,
-        Guid auditCorrelationId)
+        Guid executionId)
     {
         _inner = inner ?? throw new ArgumentNullException(nameof(inner));
         _auditWriter = auditWriter ?? throw new ArgumentNullException(nameof(auditWriter));
@@ -59,7 +59,7 @@ internal sealed class AuditingDbConnection : DbConnection
         _instanceName = instanceName ?? string.Empty;
         _sourceScript = sourceScript;
         _logger = logger ?? throw new ArgumentNullException(nameof(logger));
-        _auditCorrelationId = auditCorrelationId;
+        _executionId = executionId;
     }
 
     // ConnectionString is settable on DbConnection — forward both halves.
@@ -99,7 +99,7 @@ internal sealed class AuditingDbConnection : DbConnection
             _instanceName,
             _sourceScript,
             _logger,
-            _auditCorrelationId);
+            _executionId);
     }
 
     protected override void Dispose(bool disposing)

src/ScadaLink.SiteRuntime/Scripts/ScriptRuntimeContext.cs

@@ -106,19 +106,22 @@ public class ScriptRuntimeContext
     private readonly ICachedCallTelemetryForwarder? _cachedForwarder;
 
     /// <summary>
-    /// Audit Log #23: the execution-wide audit correlation id. Every sync
+    /// Audit Log #23: the per-execution id for this script run. Every
     /// trust-boundary audit row emitted by this script execution
-    /// (<c>ApiCall</c>, <c>DbWrite</c>) is stamped with this id so all the
-    /// rows from one script run can be correlated together.
+    /// (sync <c>ApiCall</c>/<c>DbWrite</c>, cached-call lifecycle rows,
+    /// <c>NotifySend</c>) is stamped into <c>AuditEvent.ExecutionId</c> with
+    /// this value so all the rows from one script run can be correlated
+    /// together — independently of the per-operation
+    /// <c>AuditEvent.CorrelationId</c>.
     /// </summary>
-    private readonly Guid _auditCorrelationId;
+    private readonly Guid _executionId;
 
-    /// <param name="auditCorrelationId">
-    /// Audit Log #23: the execution-wide audit correlation id. When omitted
+    /// <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
     /// inbound caller may supply one to tie the execution to an upstream
-    /// request. Stamped on the sync <c>ApiCall</c>/<c>DbWrite</c> audit rows
-    /// this execution emits.
+    /// request. Stamped into <c>AuditEvent.ExecutionId</c> on every
+    /// trust-boundary audit row this execution emits.
     /// </param>
     public ScriptRuntimeContext(
         IActorRef instanceActor,
@@ -138,7 +141,7 @@ public class ScriptRuntimeContext
         IAuditWriter? auditWriter = null,
         IOperationTrackingStore? operationTrackingStore = null,
         ICachedCallTelemetryForwarder? cachedForwarder = null,
-        Guid? auditCorrelationId = null)
+        Guid? executionId = null)
     {
         _instanceActor = instanceActor;
         _self = self;
@@ -157,7 +160,7 @@ public class ScriptRuntimeContext
         _auditWriter = auditWriter;
         _operationTrackingStore = operationTrackingStore;
         _cachedForwarder = cachedForwarder;
-        _auditCorrelationId = auditCorrelationId ?? Guid.NewGuid();
+        _executionId = executionId ?? Guid.NewGuid();
     }
 
     /// <summary>
@@ -258,7 +261,7 @@ public class ScriptRuntimeContext
     /// ExternalSystem.CachedCall("systemName", "methodName", params)
     /// </summary>
     public ExternalSystemHelper ExternalSystem => new(
-        _externalSystemClient, _instanceName, _logger, _auditCorrelationId, _auditWriter, _siteId, _sourceScript,
+        _externalSystemClient, _instanceName, _logger, _executionId, _auditWriter, _siteId, _sourceScript,
         // Audit Log #23 (M3 Bundle E — Task E3): emit CachedSubmit telemetry
         // on every ExternalSystem.CachedCall enqueue.
         _cachedForwarder);
@@ -272,7 +275,7 @@ public class ScriptRuntimeContext
         _databaseGateway,
         _instanceName,
         _logger,
-        _auditCorrelationId,
+        _executionId,
         // Audit Log #23 (M4 Bundle A): wire the IAuditWriter so
         // Database.Connection(name) returns an auditing decorator that
         // emits one DbOutbound/DbWrite row per script-initiated
@@ -299,7 +302,7 @@ public class ScriptRuntimeContext
     /// </remarks>
     public NotifyHelper Notify => new(
         _storeAndForward, _siteCommunicationActor, _siteId, _instanceName, _sourceScript, _askTimeout, _logger,
-        _auditWriter);
+        _executionId, _auditWriter);
 
     /// <summary>
     /// Audit Log #23 (M3): site-local tracking-status API for cached operations.
@@ -380,7 +383,7 @@ public class ScriptRuntimeContext
         private readonly IExternalSystemClient? _client;
         private readonly string _instanceName;
         private readonly ILogger _logger;
-        private readonly Guid _auditCorrelationId;
+        private readonly Guid _executionId;
         private readonly IAuditWriter? _auditWriter;
         private readonly string _siteId;
         private readonly string? _sourceScript;
@@ -390,7 +393,7 @@ public class ScriptRuntimeContext
         // (via InternalsVisibleTo). Production sites resolve the helper through
         // ScriptRuntimeContext.ExternalSystem.
         //
-        // Parameter ordering: auditCorrelationId sits immediately after the
+        // Parameter ordering: executionId sits immediately after the
         // ILogger across all four audit-threaded ctors (ExternalSystemHelper,
         // DatabaseHelper, AuditingDbConnection, AuditingDbCommand) — a required
         // Guid cannot follow the optional provenance params without a
@@ -400,7 +403,7 @@ public class ScriptRuntimeContext
             IExternalSystemClient? client,
             string instanceName,
             ILogger logger,
-            Guid auditCorrelationId,
+            Guid executionId,
             IAuditWriter? auditWriter = null,
             string siteId = "",
             string? sourceScript = null,
@@ -409,7 +412,7 @@ public class ScriptRuntimeContext
             _client = client;
             _instanceName = instanceName;
             _logger = logger;
-            _auditCorrelationId = auditCorrelationId;
+            _executionId = executionId;
             _auditWriter = auditWriter;
             _siteId = siteId;
             _sourceScript = sourceScript;
@@ -510,7 +513,12 @@ public class ScriptRuntimeContext
                     parameters,
                     _instanceName,
                     cancellationToken,
-                    trackedId).ConfigureAwait(false);
+                    trackedId,
+                    // Audit Log #23 (ExecutionId Task 4): thread the script
+                    // execution's ExecutionId + SourceScript so a buffered
+                    // cached call's retry-loop audit rows carry them.
+                    executionId: _executionId,
+                    sourceScript: _sourceScript).ConfigureAwait(false);
             }
             catch (Exception ex)
             {
@@ -567,7 +575,11 @@ public class ScriptRuntimeContext
                         OccurredAtUtc = DateTime.SpecifyKind(occurredAtUtc, DateTimeKind.Utc),
                         Channel = AuditChannel.ApiOutbound,
                         Kind = AuditKind.CachedSubmit,
+                        // CorrelationId stays the per-operation lifecycle id
+                        // (TrackedOperationId); ExecutionId carries the
+                        // per-execution id shared across this script run.
                         CorrelationId = trackedId.Value,
+                        ExecutionId = _executionId,
                         SourceSiteId = string.IsNullOrEmpty(_siteId) ? null : _siteId,
                         SourceInstanceId = _instanceName,
                         SourceScript = _sourceScript,
@@ -677,7 +689,10 @@ public class ScriptRuntimeContext
                         OccurredAtUtc = DateTime.SpecifyKind(occurredAtUtc, DateTimeKind.Utc),
                         Channel = AuditChannel.ApiOutbound,
                         Kind = AuditKind.ApiCallCached,
+                        // CorrelationId = per-operation lifecycle id;
+                        // ExecutionId = per-execution id for this script run.
                         CorrelationId = trackedId.Value,
+                        ExecutionId = _executionId,
                         SourceSiteId = string.IsNullOrEmpty(_siteId) ? null : _siteId,
                         SourceInstanceId = _instanceName,
                         SourceScript = _sourceScript,
@@ -738,7 +753,10 @@ public class ScriptRuntimeContext
                         OccurredAtUtc = DateTime.SpecifyKind(occurredAtUtc, DateTimeKind.Utc),
                         Channel = AuditChannel.ApiOutbound,
                         Kind = AuditKind.CachedResolve,
+                        // CorrelationId = per-operation lifecycle id;
+                        // ExecutionId = per-execution id for this script run.
                         CorrelationId = trackedId.Value,
+                        ExecutionId = _executionId,
                         SourceSiteId = string.IsNullOrEmpty(_siteId) ? null : _siteId,
                         SourceInstanceId = _instanceName,
                         SourceScript = _sourceScript,
@@ -910,9 +928,12 @@ public class ScriptRuntimeContext
                 OccurredAtUtc = DateTime.SpecifyKind(occurredAtUtc, DateTimeKind.Utc),
                 Channel = AuditChannel.ApiOutbound,
                 Kind = AuditKind.ApiCall,
-                // Audit Log #23: the execution-wide correlation id, so all the
-                // sync ApiCall/DbWrite rows from one script run share an id.
-                CorrelationId = _auditCorrelationId,
+                // Audit Log #23: a sync one-shot call has no operation
+                // lifecycle, so CorrelationId is null. ExecutionId carries the
+                // per-execution id so all the sync ApiCall/DbWrite rows from
+                // one script run can be correlated together.
+                CorrelationId = null,
+                ExecutionId = _executionId,
                 SourceSiteId = string.IsNullOrEmpty(_siteId) ? null : _siteId,
                 SourceInstanceId = _instanceName,
                 SourceScript = _sourceScript,
@@ -979,7 +1000,7 @@ public class ScriptRuntimeContext
         private readonly IDatabaseGateway? _gateway;
         private readonly string _instanceName;
         private readonly ILogger _logger;
-        private readonly Guid _auditCorrelationId;
+        private readonly Guid _executionId;
         private readonly string _siteId;
         private readonly string? _sourceScript;
         private readonly ICachedCallTelemetryForwarder? _cachedForwarder;
@@ -996,7 +1017,7 @@ public class ScriptRuntimeContext
         /// </summary>
         private readonly IAuditWriter? _auditWriter;
 
-        // Parameter ordering: auditCorrelationId sits immediately after the
+        // 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.
@@ -1004,7 +1025,7 @@ public class ScriptRuntimeContext
             IDatabaseGateway? gateway,
             string instanceName,
             ILogger logger,
-            Guid auditCorrelationId,
+            Guid executionId,
             IAuditWriter? auditWriter = null,
             string siteId = "",
             string? sourceScript = null,
@@ -1013,7 +1034,7 @@ public class ScriptRuntimeContext
             _gateway = gateway;
             _instanceName = instanceName;
             _logger = logger;
-            _auditCorrelationId = auditCorrelationId;
+            _executionId = executionId;
             _auditWriter = auditWriter;
             _siteId = siteId;
             _sourceScript = sourceScript;
@@ -1049,7 +1070,7 @@ public class ScriptRuntimeContext
                 instanceName: _instanceName,
                 sourceScript: _sourceScript,
                 logger: _logger,
-                auditCorrelationId: _auditCorrelationId);
+                executionId: _executionId);
         }
 
         /// <summary>
@@ -1080,7 +1101,12 @@ public class ScriptRuntimeContext
             try
             {
                 await _gateway.CachedWriteAsync(
-                    name, sql, parameters, _instanceName, cancellationToken, trackedId)
+                    name, sql, parameters, _instanceName, cancellationToken, trackedId,
+                    // Audit Log #23 (ExecutionId Task 4): thread the script
+                    // execution's ExecutionId + SourceScript so a buffered
+                    // cached write's retry-loop audit rows carry them.
+                    executionId: _executionId,
+                    sourceScript: _sourceScript)
                     .ConfigureAwait(false);
             }
             catch (Exception ex)
@@ -1116,7 +1142,10 @@ public class ScriptRuntimeContext
                         OccurredAtUtc = DateTime.SpecifyKind(occurredAtUtc, DateTimeKind.Utc),
                         Channel = AuditChannel.DbOutbound,
                         Kind = AuditKind.CachedSubmit,
+                        // CorrelationId = per-operation lifecycle id
+                        // (TrackedOperationId); ExecutionId = per-execution id.
                         CorrelationId = trackedId.Value,
+                        ExecutionId = _executionId,
                         SourceSiteId = string.IsNullOrEmpty(_siteId) ? null : _siteId,
                         SourceInstanceId = _instanceName,
                         SourceScript = _sourceScript,
@@ -1178,6 +1207,12 @@ public class ScriptRuntimeContext
         private readonly TimeSpan _askTimeout;
         private readonly ILogger _logger;
 
+        /// <summary>
+        /// Audit Log #23: the per-execution id for this script run, stamped
+        /// into <c>AuditEvent.ExecutionId</c> on the <c>NotifySend</c> row.
+        /// </summary>
+        private readonly Guid _executionId;
+
         /// <summary>
         /// Audit Log #23 (M4 Bundle C): best-effort emitter for the
         /// <c>Notification</c>/<c>NotifySend</c> row produced when the script
@@ -1188,6 +1223,8 @@ public class ScriptRuntimeContext
         /// </summary>
         private readonly IAuditWriter? _auditWriter;
 
+        // Parameter ordering: executionId sits immediately after the ILogger,
+        // consistent with the other audit-threaded ctors.
         internal NotifyHelper(
             StoreAndForwardService? storeAndForward,
             ICanTell? siteCommunicationActor,
@@ -1196,6 +1233,7 @@ public class ScriptRuntimeContext
             string? sourceScript,
             TimeSpan askTimeout,
             ILogger logger,
+            Guid executionId,
             IAuditWriter? auditWriter = null)
         {
             _storeAndForward = storeAndForward;
@@ -1205,6 +1243,7 @@ public class ScriptRuntimeContext
             _sourceScript = sourceScript;
             _askTimeout = askTimeout;
             _logger = logger;
+            _executionId = executionId;
             _auditWriter = auditWriter;
         }
 
@@ -1215,6 +1254,9 @@ public class ScriptRuntimeContext
         {
             return new NotifyTarget(
                 listName, _storeAndForward, _siteId, _instanceName, _sourceScript, _logger,
+                // Audit Log #23: the per-execution id stamped into the
+                // NotifySend row's ExecutionId column.
+                _executionId,
                 // Audit Log #23 (M4 Bundle C): forward the writer so Send()
                 // can emit one NotifySend(Submitted) row per accepted submission.
                 _auditWriter);
@@ -1292,6 +1334,12 @@ public class ScriptRuntimeContext
         private readonly string? _sourceScript;
         private readonly ILogger _logger;
 
+        /// <summary>
+        /// Audit Log #23: the per-execution id for this script run, stamped
+        /// into <c>AuditEvent.ExecutionId</c> on the <c>NotifySend</c> row.
+        /// </summary>
+        private readonly Guid _executionId;
+
         /// <summary>
         /// Audit Log #23 (M4 Bundle C): best-effort emitter for the
         /// <c>Notification</c>/<c>NotifySend</c> row written immediately after
@@ -1307,6 +1355,7 @@ public class ScriptRuntimeContext
             string instanceName,
             string? sourceScript,
             ILogger logger,
+            Guid executionId,
             IAuditWriter? auditWriter = null)
         {
             _listName = listName;
@@ -1315,6 +1364,7 @@ public class ScriptRuntimeContext
             _instanceName = instanceName;
             _sourceScript = sourceScript;
             _logger = logger;
+            _executionId = executionId;
             _auditWriter = auditWriter;
         }
 
@@ -1357,7 +1407,12 @@ public class ScriptRuntimeContext
                 // notification, threaded down from the script-execution context for the
                 // central audit trail. Null when no single script owns the context.
                 SourceScript: _sourceScript,
-                SiteEnqueuedAt: DateTimeOffset.UtcNow);
+                SiteEnqueuedAt: DateTimeOffset.UtcNow,
+                // OriginExecutionId (Audit Log #23): the SAME per-execution id stamped
+                // onto this run's NotifySend audit row. It rides inside the serialized
+                // payload through the S&F buffer to central, where the dispatcher echoes
+                // it onto the NotifyDeliver rows so all rows for one run share an id.
+                OriginExecutionId: _executionId);
 
             var payloadJson = JsonSerializer.Serialize(payload);
 
@@ -1431,7 +1486,10 @@ public class ScriptRuntimeContext
                     OccurredAtUtc = DateTime.SpecifyKind(occurredAtUtc, DateTimeKind.Utc),
                     Channel = AuditChannel.Notification,
                     Kind = AuditKind.NotifySend,
+                    // CorrelationId is the NotificationId-derived per-operation
+                    // lifecycle id; ExecutionId carries the per-execution id.
                     CorrelationId = correlationId,
+                    ExecutionId = _executionId,
                     SourceSiteId = string.IsNullOrEmpty(_siteId) ? null : _siteId,
                     SourceInstanceId = _instanceName,
                     SourceScript = _sourceScript,

src/ScadaLink.StoreAndForward/StoreAndForwardMessage.cs

@@ -55,4 +55,25 @@ public class StoreAndForwardMessage
     /// WP-13: Messages are NOT cleared when instance is deleted.
     /// </summary>
     public string? OriginInstanceName { get; set; }
+
+    /// <summary>
+    /// Audit Log #23 (ExecutionId Task 4): the originating script execution's
+    /// per-run correlation id, threaded from <c>ScriptRuntimeContext</c> through
+    /// the cached-call enqueue path. Carried so the store-and-forward retry loop
+    /// can stamp it onto the per-attempt / terminal cached-call audit rows
+    /// (<c>ApiCallCached</c>/<c>DbWriteCached</c> Attempted, <c>CachedResolve</c>).
+    /// <c>null</c> for non-cached-call categories (notifications) and for rows
+    /// buffered before this field existed — back-compat with old persisted rows
+    /// (the column is added by an additive migration and read as null when absent).
+    /// </summary>
+    public Guid? ExecutionId { get; set; }
+
+    /// <summary>
+    /// Audit Log #23 (ExecutionId Task 4): the originating script identifier,
+    /// threaded alongside <see cref="ExecutionId"/> from the cached-call enqueue
+    /// path so the retry-loop audit rows carry the same <c>SourceScript</c>
+    /// provenance the script-side cached rows already carry. <c>null</c> when not
+    /// known (non-cached categories, pre-migration rows).
+    /// </summary>
+    public string? SourceScript { get; set; }
 }

src/ScadaLink.StoreAndForward/StoreAndForwardService.cs

@@ -175,6 +175,18 @@ public class StoreAndForwardService
     /// it is the buffered row's <see cref="StoreAndForwardMessage.Id"/>, it is carried
     /// inside the payload, and it is the id the forwarder submits to central.
     /// </param>
+    /// <param name="executionId">
+    /// Audit Log #23 (ExecutionId Task 4): the originating script execution's
+    /// per-run correlation id. Threaded onto the buffered row so the retry-loop
+    /// cached-call audit rows carry it. <c>null</c> for callers (notifications,
+    /// pre-Task-4 callers) that do not supply one.
+    /// </param>
+    /// <param name="sourceScript">
+    /// Audit Log #23 (ExecutionId Task 4): the originating script identifier,
+    /// threaded onto the buffered row alongside <paramref name="executionId"/>
+    /// so the retry-loop audit rows carry the same provenance the script-side
+    /// cached rows do. <c>null</c> when not known.
+    /// </param>
     public async Task<StoreAndForwardResult> EnqueueAsync(
         StoreAndForwardCategory category,
         string target,
@@ -183,7 +195,9 @@ public class StoreAndForwardService
         int? maxRetries = null,
         TimeSpan? retryInterval = null,
         bool attemptImmediateDelivery = true,
-        string? messageId = null)
+        string? messageId = null,
+        Guid? executionId = null,
+        string? sourceScript = null)
     {
         var message = new StoreAndForwardMessage
         {
@@ -196,7 +210,9 @@ public class StoreAndForwardService
             RetryIntervalMs = (long)(retryInterval ?? _options.DefaultRetryInterval).TotalMilliseconds,
             CreatedAt = DateTimeOffset.UtcNow,
             Status = StoreAndForwardMessageStatus.Pending,
-            OriginInstanceName = originInstanceName
+            OriginInstanceName = originInstanceName,
+            ExecutionId = executionId,
+            SourceScript = sourceScript
         };
 
         // Attempt immediate delivery — unless the caller has already made a
@@ -492,7 +508,14 @@ public class StoreAndForwardService
                 CreatedAtUtc: message.CreatedAt.UtcDateTime,
                 OccurredAtUtc: DateTime.SpecifyKind(occurredAtUtc, DateTimeKind.Utc),
                 DurationMs: durationMs,
-                SourceInstanceId: message.OriginInstanceName);
+                SourceInstanceId: message.OriginInstanceName,
+                // Audit Log #23 (ExecutionId Task 4): the buffered message
+                // carries the originating script execution's ExecutionId +
+                // SourceScript; surface them on the context so the bridge can
+                // stamp the retry-loop cached audit rows. Null on rows buffered
+                // before Task 4 (back-compat).
+                ExecutionId: message.ExecutionId,
+                SourceScript: message.SourceScript);
         }
         catch (Exception buildEx)
         {

src/ScadaLink.StoreAndForward/StoreAndForwardStorage.cs

@@ -65,9 +65,45 @@ public class StoreAndForwardStorage
         ";
         await command.ExecuteNonQueryAsync();
 
+        // Audit Log #23 (ExecutionId Task 4): additively add the execution_id /
+        // source_script columns. CREATE TABLE IF NOT EXISTS above does NOT add
+        // columns to a table that already exists from before these fields, so a
+        // databases created by an older build needs the columns ALTER-ed in.
+        // SQLite has no "ADD COLUMN IF NOT EXISTS"; the column presence is
+        // probed first and the ALTER skipped when already there. Both columns
+        // are nullable with no default, so any row buffered before this
+        // migration reads back ExecutionId/SourceScript = null (back-compat).
+        await AddColumnIfMissingAsync(connection, "execution_id", "TEXT");
+        await AddColumnIfMissingAsync(connection, "source_script", "TEXT");
+
         _logger.LogInformation("Store-and-forward SQLite storage initialized");
     }
 
+    /// <summary>
+    /// Audit Log #23 (ExecutionId Task 4): adds a column to <c>sf_messages</c>
+    /// only when it is not already present. SQLite lacks <c>ADD COLUMN IF NOT
+    /// EXISTS</c>, so the schema is probed via <c>PRAGMA table_info</c> first.
+    /// Idempotent — safe to run on every <see cref="InitializeAsync"/>.
+    /// </summary>
+    private static async Task AddColumnIfMissingAsync(
+        SqliteConnection connection, string columnName, string columnType)
+    {
+        await using var probe = connection.CreateCommand();
+        probe.CommandText = "SELECT COUNT(*) FROM pragma_table_info('sf_messages') WHERE name = @name";
+        probe.Parameters.AddWithValue("@name", columnName);
+        var exists = Convert.ToInt32(await probe.ExecuteScalarAsync()) > 0;
+        if (exists)
+        {
+            return;
+        }
+
+        await using var alter = connection.CreateCommand();
+        // Column name + type are caller-controlled constants, never user input —
+        // safe to interpolate (parameters are not permitted in DDL).
+        alter.CommandText = $"ALTER TABLE sf_messages ADD COLUMN {columnName} {columnType}";
+        await alter.ExecuteNonQueryAsync();
+    }
+
     /// <summary>
     /// Ensures the directory for a file-backed SQLite database exists. SQLite creates
     /// the database file on demand but not its parent directory, so a configured path
@@ -105,9 +141,11 @@ public class StoreAndForwardStorage
         await using var cmd = connection.CreateCommand();
         cmd.CommandText = @"
             INSERT INTO sf_messages (id, category, target, payload_json, retry_count, max_retries,
-                                     retry_interval_ms, created_at, last_attempt_at, status, last_error, origin_instance)
+                                     retry_interval_ms, created_at, last_attempt_at, status, last_error,
+                                     origin_instance, execution_id, source_script)
             VALUES (@id, @category, @target, @payload, @retryCount, @maxRetries,
-                    @retryIntervalMs, @createdAt, @lastAttempt, @status, @lastError, @origin)";
+                    @retryIntervalMs, @createdAt, @lastAttempt, @status, @lastError,
+                    @origin, @executionId, @sourceScript)";
 
         cmd.Parameters.AddWithValue("@id", message.Id);
         cmd.Parameters.AddWithValue("@category", (int)message.Category);
@@ -122,6 +160,12 @@ public class StoreAndForwardStorage
         cmd.Parameters.AddWithValue("@status", (int)message.Status);
         cmd.Parameters.AddWithValue("@lastError", (object?)message.LastError ?? DBNull.Value);
         cmd.Parameters.AddWithValue("@origin", (object?)message.OriginInstanceName ?? DBNull.Value);
+        // Audit Log #23 (ExecutionId Task 4): the execution id is stored as its
+        // canonical string form ("D") so it round-trips cleanly through the
+        // TEXT column; null when not a cached call / not threaded.
+        cmd.Parameters.AddWithValue("@executionId",
+            message.ExecutionId.HasValue ? message.ExecutionId.Value.ToString("D") : DBNull.Value);
+        cmd.Parameters.AddWithValue("@sourceScript", (object?)message.SourceScript ?? DBNull.Value);
 
         await cmd.ExecuteNonQueryAsync();
     }
@@ -137,7 +181,8 @@ public class StoreAndForwardStorage
         await using var cmd = connection.CreateCommand();
         cmd.CommandText = @"
             SELECT id, category, target, payload_json, retry_count, max_retries,
-                   retry_interval_ms, created_at, last_attempt_at, status, last_error, origin_instance
+                   retry_interval_ms, created_at, last_attempt_at, status, last_error, origin_instance,
+                   execution_id, source_script
             FROM sf_messages
             WHERE status = @pending
               AND (last_attempt_at IS NULL
@@ -268,7 +313,8 @@ public class StoreAndForwardStorage
         var categoryFilter = category.HasValue ? " AND category = @category" : "";
         pageCmd.CommandText = $@"
             SELECT id, category, target, payload_json, retry_count, max_retries,
-                   retry_interval_ms, created_at, last_attempt_at, status, last_error, origin_instance
+                   retry_interval_ms, created_at, last_attempt_at, status, last_error, origin_instance,
+                   execution_id, source_script
             FROM sf_messages
             WHERE status = @parked{categoryFilter}
             ORDER BY created_at ASC
@@ -389,7 +435,8 @@ public class StoreAndForwardStorage
         await using var cmd = connection.CreateCommand();
         cmd.CommandText = @"
             SELECT id, category, target, payload_json, retry_count, max_retries,
-                   retry_interval_ms, created_at, last_attempt_at, status, last_error, origin_instance
+                   retry_interval_ms, created_at, last_attempt_at, status, last_error, origin_instance,
+                   execution_id, source_script
             FROM sf_messages
             WHERE id = @id";
         cmd.Parameters.AddWithValue("@id", messageId);
@@ -446,9 +493,35 @@ public class StoreAndForwardStorage
                 LastAttemptAt = reader.IsDBNull(8) ? null : DateTimeOffset.Parse(reader.GetString(8)),
                 Status = (StoreAndForwardMessageStatus)reader.GetInt32(9),
                 LastError = reader.IsDBNull(10) ? null : reader.GetString(10),
-                OriginInstanceName = reader.IsDBNull(11) ? null : reader.GetString(11)
+                OriginInstanceName = reader.IsDBNull(11) ? null : reader.GetString(11),
+                // Audit Log #23 (ExecutionId Task 4): rows persisted before the
+                // additive migration have no execution_id / source_script value;
+                // IsDBNull guards keep those reading back as null (back-compat).
+                // Guid.TryParse (not Parse) guards the retry sweep: a corrupt
+                // non-null execution_id is treated as "no execution id" rather
+                // than throwing FormatException and aborting the whole sweep.
+                ExecutionId = ParseExecutionId(reader, 12),
+                SourceScript = reader.IsDBNull(13) ? null : reader.GetString(13)
             });
         }
         return results;
     }
+
+    /// <summary>
+    /// Audit Log #23 (ExecutionId Task 4): defensively reads the
+    /// <c>execution_id</c> column. A <c>null</c> value (legacy pre-migration
+    /// rows) and a malformed non-null value both yield <c>null</c> — a corrupt
+    /// id must not throw and abort the retry sweep, which reads many rows.
+    /// </summary>
+    private static Guid? ParseExecutionId(System.Data.Common.DbDataReader reader, int ordinal)
+    {
+        if (reader.IsDBNull(ordinal))
+        {
+            return null;
+        }
+
+        return Guid.TryParse(reader.GetString(ordinal), out var executionId)
+            ? executionId
+            : null;
+    }
 }

tests/ScadaLink.AuditLog.Tests/Integration/ExecutionIdCorrelationTests.cs

@@ -0,0 +1,274 @@
+using Akka.Actor;
+using Akka.TestKit.Xunit2;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.Extensions.Options;
+using NSubstitute;
+using ScadaLink.AuditLog.Central;
+using ScadaLink.AuditLog.Site;
+using ScadaLink.AuditLog.Site.Telemetry;
+using ScadaLink.AuditLog.Tests.Integration.Infrastructure;
+using ScadaLink.Commons.Interfaces.Repositories;
+using ScadaLink.Commons.Interfaces.Services;
+using ScadaLink.Commons.Types.Audit;
+using ScadaLink.Commons.Types.Enums;
+using ScadaLink.ConfigurationDatabase;
+using ScadaLink.ConfigurationDatabase.Repositories;
+using ScadaLink.ConfigurationDatabase.Tests.Migrations;
+using ScadaLink.SiteRuntime.Scripts;
+
+namespace ScadaLink.AuditLog.Tests.Integration;
+
+/// <summary>
+/// Audit Log #23 — ExecutionId end-to-end correlation suite verifying the
+/// universal per-run correlation promise: <b>every audit row produced by one
+/// script execution carries the same non-null <see cref="AuditEvent.ExecutionId"/></b>.
+/// </summary>
+/// <remarks>
+/// <para>
+/// This is the integration-level counterpart to the unit-level
+/// <c>ExecutionCorrelationContextTests</c> in <c>ScadaLink.SiteRuntime.Tests</c>:
+/// where that test asserts the shared id on the in-memory captured rows, this
+/// suite drives the rows all the way through the production pipeline — the real
+/// <see cref="SqliteAuditWriter"/> site hot-path, the real
+/// <see cref="SiteAuditTelemetryActor"/> drain loop, the real
+/// <see cref="AuditLogIngestActor"/>, and the real <see cref="AuditLogRepository"/>
+/// over the per-class <see cref="MsSqlMigrationFixture"/> MSSQL database — then
+/// reads the rows back from the central store and asserts the shared id.
+/// </para>
+/// <para>
+/// Composes the same pipeline as the M2 <see cref="SyncCallEmissionEndToEndTests"/>
+/// and the M4 <see cref="DatabaseSyncEmissionEndToEndTests"/>: an in-memory
+/// <see cref="SqliteAuditWriter"/> + <see cref="RingBufferFallback"/> +
+/// <see cref="FallbackAuditWriter"/> on the site, drained by a real
+/// <see cref="SiteAuditTelemetryActor"/> through the shared
+/// <see cref="DirectActorSiteStreamAuditClient"/> stub that short-circuits the
+/// gRPC wire and Asks the central ingest actor. The production
+/// <see cref="ScriptRuntimeContext"/> is driven directly: one context performs
+/// two distinct trust-boundary actions — a sync <c>ExternalSystem.Call</c> and a
+/// sync <c>Database</c> write — so the two emitted audit rows originate from one
+/// execution. Each test uses a unique <c>ExecutionId</c> + <c>SourceSiteId</c>
+/// (Guid suffixes) so concurrent tests sharing the MSSQL fixture don't interfere.
+/// </para>
+/// </remarks>
+public class ExecutionIdCorrelationTests : TestKit, IClassFixture<MsSqlMigrationFixture>
+{
+    private readonly MsSqlMigrationFixture _fixture;
+
+    public ExecutionIdCorrelationTests(MsSqlMigrationFixture fixture)
+    {
+        _fixture = fixture;
+    }
+
+    private const string ConnectionName = "machineData";
+    private const string InstanceName = "Plant.Pump42";
+    private const string SourceScript = "ScriptActor:OnTick";
+
+    private static string NewSiteId() =>
+        "test-execid-" + Guid.NewGuid().ToString("N").Substring(0, 8);
+
+    private ScadaLinkDbContext CreateContext()
+    {
+        var options = new DbContextOptionsBuilder<ScadaLinkDbContext>()
+            .UseSqlServer(_fixture.ConnectionString)
+            .Options;
+        return new ScadaLinkDbContext(options);
+    }
+
+    /// <summary>
+    /// Per-test in-memory SQLite database with a tiny single-table schema the
+    /// sync DB write targets. The keep-alive root pins the in-memory file for
+    /// the duration of the test; the returned <c>live</c> connection is what the
+    /// stub gateway hands back to the auditing wrapper. Mirrors
+    /// <c>DatabaseSyncEmissionEndToEndTests.NewInMemoryDb</c>.
+    /// </summary>
+    private static SqliteConnection NewInMemoryDb(out SqliteConnection keepAlive)
+    {
+        var dbName = $"db-{Guid.NewGuid():N}";
+        var connStr = $"Data Source={dbName};Mode=Memory;Cache=Shared";
+
+        keepAlive = new SqliteConnection(connStr);
+        keepAlive.Open();
+        using (var seed = keepAlive.CreateCommand())
+        {
+            seed.CommandText =
+                "CREATE TABLE t (id INTEGER PRIMARY KEY, name TEXT NOT NULL);";
+            seed.ExecuteNonQuery();
+        }
+
+        var live = new SqliteConnection(connStr);
+        live.Open();
+        return live;
+    }
+
+    private static SqliteAuditWriter CreateInMemorySqliteWriter() =>
+        new(
+            Options.Create(new SqliteAuditWriterOptions
+            {
+                DatabasePath = "ignored",
+                BatchSize = 64,
+                ChannelCapacity = 1024,
+            }),
+            NullLogger<SqliteAuditWriter>.Instance,
+            connectionStringOverride:
+                $"Data Source=file:auditlog-execid-{Guid.NewGuid():N}?mode=memory&cache=shared");
+
+    private static IOptions<SiteAuditTelemetryOptions> FastTelemetryOptions() =>
+        Options.Create(new SiteAuditTelemetryOptions
+        {
+            BatchSize = 256,
+            // 1s on both intervals so the initial scheduled tick fires quickly
+            // — drains the SQLite Pending rows and pushes them through the stub
+            // gRPC client into the central ingest actor.
+            BusyIntervalSeconds = 1,
+            IdleIntervalSeconds = 1,
+        });
+
+    private IActorRef CreateIngestActor(IAuditLogRepository repo) =>
+        Sys.ActorOf(Props.Create(() => new AuditLogIngestActor(
+            repo,
+            NullLogger<AuditLogIngestActor>.Instance)));
+
+    private IActorRef CreateTelemetryActor(
+        ISiteAuditQueue queue,
+        ISiteStreamAuditClient client) =>
+        Sys.ActorOf(Props.Create(() => new SiteAuditTelemetryActor(
+            queue,
+            client,
+            FastTelemetryOptions(),
+            NullLogger<SiteAuditTelemetryActor>.Instance)));
+
+    [SkippableFact]
+    public async Task OneExecution_ApiCallAndDbWrite_AllCentralRows_ShareOneNonNullExecutionId()
+    {
+        Skip.IfNot(_fixture.Available, _fixture.SkipReason);
+
+        var siteId = NewSiteId();
+        // An explicit per-run execution id — the value the test asserts on every
+        // audit row produced by the single script execution below.
+        var executionId = Guid.NewGuid();
+
+        // ── Central — repository + ingest actor backed by the MSSQL fixture ──
+        await using var ingestContext = CreateContext();
+        var ingestRepo = new AuditLogRepository(ingestContext);
+        var ingestActor = CreateIngestActor(ingestRepo);
+
+        // ── Site — SQLite audit writer + ring + fallback + telemetry actor ───
+        await using var sqliteWriter = CreateInMemorySqliteWriter();
+        var ring = new RingBufferFallback();
+        var fallback = new FallbackAuditWriter(
+            sqliteWriter,
+            ring,
+            new NoOpAuditWriteFailureCounter(),
+            NullLogger<FallbackAuditWriter>.Instance);
+        var stubClient = new DirectActorSiteStreamAuditClient(ingestActor);
+        CreateTelemetryActor(sqliteWriter, stubClient);
+
+        // Outbound API client — one successful CallAsync, one audit row.
+        var externalClient = Substitute.For<IExternalSystemClient>();
+        externalClient
+            .CallAsync("ERP", "GetOrder", Arg.Any<IReadOnlyDictionary<string, object?>?>(), Arg.Any<CancellationToken>())
+            .Returns(new ExternalCallResult(true, "{}", null));
+
+        // SQLite-backed inner DB connection — the stub gateway hands it to the
+        // auditing wrapper as the connection the script would have got.
+        using var keepAlive = new SqliteConnection("Data Source=execid-k1;Mode=Memory;Cache=Shared");
+        var innerDb = NewInMemoryDb(out _);
+        var gateway = Substitute.For<IDatabaseGateway>();
+        gateway.GetConnectionAsync(ConnectionName, Arg.Any<CancellationToken>())
+            .Returns(innerDb);
+
+        // ── Act — ONE script execution: a sync ExternalSystem.Call AND a sync
+        // Database write, both performed through a SINGLE ScriptRuntimeContext
+        // stamped with the explicit executionId. Each helper emits exactly one
+        // trust-boundary audit row to the fallback writer; the telemetry actor's
+        // next tick drains both to central.
+        var context = CreateScriptContext(externalClient, gateway, fallback, siteId, executionId);
+
+        await context.ExternalSystem.Call("ERP", "GetOrder");
+
+        await using (var conn = await context.Database.Connection(ConnectionName))
+        await using (var cmd = conn.CreateCommand())
+        {
+            cmd.CommandText = "INSERT INTO t (id, name) VALUES (1, 'alpha')";
+            var affected = await cmd.ExecuteNonQueryAsync();
+            Assert.Equal(1, affected);
+        }
+
+        // ── Assert — read the rows back from the CENTRAL store filtered by the
+        // execution id; both the ApiCall and the DbWrite row must be present and
+        // every one must carry the SAME non-null ExecutionId we minted above.
+        await AwaitAssertAsync(async () =>
+        {
+            await using var readContext = CreateContext();
+            var readRepo = new AuditLogRepository(readContext);
+
+            // The ExecutionId filter dimension is the universal-correlation
+            // query an audit reader uses to pull every action of one run.
+            var rows = await readRepo.QueryAsync(
+                new AuditLogQueryFilter(ExecutionId: executionId),
+                new AuditLogPaging(PageSize: 10));
+
+            // Both trust-boundary actions of the one execution have landed.
+            Assert.Equal(2, rows.Count);
+
+            // Every central row carries the SAME non-null ExecutionId — the
+            // core promise of the per-run correlation value.
+            Assert.All(rows, r =>
+            {
+                Assert.NotNull(r.ExecutionId);
+                Assert.Equal(executionId, r.ExecutionId);
+                Assert.Equal(siteId, r.SourceSiteId);
+                // Central stamps IngestedAtUtc; the site never sets it.
+                Assert.NotNull(r.IngestedAtUtc);
+            });
+
+            // The two rows are the two distinct trust-boundary actions — one
+            // outbound API call and one outbound DB write — proving the shared
+            // id spans different channels, not two rows of the same action.
+            Assert.Single(rows, r => r.Channel == AuditChannel.ApiOutbound && r.Kind == AuditKind.ApiCall);
+            Assert.Single(rows, r => r.Channel == AuditChannel.DbOutbound && r.Kind == AuditKind.DbWrite);
+        }, TimeSpan.FromSeconds(15));
+    }
+
+    /// <summary>
+    /// Builds a production <see cref="ScriptRuntimeContext"/> wired with the
+    /// outbound external-system client, the database gateway and the audit
+    /// writer, stamped with an explicit <paramref name="executionId"/>. The
+    /// actor refs are <see cref="ActorRefs.Nobody"/> — the ExternalSystem /
+    /// Database helpers exercised here never touch them.
+    /// </summary>
+    private static ScriptRuntimeContext CreateScriptContext(
+        IExternalSystemClient externalSystemClient,
+        IDatabaseGateway databaseGateway,
+        IAuditWriter auditWriter,
+        string siteId,
+        Guid executionId)
+    {
+        var compilationService = new ScriptCompilationService(
+            NullLogger<ScriptCompilationService>.Instance);
+        var sharedScriptLibrary = new SharedScriptLibrary(
+            compilationService, NullLogger<SharedScriptLibrary>.Instance);
+
+        return new ScriptRuntimeContext(
+            ActorRefs.Nobody,
+            ActorRefs.Nobody,
+            sharedScriptLibrary,
+            currentCallDepth: 0,
+            maxCallDepth: 10,
+            askTimeout: TimeSpan.FromSeconds(5),
+            instanceName: InstanceName,
+            logger: NullLogger.Instance,
+            externalSystemClient: externalSystemClient,
+            databaseGateway: databaseGateway,
+            storeAndForward: null,
+            siteCommunicationActor: null,
+            siteId: siteId,
+            sourceScript: SourceScript,
+            auditWriter: auditWriter,
+            operationTrackingStore: null,
+            cachedForwarder: null,
+            executionId: executionId);
+    }
+}

tests/ScadaLink.AuditLog.Tests/Site/SqliteAuditWriterSchemaTests.cs

@@ -2,6 +2,8 @@ using Microsoft.Data.Sqlite;
 using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.Extensions.Options;
 using ScadaLink.AuditLog.Site;
+using ScadaLink.Commons.Entities.Audit;
+using ScadaLink.Commons.Types.Enums;
 
 namespace ScadaLink.AuditLog.Tests.Site;
 
@@ -125,4 +127,122 @@ public class SqliteAuditWriterSchemaTests
             Assert.Equal(2, value);
         }
     }
+
+    // ----- ExecutionId schema-upgrade regression (persistent auditlog.db) ----- //
+
+    /// <summary>
+    /// The OLD pre-ExecutionId-branch <c>AuditLog</c> schema — the 20-column
+    /// CREATE TABLE WITHOUT the <c>ExecutionId</c> column. A real deployment's
+    /// on-disk <c>auditlog.db</c> already contains exactly this shape, and
+    /// <c>CREATE TABLE IF NOT EXISTS</c> is a no-op against it.
+    /// </summary>
+    private const string OldPreExecutionIdSchema = """
+        CREATE TABLE IF NOT EXISTS AuditLog (
+            EventId            TEXT    NOT NULL,
+            OccurredAtUtc      TEXT    NOT NULL,
+            Channel            TEXT    NOT NULL,
+            Kind               TEXT    NOT NULL,
+            CorrelationId      TEXT    NULL,
+            SourceSiteId       TEXT    NULL,
+            SourceInstanceId   TEXT    NULL,
+            SourceScript       TEXT    NULL,
+            Actor              TEXT    NULL,
+            Target             TEXT    NULL,
+            Status             TEXT    NOT NULL,
+            HttpStatus         INTEGER NULL,
+            DurationMs         INTEGER NULL,
+            ErrorMessage       TEXT    NULL,
+            ErrorDetail        TEXT    NULL,
+            RequestSummary     TEXT    NULL,
+            ResponseSummary    TEXT    NULL,
+            PayloadTruncated   INTEGER NOT NULL,
+            Extra              TEXT    NULL,
+            ForwardState       TEXT    NOT NULL,
+            PRIMARY KEY (EventId)
+        );
+        CREATE INDEX IF NOT EXISTS IX_SiteAuditLog_ForwardState_Occurred
+            ON AuditLog (ForwardState, OccurredAtUtc);
+        """;
+
+    /// <summary>
+    /// Seeds a shared-cache in-memory database with the OLD 20-column schema and
+    /// returns the open connection. The connection MUST stay open for the
+    /// lifetime of the test: a shared-cache in-memory database is dropped once
+    /// its last connection closes, so closing this would discard the seeded
+    /// schema before the writer opens its own connection.
+    /// </summary>
+    private static SqliteConnection SeedOldSchemaDatabase(string dataSource)
+    {
+        var connection = new SqliteConnection($"Data Source={dataSource};Cache=Shared");
+        connection.Open();
+        using var cmd = connection.CreateCommand();
+        cmd.CommandText = OldPreExecutionIdSchema;
+        cmd.ExecuteNonQuery();
+        return connection;
+    }
+
+    private static SqliteAuditWriter CreateWriterOver(string dataSource)
+    {
+        var options = new SqliteAuditWriterOptions { DatabasePath = dataSource };
+        return new SqliteAuditWriter(
+            Options.Create(options),
+            NullLogger<SqliteAuditWriter>.Instance,
+            connectionStringOverride: $"Data Source={dataSource};Cache=Shared");
+    }
+
+    private static bool ColumnExists(SqliteConnection connection, string columnName)
+    {
+        using var cmd = connection.CreateCommand();
+        cmd.CommandText = "SELECT COUNT(*) FROM pragma_table_info('AuditLog') WHERE name = $name";
+        cmd.Parameters.AddWithValue("$name", columnName);
+        return Convert.ToInt32(cmd.ExecuteScalar()) > 0;
+    }
+
+    [Fact]
+    public async Task Opening_Over_PreExisting_OldSchema_Db_Adds_ExecutionId_Column_And_WriteAsync_RoundTrips()
+    {
+        var dataSource = $"file:{nameof(Opening_Over_PreExisting_OldSchema_Db_Adds_ExecutionId_Column_And_WriteAsync_RoundTrips)}-{Guid.NewGuid():N}?mode=memory&cache=shared";
+
+        // A pre-branch deployment: auditlog.db already exists with the 20-column
+        // schema and NO ExecutionId column.
+        using var seedConnection = SeedOldSchemaDatabase(dataSource);
+        Assert.False(ColumnExists(seedConnection, "ExecutionId"));
+
+        // Upgrade: a post-branch SqliteAuditWriter opens the same database. Its
+        // InitializeSchema must ALTER the missing ExecutionId column in — the
+        // CREATE TABLE IF NOT EXISTS alone is a no-op against the existing table.
+        var executionId = Guid.NewGuid();
+        await using (var writer = CreateWriterOver(dataSource))
+        {
+            Assert.True(
+                ColumnExists(seedConnection, "ExecutionId"),
+                "SqliteAuditWriter must ALTER the ExecutionId column into a pre-existing AuditLog table.");
+
+            // A WriteAsync binding $ExecutionId must now succeed and round-trip;
+            // without the ALTER it would fail with "no such column: ExecutionId"
+            // and — because audit writes are best-effort — silently drop the row.
+            var evt = new AuditEvent
+            {
+                EventId = Guid.NewGuid(),
+                OccurredAtUtc = DateTime.UtcNow,
+                Channel = AuditChannel.ApiOutbound,
+                Kind = AuditKind.ApiCall,
+                Status = AuditStatus.Delivered,
+                PayloadTruncated = false,
+                ExecutionId = executionId,
+            };
+            await writer.WriteAsync(evt);
+
+            var rows = await writer.ReadPendingAsync(limit: 10);
+            var row = Assert.Single(rows);
+            Assert.Equal(executionId, row.ExecutionId);
+        }
+
+        // Idempotency: a second writer over the now-upgraded DB must not error
+        // (the probe sees ExecutionId already present and skips the ALTER).
+        await using (var writerAgain = CreateWriterOver(dataSource))
+        {
+            Assert.True(ColumnExists(seedConnection, "ExecutionId"));
+        }
+    }
 }

tests/ScadaLink.AuditLog.Tests/Site/Telemetry/CachedCallLifecycleBridgeTests.cs

@@ -31,7 +31,9 @@ public class CachedCallLifecycleBridgeTests
         string channel = "ApiOutbound",
         int retryCount = 1,
         string? lastError = null,
-        int? httpStatus = null) =>
+        int? httpStatus = null,
+        Guid? executionId = null,
+        string? sourceScript = null) =>
         new(
             TrackedOperationId: _id,
             Channel: channel,
@@ -44,7 +46,9 @@ public class CachedCallLifecycleBridgeTests
             CreatedAtUtc: new DateTime(2026, 5, 20, 9, 0, 0, DateTimeKind.Utc),
             OccurredAtUtc: new DateTime(2026, 5, 20, 10, 0, 0, DateTimeKind.Utc),
             DurationMs: 42,
-            SourceInstanceId: "Plant.Pump42");
+            SourceInstanceId: "Plant.Pump42",
+            ExecutionId: executionId,
+            SourceScript: sourceScript);
 
     [Fact]
     public async Task TransientFailure_EmitsOneAttemptedRow_NoResolve()
@@ -184,4 +188,75 @@ public class CachedCallLifecycleBridgeTests
         Assert.Equal(42, captured.Audit.DurationMs);
         Assert.Equal(_id.Value, captured.Audit.CorrelationId);
     }
+
+    // ── Audit Log #23 (ExecutionId Task 4): ExecutionId / SourceScript ──
+
+    [Fact]
+    public async Task RetryLoopAttemptedRow_CarriesExecutionIdAndSourceScript_FromContext()
+    {
+        // Task 4: the ExecutionId + SourceScript threaded through the S&F
+        // buffer arrive on the CachedCallAttemptContext; the bridge must stamp
+        // both onto the per-attempt ApiCallCached row (previously SourceScript
+        // was hard-coded null with a "not threaded through S&F" comment).
+        var executionId = Guid.NewGuid();
+        var captured = new List<CachedCallTelemetry>();
+        _forwarder.ForwardAsync(Arg.Do<CachedCallTelemetry>(t => captured.Add(t)), Arg.Any<CancellationToken>())
+            .Returns(Task.CompletedTask);
+
+        var sut = CreateSut();
+        await sut.OnAttemptCompletedAsync(Ctx(
+            CachedCallAttemptOutcome.TransientFailure,
+            executionId: executionId,
+            sourceScript: "Plant.Pump42/OnTick"));
+
+        var packet = Assert.Single(captured);
+        Assert.Equal(AuditKind.ApiCallCached, packet.Audit.Kind);
+        Assert.Equal(executionId, packet.Audit.ExecutionId);
+        Assert.Equal("Plant.Pump42/OnTick", packet.Audit.SourceScript);
+    }
+
+    [Fact]
+    public async Task RetryLoopCachedResolveRow_CarriesExecutionIdAndSourceScript_FromContext()
+    {
+        // The terminal CachedResolve row must also carry the threaded
+        // provenance so the whole retry-loop lifecycle is correlated.
+        var executionId = Guid.NewGuid();
+        var captured = new List<CachedCallTelemetry>();
+        _forwarder.ForwardAsync(Arg.Do<CachedCallTelemetry>(t => captured.Add(t)), Arg.Any<CancellationToken>())
+            .Returns(Task.CompletedTask);
+
+        var sut = CreateSut();
+        await sut.OnAttemptCompletedAsync(Ctx(
+            CachedCallAttemptOutcome.Delivered,
+            channel: "DbOutbound",
+            executionId: executionId,
+            sourceScript: "Plant.Tank/OnAlarm"));
+
+        Assert.Equal(2, captured.Count);
+        var resolve = Assert.Single(captured, p => p.Audit.Kind == AuditKind.CachedResolve);
+        Assert.Equal(executionId, resolve.Audit.ExecutionId);
+        Assert.Equal("Plant.Tank/OnAlarm", resolve.Audit.SourceScript);
+
+        var attempted = Assert.Single(captured, p => p.Audit.Kind == AuditKind.DbWriteCached);
+        Assert.Equal(executionId, attempted.Audit.ExecutionId);
+        Assert.Equal("Plant.Tank/OnAlarm", attempted.Audit.SourceScript);
+    }
+
+    [Fact]
+    public async Task RetryLoopRow_NullExecutionIdAndSourceScript_RemainNull()
+    {
+        // Back-compat: a pre-Task-4 buffered row has no ExecutionId /
+        // SourceScript; the bridge must leave the audit row's fields null
+        // rather than throwing.
+        CachedCallTelemetry? captured = null;
+        _forwarder.ForwardAsync(Arg.Do<CachedCallTelemetry>(t => captured = t), Arg.Any<CancellationToken>())
+            .Returns(Task.CompletedTask);
+
+        var sut = CreateSut();
+        await sut.OnAttemptCompletedAsync(Ctx(CachedCallAttemptOutcome.TransientFailure));
+
+        Assert.NotNull(captured);
+        Assert.Null(captured!.Audit.ExecutionId);
+        Assert.Null(captured.Audit.SourceScript);
+    }
 }

tests/ScadaLink.CLI.Tests/Commands/AuditQueryCommandTests.cs

@@ -65,6 +65,7 @@ public class AuditQueryCommandTests
             Target = "weather-api",
             Actor = "multi-role",
             CorrelationId = "abc-123",
+            ExecutionId = "def-456",
             ErrorsOnly = false,
             PageSize = 250,
         };
@@ -81,6 +82,7 @@ public class AuditQueryCommandTests
         Assert.Equal("weather-api", parsed["target"]);
         Assert.Equal("multi-role", parsed["actor"]);
         Assert.Equal("abc-123", parsed["correlationId"]);
+        Assert.Equal("def-456", parsed["executionId"]);
         Assert.Equal("250", parsed["pageSize"]);
         Assert.Equal("2026-05-20T11:00:00.0000000+00:00", parsed["fromUtc"]);
         Assert.Equal("2026-05-20T12:00:00.0000000+00:00", parsed["toUtc"]);
@@ -155,9 +157,22 @@ public class AuditQueryCommandTests
         Assert.Null(parsed["channel"]);
         Assert.Null(parsed["status"]);
         Assert.Null(parsed["fromUtc"]);
+        Assert.Null(parsed["correlationId"]);
+        Assert.Null(parsed["executionId"]);
         Assert.Equal("100", parsed["pageSize"]);
     }
 
+    [Fact]
+    public void BuildQueryString_ExecutionId_EmitsExecutionIdParameter()
+    {
+        // --execution-id is a single-value Guid filter — mirrors --correlation-id.
+        var now = DateTimeOffset.UtcNow;
+        var args = new AuditQueryArgs { ExecutionId = "11111111-1111-1111-1111-111111111111" };
+        var qs = AuditQueryHelpers.BuildQueryString(args, now, null, null);
+        var parsed = HttpUtility.ParseQueryString(qs.TrimStart('?'));
+        Assert.Equal("11111111-1111-1111-1111-111111111111", parsed["executionId"]);
+    }
+
     // ---- HTTP execution / paging ------------------------------------------
 
     private sealed class RecordingHandler : HttpMessageHandler
@@ -281,6 +296,18 @@ public class AuditQueryCommandTests
         Assert.Empty(parse.Errors);
     }
 
+    [Fact]
+    public void Query_ExecutionIdOption_IsAccepted()
+    {
+        // --execution-id is a single-value option — mirrors --correlation-id.
+        var root = AuditCommandTestHarness.BuildRoot();
+        var parse = root.Parse(new[]
+        {
+            "audit", "query", "--execution-id", "11111111-1111-1111-1111-111111111111",
+        });
+        Assert.Empty(parse.Errors);
+    }
+
     // ---- Enum-name validation (fast-fail) ----------------------------------
 
     [Fact]

tests/ScadaLink.CentralUI.PlaywrightTests/Audit/AuditDataSeeder.cs

@@ -65,6 +65,7 @@ internal static class AuditDataSeeder
         string? target = null,
         string? actor = null,
         Guid? correlationId = null,
+        Guid? executionId = null,
         int? httpStatus = null,
         int? durationMs = null,
         string? errorMessage = null,
@@ -76,13 +77,13 @@ internal static class AuditDataSeeder
         const string sql = @"
 INSERT INTO [AuditLog]
 ([EventId], [OccurredAtUtc], [IngestedAtUtc], [Channel], [Kind], [CorrelationId],
- [SourceSiteId], [SourceInstanceId], [SourceScript], [Actor], [Target], [Status],
- [HttpStatus], [DurationMs], [ErrorMessage], [ErrorDetail], [RequestSummary],
+ [ExecutionId], [SourceSiteId], [SourceInstanceId], [SourceScript], [Actor], [Target],
+ [Status], [HttpStatus], [DurationMs], [ErrorMessage], [ErrorDetail], [RequestSummary],
  [ResponseSummary], [PayloadTruncated], [Extra], [ForwardState])
 VALUES
 (@eventId, @occurredAtUtc, SYSUTCDATETIME(), @channel, @kind, @correlationId,
- @sourceSiteId, NULL, NULL, @actor, @target, @status,
- @httpStatus, @durationMs, @errorMessage, NULL, @requestSummary,
+ @executionId, @sourceSiteId, NULL, NULL, @actor, @target,
+ @status, @httpStatus, @durationMs, @errorMessage, NULL, @requestSummary,
  @responseSummary, 0, @extra, NULL);";
 
         await using var connection = new SqlConnection(ConnectionString);
@@ -94,6 +95,7 @@ VALUES
         cmd.Parameters.AddWithValue("@channel", channel);
         cmd.Parameters.AddWithValue("@kind", kind);
         cmd.Parameters.AddWithValue("@correlationId", (object?)correlationId ?? DBNull.Value);
+        cmd.Parameters.AddWithValue("@executionId", (object?)executionId ?? DBNull.Value);
         cmd.Parameters.AddWithValue("@sourceSiteId", (object?)sourceSiteId ?? DBNull.Value);
         cmd.Parameters.AddWithValue("@actor", (object?)actor ?? DBNull.Value);
         cmd.Parameters.AddWithValue("@target", (object?)target ?? DBNull.Value);

tests/ScadaLink.CentralUI.PlaywrightTests/Audit/AuditLogPageTests.cs

@@ -24,6 +24,9 @@ namespace ScadaLink.CentralUI.PlaywrightTests.Audit;
 ///   link relies on; verified by reproducing the link target directly because
 ///   seeding a notification visible to the report page requires the Akka query
 ///   path, not just an INSERT).</item>
+///   <item><c>DrillInFromExecutionId_LandsOnAuditLogWithFilterContext</c> — the
+///   <c>?executionId=</c> drill-in (the drawer's "View this execution" action)
+///   auto-loads the grid filtered by ExecutionId.</item>
 ///   <item><c>NotificationsPage_HasViewAuditHistoryLink_WhenNotificationsExist</c> —
 ///   the report page wires drill-in links when notifications are present.</item>
 ///   <item><c>ExportCsv_LinkIsVisibleAndDownloads</c> — Export CSV button gated on
@@ -289,6 +292,64 @@ public class AuditLogPageTests
         }
     }
 
+    [Fact]
+    public async Task DrillInFromExecutionId_LandsOnAuditLogWithFilterContext()
+    {
+        // Mirrors the correlationId drill-in: the "View this execution" drawer
+        // action navigates to /audit/log?executionId={ExecutionId}. We seed a row
+        // carrying that ExecutionId, hit the deep link directly, and assert the
+        // page deserializes the param and auto-loads the seeded row.
+        if (!await AuditDataSeeder.IsAvailableAsync())
+        {
+            throw new InvalidOperationException("MSSQL unavailable; see FilterNarrowing test for setup instructions.");
+        }
+
+        var runId = Guid.NewGuid().ToString("N");
+        var targetPrefix = $"playwright-test/exec-drill-in/{runId}/";
+        var executionId = Guid.NewGuid();
+        var eventId = Guid.NewGuid();
+        var now = DateTime.UtcNow;
+
+        try
+        {
+            await AuditDataSeeder.InsertAuditEventAsync(
+                eventId: eventId,
+                occurredAtUtc: now,
+                channel: "ApiOutbound",
+                kind: "ApiCall",
+                status: "Delivered",
+                target: targetPrefix + "endpoint",
+                executionId: executionId,
+                httpStatus: 200,
+                durationMs: 11);
+
+            var page = await _fixture.NewAuthenticatedPageAsync();
+
+            // The exact URL the drawer's "View this execution" button produces.
+            await page.GotoAsync($"{PlaywrightFixture.BaseUrl}/audit/log?executionId={executionId}");
+            await page.WaitForLoadStateAsync(LoadState.NetworkIdle);
+
+            Assert.Contains($"executionId={executionId}", page.Url);
+            await Assertions.Expect(page.Locator("h1:has-text('Audit Log')")).ToBeVisibleAsync();
+            await Assertions.Expect(page.Locator("[data-test='audit-filter-bar']")).ToBeVisibleAsync();
+            await Assertions.Expect(page.Locator("[data-test='audit-results-grid']")).ToBeVisibleAsync();
+
+            // Auto-load: the query-string drill-in resolves the ?executionId=
+            // filter on OnInitialized and the seeded row appears without an
+            // Apply click.
+            var seededRow = page.Locator($"[data-test='grid-row-{eventId}']");
+            await Assertions.Expect(seededRow).ToBeVisibleAsync();
+
+            // The ExecutionId column renders the row's short-form value.
+            var execCell = page.Locator($"[data-test='execution-id-{eventId}']");
+            await Assertions.Expect(execCell).ToBeVisibleAsync();
+        }
+        finally
+        {
+            await AuditDataSeeder.DeleteByTargetPrefixAsync(targetPrefix);
+        }
+    }
+
     [Fact]
     public async Task NotificationsPage_RendersAuditDrillInLinkPattern()
     {

tests/ScadaLink.CentralUI.Tests/Audit/AuditExportEndpointsTests.cs

@@ -138,6 +138,7 @@ public class AuditExportEndpointsTests
         using (host)
         {
             var correlationId = Guid.NewGuid().ToString();
+            var executionId = Guid.NewGuid().ToString();
             var url =
                 "/api/centralui/audit/export?" +
                 "channel=ApiOutbound&" +
@@ -147,6 +148,7 @@ public class AuditExportEndpointsTests
                 "target=PaymentApi&" +
                 "actor=apikey-1&" +
                 $"correlationId={correlationId}&" +
+                $"executionId={executionId}&" +
                 "from=2026-05-20T00:00:00Z&" +
                 "to=2026-05-20T23:59:59Z";
 
@@ -167,6 +169,7 @@ public class AuditExportEndpointsTests
                     f.Target == "PaymentApi" &&
                     f.Actor == "apikey-1" &&
                     f.CorrelationId == Guid.Parse(correlationId) &&
+                    f.ExecutionId == Guid.Parse(executionId) &&
                     f.FromUtc == new DateTime(2026, 5, 20, 0, 0, 0, DateTimeKind.Utc) &&
                     f.ToUtc == new DateTime(2026, 5, 20, 23, 59, 59, DateTimeKind.Utc)),
                 Arg.Any<AuditLogPaging>(),
@@ -195,6 +198,7 @@ public class AuditExportEndpointsTests
                     f.Target == null &&
                     f.Actor == null &&
                     f.CorrelationId == null &&
+                    f.ExecutionId == null &&
                     f.FromUtc == null &&
                     f.ToUtc == null),
                 Arg.Any<AuditLogPaging>(),
@@ -222,6 +226,25 @@ public class AuditExportEndpointsTests
         }
     }
 
+    [Fact]
+    public async Task ExportEndpoint_UnparseableExecutionId_SilentlyDropped()
+    {
+        // Lax-parse contract: an unparseable executionId is dropped (no 400) —
+        // mirrors the correlationId parse.
+        var (client, repo, host) = await BuildHostAsync();
+        using (host)
+        {
+            var response = await client.GetAsync("/api/centralui/audit/export?executionId=not-a-guid");
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+            _ = await response.Content.ReadAsStringAsync();
+
+            await repo.Received().QueryAsync(
+                Arg.Is<AuditLogQueryFilter>(f => f.ExecutionId == null),
+                Arg.Any<AuditLogPaging>(),
+                Arg.Any<CancellationToken>());
+        }
+    }
+
     /// <summary>
     /// Test-only authentication handler that signs every request in as an Admin.
     /// Admin is in <c>AuditExportRoles</c>, so the endpoint's AuditExport policy

tests/ScadaLink.CentralUI.Tests/Components/Audit/AuditDrilldownDrawerTests.cs

@@ -40,6 +40,7 @@ public class AuditDrilldownDrawerTests : BunitContext
         string? responseSummary = null,
         string? extra = null,
         Guid? correlationId = null,
+        Guid? executionId = null,
         string? errorMessage = null,
         string? errorDetail = null,
         string? target = "demo-target")
@@ -51,6 +52,7 @@ public class AuditDrilldownDrawerTests : BunitContext
             Channel = channel,
             Kind = kind,
             CorrelationId = correlationId,
+            ExecutionId = executionId,
             SourceSiteId = "plant-a",
             SourceInstanceId = "boiler-3",
             SourceScript = "OnAlarm.csx",
@@ -216,6 +218,46 @@ public class AuditDrilldownDrawerTests : BunitContext
         Assert.Contains(corr.ToString(), nav.Uri);
     }
 
+    [Fact]
+    public void Drawer_NullExecutionId_HidesViewThisExecutionButton()
+    {
+        var ev = MakeEvent(executionId: null);
+
+        var cut = Render<AuditDrilldownDrawer>(p => p
+            .Add(c => c.Event, ev)
+            .Add(c => c.IsOpen, true));
+
+        Assert.DoesNotContain("data-test=\"view-this-execution\"", cut.Markup);
+    }
+
+    [Fact]
+    public void Drawer_NonNullExecutionId_ShowsViewThisExecutionButton()
+    {
+        var ev = MakeEvent(executionId: Guid.Parse("aaaaaaaa-1111-2222-3333-444444444444"));
+
+        var cut = Render<AuditDrilldownDrawer>(p => p
+            .Add(c => c.Event, ev)
+            .Add(c => c.IsOpen, true));
+
+        Assert.Contains("data-test=\"view-this-execution\"", cut.Markup);
+    }
+
+    [Fact]
+    public void ViewThisExecution_Navigates_WithExecutionIdQueryString()
+    {
+        var exec = Guid.Parse("dddddddd-cccc-bbbb-aaaa-999999999999");
+        var ev = MakeEvent(executionId: exec);
+
+        var cut = Render<AuditDrilldownDrawer>(p => p
+            .Add(c => c.Event, ev)
+            .Add(c => c.IsOpen, true));
+
+        cut.Find("[data-test=\"view-this-execution\"]").Click();
+
+        var nav = (BunitNavigationManager)Services.GetRequiredService<NavigationManager>();
+        Assert.Contains($"/audit/log?executionId={exec}", nav.Uri);
+    }
+
     [Fact]
     public async Task CopyAsCurl_InvokesClipboard_WithCurlString()
     {

tests/ScadaLink.CentralUI.Tests/Components/Audit/AuditFilterBarTests.cs

@@ -61,6 +61,7 @@ public class AuditFilterBarTests : BunitContext
             "data-test=\"filter-script\"",
             "data-test=\"filter-target\"",
             "data-test=\"filter-actor\"",
+            "data-test=\"filter-execution-id\"",
             "data-test=\"filter-errors-only\"",
         };
         foreach (var marker in markers)
@@ -178,6 +179,42 @@ public class AuditFilterBarTests : BunitContext
         Assert.Contains(AuditStatus.Failed, captured.Statuses);
     }
 
+    [Fact]
+    public void Apply_WithPastedExecutionId_MapsThroughToFilter()
+    {
+        // The operator pastes a Guid into the Execution ID box; Apply must map it
+        // straight onto AuditLogQueryFilter.ExecutionId.
+        var executionId = Guid.Parse("99999999-8888-7777-6666-555555555555");
+        AuditLogQueryFilter? captured = null;
+        var cut = Render<AuditFilterBar>(p => p
+            .Add(c => c.OnFilterChanged, EventCallback.Factory.Create<AuditLogQueryFilter>(this, f => captured = f)));
+
+        cut.Find("[data-test=\"filter-execution-id\"] input").Change(executionId.ToString());
+        cut.Find("[data-test=\"filter-apply\"]").Click();
+
+        Assert.NotNull(captured);
+        Assert.Equal(executionId, captured!.ExecutionId);
+    }
+
+    [Fact]
+    public void Apply_WithBlankOrUnparseableExecutionId_LeavesFilterExecutionIdNull()
+    {
+        // Lax parsing: a blank box yields no constraint; garbage text likewise.
+        AuditLogQueryFilter? captured = null;
+        var cut = Render<AuditFilterBar>(p => p
+            .Add(c => c.OnFilterChanged, EventCallback.Factory.Create<AuditLogQueryFilter>(this, f => captured = f)));
+
+        // Blank — never typed into.
+        cut.Find("[data-test=\"filter-apply\"]").Click();
+        Assert.NotNull(captured);
+        Assert.Null(captured!.ExecutionId);
+
+        // Unparseable paste — still dropped, no error.
+        cut.Find("[data-test=\"filter-execution-id\"] input").Change("not-a-guid");
+        cut.Find("[data-test=\"filter-apply\"]").Click();
+        Assert.Null(captured!.ExecutionId);
+    }
+
     [Fact]
     public void TimeRange_LastHour_PopulatesFromUtc_ApproxOneHourAgo()
     {

tests/ScadaLink.CentralUI.Tests/Components/Audit/AuditResultsGridTests.cs

@@ -22,7 +22,7 @@ public class AuditResultsGridTests : BunitContext
     private readonly IAuditLogQueryService _service;
     private readonly List<(AuditLogQueryFilter Filter, AuditLogPaging? Paging)> _calls = new();
 
-    private static AuditEvent MakeEvent(DateTime occurredAtUtc, AuditStatus status, AuditChannel channel = AuditChannel.ApiOutbound, AuditKind kind = AuditKind.ApiCall, string? site = "plant-a")
+    private static AuditEvent MakeEvent(DateTime occurredAtUtc, AuditStatus status, AuditChannel channel = AuditChannel.ApiOutbound, AuditKind kind = AuditKind.ApiCall, string? site = "plant-a", Guid? executionId = null)
         => new()
         {
             EventId = Guid.NewGuid(),
@@ -33,6 +33,7 @@ public class AuditResultsGridTests : BunitContext
             SourceSiteId = site,
             Target = "demo-target",
             Actor = "tester",
+            ExecutionId = executionId,
             DurationMs = 42,
             HttpStatus = status == AuditStatus.Delivered ? 200 : 500,
             ErrorMessage = status == AuditStatus.Failed ? "boom — unreachable" : null,
@@ -121,6 +122,49 @@ public class AuditResultsGridTests : BunitContext
         Assert.Equal(target.EventId, captured!.EventId);
     }
 
+    [Fact]
+    public void Render_IncludesExecutionIdColumn()
+    {
+        StubPage(new List<AuditEvent>
+        {
+            MakeEvent(DateTime.UtcNow.AddMinutes(-1), AuditStatus.Delivered),
+        });
+
+        var cut = Render<AuditResultsGrid>(p => p.Add(c => c.Filter, new AuditLogQueryFilter()));
+
+        // The ExecutionId column header is present alongside the spec columns.
+        Assert.Contains("data-test=\"col-header-ExecutionId\"", cut.Markup);
+    }
+
+    [Fact]
+    public void ExecutionId_NonNullRow_RendersShortMonospaceValue()
+    {
+        var executionId = Guid.Parse("abcdef01-2222-3333-4444-555555555555");
+        var row = MakeEvent(DateTime.UtcNow.AddMinutes(-1), AuditStatus.Delivered, executionId: executionId);
+        StubPage(new[] { row });
+
+        var cut = Render<AuditResultsGrid>(p => p.Add(c => c.Filter, new AuditLogQueryFilter()));
+
+        var cell = cut.Find($"[data-test=\"execution-id-{row.EventId}\"]");
+        // Short form: first 8 hex digits of the "N" form.
+        Assert.Equal("abcdef01", cell.TextContent.Trim());
+        // Monospace presentation; full value retained in the title attribute.
+        Assert.Contains("font-monospace", cell.GetAttribute("class") ?? string.Empty);
+        Assert.Equal(executionId.ToString(), cell.GetAttribute("title"));
+    }
+
+    [Fact]
+    public void ExecutionId_NullRow_RendersBlankPlaceholder_NoExecutionIdCell()
+    {
+        var row = MakeEvent(DateTime.UtcNow.AddMinutes(-1), AuditStatus.Delivered, executionId: null);
+        StubPage(new[] { row });
+
+        var cut = Render<AuditResultsGrid>(p => p.Add(c => c.Filter, new AuditLogQueryFilter()));
+
+        // A null ExecutionId renders the em-dash placeholder, not a value cell.
+        Assert.Empty(cut.FindAll($"[data-test=\"execution-id-{row.EventId}\"]"));
+    }
+
     [Fact]
     public void Status_FailedRow_HasErrorBadgeClass()
     {

tests/ScadaLink.CentralUI.Tests/Pages/AuditLogPageExportUrlTests.cs

@@ -75,6 +75,20 @@ public class AuditLogPageExportUrlTests
         Assert.Equal("Notification", query["channel"]);
     }
 
+    [Fact]
+    public void BuildExportUrl_ExecutionIdSet_EmitsExecutionIdParam()
+    {
+        var exec = Guid.Parse("12121212-3434-5656-7878-909090909090");
+        var filter = new AuditLogQueryFilter(ExecutionId: exec);
+
+        var url = AuditLogPage.BuildExportUrl(filter);
+
+        Assert.StartsWith("/api/centralui/audit/export?", url);
+        var query = QueryHelpers.ParseQuery(new Uri("http://x" + url).Query);
+        Assert.Single(query);
+        Assert.Equal(exec.ToString(), query["executionId"]);
+    }
+
     [Fact]
     public void BuildExportUrl_MultiValueDimensions_EmitRepeatedParams()
     {

tests/ScadaLink.CentralUI.Tests/Pages/AuditLogPageScaffoldTests.cs

@@ -176,6 +176,44 @@ public class AuditLogPageScaffoldTests : BunitContext
         });
     }
 
+    [Fact]
+    public void NavigateWithExecutionIdParam_AppliesFilter_AndAutoLoads()
+    {
+        // The "View this execution" drill-in lands on /audit/log?executionId={id}.
+        // The page parses the Guid, builds an AuditLogQueryFilter with ExecutionId
+        // set, and auto-loads the grid.
+        var executionId = Guid.Parse("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee");
+        _queryService = Substitute.For<IAuditLogQueryService>();
+        _queryService.QueryAsync(Arg.Any<AuditLogQueryFilter>(), Arg.Any<AuditLogPaging?>(), Arg.Any<CancellationToken>())
+            .Returns(Task.FromResult<IReadOnlyList<AuditEvent>>(new List<AuditEvent>()));
+
+        var cut = RenderAuditLogPageWithQuery($"executionId={executionId}", "Admin");
+
+        cut.WaitForAssertion(() =>
+        {
+            _queryService.Received().QueryAsync(
+                Arg.Is<AuditLogQueryFilter>(f => f.ExecutionId == executionId),
+                Arg.Any<AuditLogPaging?>(),
+                Arg.Any<CancellationToken>());
+        });
+    }
+
+    [Fact]
+    public void NavigateWithUnparseableExecutionIdParam_IsSilentlyDropped_NoAutoLoad()
+    {
+        _queryService = Substitute.For<IAuditLogQueryService>();
+
+        var cut = RenderAuditLogPageWithQuery("executionId=not-a-guid", "Admin");
+
+        // An unparseable executionId leaves ExecutionId null. With no other filter
+        // params present the page renders but does NOT call the query service.
+        cut.WaitForAssertion(() => Assert.Contains("Audit Log", cut.Markup));
+        _queryService.DidNotReceive().QueryAsync(
+            Arg.Any<AuditLogQueryFilter>(),
+            Arg.Any<AuditLogPaging?>(),
+            Arg.Any<CancellationToken>());
+    }
+
     [Fact]
     public void NavigateWithTargetParam_AppliesTargetFilter()
     {

tests/ScadaLink.Commons.Tests/Entities/NotificationEntityTests.cs

@@ -21,6 +21,21 @@ public class NotificationEntityTests
         Assert.Equal("SiteA", n.SourceSiteId);
     }
 
+    [Fact]
+    public void OriginExecutionId_DefaultsToNull_AndIsSettable()
+    {
+        // Audit Log #23: OriginExecutionId carries the originating script
+        // execution's id from the site so the dispatcher can echo it onto
+        // NotifyDeliver rows. Null for notifications submitted before the
+        // column existed; settable from the NotificationSubmit message.
+        var n = new Notification("id-1", NotificationType.Email, "ops-team", "subj", "body", "SiteA");
+        Assert.Null(n.OriginExecutionId);
+
+        var executionId = Guid.NewGuid();
+        n.OriginExecutionId = executionId;
+        Assert.Equal(executionId, n.OriginExecutionId);
+    }
+
     [Fact]
     public void Constructor_NullArguments_Throw()
     {

tests/ScadaLink.Commons.Tests/Messages/NotificationMessagesTests.cs

@@ -40,6 +40,47 @@ public class NotificationMessagesTests
         Assert.Null(msg.SourceScript);
     }
 
+    [Fact]
+    public void NotificationSubmit_OriginExecutionId_DefaultsToNull()
+    {
+        // Audit Log #23: OriginExecutionId is an additive trailing member — a
+        // submit built without it (old call sites / old serialized payloads)
+        // leaves the id null.
+        var msg = new NotificationSubmit(
+            "notif-3", "Operators", "Subject", "Body",
+            "site-01", "inst-1", "OnAlarm", DateTimeOffset.UtcNow);
+
+        Assert.Null(msg.OriginExecutionId);
+    }
+
+    [Fact]
+    public void NotificationSubmit_OriginExecutionId_RoundTripsWhenSupplied()
+    {
+        var executionId = Guid.NewGuid();
+        var msg = new NotificationSubmit(
+            "notif-4", "Operators", "Subject", "Body",
+            "site-01", "inst-1", "OnAlarm", DateTimeOffset.UtcNow, executionId);
+
+        Assert.Equal(executionId, msg.OriginExecutionId);
+    }
+
+    [Fact]
+    public void NotificationSubmit_OriginExecutionId_SurvivesJsonRoundTrip()
+    {
+        // The buffered S&F payload IS a serialized NotificationSubmit; the
+        // forwarder deserializes it, so OriginExecutionId must survive JSON.
+        var executionId = Guid.NewGuid();
+        var msg = new NotificationSubmit(
+            "notif-5", "Operators", "Subject", "Body",
+            "site-01", "inst-1", "OnAlarm", DateTimeOffset.UtcNow, executionId);
+
+        var json = System.Text.Json.JsonSerializer.Serialize(msg);
+        var roundTripped = System.Text.Json.JsonSerializer.Deserialize<NotificationSubmit>(json);
+
+        Assert.NotNull(roundTripped);
+        Assert.Equal(executionId, roundTripped!.OriginExecutionId);
+    }
+
     [Fact]
     public void NotificationSubmit_ValueEquality_EqualWhenAllFieldsMatch()
     {

tests/ScadaLink.ConfigurationDatabase.Tests/Migrations/AddNotificationOriginExecutionIdMigrationTests.cs

@@ -0,0 +1,70 @@
+using Xunit;
+
+namespace ScadaLink.ConfigurationDatabase.Tests.Migrations;
+
+/// <summary>
+/// Audit Log #23 (ExecutionId Task 5) integration test for the
+/// <c>AddNotificationOriginExecutionId</c> migration: applies the EF migrations
+/// to a freshly-created MSSQL test database on the running infra/mssql container
+/// and asserts that the <c>Notifications</c> table carries the new
+/// <c>OriginExecutionId</c> column as a nullable <c>uniqueidentifier</c>.
+/// </summary>
+/// <remarks>
+/// Unlike <c>AuditLog</c>, the <c>Notifications</c> table is not partitioned, so
+/// the column is a plain metadata-only <c>ALTER TABLE … ADD</c> with no index.
+/// Tests pair <see cref="SkippableFactAttribute"/> with <c>Skip.IfNot(...)</c> so
+/// the runner reports them as Skipped (not Passed) when MSSQL is unreachable. The
+/// fixture applies the migrations once at construction time.
+/// </remarks>
+public class AddNotificationOriginExecutionIdMigrationTests : IClassFixture<MsSqlMigrationFixture>
+{
+    private readonly MsSqlMigrationFixture _fixture;
+
+    public AddNotificationOriginExecutionIdMigrationTests(MsSqlMigrationFixture fixture)
+    {
+        _fixture = fixture;
+    }
+
+    [SkippableFact]
+    public async Task AppliesMigration_AddsOriginExecutionIdColumn_ToNotifications()
+    {
+        Skip.IfNot(_fixture.Available, _fixture.SkipReason);
+
+        var present = await ScalarAsync<int>(
+            "SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS " +
+            "WHERE TABLE_NAME = 'Notifications' AND COLUMN_NAME = 'OriginExecutionId' " +
+            "AND TABLE_SCHEMA = 'dbo';");
+        Assert.Equal(1, present);
+    }
+
+    [SkippableFact]
+    public async Task OriginExecutionIdColumn_IsNullableUniqueIdentifier()
+    {
+        Skip.IfNot(_fixture.Available, _fixture.SkipReason);
+
+        var dataType = await ScalarAsync<string?>(
+            "SELECT DATA_TYPE FROM INFORMATION_SCHEMA.COLUMNS " +
+            "WHERE TABLE_NAME = 'Notifications' AND COLUMN_NAME = 'OriginExecutionId';");
+        Assert.Equal("uniqueidentifier", dataType);
+
+        var isNullable = await ScalarAsync<string?>(
+            "SELECT IS_NULLABLE FROM INFORMATION_SCHEMA.COLUMNS " +
+            "WHERE TABLE_NAME = 'Notifications' AND COLUMN_NAME = 'OriginExecutionId';");
+        Assert.Equal("YES", isNullable);
+    }
+
+    // --- helpers ------------------------------------------------------------
+
+    private async Task<T> ScalarAsync<T>(string sql)
+    {
+        await using var conn = _fixture.OpenConnection();
+        await using var cmd = conn.CreateCommand();
+        cmd.CommandText = sql;
+        var result = await cmd.ExecuteScalarAsync();
+        if (result is null || result is DBNull)
+        {
+            return default!;
+        }
+        return (T)Convert.ChangeType(result, typeof(T) == typeof(string) ? typeof(string) : Nullable.GetUnderlyingType(typeof(T)) ?? typeof(T))!;
+    }
+}

tests/ScadaLink.ConfigurationDatabase.Tests/RepositoryCoverageTests.cs

@@ -268,6 +268,7 @@ public class NotificationOutboxConfigurationTests : IDisposable
         var lastAttemptAt = new DateTimeOffset(2026, 5, 19, 8, 1, 0, TimeSpan.Zero);
         var nextAttemptAt = new DateTimeOffset(2026, 5, 19, 8, 2, 0, TimeSpan.Zero);
         var deliveredAt = new DateTimeOffset(2026, 5, 19, 8, 3, 0, TimeSpan.Zero);
+        var originExecutionId = Guid.NewGuid();
 
         var notification = new Notification(id, NotificationType.Email, "Ops List",
             "High Tank Level", "Tank 4 exceeded the high level threshold.", "site-north")
@@ -279,6 +280,7 @@ public class NotificationOutboxConfigurationTests : IDisposable
             ResolvedTargets = "ops@example.test;duty@example.test",
             SourceInstanceId = "instance-42",
             SourceScript = "TankLevelAlarm",
+            OriginExecutionId = originExecutionId,
             SiteEnqueuedAt = siteEnqueuedAt,
             CreatedAt = createdAt,
             LastAttemptAt = lastAttemptAt,
@@ -311,6 +313,27 @@ public class NotificationOutboxConfigurationTests : IDisposable
         Assert.Equal(lastAttemptAt, loaded.LastAttemptAt);
         Assert.Equal(nextAttemptAt, loaded.NextAttemptAt);
         Assert.Equal(deliveredAt, loaded.DeliveredAt);
+        Assert.Equal(originExecutionId, loaded.OriginExecutionId);
+    }
+
+    [Fact]
+    public async Task Notification_NullOriginExecutionId_RoundTripsAsNull()
+    {
+        // Audit Log #23: OriginExecutionId is an additive nullable column —
+        // notifications raised outside a script execution (or submitted before
+        // the column existed) persist and reload it as null.
+        var id = Guid.NewGuid().ToString();
+        var notification = new Notification(id, NotificationType.Email, "Ops List",
+            "Subject", "Body", "site-north");
+
+        _context.Notifications.Add(notification);
+        await _context.SaveChangesAsync();
+        _context.ChangeTracker.Clear();
+
+        var loaded = await _context.Notifications.FindAsync(id);
+
+        Assert.NotNull(loaded);
+        Assert.Null(loaded!.OriginExecutionId);
     }
 
     [Fact]

tests/ScadaLink.ExternalSystemGateway.Tests/DatabaseGatewayTests.cs

@@ -101,15 +101,27 @@ public class DatabaseGatewayTests
 
         var gateway = new DatabaseGateway(_repository, NullLogger<DatabaseGateway>.Instance, storeAndForward: sf);
 
+        // Audit Log #23 (ExecutionId Task 4): a known execution id / source
+        // script so the gateway -> EnqueueAsync hop can be asserted below.
+        var executionId = Guid.NewGuid();
+        const string sourceScript = "ScriptActor:WriteAudit";
+
         await gateway.CachedWriteAsync("testDb", "INSERT INTO t VALUES (@v)",
-            new Dictionary<string, object?> { ["v"] = 1 });
+            new Dictionary<string, object?> { ["v"] = 1 },
+            executionId: executionId, sourceScript: sourceScript);
 
         var depth = await storage.GetBufferDepthByCategoryAsync();
         Assert.Equal(1, depth[ScadaLink.Commons.Types.Enums.StoreAndForwardCategory.CachedDbWrite]);
 
-        var (maxRetries, retryIntervalMs) = ReadBufferedRetrySettings(connStr);
-        Assert.Equal(5, maxRetries);
-        Assert.Equal((long)TimeSpan.FromSeconds(12).TotalMilliseconds, retryIntervalMs);
+        var buffered = ReadBufferedRetrySettings(connStr);
+        Assert.Equal(5, buffered.MaxRetries);
+        Assert.Equal((long)TimeSpan.FromSeconds(12).TotalMilliseconds, buffered.RetryIntervalMs);
+
+        // ExecutionId Task 4: the gateway must forward executionId / sourceScript
+        // into EnqueueAsync, and the S&F layer must persist them on the
+        // sf_messages row so the retry loop can stamp the right provenance.
+        Assert.Equal(executionId, buffered.ExecutionId);
+        Assert.Equal(sourceScript, buffered.SourceScript);
     }
 
     [Fact]
@@ -148,21 +160,27 @@ public class DatabaseGatewayTests
 
         await gateway.CachedWriteAsync("testDb", "INSERT INTO t VALUES (1)");
 
-        var (maxRetries, _) = ReadBufferedRetrySettings(connStr);
+        var (maxRetries, _, _, _) = ReadBufferedRetrySettings(connStr);
         // Must be the bounded S&F default, never 0 — a stored 0 would mean retry-forever.
         Assert.Equal(99, maxRetries);
         Assert.NotEqual(0, maxRetries);
     }
 
-    private static (int MaxRetries, long RetryIntervalMs) ReadBufferedRetrySettings(string connStr)
+    private static (int MaxRetries, long RetryIntervalMs, Guid? ExecutionId, string? SourceScript)
+        ReadBufferedRetrySettings(string connStr)
     {
         using var conn = new Microsoft.Data.Sqlite.SqliteConnection(connStr);
         conn.Open();
         using var cmd = conn.CreateCommand();
-        cmd.CommandText = "SELECT max_retries, retry_interval_ms FROM sf_messages";
+        cmd.CommandText =
+            "SELECT max_retries, retry_interval_ms, execution_id, source_script FROM sf_messages";
         using var reader = cmd.ExecuteReader();
         Assert.True(reader.Read(), "expected exactly one buffered message");
-        var result = (reader.GetInt32(0), reader.GetInt64(1));
+        var result = (
+            reader.GetInt32(0),
+            reader.GetInt64(1),
+            reader.IsDBNull(2) ? (Guid?)null : Guid.Parse(reader.GetString(2)),
+            reader.IsDBNull(3) ? null : reader.GetString(3));
         Assert.False(reader.Read(), "expected exactly one buffered message");
         return result;
     }

tests/ScadaLink.ExternalSystemGateway.Tests/ExternalSystemClientTests.cs

@@ -371,26 +371,45 @@ public class ExternalSystemClientTests
             _httpClientFactory, _repository, NullLogger<ExternalSystemClient>.Instance,
             storeAndForward: sf);
 
-        var result = await client.CachedCallAsync("TestAPI", "postData");
+        // Audit Log #23 (ExecutionId Task 4): a known execution id / source
+        // script so the gateway -> EnqueueAsync hop can be asserted below.
+        var executionId = Guid.NewGuid();
+        const string sourceScript = "ScriptActor:CheckPressure";
+
+        var result = await client.CachedCallAsync(
+            "TestAPI", "postData",
+            executionId: executionId, sourceScript: sourceScript);
         Assert.True(result.WasBuffered);
 
         var depth = await storage.GetBufferDepthByCategoryAsync();
         Assert.Equal(1, depth[ScadaLink.Commons.Types.Enums.StoreAndForwardCategory.ExternalSystem]);
 
-        var (maxRetries, retryIntervalMs) = ReadBufferedRetrySettings(connStr);
-        Assert.Equal(7, maxRetries);
-        Assert.Equal((long)TimeSpan.FromSeconds(42).TotalMilliseconds, retryIntervalMs);
+        var buffered = ReadBufferedRetrySettings(connStr);
+        Assert.Equal(7, buffered.MaxRetries);
+        Assert.Equal((long)TimeSpan.FromSeconds(42).TotalMilliseconds, buffered.RetryIntervalMs);
+
+        // ExecutionId Task 4: the gateway must forward executionId / sourceScript
+        // into EnqueueAsync, and the S&F layer must persist them on the
+        // sf_messages row so the retry loop can stamp the right provenance.
+        Assert.Equal(executionId, buffered.ExecutionId);
+        Assert.Equal(sourceScript, buffered.SourceScript);
     }
 
-    private static (int MaxRetries, long RetryIntervalMs) ReadBufferedRetrySettings(string connStr)
+    private static (int MaxRetries, long RetryIntervalMs, Guid? ExecutionId, string? SourceScript)
+        ReadBufferedRetrySettings(string connStr)
     {
         using var conn = new SqliteConnection(connStr);
         conn.Open();
         using var cmd = conn.CreateCommand();
-        cmd.CommandText = "SELECT max_retries, retry_interval_ms FROM sf_messages";
+        cmd.CommandText =
+            "SELECT max_retries, retry_interval_ms, execution_id, source_script FROM sf_messages";
         using var reader = cmd.ExecuteReader();
         Assert.True(reader.Read(), "expected exactly one buffered message");
-        var result = (reader.GetInt32(0), reader.GetInt64(1));
+        var result = (
+            reader.GetInt32(0),
+            reader.GetInt64(1),
+            reader.IsDBNull(2) ? (Guid?)null : Guid.Parse(reader.GetString(2)),
+            reader.IsDBNull(3) ? null : reader.GetString(3));
         Assert.False(reader.Read(), "expected exactly one buffered message");
         return result;
     }
@@ -436,7 +455,7 @@ public class ExternalSystemClientTests
 
         await client.CachedCallAsync("TestAPI", "postData");
 
-        var (maxRetries, _) = ReadBufferedRetrySettings(connStr);
+        var (maxRetries, _, _, _) = ReadBufferedRetrySettings(connStr);
         // Must be the bounded S&F default, never 0 — a stored 0 would mean retry-forever.
         Assert.Equal(99, maxRetries);
         Assert.NotEqual(0, maxRetries);

tests/ScadaLink.InboundAPI.Tests/Middleware/AuditWriteMiddlewareTests.cs

@@ -351,12 +351,14 @@ public class AuditWriteMiddlewareTests
     }
 
     // ---------------------------------------------------------------------
-    // Correlation id — Audit Log #23: each inbound row carries a fresh
-    // per-request correlation id so inbound rows are correlatable.
+    // Execution id — Audit Log #23: each inbound row carries a fresh
+    // per-request execution id so inbound rows are correlatable. The inbound
+    // row's CorrelationId stays null — CorrelationId is purely the
+    // per-operation-lifecycle id and an inbound request is a one-shot.
     // ---------------------------------------------------------------------
 
     [Fact]
-    public async Task InboundRow_CarriesNonNull_CorrelationId()
+    public async Task InboundRow_CarriesNonNull_ExecutionId_And_NullCorrelationId()
     {
         var writer = new RecordingAuditWriter();
         var ctx = BuildContext();
@@ -369,12 +371,15 @@ public class AuditWriteMiddlewareTests
         await mw.InvokeAsync(ctx);
 
         var evt = Assert.Single(writer.Events);
-        Assert.NotNull(evt.CorrelationId);
-        Assert.NotEqual(Guid.Empty, evt.CorrelationId!.Value);
+        Assert.NotNull(evt.ExecutionId);
+        Assert.NotEqual(Guid.Empty, evt.ExecutionId!.Value);
+        // CorrelationId is the per-operation-lifecycle id; an inbound request
+        // is a one-shot with no multi-row operation to correlate.
+        Assert.Null(evt.CorrelationId);
     }
 
     [Fact]
-    public async Task SeparateRequests_GetDistinct_CorrelationIds()
+    public async Task SeparateRequests_GetDistinct_ExecutionIds()
     {
         var writer = new RecordingAuditWriter();
         var mw = CreateMiddleware(hc =>
@@ -387,7 +392,7 @@ public class AuditWriteMiddlewareTests
         await mw.InvokeAsync(BuildContext());
 
         Assert.Equal(2, writer.Events.Count);
-        Assert.NotEqual(writer.Events[0].CorrelationId, writer.Events[1].CorrelationId);
+        Assert.NotEqual(writer.Events[0].ExecutionId, writer.Events[1].ExecutionId);
     }
 
     [Fact]

tests/ScadaLink.ManagementService.Tests/AuditEndpointsTests.cs

@@ -428,6 +428,38 @@ public class AuditEndpointsTests
         Assert.Null(filter.Statuses);
     }
 
+    [Fact]
+    public void ParseFilter_ExecutionId_ParsesIntoSingleValueGuid()
+    {
+        // executionId is a single-value Guid? filter — mirrors correlationId.
+        var executionId = Guid.NewGuid();
+        var query = new Microsoft.AspNetCore.Http.QueryCollection(
+            new Dictionary<string, Microsoft.Extensions.Primitives.StringValues>
+            {
+                ["executionId"] = executionId.ToString(),
+            });
+
+        var filter = AuditEndpoints.ParseFilter(query);
+
+        Assert.Equal(executionId, filter.ExecutionId);
+    }
+
+    [Fact]
+    public void ParseFilter_UnparseableExecutionId_IsDroppedSilently()
+    {
+        // Lax-parse contract: an unparseable executionId is dropped (no 400) —
+        // mirrors the correlationId parse.
+        var query = new Microsoft.AspNetCore.Http.QueryCollection(
+            new Dictionary<string, Microsoft.Extensions.Primitives.StringValues>
+            {
+                ["executionId"] = "not-a-guid",
+            });
+
+        var filter = AuditEndpoints.ParseFilter(query);
+
+        Assert.Null(filter.ExecutionId);
+    }
+
     [Fact]
     public async Task Query_RepeatedChannelParams_ReachRepositoryAsMultiValueFilter()
     {

tests/ScadaLink.NotificationOutbox.Tests/NotificationOutboxActorAttemptEmissionTests.cs

@@ -94,7 +94,8 @@ public class NotificationOutboxActorAttemptEmissionTests : TestKit
     private static Notification MakeNotification(
         Guid? notificationId = null,
         string sourceSite = "site-1",
-        int retryCount = 0)
+        int retryCount = 0,
+        Guid? originExecutionId = null)
     {
         return new Notification(
             (notificationId ?? Guid.NewGuid()).ToString("D"),
@@ -108,6 +109,7 @@ public class NotificationOutboxActorAttemptEmissionTests : TestKit
             CreatedAt = DateTimeOffset.UtcNow,
             SourceInstanceId = "instance-42",
             SourceScript = "AlarmScript",
+            OriginExecutionId = originExecutionId,
         };
     }
 
@@ -162,6 +164,49 @@ public class NotificationOutboxActorAttemptEmissionTests : TestKit
         });
     }
 
+    [Fact]
+    public void Attempt_CarriesOriginExecutionId_AsExecutionId()
+    {
+        // Audit Log #23: the Attempted NotifyDeliver row must echo the
+        // notification's OriginExecutionId so all rows for one run share an id.
+        SetupSmtpRetryPolicy(maxRetries: 5, retryDelay: TimeSpan.FromMinutes(1));
+        var executionId = Guid.NewGuid();
+        var notification = MakeNotification(originExecutionId: executionId);
+        _outboxRepository.GetDueAsync(Arg.Any<DateTimeOffset>(), Arg.Any<int>(), Arg.Any<CancellationToken>())
+            .Returns(new[] { notification });
+        var adapter = new StubAdapter(() => DeliveryOutcome.Success("ops@example.com"));
+        var actor = CreateActor([adapter]);
+
+        actor.Tell(InternalMessages.DispatchTick.Instance);
+
+        AwaitAssert(() =>
+        {
+            var attempted = EventsByStatus(AuditStatus.Attempted);
+            Assert.Single(attempted);
+            Assert.Equal(executionId, attempted[0].ExecutionId);
+        });
+    }
+
+    [Fact]
+    public void Attempt_NullOriginExecutionId_HasNullExecutionId()
+    {
+        SetupSmtpRetryPolicy(maxRetries: 5, retryDelay: TimeSpan.FromMinutes(1));
+        var notification = MakeNotification(originExecutionId: null);
+        _outboxRepository.GetDueAsync(Arg.Any<DateTimeOffset>(), Arg.Any<int>(), Arg.Any<CancellationToken>())
+            .Returns(new[] { notification });
+        var adapter = new StubAdapter(() => DeliveryOutcome.Success("ops@example.com"));
+        var actor = CreateActor([adapter]);
+
+        actor.Tell(InternalMessages.DispatchTick.Instance);
+
+        AwaitAssert(() =>
+        {
+            var attempted = EventsByStatus(AuditStatus.Attempted);
+            Assert.Single(attempted);
+            Assert.Null(attempted[0].ExecutionId);
+        });
+    }
+
     [Fact]
     public void Attempt_TransientFailure_EmitsEvent_StatusAttempted_ErrorMessageSet()
     {

tests/ScadaLink.NotificationOutbox.Tests/NotificationOutboxActorIngestTests.cs

@@ -39,7 +39,8 @@ public class NotificationOutboxActorIngestTests : TestKit
             NullLogger<NotificationOutboxActor>.Instance)));
     }
 
-    private static NotificationSubmit MakeSubmit(string? notificationId = null)
+    private static NotificationSubmit MakeSubmit(
+        string? notificationId = null, Guid? originExecutionId = null)
     {
         return new NotificationSubmit(
             NotificationId: notificationId ?? Guid.NewGuid().ToString(),
@@ -49,7 +50,8 @@ public class NotificationOutboxActorIngestTests : TestKit
             SourceSiteId: "site-1",
             SourceInstanceId: "instance-42",
             SourceScript: "AlarmScript",
-            SiteEnqueuedAt: new DateTimeOffset(2026, 5, 19, 8, 30, 0, TimeSpan.Zero));
+            SiteEnqueuedAt: new DateTimeOffset(2026, 5, 19, 8, 30, 0, TimeSpan.Zero),
+            OriginExecutionId: originExecutionId);
     }
 
     [Fact]
@@ -83,6 +85,42 @@ public class NotificationOutboxActorIngestTests : TestKit
             Arg.Any<CancellationToken>());
     }
 
+    [Fact]
+    public void NotificationSubmit_CopiesOriginExecutionId_OntoPersistedNotification()
+    {
+        // Audit Log #23: the originating script execution's id rides on the
+        // NotificationSubmit and must be persisted on the Notification row so
+        // the dispatcher can later echo it onto NotifyDeliver audit rows.
+        _repository.InsertIfNotExistsAsync(Arg.Any<Notification>(), Arg.Any<CancellationToken>())
+            .Returns(true);
+        var executionId = Guid.NewGuid();
+        var submit = MakeSubmit(originExecutionId: executionId);
+        var actor = CreateActor();
+
+        actor.Tell(submit, TestActor);
+
+        ExpectMsg<NotificationSubmitAck>();
+        _repository.Received(1).InsertIfNotExistsAsync(
+            Arg.Is<Notification>(n => n.OriginExecutionId == executionId),
+            Arg.Any<CancellationToken>());
+    }
+
+    [Fact]
+    public void NotificationSubmit_NullOriginExecutionId_PersistsNull()
+    {
+        _repository.InsertIfNotExistsAsync(Arg.Any<Notification>(), Arg.Any<CancellationToken>())
+            .Returns(true);
+        var submit = MakeSubmit(originExecutionId: null);
+        var actor = CreateActor();
+
+        actor.Tell(submit, TestActor);
+
+        ExpectMsg<NotificationSubmitAck>();
+        _repository.Received(1).InsertIfNotExistsAsync(
+            Arg.Is<Notification>(n => n.OriginExecutionId == null),
+            Arg.Any<CancellationToken>());
+    }
+
     [Fact]
     public void DuplicateSubmit_RepositoryReturnsFalse_StillAcksAccepted()
     {

tests/ScadaLink.NotificationOutbox.Tests/NotificationOutboxActorTerminalEmissionTests.cs

@@ -87,7 +87,8 @@ public class NotificationOutboxActorTerminalEmissionTests : TestKit
     private static Notification MakeNotification(
         NotificationStatus status = NotificationStatus.Pending,
         int retryCount = 0,
-        Guid? notificationId = null)
+        Guid? notificationId = null,
+        Guid? originExecutionId = null)
     {
         return new Notification(
             (notificationId ?? Guid.NewGuid()).ToString("D"),
@@ -100,6 +101,7 @@ public class NotificationOutboxActorTerminalEmissionTests : TestKit
             Status = status,
             RetryCount = retryCount,
             CreatedAt = DateTimeOffset.UtcNow,
+            OriginExecutionId = originExecutionId,
         };
     }
 
@@ -145,6 +147,50 @@ public class NotificationOutboxActorTerminalEmissionTests : TestKit
         });
     }
 
+    [Fact]
+    public void Terminal_Delivered_CarriesOriginExecutionId_AsExecutionId()
+    {
+        // Audit Log #23: the terminal NotifyDeliver row must echo the
+        // notification's OriginExecutionId so it shares the per-run id with
+        // the site-emitted NotifySend row.
+        SetupSmtpRetryPolicy(maxRetries: 5, retryDelay: TimeSpan.FromMinutes(1));
+        var executionId = Guid.NewGuid();
+        var notification = MakeNotification(originExecutionId: executionId);
+        _outboxRepository.GetDueAsync(Arg.Any<DateTimeOffset>(), Arg.Any<int>(), Arg.Any<CancellationToken>())
+            .Returns(new[] { notification });
+        var adapter = new StubAdapter(() => DeliveryOutcome.Success("ops@example.com"));
+        var actor = CreateActor([adapter]);
+
+        actor.Tell(InternalMessages.DispatchTick.Instance);
+
+        AwaitAssert(() =>
+        {
+            var delivered = EventsByStatus(AuditStatus.Delivered);
+            Assert.Single(delivered);
+            Assert.Equal(executionId, delivered[0].ExecutionId);
+        });
+    }
+
+    [Fact]
+    public void Terminal_Delivered_NullOriginExecutionId_HasNullExecutionId()
+    {
+        SetupSmtpRetryPolicy(maxRetries: 5, retryDelay: TimeSpan.FromMinutes(1));
+        var notification = MakeNotification(originExecutionId: null);
+        _outboxRepository.GetDueAsync(Arg.Any<DateTimeOffset>(), Arg.Any<int>(), Arg.Any<CancellationToken>())
+            .Returns(new[] { notification });
+        var adapter = new StubAdapter(() => DeliveryOutcome.Success("ops@example.com"));
+        var actor = CreateActor([adapter]);
+
+        actor.Tell(InternalMessages.DispatchTick.Instance);
+
+        AwaitAssert(() =>
+        {
+            var delivered = EventsByStatus(AuditStatus.Delivered);
+            Assert.Single(delivered);
+            Assert.Null(delivered[0].ExecutionId);
+        });
+    }
+
     [Fact]
     public void Terminal_Parked_OnPermanentFailure_EmitsEvent_StatusParked()
     {
@@ -166,6 +212,31 @@ public class NotificationOutboxActorTerminalEmissionTests : TestKit
         });
     }
 
+    [Fact]
+    public void Terminal_Parked_CarriesOriginExecutionId_AsExecutionId()
+    {
+        // Audit Log #23: the Parked terminal NotifyDeliver row flows through the
+        // same BuildNotifyDeliverEvent path as the Delivered row, so it must
+        // likewise echo the notification's OriginExecutionId — sharing the
+        // per-run id with the site-emitted NotifySend row.
+        SetupSmtpRetryPolicy(maxRetries: 5, retryDelay: TimeSpan.FromMinutes(1));
+        var executionId = Guid.NewGuid();
+        var notification = MakeNotification(originExecutionId: executionId);
+        _outboxRepository.GetDueAsync(Arg.Any<DateTimeOffset>(), Arg.Any<int>(), Arg.Any<CancellationToken>())
+            .Returns(new[] { notification });
+        var adapter = new StubAdapter(() => DeliveryOutcome.Permanent("invalid recipient address"));
+        var actor = CreateActor([adapter]);
+
+        actor.Tell(InternalMessages.DispatchTick.Instance);
+
+        AwaitAssert(() =>
+        {
+            var parked = EventsByStatus(AuditStatus.Parked);
+            Assert.Single(parked);
+            Assert.Equal(executionId, parked[0].ExecutionId);
+        });
+    }
+
     [Fact]
     public void Terminal_Parked_OnTransientReachingMaxRetries_EmitsEvent_StatusParked()
     {

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

@@ -39,6 +39,12 @@ public class DatabaseCachedWriteEmissionTests
     private const string InstanceName = "Plant.Pump42";
     private const string SourceScript = "ScriptActor:WriteAudit";
 
+    /// <summary>
+    /// Audit Log #23: a fixed per-execution id so the cached-row tests can
+    /// assert <see cref="AuditEvent.ExecutionId"/> against a known value.
+    /// </summary>
+    private static readonly Guid TestExecutionId = Guid.NewGuid();
+
     private static ScriptRuntimeContext.DatabaseHelper CreateHelper(
         IDatabaseGateway gateway,
         ICachedCallTelemetryForwarder? forwarder)
@@ -47,9 +53,10 @@ public class DatabaseCachedWriteEmissionTests
             gateway,
             InstanceName,
             NullLogger.Instance,
-            // Audit Log #23: execution-wide correlation id. Cached rows keep
-            // CorrelationId = TrackedOperationId, so any value works here.
-            Guid.NewGuid(),
+            // Audit Log #23: the per-execution id stamped into ExecutionId on
+            // every script-side row. Cached rows keep CorrelationId =
+            // TrackedOperationId (the per-operation lifecycle id).
+            TestExecutionId,
             siteId: SiteId,
             sourceScript: SourceScript,
             cachedForwarder: forwarder);
@@ -65,7 +72,8 @@ public class DatabaseCachedWriteEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 InstanceName,
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             .Returns(Task.CompletedTask);
         var forwarder = new CapturingForwarder();
 
@@ -79,7 +87,10 @@ public class DatabaseCachedWriteEmissionTests
         Assert.Equal(AuditKind.CachedSubmit, packet.Audit.Kind);
         Assert.Equal(AuditStatus.Submitted, packet.Audit.Status);
         Assert.Equal("myDb", packet.Audit.Target);
+        // CorrelationId is the per-operation lifecycle id (TrackedOperationId);
+        // ExecutionId is the per-execution id from the runtime context.
         Assert.Equal(trackedId.Value, packet.Audit.CorrelationId);
+        Assert.Equal(TestExecutionId, packet.Audit.ExecutionId);
 
         Assert.Equal(trackedId, packet.Operational.TrackedOperationId);
         Assert.Equal("DbOutbound", packet.Operational.Channel);
@@ -100,7 +111,8 @@ public class DatabaseCachedWriteEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 It.IsAny<string?>(),
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             .Returns(Task.CompletedTask);
         var forwarder = new CapturingForwarder();
 
@@ -124,7 +136,8 @@ public class DatabaseCachedWriteEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 It.IsAny<string?>(),
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             .Returns(Task.CompletedTask);
         var forwarder = new CapturingForwarder();
 
@@ -137,7 +150,48 @@ public class DatabaseCachedWriteEmissionTests
             It.IsAny<IReadOnlyDictionary<string, object?>?>(),
             InstanceName,
             It.IsAny<CancellationToken>(),
-            trackedId),
+            trackedId,
+            It.IsAny<Guid?>(), It.IsAny<string?>()),
+            Times.Once);
+    }
+
+    /// <summary>
+    /// Audit Log #23 (ExecutionId Task 4): the helper → gateway hop of the
+    /// threading chain. The cached-write helper must forward the runtime
+    /// context's <c>ExecutionId</c> and <c>SourceScript</c> verbatim into
+    /// <see cref="IDatabaseGateway.CachedWriteAsync"/> — so the buffered retry
+    /// loop later stamps the right provenance onto its audit rows. This
+    /// asserts the exact id/script (not <c>It.IsAny</c>), so a regression that
+    /// dropped the threading would fail here.
+    /// </summary>
+    [Fact]
+    public async Task CachedWrite_ThreadsExecutionIdAndSourceScript_IntoGateway()
+    {
+        var gateway = new Mock<IDatabaseGateway>();
+        gateway
+            .Setup(g => g.CachedWriteAsync(
+                "myDb", "INSERT INTO t VALUES (1)",
+                It.IsAny<IReadOnlyDictionary<string, object?>?>(),
+                InstanceName,
+                It.IsAny<CancellationToken>(),
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
+            .Returns(Task.CompletedTask);
+        var forwarder = new CapturingForwarder();
+
+        var helper = CreateHelper(gateway.Object, forwarder);
+        await helper.CachedWrite("myDb", "INSERT INTO t VALUES (1)");
+
+        // The known TestExecutionId and SourceScript must reach the gateway
+        // unchanged — these are what the S&F retry loop persists and replays.
+        gateway.Verify(g => g.CachedWriteAsync(
+            "myDb", "INSERT INTO t VALUES (1)",
+            It.IsAny<IReadOnlyDictionary<string, object?>?>(),
+            InstanceName,
+            It.IsAny<CancellationToken>(),
+            It.IsAny<TrackedOperationId?>(),
+            It.Is<Guid?>(id => id == TestExecutionId),
+            It.Is<string?>(s => s == SourceScript)),
             Times.Once);
     }
 
@@ -151,7 +205,8 @@ public class DatabaseCachedWriteEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 It.IsAny<string?>(),
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             .Returns(Task.CompletedTask);
         var forwarder = new CapturingForwarder
         {
@@ -167,7 +222,8 @@ public class DatabaseCachedWriteEmissionTests
             It.IsAny<IReadOnlyDictionary<string, object?>?>(),
             InstanceName,
             It.IsAny<CancellationToken>(),
-            trackedId),
+            trackedId,
+            It.IsAny<Guid?>(), It.IsAny<string?>()),
             Times.Once);
     }
 }

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

@@ -49,27 +49,27 @@ public class DatabaseSyncEmissionTests
     private const string ConnectionName = "machineData";
 
     /// <summary>
-    /// Audit Log #23: a fixed execution-wide correlation id used by the
-    /// default <see cref="CreateHelper(IDatabaseGateway, IAuditWriter?)"/>
+    /// Audit Log #23: a fixed per-execution id used by the default
+    /// <see cref="CreateHelper(IDatabaseGateway, IAuditWriter?)"/>
     /// overload so assertions can compare against a known value.
     /// </summary>
-    private static readonly Guid TestCorrelationId = Guid.NewGuid();
+    private static readonly Guid TestExecutionId = Guid.NewGuid();
 
     private static ScriptRuntimeContext.DatabaseHelper CreateHelper(
         IDatabaseGateway gateway,
         IAuditWriter? auditWriter)
-        => CreateHelper(gateway, auditWriter, TestCorrelationId);
+        => CreateHelper(gateway, auditWriter, TestExecutionId);
 
     private static ScriptRuntimeContext.DatabaseHelper CreateHelper(
         IDatabaseGateway gateway,
         IAuditWriter? auditWriter,
-        Guid correlationId)
+        Guid executionId)
     {
         return new ScriptRuntimeContext.DatabaseHelper(
             gateway,
             InstanceName,
             NullLogger.Instance,
-            correlationId,
+            executionId,
             auditWriter: auditWriter,
             siteId: SiteId,
             sourceScript: SourceScript,
@@ -282,14 +282,16 @@ public class DatabaseSyncEmissionTests
         Assert.Equal(SourceScript, evt.SourceScript);
         // Outbound channel: Actor carries the calling script identity.
         Assert.Equal(SourceScript, evt.Actor);
-        // Audit Log #23: the sync DbWrite row now carries the execution-wide
-        // correlation id the helper was constructed with.
-        Assert.Equal(TestCorrelationId, evt.CorrelationId);
+        // Audit Log #23: the sync DbWrite row carries the per-execution id the
+        // helper was constructed with in ExecutionId. CorrelationId is null —
+        // a sync one-shot call has no operation lifecycle.
+        Assert.Equal(TestExecutionId, evt.ExecutionId);
+        Assert.Null(evt.CorrelationId);
         Assert.NotEqual(Guid.Empty, evt.EventId);
     }
 
     [Fact]
-    public async Task SyncDbWrite_StampsExecutionCorrelationId()
+    public async Task SyncDbWrite_StampsExecutionId_AndNullCorrelationId()
     {
         using var keepAlive = new SqliteConnection("Data Source=kc;Mode=Memory;Cache=Shared");
         var inner = NewInMemoryDb(out var _);
@@ -298,16 +300,18 @@ public class DatabaseSyncEmissionTests
             .Setup(g => g.GetConnectionAsync(ConnectionName, It.IsAny<CancellationToken>()))
             .ReturnsAsync(inner);
         var writer = new CapturingAuditWriter();
-        var correlationId = Guid.NewGuid();
+        var executionId = Guid.NewGuid();
 
-        var helper = CreateHelper(gateway.Object, writer, correlationId);
+        var helper = CreateHelper(gateway.Object, writer, executionId);
         await using var conn = await helper.Connection(ConnectionName);
         await using var cmd = conn.CreateCommand();
         cmd.CommandText = "INSERT INTO t (id, name) VALUES (7, 'eta')";
         await cmd.ExecuteNonQueryAsync();
 
         var evt = Assert.Single(writer.Events);
-        Assert.Equal(correlationId, evt.CorrelationId);
+        Assert.Equal(executionId, evt.ExecutionId);
+        // Sync one-shot call: CorrelationId is null (no operation lifecycle).
+        Assert.Null(evt.CorrelationId);
     }
 
     [Fact]

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

@@ -16,13 +16,15 @@ namespace ScadaLink.SiteRuntime.Tests.Scripts;
 /// <list type="bullet">
 /// <item><description>
 /// The <c>?? Guid.NewGuid()</c> fallback in the <see cref="ScriptRuntimeContext"/>
-/// ctor: when no audit correlation id is supplied (tag-change / timer-triggered
+/// ctor: when no execution id is supplied (tag-change / timer-triggered
 /// executions) a fresh, non-empty id is minted and stamped on the emitted rows.
 /// </description></item>
 /// <item><description>
 /// The execution-wide contract: an <c>ExternalSystem.Call</c> and a sync
 /// <c>Database</c> write performed through ONE context share a single
-/// <see cref="AuditEvent.CorrelationId"/>.
+/// <see cref="AuditEvent.ExecutionId"/>. The per-operation
+/// <see cref="AuditEvent.CorrelationId"/> stays null for these sync one-shot
+/// calls — a sync call has no operation lifecycle.
 /// </description></item>
 /// </list>
 /// </summary>
@@ -53,14 +55,14 @@ public class ExecutionCorrelationContextTests
     /// system client, database gateway and audit writer the cross-helper test
     /// needs. The actor refs are <see cref="ActorRefs.Nobody"/> — the
     /// integration helpers (ExternalSystem / Database) never touch them — and
-    /// <paramref name="auditCorrelationId"/> defaults to null so the ctor's
+    /// <paramref name="executionId"/> defaults to null so the ctor's
     /// <c>?? Guid.NewGuid()</c> fallback is exercised unless a test supplies one.
     /// </summary>
     private static ScriptRuntimeContext CreateContext(
         IExternalSystemClient? externalSystemClient,
         IDatabaseGateway? databaseGateway,
         IAuditWriter? auditWriter,
-        Guid? auditCorrelationId = null)
+        Guid? executionId = null)
     {
         var compilationService = new ScriptCompilationService(
             NullLogger<ScriptCompilationService>.Instance);
@@ -85,7 +87,7 @@ public class ExecutionCorrelationContextTests
             auditWriter: auditWriter,
             operationTrackingStore: null,
             cachedForwarder: null,
-            auditCorrelationId: auditCorrelationId);
+            executionId: executionId);
     }
 
     /// <summary>
@@ -113,9 +115,9 @@ public class ExecutionCorrelationContextTests
     }
 
     [Fact]
-    public async Task NoCorrelationIdSupplied_SyncCall_StampsFreshNonEmptyCorrelationId()
+    public async Task NoExecutionIdSupplied_SyncCall_StampsFreshNonEmptyExecutionId()
     {
-        // No auditCorrelationId argument — the ScriptRuntimeContext ctor's
+        // No executionId argument — the ScriptRuntimeContext ctor's
         // `?? Guid.NewGuid()` fallback must mint one (this is the unsupplied-id
         // branch every other audit test bypasses by passing an explicit id).
         var client = new Mock<IExternalSystemClient>();
@@ -128,17 +130,19 @@ public class ExecutionCorrelationContextTests
         await context.ExternalSystem.Call("ERP", "GetOrder");
 
         var evt = Assert.Single(writer.Events);
-        Assert.NotNull(evt.CorrelationId);
-        Assert.NotEqual(Guid.Empty, evt.CorrelationId!.Value);
+        Assert.NotNull(evt.ExecutionId);
+        Assert.NotEqual(Guid.Empty, evt.ExecutionId!.Value);
+        // A sync one-shot call has no operation lifecycle — CorrelationId is null.
+        Assert.Null(evt.CorrelationId);
     }
 
     [Fact]
-    public async Task SameContext_ApiCallAndDbWrite_ShareTheSameCorrelationId()
+    public async Task SameContext_ApiCallAndDbWrite_ShareTheSameExecutionId()
     {
         // The execution-wide contract: an ExternalSystem.Call AND a sync
         // Database write performed through ONE ScriptRuntimeContext must both
-        // carry the same execution correlation id, so an audit reader can tie
-        // every trust-boundary action from one script run together.
+        // carry the same ExecutionId, so an audit reader can tie every
+        // trust-boundary action from one script run together.
         using var keepAlive = new SqliteConnection("Data Source=ecc;Mode=Memory;Cache=Shared");
         var innerDb = NewInMemoryDb(out var _);
 
@@ -170,10 +174,13 @@ public class ExecutionCorrelationContextTests
         var apiRow = Assert.Single(writer.Events, e => e.Channel == AuditChannel.ApiOutbound);
         var dbRow = Assert.Single(writer.Events, e => e.Channel == AuditChannel.DbOutbound);
 
-        Assert.NotNull(apiRow.CorrelationId);
-        Assert.NotEqual(Guid.Empty, apiRow.CorrelationId!.Value);
+        Assert.NotNull(apiRow.ExecutionId);
+        Assert.NotEqual(Guid.Empty, apiRow.ExecutionId!.Value);
         // The ApiCall row and the DbWrite row, emitted by two different helpers
-        // resolved off one context, carry the identical execution correlation id.
-        Assert.Equal(apiRow.CorrelationId, dbRow.CorrelationId);
+        // resolved off one context, carry the identical ExecutionId.
+        Assert.Equal(apiRow.ExecutionId, dbRow.ExecutionId);
+        // Both are sync one-shot calls — neither carries a CorrelationId.
+        Assert.Null(apiRow.CorrelationId);
+        Assert.Null(dbRow.CorrelationId);
     }
 }

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

@@ -41,6 +41,12 @@ public class ExternalSystemCachedCallEmissionTests
     private const string InstanceName = "Plant.Pump42";
     private const string SourceScript = "ScriptActor:CheckPressure";
 
+    /// <summary>
+    /// Audit Log #23: a fixed per-execution id so the cached-row tests can
+    /// assert <see cref="AuditEvent.ExecutionId"/> against a known value.
+    /// </summary>
+    private static readonly Guid TestExecutionId = Guid.NewGuid();
+
     private static ScriptRuntimeContext.ExternalSystemHelper CreateHelper(
         IExternalSystemClient client,
         ICachedCallTelemetryForwarder? forwarder)
@@ -49,9 +55,10 @@ public class ExternalSystemCachedCallEmissionTests
             client,
             InstanceName,
             NullLogger.Instance,
-            // Audit Log #23: execution-wide correlation id. Cached rows keep
-            // CorrelationId = TrackedOperationId, so any value works here.
-            Guid.NewGuid(),
+            // Audit Log #23: the per-execution id stamped into ExecutionId on
+            // every script-side row. Cached rows keep CorrelationId =
+            // TrackedOperationId (the per-operation lifecycle id).
+            TestExecutionId,
             auditWriter: null,
             siteId: SiteId,
             sourceScript: SourceScript,
@@ -68,7 +75,8 @@ public class ExternalSystemCachedCallEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 InstanceName,
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             .ReturnsAsync(new ExternalCallResult(true, null, null, WasBuffered: true));
         var forwarder = new CapturingForwarder();
 
@@ -83,7 +91,10 @@ public class ExternalSystemCachedCallEmissionTests
         Assert.Equal(AuditKind.CachedSubmit, packet.Audit.Kind);
         Assert.Equal(AuditStatus.Submitted, packet.Audit.Status);
         Assert.Equal("ERP.GetOrder", packet.Audit.Target);
+        // CorrelationId is the per-operation lifecycle id (TrackedOperationId);
+        // ExecutionId is the per-execution id from the runtime context.
         Assert.Equal(trackedId.Value, packet.Audit.CorrelationId);
+        Assert.Equal(TestExecutionId, packet.Audit.ExecutionId);
         Assert.Equal(AuditForwardState.Pending, packet.Audit.ForwardState);
 
         // Operational mirror — same id, Submitted, RetryCount 0, not terminal.
@@ -107,7 +118,8 @@ public class ExternalSystemCachedCallEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 InstanceName,
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             .ReturnsAsync(new ExternalCallResult(true, "{\"ok\":true}", null, WasBuffered: false));
         var forwarder = new CapturingForwarder();
 
@@ -143,7 +155,8 @@ public class ExternalSystemCachedCallEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 It.IsAny<string?>(),
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             .ReturnsAsync(new ExternalCallResult(true, null, null, WasBuffered: true));
         var forwarder = new CapturingForwarder();
 
@@ -162,14 +175,56 @@ public class ExternalSystemCachedCallEmissionTests
             It.IsAny<IReadOnlyDictionary<string, object?>?>(),
             InstanceName,
             It.IsAny<CancellationToken>(),
-            id1),
+            id1,
+            It.IsAny<Guid?>(), It.IsAny<string?>()),
             Times.Once);
         client.Verify(c => c.CachedCallAsync(
             "ERP", "GetOrder",
             It.IsAny<IReadOnlyDictionary<string, object?>?>(),
             InstanceName,
             It.IsAny<CancellationToken>(),
-            id2),
+            id2,
+            It.IsAny<Guid?>(), It.IsAny<string?>()),
+            Times.Once);
+    }
+
+    /// <summary>
+    /// Audit Log #23 (ExecutionId Task 4): the helper → gateway hop of the
+    /// threading chain. The cached-call helper must forward the runtime
+    /// context's <c>ExecutionId</c> and <c>SourceScript</c> verbatim into
+    /// <see cref="IExternalSystemClient.CachedCallAsync"/> — so the buffered
+    /// retry loop later stamps the right provenance onto its audit rows.
+    /// This asserts the exact id/script (not <c>It.IsAny</c>), so a regression
+    /// that dropped the threading would fail here.
+    /// </summary>
+    [Fact]
+    public async Task CachedCall_ThreadsExecutionIdAndSourceScript_IntoClient()
+    {
+        var client = new Mock<IExternalSystemClient>();
+        client
+            .Setup(c => c.CachedCallAsync(
+                "ERP", "GetOrder",
+                It.IsAny<IReadOnlyDictionary<string, object?>?>(),
+                InstanceName,
+                It.IsAny<CancellationToken>(),
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
+            .ReturnsAsync(new ExternalCallResult(true, null, null, WasBuffered: true));
+        var forwarder = new CapturingForwarder();
+
+        var helper = CreateHelper(client.Object, forwarder);
+        await helper.CachedCall("ERP", "GetOrder");
+
+        // The known TestExecutionId and SourceScript must reach the client
+        // unchanged — these are what the S&F retry loop persists and replays.
+        client.Verify(c => c.CachedCallAsync(
+            "ERP", "GetOrder",
+            It.IsAny<IReadOnlyDictionary<string, object?>?>(),
+            InstanceName,
+            It.IsAny<CancellationToken>(),
+            It.IsAny<TrackedOperationId?>(),
+            It.Is<Guid?>(id => id == TestExecutionId),
+            It.Is<string?>(s => s == SourceScript)),
             Times.Once);
     }
 
@@ -183,7 +238,8 @@ public class ExternalSystemCachedCallEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 It.IsAny<string?>(),
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             .ReturnsAsync(new ExternalCallResult(true, null, null, WasBuffered: true));
         var forwarder = new CapturingForwarder
         {
@@ -202,7 +258,8 @@ public class ExternalSystemCachedCallEmissionTests
             It.IsAny<IReadOnlyDictionary<string, object?>?>(),
             InstanceName,
             It.IsAny<CancellationToken>(),
-            trackedId),
+            trackedId,
+            It.IsAny<Guid?>(), It.IsAny<string?>()),
             Times.Once);
     }
 
@@ -216,7 +273,8 @@ public class ExternalSystemCachedCallEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 It.IsAny<string?>(),
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             .ReturnsAsync(new ExternalCallResult(true, null, null, WasBuffered: true));
         var forwarder = new CapturingForwarder();
 
@@ -242,7 +300,8 @@ public class ExternalSystemCachedCallEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 It.IsAny<string?>(),
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             .ReturnsAsync(new ExternalCallResult(true, null, null, WasBuffered: true));
 
         var helper = CreateHelper(client.Object, forwarder: null);
@@ -254,7 +313,8 @@ public class ExternalSystemCachedCallEmissionTests
             It.IsAny<IReadOnlyDictionary<string, object?>?>(),
             InstanceName,
             It.IsAny<CancellationToken>(),
-            trackedId),
+            trackedId,
+            It.IsAny<Guid?>(), It.IsAny<string?>()),
             Times.Once);
     }
 
@@ -283,7 +343,8 @@ public class ExternalSystemCachedCallEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 InstanceName,
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             // WasBuffered=false — the immediate HTTP attempt succeeded; S&F
             // is bypassed entirely.
             .ReturnsAsync(new ExternalCallResult(true, "{\"ok\":true}", null, WasBuffered: false));
@@ -298,6 +359,7 @@ public class ExternalSystemCachedCallEmissionTests
         var submit = forwarder.Telemetry[0];
         Assert.Equal(AuditKind.CachedSubmit, submit.Audit.Kind);
         Assert.Equal(AuditStatus.Submitted, submit.Audit.Status);
+        Assert.Equal(TestExecutionId, submit.Audit.ExecutionId);
         Assert.Equal(trackedId, submit.Operational.TrackedOperationId);
         Assert.Null(submit.Operational.TerminalAtUtc);
 
@@ -305,7 +367,10 @@ public class ExternalSystemCachedCallEmissionTests
         Assert.Equal(AuditChannel.ApiOutbound, attempted.Audit.Channel);
         Assert.Equal(AuditKind.ApiCallCached, attempted.Audit.Kind);
         Assert.Equal(AuditStatus.Attempted, attempted.Audit.Status);
+        // Cached rows: CorrelationId = TrackedOperationId; ExecutionId is the
+        // per-execution id from the runtime context.
         Assert.Equal(trackedId.Value, attempted.Audit.CorrelationId);
+        Assert.Equal(TestExecutionId, attempted.Audit.ExecutionId);
         Assert.Equal("ERP.GetOrder", attempted.Audit.Target);
         Assert.Equal(trackedId, attempted.Operational.TrackedOperationId);
         Assert.Equal("Attempted", attempted.Operational.Status);
@@ -316,6 +381,7 @@ public class ExternalSystemCachedCallEmissionTests
         Assert.Equal(AuditKind.CachedResolve, resolve.Audit.Kind);
         Assert.Equal(AuditStatus.Delivered, resolve.Audit.Status);
         Assert.Equal(trackedId.Value, resolve.Audit.CorrelationId);
+        Assert.Equal(TestExecutionId, resolve.Audit.ExecutionId);
         Assert.Equal(trackedId, resolve.Operational.TrackedOperationId);
         Assert.Equal("Delivered", resolve.Operational.Status);
         // Terminal row carries TerminalAtUtc.
@@ -339,7 +405,8 @@ public class ExternalSystemCachedCallEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 InstanceName,
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             .ReturnsAsync(new ExternalCallResult(
                 false, null, "Permanent error: HTTP 422 bad payload", WasBuffered: false));
         var forwarder = new CapturingForwarder();
@@ -381,7 +448,8 @@ public class ExternalSystemCachedCallEmissionTests
                 It.IsAny<IReadOnlyDictionary<string, object?>?>(),
                 InstanceName,
                 It.IsAny<CancellationToken>(),
-                It.IsAny<TrackedOperationId?>()))
+                It.IsAny<TrackedOperationId?>(),
+                It.IsAny<Guid?>(), It.IsAny<string?>()))
             // S&F took ownership — Attempted + Resolve come from the
             // CachedCallLifecycleBridge driven by the retry loop, not the helper.
             .ReturnsAsync(new ExternalCallResult(true, null, null, WasBuffered: true));

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

@@ -46,27 +46,27 @@ public class ExternalSystemCallAuditEmissionTests
     private const string SourceScript = "ScriptActor:CheckPressure";
 
     /// <summary>
-    /// Audit Log #23: a fixed execution-wide correlation id used by the
-    /// default <see cref="CreateHelper(IExternalSystemClient, IAuditWriter?)"/>
+    /// Audit Log #23: a fixed per-execution id used by the default
+    /// <see cref="CreateHelper(IExternalSystemClient, IAuditWriter?)"/>
     /// overload so assertions can compare against a known value.
     /// </summary>
-    private static readonly Guid TestCorrelationId = Guid.NewGuid();
+    private static readonly Guid TestExecutionId = Guid.NewGuid();
 
     private static ScriptRuntimeContext.ExternalSystemHelper CreateHelper(
         IExternalSystemClient client,
         IAuditWriter? auditWriter)
-        => CreateHelper(client, auditWriter, TestCorrelationId);
+        => CreateHelper(client, auditWriter, TestExecutionId);
 
     private static ScriptRuntimeContext.ExternalSystemHelper CreateHelper(
         IExternalSystemClient client,
         IAuditWriter? auditWriter,
-        Guid correlationId)
+        Guid executionId)
     {
         return new ScriptRuntimeContext.ExternalSystemHelper(
             client,
             InstanceName,
             NullLogger.Instance,
-            correlationId,
+            executionId,
             auditWriter,
             SiteId,
             SourceScript);
@@ -225,47 +225,54 @@ public class ExternalSystemCallAuditEmissionTests
         Assert.Equal(SourceScript, evt.SourceScript);
         // Outbound channel: Actor carries the calling script identity.
         Assert.Equal(SourceScript, evt.Actor);
-        // Audit Log #23: the sync ApiCall row now carries the execution-wide
-        // correlation id the helper was constructed with.
-        Assert.Equal(TestCorrelationId, evt.CorrelationId);
+        // Audit Log #23: the sync ApiCall row carries the per-execution id the
+        // helper was constructed with in ExecutionId. CorrelationId is null —
+        // a sync one-shot call has no operation lifecycle.
+        Assert.Equal(TestExecutionId, evt.ExecutionId);
+        Assert.Null(evt.CorrelationId);
     }
 
     [Fact]
-    public async Task Call_SyncApiCall_StampsExecutionCorrelationId()
+    public async Task Call_SyncApiCall_StampsExecutionId_AndNullCorrelationId()
     {
         var client = new Mock<IExternalSystemClient>();
         client
             .Setup(c => c.CallAsync("ERP", "GetOrder", It.IsAny<IReadOnlyDictionary<string, object?>?>(), It.IsAny<CancellationToken>()))
             .ReturnsAsync(new ExternalCallResult(true, "{}", null));
         var writer = new CapturingAuditWriter();
-        var correlationId = Guid.NewGuid();
+        var executionId = Guid.NewGuid();
 
-        var helper = CreateHelper(client.Object, writer, correlationId);
+        var helper = CreateHelper(client.Object, writer, executionId);
         await helper.Call("ERP", "GetOrder");
 
         var evt = Assert.Single(writer.Events);
-        Assert.Equal(correlationId, evt.CorrelationId);
+        Assert.Equal(executionId, evt.ExecutionId);
+        // Sync one-shot call: CorrelationId is null (no operation lifecycle).
+        Assert.Null(evt.CorrelationId);
     }
 
     [Fact]
-    public async Task Call_TwoCallsOnSameHelper_ShareTheSameCorrelationId()
+    public async Task Call_TwoCallsOnSameHelper_ShareTheSameExecutionId()
     {
         var client = new Mock<IExternalSystemClient>();
         client
             .Setup(c => c.CallAsync(It.IsAny<string>(), It.IsAny<string>(), It.IsAny<IReadOnlyDictionary<string, object?>?>(), It.IsAny<CancellationToken>()))
             .ReturnsAsync(new ExternalCallResult(true, "{}", null));
         var writer = new CapturingAuditWriter();
-        var correlationId = Guid.NewGuid();
+        var executionId = Guid.NewGuid();
 
-        var helper = CreateHelper(client.Object, writer, correlationId);
+        var helper = CreateHelper(client.Object, writer, executionId);
         await helper.Call("ERP", "GetOrder");
         await helper.Call("ERP", "GetCustomer");
 
         Assert.Equal(2, writer.Events.Count);
-        // Both sync ApiCall rows from one execution carry the same id.
-        Assert.Equal(correlationId, writer.Events[0].CorrelationId);
-        Assert.Equal(correlationId, writer.Events[1].CorrelationId);
-        Assert.Equal(writer.Events[0].CorrelationId, writer.Events[1].CorrelationId);
+        // Both sync ApiCall rows from one execution carry the same ExecutionId.
+        Assert.Equal(executionId, writer.Events[0].ExecutionId);
+        Assert.Equal(executionId, writer.Events[1].ExecutionId);
+        Assert.Equal(writer.Events[0].ExecutionId, writer.Events[1].ExecutionId);
+        // Neither sync call carries a CorrelationId.
+        Assert.Null(writer.Events[0].CorrelationId);
+        Assert.Null(writer.Events[1].CorrelationId);
     }
 
     [Fact]

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

@@ -60,7 +60,8 @@ public class NotifyHelperTests : TestKit, IAsyncLifetime, IDisposable
 
     private ScriptRuntimeContext.NotifyHelper CreateHelper(
         IActorRef siteCommunicationActor,
-        string? sourceScript = null)
+        string? sourceScript = null,
+        Guid? executionId = null)
     {
         return new ScriptRuntimeContext.NotifyHelper(
             _saf,
@@ -69,7 +70,8 @@ public class NotifyHelperTests : TestKit, IAsyncLifetime, IDisposable
             "Plant.Pump3",
             sourceScript,
             TimeSpan.FromSeconds(3),
-            NullLogger.Instance);
+            NullLogger.Instance,
+            executionId ?? Guid.NewGuid());
     }
 
     [Fact]
@@ -133,6 +135,27 @@ public class NotifyHelperTests : TestKit, IAsyncLifetime, IDisposable
         Assert.Equal("ScriptActor:MonitorSpeed", payload!.SourceScript);
     }
 
+    [Fact]
+    public async Task Send_StampsExecutionId_OnTheNotificationSubmitPayload()
+    {
+        // Audit Log #23 (ExecutionId Task 5): Notify.Send must stamp the
+        // script run's ExecutionId onto the NotificationSubmit so it rides
+        // inside the serialized S&F payload to central, where the dispatcher
+        // echoes it onto the NotifyDeliver rows. This is the SAME id stamped
+        // onto the site-emitted NotifySend audit row.
+        var executionId = Guid.NewGuid();
+        var commProbe = CreateTestProbe();
+        var notify = CreateHelper(commProbe.Ref, executionId: executionId);
+
+        var notificationId = await notify.To("Operators").Send("Pump alarm", "Pump 3 tripped");
+
+        var buffered = await _saf.GetMessageByIdAsync(notificationId);
+        Assert.NotNull(buffered);
+        var payload = JsonSerializer.Deserialize<NotificationSubmit>(buffered!.PayloadJson);
+        Assert.NotNull(payload);
+        Assert.Equal(executionId, payload!.OriginExecutionId);
+    }
+
     [Fact]
     public async Task Send_WhenHelperHasNoSourceScript_LeavesSourceScriptNull()
     {

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

@@ -53,6 +53,12 @@ public class NotifySendAuditEmissionTests : TestKit, IAsyncLifetime, IDisposable
     private const string Subject = "Pump alarm";
     private const string Body = "Pump 3 tripped";
 
+    /// <summary>
+    /// Audit Log #23: a fixed per-execution id so the NotifySend test can
+    /// assert <see cref="AuditEvent.ExecutionId"/> against a known value.
+    /// </summary>
+    private static readonly Guid TestExecutionId = Guid.NewGuid();
+
     private readonly SqliteConnection _keepAlive;
     private readonly StoreAndForwardStorage _storage;
     private readonly StoreAndForwardService _saf;
@@ -102,6 +108,7 @@ public class NotifySendAuditEmissionTests : TestKit, IAsyncLifetime, IDisposable
             sourceScript,
             TimeSpan.FromSeconds(3),
             NullLogger.Instance,
+            TestExecutionId,
             auditWriter);
     }
 
@@ -214,12 +221,14 @@ public class NotifySendAuditEmissionTests : TestKit, IAsyncLifetime, IDisposable
 
         // NotificationId is minted as Guid.NewGuid().ToString("N") — the 32-char
         // hex form, which Guid.TryParse accepts. The audit row's CorrelationId
-        // must round-trip back to the same Guid value.
+        // must round-trip back to the same Guid value (the per-operation
+        // lifecycle id). ExecutionId carries the per-execution id instead.
         Assert.True(Guid.TryParse(notificationId, out var expected),
             $"NotificationId '{notificationId}' should be a parseable Guid");
         var evt = writer.Events[0];
         Assert.NotNull(evt.CorrelationId);
         Assert.Equal(expected, evt.CorrelationId);
+        Assert.Equal(TestExecutionId, evt.ExecutionId);
     }
 
     [Fact]

tests/ScadaLink.StoreAndForward.Tests/CachedCallAttemptEmissionTests.cs

@@ -277,6 +277,86 @@ public class CachedCallAttemptEmissionTests : IAsyncLifetime, IDisposable
         Assert.Equal(trackedId, _observer.Notifications[1].TrackedOperationId);
     }
 
+    // ── Audit Log #23 (ExecutionId Task 4): ExecutionId / SourceScript ──
+
+    [Fact]
+    public async Task Attempt_CarriesExecutionIdAndSourceScript_FromBufferedMessage()
+    {
+        // A buffered cached call carries the originating script execution's
+        // ExecutionId + SourceScript. The retry sweep must surface both on the
+        // CachedCallAttemptContext handed to the observer so the audit bridge
+        // can stamp them on the retry-loop cached rows.
+        var executionId = Guid.NewGuid();
+        _service.RegisterDeliveryHandler(StoreAndForwardCategory.ExternalSystem,
+            _ => throw new HttpRequestException("HTTP 503"));
+
+        var trackedId = TrackedOperationId.New();
+        await _service.EnqueueAsync(
+            StoreAndForwardCategory.ExternalSystem,
+            "ERP",
+            """{"payload":"x"}""",
+            originInstanceName: "Plant.Pump42",
+            maxRetries: 5,
+            retryInterval: TimeSpan.Zero,
+            attemptImmediateDelivery: false,
+            messageId: trackedId.ToString(),
+            executionId: executionId,
+            sourceScript: "Plant.Pump42/OnTick");
+
+        await _service.RetryPendingMessagesAsync();
+
+        var notification = Assert.Single(_observer.Notifications);
+        Assert.Equal(executionId, notification.ExecutionId);
+        Assert.Equal("Plant.Pump42/OnTick", notification.SourceScript);
+    }
+
+    [Fact]
+    public async Task Attempt_NullExecutionIdAndSourceScript_SurfaceAsNull()
+    {
+        // Back-compat: a row buffered without ExecutionId / SourceScript (legacy
+        // enqueue path) must surface them as null on the context, not throw.
+        _service.RegisterDeliveryHandler(StoreAndForwardCategory.ExternalSystem,
+            _ => Task.FromResult(true));
+        var trackedId = await EnqueueBufferedAsync(
+            StoreAndForwardCategory.ExternalSystem, "ERP");
+
+        await _service.RetryPendingMessagesAsync();
+
+        var notification = Assert.Single(_observer.Notifications);
+        Assert.Null(notification.ExecutionId);
+        Assert.Null(notification.SourceScript);
+    }
+
+    [Fact]
+    public async Task TerminalResolve_CarriesExecutionIdAndSourceScript()
+    {
+        // The terminal Delivered notification must also carry the threaded
+        // provenance so the CachedResolve audit row is correlated.
+        var executionId = Guid.NewGuid();
+        _service.RegisterDeliveryHandler(StoreAndForwardCategory.CachedDbWrite,
+            _ => Task.FromResult(true));
+
+        var trackedId = TrackedOperationId.New();
+        await _service.EnqueueAsync(
+            StoreAndForwardCategory.CachedDbWrite,
+            "myDb",
+            """{"payload":"x"}""",
+            originInstanceName: "Plant.Tank",
+            maxRetries: 3,
+            retryInterval: TimeSpan.Zero,
+            attemptImmediateDelivery: false,
+            messageId: trackedId.ToString(),
+            executionId: executionId,
+            sourceScript: "Plant.Tank/OnAlarm");
+
+        await _service.RetryPendingMessagesAsync();
+
+        var notification = Assert.Single(_observer.Notifications);
+        Assert.Equal(CachedCallAttemptOutcome.Delivered, notification.Outcome);
+        Assert.Equal(executionId, notification.ExecutionId);
+        Assert.Equal("Plant.Tank/OnAlarm", notification.SourceScript);
+    }
+
     // ── Best-effort contract: observer throws must NOT corrupt retry bookkeeping ──
 
     [Fact]

tests/ScadaLink.StoreAndForward.Tests/NotificationForwarderTests.cs

@@ -26,7 +26,8 @@ public class NotificationForwarderTests : TestKit
     private static StoreAndForwardMessage BufferedNotification(
         string id = "msg-1", string listName = "Operators",
         string subject = "Pump alarm", string message = "Pump 3 tripped",
-        string? originInstance = "Plant.Pump3", string? sourceScript = "alarmScript")
+        string? originInstance = "Plant.Pump3", string? sourceScript = "alarmScript",
+        Guid? originExecutionId = null)
     {
         var payload = JsonSerializer.Serialize(new NotificationSubmit(
             NotificationId: id,
@@ -37,7 +38,8 @@ public class NotificationForwarderTests : TestKit
             SourceSiteId: string.Empty,
             SourceInstanceId: originInstance,
             SourceScript: sourceScript,
-            SiteEnqueuedAt: DateTimeOffset.UtcNow));
+            SiteEnqueuedAt: DateTimeOffset.UtcNow,
+            OriginExecutionId: originExecutionId));
         return new StoreAndForwardMessage
         {
             Id = id,
@@ -78,6 +80,33 @@ public class NotificationForwarderTests : TestKit
         Assert.True(await deliverTask);
     }
 
+    [Fact]
+    public async Task Deliver_PreservesOriginExecutionId_FromBufferedPayload()
+    {
+        // Audit Log #23: the buffered payload's OriginExecutionId is the per-run
+        // id stamped at Notify.Send time. The forwarder re-stamps only the four
+        // fields it authoritatively owns (NotificationId, ListName, SourceSiteId,
+        // SourceInstanceId) via the `with` expression — OriginExecutionId is
+        // preserved precisely BY being absent from that `with` block. This test
+        // pins that: if OriginExecutionId is ever added to the `with` expression
+        // (e.g. reset to null), the forwarded NotificationSubmit would lose the
+        // per-run id and central could not echo it onto NotifyDeliver rows.
+        var centralProbe = CreateTestProbe();
+        var forwarder = new NotificationForwarder(
+            centralProbe.Ref, "site-7", ForwardTimeout);
+
+        var executionId = Guid.NewGuid();
+        var msg = BufferedNotification(id: "msg-exec", originExecutionId: executionId);
+
+        var deliverTask = forwarder.DeliverAsync(msg);
+
+        var submit = centralProbe.ExpectMsg<NotificationSubmit>();
+        Assert.Equal(executionId, submit.OriginExecutionId);
+        centralProbe.Reply(new NotificationSubmitAck(submit.NotificationId, Accepted: true, Error: null));
+
+        Assert.True(await deliverTask);
+    }
+
     [Fact]
     public async Task Deliver_FallsBackToTarget_WhenPayloadListNameIsEmpty()
     {

tests/ScadaLink.StoreAndForward.Tests/StoreAndForwardStorageTests.cs

@@ -293,6 +293,165 @@ public class StoreAndForwardStorageTests : IAsyncLifetime, IDisposable
         Assert.True(count >= 1);
     }
 
+    // ── Audit Log #23 (ExecutionId Task 4): execution_id / source_script ──
+
+    [Fact]
+    public async Task EnqueueAsync_RoundTripsExecutionIdAndSourceScript()
+    {
+        // A cached call buffered on a transient failure carries the originating
+        // script execution's ExecutionId + SourceScript; both must survive a
+        // persist + read-back so the retry loop can stamp them on audit rows.
+        var executionId = Guid.NewGuid();
+        var message = CreateMessage("exec1", StoreAndForwardCategory.ExternalSystem);
+        message.ExecutionId = executionId;
+        message.SourceScript = "Plant.Pump42/OnTick";
+
+        await _storage.EnqueueAsync(message);
+
+        var retrieved = await _storage.GetMessageByIdAsync("exec1");
+        Assert.NotNull(retrieved);
+        Assert.Equal(executionId, retrieved!.ExecutionId);
+        Assert.Equal("Plant.Pump42/OnTick", retrieved.SourceScript);
+    }
+
+    [Fact]
+    public async Task EnqueueAsync_NullExecutionIdAndSourceScript_RoundTripAsNull()
+    {
+        // Non-cached-call enqueues (notifications) supply neither field — they
+        // must round-trip as null rather than throwing or coercing.
+        var message = CreateMessage("noexec1", StoreAndForwardCategory.Notification);
+        Assert.Null(message.ExecutionId);
+        Assert.Null(message.SourceScript);
+
+        await _storage.EnqueueAsync(message);
+
+        var retrieved = await _storage.GetMessageByIdAsync("noexec1");
+        Assert.NotNull(retrieved);
+        Assert.Null(retrieved!.ExecutionId);
+        Assert.Null(retrieved.SourceScript);
+    }
+
+    [Fact]
+    public async Task ExecutionIdAndSourceScript_SurviveRetrySweepRead()
+    {
+        // The retry sweep reads due rows via GetMessagesForRetryAsync; the new
+        // fields must be present on that read path too (it is the path that
+        // feeds the CachedCallAttemptContext).
+        var executionId = Guid.NewGuid();
+        var message = CreateMessage("sweep1", StoreAndForwardCategory.CachedDbWrite);
+        message.ExecutionId = executionId;
+        message.SourceScript = "Plant.Tank/OnAlarm";
+        message.LastAttemptAt = null; // due immediately
+        await _storage.EnqueueAsync(message);
+
+        var due = await _storage.GetMessagesForRetryAsync();
+
+        var row = Assert.Single(due, m => m.Id == "sweep1");
+        Assert.Equal(executionId, row.ExecutionId);
+        Assert.Equal("Plant.Tank/OnAlarm", row.SourceScript);
+    }
+
+    [Fact]
+    public async Task LegacyRowWithoutNewColumns_ReadsBackAsNull()
+    {
+        // Back-compat: a row persisted by a build that pre-dates the
+        // execution_id / source_script columns must still deserialize, with
+        // ExecutionId / SourceScript reading back as null. Simulate the legacy
+        // schema by dropping the table and recreating it without the columns,
+        // inserting directly, then running InitializeAsync (which ALTER-adds
+        // the columns) and reading the row back.
+        await using (var setup = new SqliteConnection($"Data Source={_dbName};Mode=Memory;Cache=Shared"))
+        {
+            await setup.OpenAsync();
+            await using var drop = setup.CreateCommand();
+            drop.CommandText = @"
+                DROP TABLE IF EXISTS sf_messages;
+                CREATE TABLE sf_messages (
+                    id                TEXT PRIMARY KEY,
+                    category          INTEGER NOT NULL,
+                    target            TEXT    NOT NULL,
+                    payload_json      TEXT    NOT NULL,
+                    retry_count       INTEGER NOT NULL DEFAULT 0,
+                    max_retries       INTEGER NOT NULL DEFAULT 50,
+                    retry_interval_ms INTEGER NOT NULL DEFAULT 30000,
+                    created_at        TEXT    NOT NULL,
+                    last_attempt_at   TEXT,
+                    status            INTEGER NOT NULL DEFAULT 0,
+                    last_error        TEXT,
+                    origin_instance   TEXT
+                );
+                INSERT INTO sf_messages (id, category, target, payload_json, created_at, status)
+                VALUES ('legacy1', 0, 'ERP', '{}', '2026-01-01T00:00:00.0000000+00:00', 0);";
+            await drop.ExecuteNonQueryAsync();
+        }
+
+        // InitializeAsync must additively ALTER-in the new columns without
+        // disturbing the pre-existing legacy row.
+        await _storage.InitializeAsync();
+
+        var retrieved = await _storage.GetMessageByIdAsync("legacy1");
+        Assert.NotNull(retrieved);
+        Assert.Equal("legacy1", retrieved!.Id);
+        Assert.Null(retrieved.ExecutionId);
+        Assert.Null(retrieved.SourceScript);
+    }
+
+    [Fact]
+    public async Task MalformedExecutionId_ReadsBackAsNull_DoesNotAbortRetrySweep()
+    {
+        // Defensive read path: a corrupt (non-null, non-GUID) execution_id must
+        // be treated as "no execution id" rather than throwing FormatException
+        // — a single bad row must not abort the whole GetMessagesForRetryAsync
+        // sweep, which reads many rows. Persist two due rows, then corrupt the
+        // execution_id of one directly in the DB.
+        var goodId = Guid.NewGuid();
+        var good = CreateMessage("good1", StoreAndForwardCategory.ExternalSystem);
+        good.ExecutionId = goodId;
+        good.LastAttemptAt = null; // due immediately
+        await _storage.EnqueueAsync(good);
+
+        var bad = CreateMessage("bad1", StoreAndForwardCategory.ExternalSystem);
+        bad.ExecutionId = Guid.NewGuid();
+        bad.LastAttemptAt = null; // due immediately
+        await _storage.EnqueueAsync(bad);
+
+        await using (var conn = new SqliteConnection($"Data Source={_dbName};Mode=Memory;Cache=Shared"))
+        {
+            await conn.OpenAsync();
+            await using var corrupt = conn.CreateCommand();
+            corrupt.CommandText =
+                "UPDATE sf_messages SET execution_id = 'not-a-guid' WHERE id = 'bad1';";
+            await corrupt.ExecuteNonQueryAsync();
+        }
+
+        // The sweep must not throw; the corrupt row reads back with a null
+        // ExecutionId, the well-formed row keeps its value.
+        var due = await _storage.GetMessagesForRetryAsync();
+        Assert.Null(Assert.Single(due, m => m.Id == "bad1").ExecutionId);
+        Assert.Equal(goodId, Assert.Single(due, m => m.Id == "good1").ExecutionId);
+
+        // The single-row read path is equally defensive.
+        var retrieved = await _storage.GetMessageByIdAsync("bad1");
+        Assert.NotNull(retrieved);
+        Assert.Null(retrieved!.ExecutionId);
+    }
+
+    [Fact]
+    public async Task InitializeAsync_IsIdempotent_WhenColumnsAlreadyExist()
+    {
+        // The additive ALTER must not fail on a second InitializeAsync call
+        // (SQLite has no ADD COLUMN IF NOT EXISTS — the probe must skip it).
+        await _storage.InitializeAsync();
+        await _storage.InitializeAsync();
+
+        var message = CreateMessage("idem1", StoreAndForwardCategory.ExternalSystem);
+        message.ExecutionId = Guid.NewGuid();
+        await _storage.EnqueueAsync(message);
+        var retrieved = await _storage.GetMessageByIdAsync("idem1");
+        Assert.NotNull(retrieved);
+        Assert.Equal(message.ExecutionId, retrieved!.ExecutionId);
+    }
+
     private static StoreAndForwardMessage CreateMessage(string id, StoreAndForwardCategory category)
     {
         return new StoreAndForwardMessage