diff --git a/examples/audience/Assets/SampleApp/Scripts/AudienceSample.Events.cs b/examples/audience/Assets/SampleApp/Scripts/AudienceSample.Events.cs
index 301661e8d..455b3fa2a 100644
--- a/examples/audience/Assets/SampleApp/Scripts/AudienceSample.Events.cs
+++ b/examples/audience/Assets/SampleApp/Scripts/AudienceSample.Events.cs
@@ -3,6 +3,7 @@
 using System;
 using System.Collections.Generic;
 using System.Globalization;
+using System.Linq;
 using UnityEngine.UIElements;
 
 namespace Immutable.Audience.Samples.SampleApp
@@ -38,6 +39,18 @@ internal readonly struct EventSpec
 
         private const string OptionalEnumSentinel = "(not set)";
 
+        private static readonly string[] ProgressionStatusValues =
+            Enum.GetValues(typeof(ProgressionStatus))
+                .Cast<ProgressionStatus>()
+                .Select(s => s.ToLowercaseString())
+                .ToArray();
+
+        private static readonly string[] ResourceFlowValues =
+            Enum.GetValues(typeof(ResourceFlow))
+                .Cast<ResourceFlow>()
+                .Select(f => f.ToLowercaseString())
+                .ToArray();
+
         // ---- Event catalogue ----
 
         internal static readonly EventSpec[] Catalogue =
@@ -63,7 +76,7 @@ internal readonly struct EventSpec
             // it as auto-tracked on Init with no public typed class; firing it
             // from the Send button would double-emit.
             new EventSpec(EventNames.Progression, new[] {
-                EventField.Enum(EventPropertyKeys.Status, new[] { "start", "complete", "fail" }),
+                EventField.Enum(EventPropertyKeys.Status, ProgressionStatusValues),
                 EventField.Text(EventPropertyKeys.World,         optional: true),
                 EventField.Text(EventPropertyKeys.Level,         optional: true),
                 EventField.Text(EventPropertyKeys.Stage,         optional: true),
@@ -71,7 +84,7 @@ internal readonly struct EventSpec
                 EventField.Number(EventPropertyKeys.DurationSec, optional: true),
             }),
             new EventSpec(EventNames.Resource, new[] {
-                EventField.Enum(EventPropertyKeys.Flow, new[] { "sink", "source" }),
+                EventField.Enum(EventPropertyKeys.Flow, ResourceFlowValues),
                 EventField.Text(EventPropertyKeys.Currency),
                 EventField.Number(EventPropertyKeys.Amount),
                 EventField.Text(EventPropertyKeys.ItemType, optional: true),
@@ -103,33 +116,33 @@ internal readonly struct EventSpec
                     return new Progression
                     {
                         Status = ParseProgressionStatus(props),
-                        World = OptionalString(props, "world"),
-                        Level = OptionalString(props, "level"),
-                        Stage = OptionalString(props, "stage"),
-                        Score = OptionalInt(props, "score"),
-                        DurationSec = OptionalFloat(props, "durationSec"),
+                        World = OptionalString(props, EventPropertyKeys.World),
+                        Level = OptionalString(props, EventPropertyKeys.Level),
+                        Stage = OptionalString(props, EventPropertyKeys.Stage),
+                        Score = OptionalInt(props, EventPropertyKeys.Score),
+                        DurationSec = OptionalFloat(props, EventPropertyKeys.DurationSec),
                     };
                 case EventNames.Resource:
                     return new Resource
                     {
                         Flow = ParseResourceFlow(props),
-                        Currency = OptionalString(props, "currency") ?? "",
-                        Amount = OptionalFloat(props, "amount") ?? 0f,
-                        ItemType = OptionalString(props, "itemType"),
-                        ItemId = OptionalString(props, "itemId"),
+                        Currency = OptionalString(props, EventPropertyKeys.Currency) ?? "",
+                        Amount = OptionalFloat(props, EventPropertyKeys.Amount) ?? 0f,
+                        ItemType = OptionalString(props, EventPropertyKeys.ItemType),
+                        ItemId = OptionalString(props, EventPropertyKeys.ItemId),
                     };
                 case EventNames.Purchase:
                     return new Purchase
                     {
-                        Currency = OptionalString(props, "currency") ?? "",
-                        Value = OptionalDecimal(props, "value") ?? 0m,
-                        ItemId = OptionalString(props, "itemId"),
-                        ItemName = OptionalString(props, "itemName"),
-                        Quantity = OptionalInt(props, "quantity"),
-                        TransactionId = OptionalString(props, "transactionId"),
+                        Currency = OptionalString(props, EventPropertyKeys.Currency) ?? "",
+                        Value = OptionalDecimal(props, EventPropertyKeys.Value) ?? 0m,
+                        ItemId = OptionalString(props, EventPropertyKeys.ItemId),
+                        ItemName = OptionalString(props, EventPropertyKeys.ItemName),
+                        Quantity = OptionalInt(props, EventPropertyKeys.Quantity),
+                        TransactionId = OptionalString(props, EventPropertyKeys.TransactionId),
                     };
                 case EventNames.MilestoneReached:
-                    return new MilestoneReached { Name = OptionalString(props, "name") ?? "" };
+                    return new MilestoneReached { Name = OptionalString(props, EventPropertyKeys.Name) ?? "" };
                 default:
                     return null;
             }
@@ -137,27 +150,20 @@ internal readonly struct EventSpec
 
         private static ProgressionStatus? ParseProgressionStatus(Dictionary<string, object> props)
         {
-            var s = OptionalString(props, "status");
+            var s = OptionalString(props, EventPropertyKeys.Status);
             if (string.IsNullOrEmpty(s)) return null;
-            return s switch
-            {
-                "start"    => ProgressionStatus.Start,
-                "complete" => ProgressionStatus.Complete,
-                "fail"     => ProgressionStatus.Fail,
-                _          => (ProgressionStatus?)null,
-            };
+            foreach (ProgressionStatus value in Enum.GetValues(typeof(ProgressionStatus)))
+                if (value.ToLowercaseString() == s) return value;
+            return null;
         }
 
         private static ResourceFlow? ParseResourceFlow(Dictionary<string, object> props)
         {
-            var s = OptionalString(props, "flow");
+            var s = OptionalString(props, EventPropertyKeys.Flow);
             if (string.IsNullOrEmpty(s)) return null;
-            return s switch
-            {
-                "source" => ResourceFlow.Source,
-                "sink"   => ResourceFlow.Sink,
-                _        => (ResourceFlow?)null,
-            };
+            foreach (ResourceFlow value in Enum.GetValues(typeof(ResourceFlow)))
+                if (value.ToLowercaseString() == s) return value;
+            return null;
         }
 
         private static string? OptionalString(Dictionary<string, object> props, string key) =>
diff --git a/examples/audience/Assets/SampleApp/Scripts/AudienceSample.UI.cs b/examples/audience/Assets/SampleApp/Scripts/AudienceSample.UI.cs
index 1c70fbd78..5b0a81c48 100644
--- a/examples/audience/Assets/SampleApp/Scripts/AudienceSample.UI.cs
+++ b/examples/audience/Assets/SampleApp/Scripts/AudienceSample.UI.cs
@@ -16,22 +16,42 @@ public sealed partial class AudienceSample
         // ---- Constants & tables ----
 
         private static readonly ConsentLevel[] ConsentOrder = { ConsentLevel.None, ConsentLevel.Anonymous, ConsentLevel.Full };
-        private static readonly string[] ConsentStateClass = { "state-err", "state-warn", "state-ok" };
+        private static readonly string[] ConsentStateClass = { SampleAppUi.Css.StateErr, SampleAppUi.Css.StateWarn, SampleAppUi.Css.StateOk };
 
         private static readonly (string TabId, string PanelId)[] Tabs =
         {
-            ("tab-setup",        "panel-setup"),
-            ("tab-consent",      "panel-consent"),
-            ("tab-typed-events", "panel-typed-events"),
-            ("tab-identity",     "panel-identity"),
+            (SampleAppUi.Tabs.Setup,       SampleAppUi.Panels.Setup),
+            (SampleAppUi.Tabs.Consent,     SampleAppUi.Panels.Consent),
+            (SampleAppUi.Tabs.TypedEvents, SampleAppUi.Panels.TypedEvents),
+            (SampleAppUi.Tabs.Identity,    SampleAppUi.Panels.Identity),
         };
 
-        private static readonly string[] StateClasses = { "state-ok", "state-warn", "state-err", "dim" };
+        private static readonly string[] StateClasses = { SampleAppUi.Css.StateOk, SampleAppUi.Css.StateWarn, SampleAppUi.Css.StateErr, SampleAppUi.Css.Dim };
 
         private const int CollapseThreshold = 240;
         private const int StatusPollIntervalMs = 500;
         private const float NarrowBreakpointPx = 1024f;
 
+        // Log pane drag-resize bounds and main-column padding tracker.
+        private const float LogResizeMinHeight = 120f;
+        private const float LogResizeMaxHeight = 1400f;
+        private const float MainPaddingBottomPx = 64f;
+        // Pixel slack used when deciding whether the log was at the bottom
+        // before a content mutation; treated as "at bottom" if within this.
+        private const float LogScrollBottomEpsilonPx = 4f;
+
+        // Toast / flash timings.
+        private const int CopyButtonRevertMs = 800;
+        private const int CopiedFlashDurationMs = 1500;
+
+        // Local-time format for the per-row timestamp (header) and the
+        // round-trip ISO format used in the copy-to-clipboard payload.
+        private const string LogRowTimestampFormat = "HH:mm:ss.fff";
+
+        // ✓ glyph injected into the runtime Toggle so the checked state
+        // shows a tick rather than a bare coloured square.
+        private const string DebugToggleTickGlyph = "✓";
+
         // ---- UI document state ----
         // All fields below are populated by BindElements before any other access.
 #pragma warning disable 8618
@@ -105,7 +125,7 @@ private void InitializeUi()
 
             _sdkVersionLabel.text = $"v{Immutable.Audience.Constants.LibraryVersion}";
             OnSdkStateChanged();
-            AppendLog("READY", "Sample app loaded. Paste a publishable key and click Init.", LogLevel.Info, LogSource.App);
+            AppendLog(SampleAppUi.LogLabels.Ready, SampleAppUi.Messages.Ready, LogLevel.Info, LogSource.App);
 
             // Status bar mirrors live SDK state (UserId, SessionId, QueueSize) —
             // poll instead of subscribing because the SDK doesn't expose changes.
@@ -120,9 +140,9 @@ private bool LoadUiDocument()
         {
             var doc = GetComponent<UIDocument>() ?? gameObject.AddComponent<UIDocument>();
             if (doc.panelSettings == null)
-                doc.panelSettings = Resources.Load<PanelSettings>("AudienceSampleAppPanelSettings");
+                doc.panelSettings = Resources.Load<PanelSettings>(SampleAppUi.Resources.PanelSettings);
 
-            var tree = Resources.Load<VisualTreeAsset>("AudienceSample");
+            var tree = Resources.Load<VisualTreeAsset>(SampleAppUi.Resources.SampleAppTree);
             if (tree == null)
             {
                 Debug.LogError("[Audience Sample] missing Resources/AudienceSample.uxml");
@@ -137,7 +157,7 @@ private bool LoadUiDocument()
 
             _root.Clear();
             tree.CloneTree(_root);
-            var uss = Resources.Load<StyleSheet>("AudienceSample");
+            var uss = Resources.Load<StyleSheet>(SampleAppUi.Resources.SampleAppStyleSheet);
             if (uss != null) _root.styleSheets.Add(uss);
             return true;
         }
@@ -150,71 +170,71 @@ private T Require<T>(string name) where T : VisualElement =>
 
         private void BindElements()
         {
-            _prodWarning      = Require<Label>("prod-warning");
-            _sdkVersionLabel  = Require<Label>("sdk-version");
+            _prodWarning      = Require<Label>(SampleAppUi.ProdWarning);
+            _sdkVersionLabel  = Require<Label>(SampleAppUi.Layout.SdkVersion);
 
-            _statusEndpoint = Require<Label>("status-endpoint");
-            _statusConsent  = Require<Label>("status-consent");
-            _statusAnon     = Require<Label>("status-anon");
-            _statusUser     = Require<Label>("status-user");
-            _statusSession  = Require<Label>("status-session");
-            _statusQueue    = Require<Label>("status-queue");
+            _statusEndpoint = Require<Label>(SampleAppUi.StatusBar.Endpoint);
+            _statusConsent  = Require<Label>(SampleAppUi.StatusBar.Consent);
+            _statusAnon     = Require<Label>(SampleAppUi.StatusBar.Anon);
+            _statusUser     = Require<Label>(SampleAppUi.StatusBar.User);
+            _statusSession  = Require<Label>(SampleAppUi.StatusBar.Session);
+            _statusQueue    = Require<Label>(SampleAppUi.StatusBar.Queue);
 
             foreach (var (tabId, _) in Tabs) _tabButtons.Add(Require<Button>(tabId));
 
-            _publishableKey = Require<TextField>("publishable-key");
-            _baseUrl        = Require<TextField>("base-url");
-            _initialConsent = Require<DropdownField>("initial-consent");
-            _debug          = Require<Toggle>("debug");
+            _publishableKey = Require<TextField>(SampleAppUi.Setup.PublishableKey);
+            _baseUrl        = Require<TextField>(SampleAppUi.Setup.BaseUrl);
+            _initialConsent = Require<DropdownField>(SampleAppUi.Setup.InitialConsent);
+            _debug          = Require<Toggle>(SampleAppUi.Setup.Debug);
             // Inject a tick Label — Unity 2021.3 runtime panels render the
             // checked state as a plain coloured square otherwise. USS hides
             // the tick when unchecked.
-            var debugCheckmark = _debug.Q<VisualElement>(className: "unity-toggle__checkmark");
+            var debugCheckmark = _debug.Q<VisualElement>(className: SampleAppUi.Css.UnityToggleCheckmark);
             if (debugCheckmark != null)
             {
-                var tick = new Label("✓");
-                tick.AddToClassList("debug-tick");
+                var tick = new Label(DebugToggleTickGlyph);
+                tick.AddToClassList(SampleAppUi.Css.DebugTick);
                 tick.pickingMode = PickingMode.Ignore;
                 debugCheckmark.Add(tick);
             }
-            _flushInterval = Require<TextField>("flush-interval");
-            _flushSize     = Require<TextField>("flush-size");
-            _btnInit       = Require<Button>("btn-init");
-            _btnPage       = Require<Button>("btn-page");
-            _btnFlush      = Require<Button>("btn-flush");
-            _btnReset      = Require<Button>("btn-reset");
-            _btnShutdown   = Require<Button>("btn-shutdown");
-            _btnDeleteData = Require<Button>("btn-delete-data");
+            _flushInterval = Require<TextField>(SampleAppUi.Setup.FlushInterval);
+            _flushSize     = Require<TextField>(SampleAppUi.Setup.FlushSize);
+            _btnInit       = Require<Button>(SampleAppUi.Buttons.Init);
+            _btnPage       = Require<Button>(SampleAppUi.Buttons.Page);
+            _btnFlush      = Require<Button>(SampleAppUi.Buttons.Flush);
+            _btnReset      = Require<Button>(SampleAppUi.Buttons.Reset);
+            _btnShutdown   = Require<Button>(SampleAppUi.Buttons.Shutdown);
+            _btnDeleteData = Require<Button>(SampleAppUi.Buttons.DeleteData);
 
             _consentPills = new Dictionary<ConsentLevel, Button>
             {
-                [ConsentLevel.None]      = Require<Button>("btn-consent-none"),
-                [ConsentLevel.Anonymous] = Require<Button>("btn-consent-anon"),
-                [ConsentLevel.Full]      = Require<Button>("btn-consent-full"),
+                [ConsentLevel.None]      = Require<Button>(SampleAppUi.Buttons.ConsentNone),
+                [ConsentLevel.Anonymous] = Require<Button>(SampleAppUi.Buttons.ConsentAnon),
+                [ConsentLevel.Full]      = Require<Button>(SampleAppUi.Buttons.ConsentFull),
             };
 
-            _typedEventsHost  = Require<VisualElement>("typed-events-host");
-            _customEventName  = Require<TextField>("custom-event-name");
-            _customEventProps = Require<TextField>("custom-event-props");
-            _btnCustomEvent   = Require<Button>("btn-custom-event");
-
-            _identityUserId       = Require<Label>("identity-user-id");
-            _identityIdentityType = Require<Label>("identity-identity-type");
-            _identityTraits       = Require<Label>("identity-traits");
-            _identityAliases      = Require<Label>("identity-aliases");
-            _identifyId           = Require<TextField>("id-id");
-            _identifyType         = Require<DropdownField>("id-type");
-            _identifyTraits       = Require<TextField>("id-traits");
-            _btnIdentify          = Require<Button>("btn-identify");
-            _traitsUpdate         = Require<TextField>("traits-update");
-            _btnIdentifyTraits    = Require<Button>("btn-identify-traits");
-            _aliasFromId          = Require<TextField>("alias-from-id");
-            _aliasFromType        = Require<DropdownField>("alias-from-type");
-            _aliasToId            = Require<TextField>("alias-to-id");
-            _aliasToType          = Require<DropdownField>("alias-to-type");
-            _btnAlias             = Require<Button>("btn-alias");
-
-            _logView = Require<ScrollView>("log");
+            _typedEventsHost  = Require<VisualElement>(SampleAppUi.Layout.TypedEventsHost);
+            _customEventName  = Require<TextField>(SampleAppUi.CustomEvent.Name);
+            _customEventProps = Require<TextField>(SampleAppUi.CustomEvent.Props);
+            _btnCustomEvent   = Require<Button>(SampleAppUi.Buttons.CustomEvent);
+
+            _identityUserId       = Require<Label>(SampleAppUi.IdentityPanel.UserId);
+            _identityIdentityType = Require<Label>(SampleAppUi.IdentityPanel.IdentityType);
+            _identityTraits       = Require<Label>(SampleAppUi.IdentityPanel.Traits);
+            _identityAliases      = Require<Label>(SampleAppUi.IdentityPanel.Aliases);
+            _identifyId           = Require<TextField>(SampleAppUi.IdentityFields.Id);
+            _identifyType         = Require<DropdownField>(SampleAppUi.IdentityFields.Type);
+            _identifyTraits       = Require<TextField>(SampleAppUi.IdentityFields.Traits);
+            _btnIdentify          = Require<Button>(SampleAppUi.Buttons.Identify);
+            _traitsUpdate         = Require<TextField>(SampleAppUi.IdentityFields.TraitsUpdate);
+            _btnIdentifyTraits    = Require<Button>(SampleAppUi.Buttons.IdentifyTraits);
+            _aliasFromId          = Require<TextField>(SampleAppUi.IdentityFields.AliasFromId);
+            _aliasFromType        = Require<DropdownField>(SampleAppUi.IdentityFields.AliasFromType);
+            _aliasToId            = Require<TextField>(SampleAppUi.IdentityFields.AliasToId);
+            _aliasToType          = Require<DropdownField>(SampleAppUi.IdentityFields.AliasToType);
+            _btnAlias             = Require<Button>(SampleAppUi.Buttons.Alias);
+
+            _logView = Require<ScrollView>(SampleAppUi.LogScrollView);
             _logView.mode = ScrollViewMode.Vertical;
 
             // USS selector for this property doesn't match in Unity 2021.3
@@ -223,7 +243,7 @@ private void BindElements()
             // scroller never engages.
             _logView.contentContainer.style.flexShrink = 0;
 
-            _logCount = Require<Label>("log-count");
+            _logCount = Require<Label>(SampleAppUi.Layout.LogCount);
         }
 
         private void PopulateDropdowns()
@@ -247,7 +267,7 @@ private void PopulateDropdowns()
         private void RegisterHandlers()
         {
             // Log pane drag-resize — UI Toolkit has no `resize: vertical`.
-            var logHandle = Require<VisualElement>("log-resize-handle");
+            var logHandle = Require<VisualElement>(SampleAppUi.Layout.LogResizeHandle);
             float dragStartY = 0, dragStartH = 0;
             logHandle.RegisterCallback<PointerDownEvent>(evt =>
             {
@@ -261,8 +281,8 @@ private void RegisterHandlers()
                 // Snapshot "was at bottom?" before the resize so we re-pin
                 // once the new viewport height settles the scrollable rect.
                 var s = _logView.verticalScroller;
-                bool wasAtBottom = s.highValue <= 0 || (s.highValue - s.value) < 4f;
-                var h = Mathf.Clamp(dragStartH + evt.position.y - dragStartY, 120f, 1400f);
+                bool wasAtBottom = s.highValue <= 0 || (s.highValue - s.value) < LogScrollBottomEpsilonPx;
+                var h = Mathf.Clamp(dragStartH + evt.position.y - dragStartY, LogResizeMinHeight, LogResizeMaxHeight);
                 _logView.style.height = h;
                 _logView.style.minHeight = h;
                 _logView.style.maxHeight = h;
@@ -294,7 +314,7 @@ private void RegisterHandlers()
             _btnAlias.clicked += OnAlias;
             _btnCustomEvent.clicked += OnSendCustomEvent;
 
-            var btnCopyLog = Require<Button>("btn-copy-log");
+            var btnCopyLog = Require<Button>(SampleAppUi.Buttons.CopyLog);
             btnCopyLog.clicked += () =>
             {
                 var sb = new StringBuilder();
@@ -302,10 +322,10 @@ private void RegisterHandlers()
                     if (child.userData is LogEntry e)
                         sb.Append(FormatLogEntry(e, singleLine: true)).Append('\n');
                 GUIUtility.systemCopyBuffer = sb.ToString();
-                btnCopyLog.text = "Copied";
-                btnCopyLog.schedule.Execute(() => btnCopyLog.text = "Copy").StartingIn(800);
+                btnCopyLog.text = SampleAppUi.ButtonText.Copied;
+                btnCopyLog.schedule.Execute(() => btnCopyLog.text = SampleAppUi.ButtonText.Copy).StartingIn(CopyButtonRevertMs);
             };
-            Require<Button>("btn-clear-log").clicked += () => { _logView.Clear(); _logCount.text = "0"; };
+            Require<Button>(SampleAppUi.Buttons.ClearLog).clicked += () => { _logView.Clear(); _logCount.text = "0"; };
 
             foreach (var pill in _consentPills) pill.Value.clicked += () => OnSetConsent(pill.Key);
 
@@ -314,7 +334,7 @@ private void RegisterHandlers()
                 var panelId = Tabs.First(t => t.TabId == tab.name).PanelId;
                 tab.clicked += () => ActivateTab(panelId, moveFocus: false);
             }
-            Require<VisualElement>("tab-bar").RegisterCallback<KeyDownEvent>(evt =>
+            Require<VisualElement>(SampleAppUi.Layout.TabBar).RegisterCallback<KeyDownEvent>(evt =>
             {
                 int current = -1;
                 for (int i = 0; i < _tabButtons.Count; i++)
@@ -336,14 +356,14 @@ private void RegisterHandlers()
             foreach (var field in new INotifyValueChanged<string>[] { _aliasFromId, _aliasToId, _aliasFromType, _aliasToType })
                 field.RegisterValueChangedCallback(_ => _btnAlias.SetEnabled(_initialised && IsAliasReady()));
 
-            foreach (var label in _root.Query<Label>(className: "status-value").ToList())
+            foreach (var label in _root.Query<Label>(className: SampleAppUi.Css.StatusValue).ToList())
                 label.RegisterCallback<ClickEvent>(_ =>
                 {
                     // Ignore re-clicks during the flash — label.text is
                     // "Copied!" right now, so re-copying would put that
                     // on the clipboard.
-                    if (label.ClassListContains("copied")) return;
-                    if (string.IsNullOrEmpty(label.text) || label.text == "—") return;
+                    if (label.ClassListContains(SampleAppUi.Css.Copied)) return;
+                    if (string.IsNullOrEmpty(label.text) || label.text == SampleAppUi.StatusBar.EmptyText) return;
                     GUIUtility.systemCopyBuffer = label.text;
                     label.text = "Copied!";
                     FlashCopied(label);
@@ -355,27 +375,27 @@ private static void RegisterPlaceholder(TextField? field)
         {
             if (field == null) return;
             var host = field.parent;
-            if (host == null || !host.ClassListContains("placeholder-host")) return;
-            var placeholder = host.Q<Label>(className: "field-placeholder");
+            if (host == null || !host.ClassListContains(SampleAppUi.Css.PlaceholderHost)) return;
+            var placeholder = host.Q<Label>(className: SampleAppUi.Css.FieldPlaceholder);
             if (placeholder != null) placeholder.pickingMode = PickingMode.Ignore;
-            void Refresh() => host.EnableInClassList("has-value", !string.IsNullOrEmpty(field.value));
+            void Refresh() => host.EnableInClassList(SampleAppUi.Css.HasValue, !string.IsNullOrEmpty(field.value));
             field.RegisterValueChangedCallback(_ => Refresh());
-            field.RegisterCallback<FocusInEvent>(_ => host.AddToClassList("is-focused"));
-            field.RegisterCallback<FocusOutEvent>(_ => host.RemoveFromClassList("is-focused"));
+            field.RegisterCallback<FocusInEvent>(_ => host.AddToClassList(SampleAppUi.Css.IsFocused));
+            field.RegisterCallback<FocusOutEvent>(_ => host.RemoveFromClassList(SampleAppUi.Css.IsFocused));
             Refresh();
         }
 
         // Click + Enter/Space toggle .open on every .accordion-header in the tree.
         private void RegisterAccordionToggles()
         {
-            foreach (var header in _root.Query<VisualElement>(className: "accordion-header").ToList())
+            foreach (var header in _root.Query<VisualElement>(className: SampleAppUi.Css.AccordionHeader).ToList())
             {
                 var item = header.parent;
-                var arrow = header.Q<Label>(className: "accordion-arrow");
+                var arrow = header.Q<Label>(className: SampleAppUi.Css.AccordionArrow);
                 void Toggle()
                 {
-                    var nowOpen = !item.ClassListContains("open");
-                    item.EnableInClassList("open", nowOpen);
+                    var nowOpen = !item.ClassListContains(SampleAppUi.Css.Open);
+                    item.EnableInClassList(SampleAppUi.Css.Open, nowOpen);
                     if (arrow != null) arrow.text = nowOpen ? "▾" : "▸";
                 }
                 header.RegisterCallback<ClickEvent>(evt => { if (!(evt.target is Button)) Toggle(); });
@@ -393,13 +413,12 @@ void Toggle()
         // it — visible layout jump.
         private void RegisterPageLayoutTracking()
         {
-            var pageScroll = Require<ScrollView>("page-scroll");
-            var controls   = Require<VisualElement>("controls-column");
-            var logCol     = Require<VisualElement>("log-column");
-            const float MainPaddingBottom = 64f;
+            var pageScroll = Require<ScrollView>(SampleAppUi.Layout.PageScroll);
+            var controls   = Require<VisualElement>(SampleAppUi.Layout.ControlsColumn);
+            var logCol     = Require<VisualElement>(SampleAppUi.Layout.LogColumn);
             void Update()
             {
-                var needed = Mathf.Max(controls.layout.height, logCol.layout.height) + MainPaddingBottom;
+                var needed = Mathf.Max(controls.layout.height, logCol.layout.height) + MainPaddingBottomPx;
                 if (float.IsNaN(needed) || needed <= 0f) return;
                 pageScroll.contentContainer.style.minHeight = needed;
             }
@@ -413,16 +432,16 @@ void Update()
         // GeometryChangedEvent. Idempotent — only mutates on the boolean flip.
         private void RegisterResponsiveLayout()
         {
-            var grid = Require<VisualElement>("sample-app-grid");
+            var grid = Require<VisualElement>(SampleAppUi.Layout.SampleAppGrid);
             void Update()
             {
                 var w = _root.layout.width;
                 if (float.IsNaN(w) || w <= 0f) return;
                 var shouldBeNarrow = w < NarrowBreakpointPx;
-                var isNarrow = grid.ClassListContains("narrow");
+                var isNarrow = grid.ClassListContains(SampleAppUi.Css.Narrow);
                 if (shouldBeNarrow == isNarrow) return;
-                if (shouldBeNarrow) grid.AddToClassList("narrow");
-                else grid.RemoveFromClassList("narrow");
+                if (shouldBeNarrow) grid.AddToClassList(SampleAppUi.Css.Narrow);
+                else grid.RemoveFromClassList(SampleAppUi.Css.Narrow);
             }
             _root.RegisterCallback<GeometryChangedEvent>(_ => Update());
             _root.schedule.Execute(Update).StartingIn(0);
@@ -435,14 +454,14 @@ void Update()
         private void PopulateTypedEventAccordions()
         {
             _typedEventsHost.Clear();
-            var template = Resources.Load<VisualTreeAsset>("Templates/Accordion");
+            var template = Resources.Load<VisualTreeAsset>(SampleAppUi.Resources.AccordionTemplate);
             if (template == null) { Debug.LogError("[Audience Sample] missing Resources/Templates/Accordion.uxml"); return; }
 
             foreach (var spec in Catalogue)
             {
-                var item = template.Instantiate().Q<VisualElement>("accordion-item");
-                item.Q<Label>("accordion-title").text = spec.Name.ToUpperInvariant();
-                var content = item.Q<VisualElement>("accordion-content");
+                var item = template.Instantiate().Q<VisualElement>(SampleAppUi.Layout.AccordionItem);
+                item.Q<Label>(SampleAppUi.Layout.AccordionTitle).text = spec.Name.ToUpperInvariant();
+                var content = item.Q<VisualElement>(SampleAppUi.Layout.AccordionContent);
 
                 var inputs = new Dictionary<string, VisualElement>();
                 foreach (var field in spec.Fields)
@@ -460,10 +479,10 @@ private void PopulateTypedEventAccordions()
                     input.name = $"typed-{spec.Name.Replace('_', '-')}-{field.Key.ToLowerInvariant().Replace('_', '-')}";
 
                     var row = new VisualElement();
-                    row.AddToClassList("field");
+                    row.AddToClassList(SampleAppUi.Css.Field);
                     var typeHint = field.EnumValues != null ? string.Join(" | ", field.EnumValues) : field.Kind.ToString().ToLowerInvariant();
                     var label = new Label((field.Key + (field.Optional ? "?" : "") + ": " + typeHint).ToUpperInvariant());
-                    label.AddToClassList("field-label");
+                    label.AddToClassList(SampleAppUi.Css.FieldLabel);
                     row.Add(label);
                     row.Add(input);
                     content.Add(row);
@@ -471,9 +490,9 @@ private void PopulateTypedEventAccordions()
                 }
 
                 var actions = new VisualElement();
-                actions.AddToClassList("actions");
-                actions.AddToClassList("last");
-                var send = new Button { text = "Send" };
+                actions.AddToClassList(SampleAppUi.Css.Actions);
+                actions.AddToClassList(SampleAppUi.Css.Last);
+                var send = new Button { text = SampleAppUi.ButtonText.Send };
                 send.name = $"btn-typed-{spec.Name.Replace('_', '-')}";
                 send.SetEnabled(false);
                 var capturedSpec = spec;
@@ -492,12 +511,12 @@ private void ActivateTab(string panelId, bool moveFocus)
             foreach (var tab in _tabButtons)
             {
                 bool isActive = Tabs.First(t => t.TabId == tab.name).PanelId == panelId;
-                tab.EnableInClassList("active", isActive);
+                tab.EnableInClassList(SampleAppUi.ActiveClass, isActive);
                 tab.tabIndex = isActive ? 0 : -1;
                 if (isActive && moveFocus) tab.Focus();
             }
             foreach (var (_, pId) in Tabs)
-                Require<VisualElement>(pId).EnableInClassList("active", pId == panelId);
+                Require<VisualElement>(pId).EnableInClassList(SampleAppUi.ActiveClass, pId == panelId);
         }
 
         // ---- Refresh / state-driven re-render ----
@@ -515,7 +534,7 @@ private void RefreshStatusBar()
             string? endpoint = hasOverride ? overrideUrl : derivedFromKey;
             bool warnState = hasOverride || (!keyEmpty && !isTest);
             SetStatusCell(_statusEndpoint, endpoint, warnState ? "state-warn" : "state-ok");
-            _prodWarning.EnableInClassList("hidden", hasOverride || keyEmpty || isTest);
+            _prodWarning.EnableInClassList(SampleAppUi.HiddenClass, hasOverride || keyEmpty || isTest);
 
             var consent = _initialised ? ImmutableAudience.CurrentConsent : ConsentOrder[Mathf.Clamp(_initialConsent?.index ?? 0, 0, ConsentOrder.Length - 1)];
             int cIdx = Array.IndexOf(ConsentOrder, consent);
@@ -530,7 +549,7 @@ private void RefreshStatusBar()
         private void RefreshConsentPills()
         {
             foreach (var kvp in _consentPills)
-                kvp.Value.EnableInClassList("active", _initialised && ImmutableAudience.CurrentConsent == kvp.Key);
+                kvp.Value.EnableInClassList(SampleAppUi.ActiveClass, _initialised && ImmutableAudience.CurrentConsent == kvp.Key);
         }
 
         private void RefreshInitState()
@@ -545,10 +564,10 @@ private void RefreshInitState()
 
         private void RefreshIdentityPanel()
         {
-            _identityUserId.text       = ImmutableAudience.UserId ?? "—";
-            _identityIdentityType.text = _mirrorIdentityType ?? "—";
-            _identityTraits.text       = _mirrorTraits != null ? Json.Serialize(_mirrorTraits, 2) : "—";
-            _identityAliases.text      = _mirrorAliases.Count == 0 ? "—" : string.Join("\n", _mirrorAliases);
+            _identityUserId.text       = ImmutableAudience.UserId ?? SampleAppUi.StatusBar.EmptyText;
+            _identityIdentityType.text = _mirrorIdentityType ?? SampleAppUi.StatusBar.EmptyText;
+            _identityTraits.text       = _mirrorTraits != null ? Json.Serialize(_mirrorTraits, 2) : SampleAppUi.StatusBar.EmptyText;
+            _identityAliases.text      = _mirrorAliases.Count == 0 ? SampleAppUi.StatusBar.EmptyText : string.Join("\n", _mirrorAliases);
         }
 
         // ---- Form capture (UXML state → DTOs handed to main) ----
@@ -647,11 +666,11 @@ private static void SetStatusCell(Label label, string? value, string stateClass)
             // Don't overwrite a label mid-flash — without this the next
             // RefreshStatusBar poll tick would wipe "Copied!". FlashCopied
             // removes .copied when the flash window ends.
-            if (label.ClassListContains("copied")) return;
+            if (label.ClassListContains(SampleAppUi.Css.Copied)) return;
             bool empty = string.IsNullOrEmpty(value);
-            label.text = empty ? "—" : value;
+            label.text = empty ? SampleAppUi.StatusBar.EmptyText : value;
             foreach (var c in StateClasses) label.RemoveFromClassList(c);
-            label.AddToClassList(empty ? "dim" : stateClass);
+            label.AddToClassList(empty ? SampleAppUi.Css.Dim : stateClass);
         }
 
         private bool IsAliasReady()
@@ -667,8 +686,8 @@ private static bool IsTestKey(string? key) =>
 
         private static void FlashCopied(VisualElement ve)
         {
-            ve.AddToClassList("copied");
-            ve.schedule.Execute(() => ve.RemoveFromClassList("copied")).StartingIn(1500);
+            ve.AddToClassList(SampleAppUi.Css.Copied);
+            ve.schedule.Execute(() => ve.RemoveFromClassList(SampleAppUi.Css.Copied)).StartingIn(CopiedFlashDurationMs);
         }
 
         // ---- Log pane mechanics (types) ----
@@ -701,7 +720,7 @@ private void AppendLog(string label, string? body, LogLevel level, LogSource sou
 
             // Snapshot "was at bottom?" before adding — stateless per-row check.
             var s = _logView.verticalScroller;
-            bool wasAtBottom = s.highValue <= 0 || (s.highValue - s.value) < 4f;
+            bool wasAtBottom = s.highValue <= 0 || (s.highValue - s.value) < LogScrollBottomEpsilonPx;
 
             var row = BuildLogRow(new LogEntry(DateTime.Now, label, body, level, source));
             _logView.Add(row);
@@ -726,35 +745,35 @@ private VisualElement BuildLogRow(LogEntry entry)
             // children and reconstruct the clipboard payload — single source
             // of truth for log data is the visual tree.
             row.userData = entry;
-            row.AddToClassList("log-row");
-            row.AddToClassList("log-" + entry.Level.ToString().ToLowerInvariant());
+            row.AddToClassList(SampleAppUi.Css.LogRow);
+            row.AddToClassList(SampleAppUi.Css.LogLevelPrefix + entry.Level.ToString().ToLowerInvariant());
 
             var head = new VisualElement();
-            head.AddToClassList("log-row-head");
+            head.AddToClassList(SampleAppUi.Css.LogRowHead);
 
-            var ts = new Label(entry.Timestamp.ToString("HH:mm:ss.fff", CultureInfo.InvariantCulture));
-            ts.AddToClassList("log-ts");
+            var ts = new Label(entry.Timestamp.ToString(LogRowTimestampFormat, CultureInfo.InvariantCulture));
+            ts.AddToClassList(SampleAppUi.Css.LogTs);
             head.Add(ts);
 
-            var badge = new Label(entry.Source == LogSource.Sdk ? "SDK" : "APP");
-            badge.AddToClassList("log-badge");
-            badge.AddToClassList(entry.Source == LogSource.Sdk ? "badge-sdk" : "badge-app");
+            var badge = new Label(entry.Source == LogSource.Sdk ? SampleAppUi.LogBadgeText.Sdk : SampleAppUi.LogBadgeText.App);
+            badge.AddToClassList(SampleAppUi.Css.LogBadge);
+            badge.AddToClassList(entry.Source == LogSource.Sdk ? SampleAppUi.Css.BadgeSdk : SampleAppUi.Css.BadgeApp);
             head.Add(badge);
 
             var label = new Label(entry.Label);
-            label.AddToClassList("log-label");
+            label.AddToClassList(SampleAppUi.Css.LogLabel);
             head.Add(label);
 
             // Two overlapping 10×10 squares drawn entirely via USS borders —
             // font-independent, unlike a Unicode glyph which Roboto-Regular
             // doesn't reliably carry past the basic Latin range.
             var copy = new Button();
-            copy.AddToClassList("log-copy");
+            copy.AddToClassList(SampleAppUi.Css.LogCopy);
             var copyBack = new VisualElement();
-            copyBack.AddToClassList("log-copy-back");
+            copyBack.AddToClassList(SampleAppUi.Css.LogCopyBack);
             copyBack.pickingMode = PickingMode.Ignore;
             var copyFront = new VisualElement();
-            copyFront.AddToClassList("log-copy-front");
+            copyFront.AddToClassList(SampleAppUi.Css.LogCopyFront);
             copyFront.pickingMode = PickingMode.Ignore;
             copy.Add(copyBack);
             copy.Add(copyFront);
@@ -765,13 +784,13 @@ private VisualElement BuildLogRow(LogEntry entry)
             if (!string.IsNullOrEmpty(entry.Body))
             {
                 var bodyLabel = new Label(entry.Body);
-                bodyLabel.AddToClassList("log-body");
+                bodyLabel.AddToClassList(SampleAppUi.Css.LogBody);
                 row.Add(bodyLabel);
-                if (entry.Body.Length > CollapseThreshold) row.AddToClassList("collapsed");
+                if (entry.Body.Length > CollapseThreshold) row.AddToClassList(SampleAppUi.Css.Collapsed);
                 head.RegisterCallback<ClickEvent>(evt =>
                 {
                     if (evt.target is Button) return;
-                    row.EnableInClassList("collapsed", !row.ClassListContains("collapsed"));
+                    row.EnableInClassList(SampleAppUi.Css.Collapsed, !row.ClassListContains(SampleAppUi.Css.Collapsed));
                 });
             }
             return row;
@@ -781,7 +800,7 @@ private static string FormatLogEntry(LogEntry entry, bool singleLine)
         {
             var sb = new StringBuilder()
                 .Append(entry.Timestamp.ToString(Constants.IsoTimestampFormat, CultureInfo.InvariantCulture))
-                .Append(" [").Append(entry.Source == LogSource.Sdk ? "SDK" : "APP").Append("] ")
+                .Append(" [").Append(entry.Source == LogSource.Sdk ? SampleAppUi.LogBadgeText.Sdk : SampleAppUi.LogBadgeText.App).Append("] ")
                 .Append(entry.Label);
             if (!string.IsNullOrEmpty(entry.Body))
                 sb.Append(singleLine ? ' ' : '\n').Append(entry.Body);
diff --git a/examples/audience/Assets/SampleApp/Scripts/AudienceSample.cs b/examples/audience/Assets/SampleApp/Scripts/AudienceSample.cs
index 225994742..4f6564bb2 100644
--- a/examples/audience/Assets/SampleApp/Scripts/AudienceSample.cs
+++ b/examples/audience/Assets/SampleApp/Scripts/AudienceSample.cs
@@ -55,7 +55,7 @@ private void OnDestroy()
 
         // ---- SDK action handlers: SDK lifecycle ----
 
-        private void OnInit() => RunAndLog("INIT", () =>
+        private void OnInit() => RunAndLog(SampleAppUi.LogLabels.Init, () =>
         {
             var form = CaptureInitForm();
             var config = BuildAudienceConfig(form, OnSdkError);
@@ -65,7 +65,7 @@ private void OnInit() => RunAndLog("INIT", () =>
             return Json.Serialize(BuildConfigEcho(config), 2);
         });
 
-        private void OnShutdown() => RunAndLog("shutdown()", () =>
+        private void OnShutdown() => RunAndLog(SampleAppUi.LogLabels.Shutdown, () =>
         {
             ImmutableAudience.Shutdown();
             _initialised = false;
@@ -74,7 +74,7 @@ private void OnShutdown() => RunAndLog("shutdown()", () =>
             return "SDK stopped";
         });
 
-        private void OnReset() => RunAndLog("reset()", () =>
+        private void OnReset() => RunAndLog(SampleAppUi.LogLabels.Reset, () =>
         {
             ImmutableAudience.Reset();
             ResetIdentityMirror();
@@ -84,21 +84,21 @@ private void OnReset() => RunAndLog("reset()", () =>
 
         private async Task OnFlushAsync()
         {
-            try { await ImmutableAudience.FlushAsync(); AppendLog("flush()", "queue flushed", LogLevel.Ok, LogSource.App); OnSdkStateChanged(); }
-            catch (Exception ex) { AppendLog("flush()", ex.Message, LogLevel.Err, LogSource.App); }
+            try { await ImmutableAudience.FlushAsync(); AppendLog(SampleAppUi.LogLabels.Flush, "queue flushed", LogLevel.Ok, LogSource.App); OnSdkStateChanged(); }
+            catch (Exception ex) { AppendLog(SampleAppUi.LogLabels.Flush, ex.Message, LogLevel.Err, LogSource.App); }
         }
 
         private async Task OnDeleteDataAsync()
         {
-            AppendLog("deleteData()", "erasure request dispatched", LogLevel.Info, LogSource.App);
+            AppendLog(SampleAppUi.LogLabels.DeleteData, "erasure request dispatched", LogLevel.Info, LogSource.App);
             try
             {
                 await ImmutableAudience.DeleteData();
-                AppendLog("deleteData()", "backend acknowledged", LogLevel.Ok, LogSource.App);
+                AppendLog(SampleAppUi.LogLabels.DeleteData, "backend acknowledged", LogLevel.Ok, LogSource.App);
             }
             catch (Exception ex)
             {
-                AppendLog("deleteData()", ex.Message, LogLevel.Err, LogSource.App);
+                AppendLog(SampleAppUi.LogLabels.DeleteData, ex.Message, LogLevel.Err, LogSource.App);
             }
         }
 
@@ -106,7 +106,7 @@ private async Task OnDeleteDataAsync()
 
         // v1 has no typed Screen API; Plan §10 specifies a custom Track call
         // as the studio-facing pattern for scene coverage. Demo follows that.
-        private void OnPage() => RunAndLog("page()", () =>
+        private void OnPage() => RunAndLog(SampleAppUi.LogLabels.Page, () =>
         {
             GuardConsentForTrack();
             var screen = SceneManager.GetActiveScene().name;
@@ -120,7 +120,7 @@ private void OnPage() => RunAndLog("page()", () =>
         // rest stay on the string overload. Typed validation errors are
         // expected for user input — let them propagate through RunAndLog.
         private void OnSendCatalogueEvent(EventSpec spec, Dictionary<string, VisualElement> inputs) =>
-            RunAndLog("track()", () =>
+            RunAndLog(SampleAppUi.LogLabels.Track, () =>
             {
                 GuardConsentForTrack();
                 var props = BuildPropsDictionary(spec, inputs);
@@ -148,7 +148,7 @@ private void OnSendCatalogueEvent(EventSpec spec, Dictionary<string, VisualEleme
         // SDK drops via Log.Warn when name is empty or consent is None; that
         // warning surfaces in the pane via Log.Writer, so no sample-side
         // check is needed beyond GuardConsentForTrack.
-        private void OnSendCustomEvent() => RunAndLog("track()", () =>
+        private void OnSendCustomEvent() => RunAndLog(SampleAppUi.LogLabels.Track, () =>
         {
             GuardConsentForTrack();
             var f = CaptureCustomEventForm();
@@ -164,7 +164,7 @@ private void OnSendCustomEvent() => RunAndLog("track()", () =>
         // None purges the queue + clears the anonymous ID; dropping below Full
         // clears UserId. Mirror is reset whenever the new level can no longer
         // identify.
-        private void OnSetConsent(ConsentLevel level) => RunAndLog("setConsent()", () =>
+        private void OnSetConsent(ConsentLevel level) => RunAndLog(SampleAppUi.LogLabels.SetConsent, () =>
         {
             var previous = ImmutableAudience.CurrentConsent;
             ImmutableAudience.SetConsent(level);
@@ -175,9 +175,9 @@ private void OnSetConsent(ConsentLevel level) => RunAndLog("setConsent()", () =>
                 ["to"] = level.ToLowercaseString(),
             };
             var effects = new List<string>();
-            if (previous == ConsentLevel.None && level != ConsentLevel.None) effects.Add("queue started, session created");
-            if (level == ConsentLevel.None) effects.Add("queue purged, anonymous ID cleared");
-            if (!level.CanIdentify() && previous.CanIdentify()) effects.Add("userId cleared");
+            if (previous == ConsentLevel.None && level != ConsentLevel.None) effects.Add(SampleAppUi.Messages.QueueStartedSessionCreated);
+            if (level == ConsentLevel.None) effects.Add(SampleAppUi.Messages.QueuePurgedAnonymousIdCleared);
+            if (!level.CanIdentify() && previous.CanIdentify()) effects.Add(SampleAppUi.Messages.UserIdCleared);
             if (effects.Count > 0) payload["effects"] = effects;
             OnSdkStateChanged();
             return Json.Serialize(payload, 2);
@@ -185,7 +185,7 @@ private void OnSetConsent(ConsentLevel level) => RunAndLog("setConsent()", () =>
 
         // ---- SDK action handlers: identity ----
 
-        private void OnIdentify() => RunAndLog("identify()", () =>
+        private void OnIdentify() => RunAndLog(SampleAppUi.LogLabels.Identify, () =>
         {
             var f = CaptureIdentifyForm();
             var traits = ParseTraits(f.RawTraits);
@@ -198,27 +198,27 @@ private void OnIdentify() => RunAndLog("identify()", () =>
             OnSdkStateChanged();
             var payload = new Dictionary<string, object>
             {
-                ["id"]           = f.Id,
+                ["id"]                       = f.Id,
                 [MessageFields.IdentityType] = f.Type,
-                ["accepted"]     = accepted,
+                ["accepted"]                 = accepted,
             };
             if (traits != null) payload[MessageFields.Traits] = traits;
             return Json.Serialize(payload, 2);
         });
 
-        private void OnIdentifyTraits() => RunAndLog("identify(traits)", () =>
+        private void OnIdentifyTraits() => RunAndLog(SampleAppUi.LogLabels.IdentifyTraits, () =>
         {
             var userId = ImmutableAudience.UserId;
-            if (string.IsNullOrEmpty(userId)) throw new InvalidOperationException("no active identity — call Identify first");
+            if (string.IsNullOrEmpty(userId)) throw new InvalidOperationException(SampleAppUi.Messages.NoActiveIdentity);
             var traits = ParseTraits(CaptureTraitsUpdate());
-            if (traits == null || traits.Count == 0) throw new InvalidOperationException("traits required");
+            if (traits == null || traits.Count == 0) throw new InvalidOperationException(SampleAppUi.Messages.TraitsRequired);
             ImmutableAudience.Identify(userId, ParseIdentityType(_mirrorIdentityType), traits);
             _mirrorTraits = traits;
             OnSdkStateChanged();
             return Json.Serialize(traits, 2);
         });
 
-        private void OnAlias() => RunAndLog("alias()", () =>
+        private void OnAlias() => RunAndLog(SampleAppUi.LogLabels.Alias, () =>
         {
             var f = CaptureAliasForm();
             ImmutableAudience.Alias(f.FromId, ParseIdentityType(f.FromType), f.ToId, ParseIdentityType(f.ToType));
@@ -244,7 +244,7 @@ private void OnAlias() => RunAndLog("alias()", () =>
         // Fires from background flush threads; AppendLog marshals to main.
         // Body is JSON for parity with handler "Copy" output.
         private void OnSdkError(AudienceError err) =>
-            AppendLog("onError", Json.Serialize(new Dictionary<string, object>
+            AppendLog(SampleAppUi.LogLabels.OnError, Json.Serialize(new Dictionary<string, object>
             {
                 ["code"] = err.Code.ToString(),
                 ["message"] = err.Message,
@@ -254,20 +254,18 @@ private void OnSdkError(AudienceError err) =>
         // the main-thread marshal.
         private void RouteSdkLogToPane(string msg)
         {
-            const string warnTag = "[ImmutableAudience] WARN:";
-            const string prefix = "[ImmutableAudience]";
             string body = msg;
             var level = LogLevel.Debug;
-            if (msg.StartsWith(warnTag, StringComparison.Ordinal))
+            if (msg.StartsWith(Immutable.Audience.Log.WarnPrefix, StringComparison.Ordinal))
             {
                 level = LogLevel.Warn;
-                body = msg.Substring(warnTag.Length).TrimStart();
+                body = msg.Substring(Immutable.Audience.Log.WarnPrefix.Length).TrimStart();
             }
-            else if (msg.StartsWith(prefix, StringComparison.Ordinal))
+            else if (msg.StartsWith(Immutable.Audience.Log.Prefix, StringComparison.Ordinal))
             {
-                body = msg.Substring(prefix.Length).TrimStart();
+                body = msg.Substring(Immutable.Audience.Log.Prefix.Length).TrimStart();
             }
-            AppendLog("sdk", body, level, LogSource.Sdk);
+            AppendLog(SampleAppUi.LogLabels.Sdk, body, level, LogSource.Sdk);
         }
 
         // ---- Handler scaffolding ----
@@ -322,7 +320,7 @@ private AudienceConfig BuildAudienceConfig(InitForm form, Action<AudienceError>
             if (form.FlushIntervalMs is int flushMs && flushMs > 0)
             {
                 if (flushMs < 1000)
-                    AppendLog("INIT", $"flushInterval {flushMs}ms below 1s — clamped", LogLevel.Warn, LogSource.App);
+                    AppendLog(SampleAppUi.LogLabels.Init, $"flushInterval {flushMs}ms below 1s — clamped", LogLevel.Warn, LogSource.App);
                 config.FlushIntervalSeconds = Math.Max(1, flushMs / 1000);
             }
             if (form.FlushSize is int flushSize && flushSize > 0)
@@ -372,19 +370,7 @@ private void ResetIdentityMirror()
         private static Dictionary<string, object>? ParseTraits(string? raw) =>
             string.IsNullOrWhiteSpace(raw) ? null : JsonReader.DeserializeObject(raw!);
 
-        // Parses a wire-format identity string (e.g. "steam") back into the
-        // IdentityType enum the SDK now requires. Falls back to Custom for
-        // unknown or empty values.
-        private static IdentityType ParseIdentityType(string? value) => (value ?? "").ToLowerInvariant() switch
-        {
-            "passport" => IdentityType.Passport,
-            "steam"    => IdentityType.Steam,
-            "epic"     => IdentityType.Epic,
-            "google"   => IdentityType.Google,
-            "apple"    => IdentityType.Apple,
-            "discord"  => IdentityType.Discord,
-            "email"    => IdentityType.Email,
-            _          => IdentityType.Custom,
-        };
+        private static IdentityType ParseIdentityType(string? value) =>
+            IdentityTypeExtensions.ParseLowercaseString(value);
     }
 }
diff --git a/examples/audience/Assets/SampleApp/Scripts/SampleAppUi.cs b/examples/audience/Assets/SampleApp/Scripts/SampleAppUi.cs
new file mode 100644
index 000000000..e48ff4d9a
--- /dev/null
+++ b/examples/audience/Assets/SampleApp/Scripts/SampleAppUi.cs
@@ -0,0 +1,305 @@
+#nullable enable
+
+namespace Immutable.Audience.Samples.SampleApp
+{
+    // Strings shared between sample-app production code (UXML markup,
+    // AudienceSample.UI.cs, AudienceSample.cs) and the live-fire tests
+    // under Tests/Runtime/. Lives in Scripts so production can reference
+    // it; the Tests assembly already references Scripts.
+    //
+    // If a production string drifts from a constant here, the matching
+    // test fails (Q<> returns null on .Click(), or WaitForLogEntry times
+    // out).
+    internal static class SampleAppUi
+    {
+        // Scene asset name registered in EditorBuildSettings.
+        internal const string SceneName = "SampleApp";
+
+        // The env var that carries the sandbox publishable key into the
+        // built player at test time. Test runs inject it on the Unity CLI;
+        // CI wires it from the AUDIENCE_TEST_PUBLISHABLE_KEY repo secret.
+        internal const string EnvKey = "AUDIENCE_TEST_PUBLISHABLE_KEY";
+
+        // Mirrors Constants.SandboxBaseUrl — used by the BaseUrl-override test.
+        internal const string SandboxBaseUrl = "https://api.sandbox.immutable.com";
+
+        // ---- UXML element names ----
+        // All names verified against examples/audience/Assets/SampleApp/Resources/AudienceSample.uxml.
+
+        internal static class Setup
+        {
+            internal const string PublishableKey = "publishable-key";
+            internal const string InitialConsent = "initial-consent";
+            internal const string BaseUrl = "base-url";
+            internal const string Debug = "debug";
+            internal const string FlushInterval = "flush-interval";
+            internal const string FlushSize = "flush-size";
+        }
+
+        internal static class Buttons
+        {
+            internal const string Init = "btn-init";
+            internal const string Page = "btn-page";
+            internal const string Flush = "btn-flush";
+            internal const string Reset = "btn-reset";
+            internal const string Shutdown = "btn-shutdown";
+            internal const string DeleteData = "btn-delete-data";
+            internal const string ConsentNone = "btn-consent-none";
+            internal const string ConsentAnon = "btn-consent-anon";
+            internal const string ConsentFull = "btn-consent-full";
+            internal const string CustomEvent = "btn-custom-event";
+            internal const string Identify = "btn-identify";
+            internal const string IdentifyTraits = "btn-identify-traits";
+            internal const string Alias = "btn-alias";
+            internal const string ClearLog = "btn-clear-log";
+            internal const string CopyLog = "btn-copy-log";
+
+            // Mirrors AudienceSample.UI.cs PopulateTypedEventAccordions naming:
+            //   send.name = $"btn-typed-{spec.Name.Replace('_', '-')}";
+            internal static string TypedEvent(string specName) =>
+                "btn-typed-" + specName.Replace('_', '-');
+        }
+
+        internal static class CustomEvent
+        {
+            internal const string Name = "custom-event-name";
+            internal const string Props = "custom-event-props";
+        }
+
+        internal static class IdentityFields
+        {
+            internal const string Id = "id-id";
+            internal const string Traits = "id-traits";
+            internal const string Type = "id-type";
+            internal const string TraitsUpdate = "traits-update";
+            internal const string AliasFromId = "alias-from-id";
+            internal const string AliasFromType = "alias-from-type";
+            internal const string AliasToId = "alias-to-id";
+            internal const string AliasToType = "alias-to-type";
+        }
+
+        internal static class StatusBar
+        {
+            internal const string Consent = "status-consent";
+            internal const string Endpoint = "status-endpoint";
+            internal const string Anon = "status-anon";
+            internal const string User = "status-user";
+            internal const string Session = "status-session";
+            internal const string Queue = "status-queue";
+
+            // Mirrors AudienceSample.UI.cs SetStatusCell — the placeholder
+            // used when a status cell has no value.
+            internal const string EmptyText = "—";
+        }
+
+        internal static class IdentityPanel
+        {
+            internal const string UserId = "identity-user-id";
+            internal const string IdentityType = "identity-identity-type";
+            internal const string Traits = "identity-traits";
+            internal const string Aliases = "identity-aliases";
+        }
+
+        internal static class Tabs
+        {
+            internal const string Setup = "tab-setup";
+            internal const string Consent = "tab-consent";
+            internal const string TypedEvents = "tab-typed-events";
+            internal const string Identity = "tab-identity";
+        }
+
+        internal static class Panels
+        {
+            internal const string Setup = "panel-setup";
+            internal const string Consent = "panel-consent";
+            internal const string TypedEvents = "panel-typed-events";
+            internal const string Identity = "panel-identity";
+        }
+
+        // The ScrollView that holds log rows. SampleAppTestHelpers queries
+        // it as `root.Q<ScrollView>(SampleAppUi.LogScrollView)`.
+        internal const string LogScrollView = "log";
+
+        // The banner that warns when the publishable key looks like a prod
+        // key. Toggled via the "hidden" CSS class.
+        internal const string ProdWarning = "prod-warning";
+
+        // ---- Layout-internal element names ----
+        // Tests do not currently reference these, but production AudienceSample.UI.cs
+        // looks them up by name via Require<>() / Q<>(). Listed here so a UXML
+        // rename has a single home to update.
+        internal static class Layout
+        {
+            internal const string SdkVersion = "sdk-version";
+            internal const string TabBar = "tab-bar";
+            internal const string TypedEventsHost = "typed-events-host";
+            internal const string LogResizeHandle = "log-resize-handle";
+            internal const string PageScroll = "page-scroll";
+            internal const string ControlsColumn = "controls-column";
+            internal const string LogColumn = "log-column";
+            internal const string SampleAppGrid = "sample-app-grid";
+            internal const string LogCount = "log-count";
+            internal const string AccordionItem = "accordion-item";
+            internal const string AccordionTitle = "accordion-title";
+            internal const string AccordionContent = "accordion-content";
+        }
+
+        // ---- Log badge text ----
+        // Two-letter pill text on every log row, picked by LogSource.
+        internal static class LogBadgeText
+        {
+            internal const string Sdk = "SDK";
+            internal const string App = "APP";
+        }
+
+        // ---- Button text ----
+        // Visible text on dynamically-built buttons (UXML-defined buttons
+        // carry their text as XML attributes).
+        internal static class ButtonText
+        {
+            internal const string Send = "Send";
+            internal const string Copy = "Copy";
+            internal const string Copied = "Copied";
+        }
+
+        // ---- Resources paths ----
+        // Names passed to Resources.Load<T>() for sample-app assets. Must
+        // mirror filenames under examples/audience/Assets/SampleApp/Resources/.
+        internal static class Resources
+        {
+            internal const string PanelSettings = "AudienceSampleAppPanelSettings";
+            internal const string SampleAppTree = "AudienceSample";
+            internal const string SampleAppStyleSheet = "AudienceSample";
+            internal const string AccordionTemplate = "Templates/Accordion";
+        }
+
+        // ---- Human-readable side messages ----
+        // Strings the sample app surfaces to the user via the log pane on
+        // consent / identity flows. Listed here so a translation pass would
+        // touch one file.
+        internal static class Messages
+        {
+            internal const string QueueStartedSessionCreated = "queue started, session created";
+            internal const string QueuePurgedAnonymousIdCleared = "queue purged, anonymous ID cleared";
+            internal const string UserIdCleared = "userId cleared";
+            internal const string NoActiveIdentity = "no active identity — call Identify first";
+            internal const string TraitsRequired = "traits required";
+            internal const string Ready = "Sample app loaded. Paste a publishable key and click Init.";
+        }
+
+        // Mirrors AudienceSample.UI.cs PopulateTypedEventAccordions naming:
+        //   input.name = $"typed-{spec.Name.Replace('_', '-')}-{field.Key.ToLowerInvariant().Replace('_', '-')}";
+        internal static string TypedEventField(string specName, string fieldKey) =>
+            "typed-" + specName.Replace('_', '-') + "-" + fieldKey.ToLowerInvariant().Replace('_', '-');
+
+        // ---- CSS classes ----
+
+        // Toggled by ActivateTab on tab buttons + panels, by RefreshConsentPills
+        // on consent buttons, etc.
+        internal const string ActiveClass = "active";
+
+        // Toggled by RefreshStatusBar on the prod-warning banner.
+        internal const string HiddenClass = "hidden";
+
+        // Every other CSS class string the sample's Scripts manipulate. Each
+        // is also defined in AudienceSample.uxml and AudienceSample.uss; a
+        // rename in the stylesheet must update the matching entry here.
+        internal static class Css
+        {
+            // Status-cell colour variants applied via SetStatusCell.
+            internal const string StateOk = "state-ok";
+            internal const string StateWarn = "state-warn";
+            internal const string StateErr = "state-err";
+            internal const string Dim = "dim";
+
+            // Click-to-copy flash on status cells and log rows.
+            internal const string Copied = "copied";
+
+            // Mobile-narrow grid breakpoint (USS lacks @media at runtime).
+            internal const string Narrow = "narrow";
+
+            // Placeholder fade-out trigger; both flip together.
+            internal const string PlaceholderHost = "placeholder-host";
+            internal const string FieldPlaceholder = "field-placeholder";
+            internal const string HasValue = "has-value";
+            internal const string IsFocused = "is-focused";
+
+            // Field row layout in typed-event accordions.
+            internal const string Field = "field";
+            internal const string FieldLabel = "field-label";
+            internal const string Actions = "actions";
+
+            // Marks the trailing actions row in a typed-event accordion so
+            // the USS rule can drop the bottom border on the last entry.
+            internal const string Last = "last";
+
+            // Status-cell click-to-copy hook.
+            internal const string StatusValue = "status-value";
+
+            // Accordion header / arrow / open state on typed-event rows.
+            internal const string AccordionHeader = "accordion-header";
+            internal const string AccordionArrow = "accordion-arrow";
+            internal const string Open = "open";
+
+            // Log row chrome.
+            internal const string LogRow = "log-row";
+            internal const string LogRowHead = "log-row-head";
+            internal const string LogTs = "log-ts";
+            internal const string LogBadge = "log-badge";
+            internal const string LogLabel = "log-label";
+            internal const string LogCopy = "log-copy";
+            internal const string LogCopyBack = "log-copy-back";
+            internal const string LogCopyFront = "log-copy-front";
+            internal const string LogBody = "log-body";
+
+            // Log row level-prefix; final class is e.g. "log-warn".
+            internal const string LogLevelPrefix = "log-";
+
+            // Badge variant for SDK vs App rows.
+            internal const string BadgeSdk = "badge-sdk";
+            internal const string BadgeApp = "badge-app";
+
+            // Long-body collapse toggle on log rows.
+            internal const string Collapsed = "collapsed";
+
+            // Tick label injected into Unity's runtime Toggle so .checked
+            // renders a glyph not a coloured square.
+            internal const string DebugTick = "debug-tick";
+            internal const string UnityToggleCheckmark = "unity-toggle__checkmark";
+        }
+
+        // ---- Log labels ----
+        // Mirrors AudienceSample.cs: every RunAndLog(label, ...) and
+        // AppendLog(label, ...) call. Tests await these via WaitForLogEntry.
+
+        internal static class LogLabels
+        {
+            internal const string Init = "INIT";
+            internal const string Page = "page()";
+            internal const string Flush = "flush()";
+            internal const string Reset = "reset()";
+            internal const string Shutdown = "shutdown()";
+            internal const string DeleteData = "deleteData()";
+            internal const string Track = "track()";
+            internal const string SetConsent = "setConsent()";
+            internal const string Identify = "identify()";
+            internal const string IdentifyTraits = "identify(traits)";
+            internal const string Alias = "alias()";
+
+            // Sample-app-only labels (no SDK action behind them).
+            internal const string Ready = "READY";
+            internal const string Sdk = "sdk";
+            internal const string OnError = "onError";
+        }
+
+        // ---- Consent dropdown / status values ----
+        // Mirrors ConsentLevel.ToLowercaseString().
+
+        internal static class Consent
+        {
+            internal const string None = "none";
+            internal const string Anonymous = "anonymous";
+            internal const string Full = "full";
+        }
+    }
+}
diff --git a/examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppUi.cs.meta b/examples/audience/Assets/SampleApp/Scripts/SampleAppUi.cs.meta
similarity index 100%
rename from examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppUi.cs.meta
rename to examples/audience/Assets/SampleApp/Scripts/SampleAppUi.cs.meta
diff --git a/examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppLiveFireTests.cs b/examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppLiveFireTests.cs
index cee8ca7af..5a8cd50d7 100644
--- a/examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppLiveFireTests.cs
+++ b/examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppLiveFireTests.cs
@@ -144,35 +144,35 @@ public IEnumerator InitTrackFlush_AgainstSandbox_FlushReportsOk()
         public IEnumerator Event_Progression_FlushReportsOk()
         {
             // Progression's only required field is `status` (enum, defaults to "start").
-            yield return DriveTypedEventAndFlush(SampleAppUi.Buttons.TypedEvent("progression"));
+            yield return DriveTypedEventAndFlush(SampleAppUi.Buttons.TypedEvent(EventNames.Progression));
         }
 
         [UnityTest]
         public IEnumerator TypedEvent_Resource_FlushReportsOk()
         {
-            yield return DriveTypedEventAndFlush(SampleAppUi.Buttons.TypedEvent("resource"), root =>
+            yield return DriveTypedEventAndFlush(SampleAppUi.Buttons.TypedEvent(EventNames.Resource), root =>
             {
-                root.Q<TextField>(SampleAppUi.TypedEventField("resource", "currency")).value = "GOLD";
-                root.Q<TextField>(SampleAppUi.TypedEventField("resource", "amount")).value = "100";
+                root.Q<TextField>(SampleAppUi.TypedEventField(EventNames.Resource, "currency")).value = "GOLD";
+                root.Q<TextField>(SampleAppUi.TypedEventField(EventNames.Resource, "amount")).value = "100";
             });
         }
 
         [UnityTest]
         public IEnumerator TypedEvent_Purchase_FlushReportsOk()
         {
-            yield return DriveTypedEventAndFlush(SampleAppUi.Buttons.TypedEvent("purchase"), root =>
+            yield return DriveTypedEventAndFlush(SampleAppUi.Buttons.TypedEvent(EventNames.Purchase), root =>
             {
-                root.Q<TextField>(SampleAppUi.TypedEventField("purchase", "currency")).value = "USD";
-                root.Q<TextField>(SampleAppUi.TypedEventField("purchase", "value")).value = "9.99";
+                root.Q<TextField>(SampleAppUi.TypedEventField(EventNames.Purchase, "currency")).value = "USD";
+                root.Q<TextField>(SampleAppUi.TypedEventField(EventNames.Purchase, "value")).value = "9.99";
             });
         }
 
         [UnityTest]
         public IEnumerator TypedEvent_MilestoneReached_FlushReportsOk()
         {
-            yield return DriveTypedEventAndFlush(SampleAppUi.Buttons.TypedEvent("milestone_reached"), root =>
+            yield return DriveTypedEventAndFlush(SampleAppUi.Buttons.TypedEvent(EventNames.MilestoneReached), root =>
             {
-                root.Q<TextField>(SampleAppUi.TypedEventField("milestone_reached", "name")).value = "il2cpp_smoke";
+                root.Q<TextField>(SampleAppUi.TypedEventField(EventNames.MilestoneReached, "name")).value = "il2cpp_smoke";
             });
         }
 
diff --git a/examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppUi.cs b/examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppUi.cs
deleted file mode 100644
index 49243a114..000000000
--- a/examples/audience/Assets/SampleApp/Tests/Runtime/SampleAppUi.cs
+++ /dev/null
@@ -1,177 +0,0 @@
-#nullable enable
-
-namespace Immutable.Audience.Samples.SampleApp.Tests
-{
-    // Single source of truth for the literal strings that the live-fire tests
-    // touch — UXML element names, log labels, consent values, CSS classes,
-    // SDK paths.
-    //
-    // Every constant below is mirrored in production code (UXML markup,
-    // AudienceSample.UI.cs, AudienceSample.cs, ConsentLevel.cs,
-    // AudiencePaths.cs). Each section's docstring names the source so a
-    // future change in production can be traced back to here.
-    //
-    // If the production string drifts, the corresponding test fails loudly
-    // (Q<> returns null → NRE on .Click(), or WaitForLogEntry times out).
-    // Drift is caught at the next CI run, not silently.
-    internal static class SampleAppUi
-    {
-        // Scene asset name registered in EditorBuildSettings.
-        internal const string SceneName = "SampleApp";
-
-        // The env var that carries the sandbox publishable key into the
-        // built player at test time. Test runs inject it on the Unity CLI;
-        // CI wires it from the AUDIENCE_TEST_PUBLISHABLE_KEY repo secret.
-        internal const string EnvKey = "AUDIENCE_TEST_PUBLISHABLE_KEY";
-
-        // Mirrors AudiencePaths.RootDirName — the SDK persists consent /
-        // identity / queue under <persistentDataPath>/imtbl_audience. SetUp
-        // wipes this between tests so on-disk state can't leak.
-        internal const string SdkPersistedDirName = "imtbl_audience";
-
-        // Mirrors Constants.SandboxBaseUrl — used by the BaseUrl-override test.
-        internal const string SandboxBaseUrl = "https://api.sandbox.immutable.com";
-
-        // ---- UXML element names ----
-        // All names verified against examples/audience/Assets/SampleApp/Resources/AudienceSample.uxml.
-
-        internal static class Setup
-        {
-            internal const string PublishableKey = "publishable-key";
-            internal const string InitialConsent = "initial-consent";
-            internal const string BaseUrl = "base-url";
-            internal const string Debug = "debug";
-            internal const string FlushInterval = "flush-interval";
-            internal const string FlushSize = "flush-size";
-        }
-
-        internal static class Buttons
-        {
-            internal const string Init = "btn-init";
-            internal const string Page = "btn-page";
-            internal const string Flush = "btn-flush";
-            internal const string Reset = "btn-reset";
-            internal const string Shutdown = "btn-shutdown";
-            internal const string DeleteData = "btn-delete-data";
-            internal const string ConsentNone = "btn-consent-none";
-            internal const string ConsentAnon = "btn-consent-anon";
-            internal const string ConsentFull = "btn-consent-full";
-            internal const string CustomEvent = "btn-custom-event";
-            internal const string Identify = "btn-identify";
-            internal const string IdentifyTraits = "btn-identify-traits";
-            internal const string Alias = "btn-alias";
-            internal const string ClearLog = "btn-clear-log";
-            internal const string CopyLog = "btn-copy-log";
-
-            // Mirrors AudienceSample.UI.cs PopulateTypedEventAccordions naming:
-            //   send.name = $"btn-typed-{spec.Name.Replace('_', '-')}";
-            internal static string TypedEvent(string specName) =>
-                "btn-typed-" + specName.Replace('_', '-');
-        }
-
-        internal static class CustomEvent
-        {
-            internal const string Name = "custom-event-name";
-            internal const string Props = "custom-event-props";
-        }
-
-        internal static class IdentityFields
-        {
-            internal const string Id = "id-id";
-            internal const string Traits = "id-traits";
-            internal const string Type = "id-type";
-            internal const string TraitsUpdate = "traits-update";
-            internal const string AliasFromId = "alias-from-id";
-            internal const string AliasToId = "alias-to-id";
-        }
-
-        internal static class StatusBar
-        {
-            internal const string Consent = "status-consent";
-            internal const string Endpoint = "status-endpoint";
-            internal const string Anon = "status-anon";
-            internal const string User = "status-user";
-            internal const string Session = "status-session";
-            internal const string Queue = "status-queue";
-
-            // Mirrors AudienceSample.UI.cs SetStatusCell — the placeholder
-            // used when a status cell has no value.
-            internal const string EmptyText = "—";
-        }
-
-        internal static class IdentityPanel
-        {
-            internal const string UserId = "identity-user-id";
-            internal const string IdentityType = "identity-identity-type";
-            internal const string Traits = "identity-traits";
-            internal const string Aliases = "identity-aliases";
-        }
-
-        internal static class Tabs
-        {
-            internal const string Setup = "tab-setup";
-            internal const string Consent = "tab-consent";
-            internal const string TypedEvents = "tab-typed-events";
-            internal const string Identity = "tab-identity";
-        }
-
-        internal static class Panels
-        {
-            internal const string Setup = "panel-setup";
-            internal const string Consent = "panel-consent";
-            internal const string TypedEvents = "panel-typed-events";
-            internal const string Identity = "panel-identity";
-        }
-
-        // The ScrollView that holds log rows. SampleAppTestHelpers queries
-        // it as `root.Q<ScrollView>(SampleAppUi.LogScrollView)`.
-        internal const string LogScrollView = "log";
-
-        // The banner that warns when the publishable key looks like a prod
-        // key. Toggled via the "hidden" CSS class.
-        internal const string ProdWarning = "prod-warning";
-
-        // Mirrors AudienceSample.UI.cs PopulateTypedEventAccordions naming:
-        //   input.name = $"typed-{spec.Name.Replace('_', '-')}-{field.Key.ToLowerInvariant().Replace('_', '-')}";
-        internal static string TypedEventField(string specName, string fieldKey) =>
-            "typed-" + specName.Replace('_', '-') + "-" + fieldKey.ToLowerInvariant().Replace('_', '-');
-
-        // ---- CSS classes ----
-
-        // Toggled by ActivateTab on tab buttons + panels, by RefreshConsentPills
-        // on consent buttons, etc.
-        internal const string ActiveClass = "active";
-
-        // Toggled by RefreshStatusBar on the prod-warning banner.
-        internal const string HiddenClass = "hidden";
-
-        // ---- Log labels ----
-        // Mirrors AudienceSample.cs: every RunAndLog(label, ...) and
-        // AppendLog(label, ...) call. Tests await these via WaitForLogEntry.
-
-        internal static class LogLabels
-        {
-            internal const string Init = "INIT";
-            internal const string Page = "page()";
-            internal const string Flush = "flush()";
-            internal const string Reset = "reset()";
-            internal const string Shutdown = "shutdown()";
-            internal const string DeleteData = "deleteData()";
-            internal const string Track = "track()";
-            internal const string SetConsent = "setConsent()";
-            internal const string Identify = "identify()";
-            internal const string IdentifyTraits = "identify(traits)";
-            internal const string Alias = "alias()";
-        }
-
-        // ---- Consent dropdown / status values ----
-        // Mirrors ConsentLevel.ToLowercaseString().
-
-        internal static class Consent
-        {
-            internal const string None = "none";
-            internal const string Anonymous = "anonymous";
-            internal const string Full = "full";
-        }
-    }
-}
diff --git a/src/Packages/Audience/Runtime/Core/Constants.cs b/src/Packages/Audience/Runtime/Core/Constants.cs
index a8fe1eebc..b6ffa37e9 100644
--- a/src/Packages/Audience/Runtime/Core/Constants.cs
+++ b/src/Packages/Audience/Runtime/Core/Constants.cs
@@ -25,6 +25,35 @@ internal static class Constants
         internal const string RoundTripNumberFormat = "R";
         internal const int ControlPlaneRequestTimeoutSeconds = 30;
 
+        // How long we wait for one POST before giving up.
+        // Without this, one stuck request can block everything else.
+        internal const int MessagesRequestTimeoutSeconds = 30;
+
+        // How long we wait before retrying after a failed POST. Doubles each time.
+        internal const int HttpBackoff1stMs = 5_000;
+        internal const int HttpBackoff2ndMs = 10_000;
+        internal const int HttpBackoff3rdMs = 20_000;
+        internal const int HttpBackoff4thMs = 40_000;
+        internal const int HttpBackoffCapMs = 60_000;
+
+        // How often a session_heartbeat is emitted while a session is live.
+        internal const int SessionHeartbeatIntervalMs = 60_000;
+
+        // How long a paused session can stay paused before Resume rolls it.
+        internal const int SessionPauseTimeoutMs = 30_000;
+
+        // How long we wait for an in-flight heartbeat callback to finish during teardown.
+        internal const int SessionHeartbeatDrainTimeoutMs = 1_000;
+
+        // How long we wait for the previous heartbeat to clear when Start is called twice.
+        internal const int SessionStartDrainTimeoutMs = 500;
+
+        // How many times we retry the consent-sync PUT after a 429.
+        internal const int ConsentSyncMaxAttempts = 4;
+
+        // How long we wait before the first consent-sync retry. Doubles each time.
+        internal const int ConsentSyncBaseRetryMs = 1_000;
+
         internal const string LibraryName = "com.immutable.audience";
         internal const string LibraryVersion = "0.1.0";
         internal const string Surface = "unity";
diff --git a/src/Packages/Audience/Runtime/Core/Session.cs b/src/Packages/Audience/Runtime/Core/Session.cs
index 603cd25b0..6670ec61f 100644
--- a/src/Packages/Audience/Runtime/Core/Session.cs
+++ b/src/Packages/Audience/Runtime/Core/Session.cs
@@ -23,17 +23,6 @@ namespace Immutable.Audience
     // any thread.
     internal sealed class Session : IDisposable
     {
-        internal const int HeartbeatIntervalMs = 60_000;
-
-        // 30s: alt-tab beyond this rolls the session on Resume.
-        internal const int PauseTimeoutMs = 30_000;
-
-        // How long we wait for an in-flight heartbeat callback to finish during teardown.
-        internal const int HeartbeatDrainTimeoutMs = 1_000;
-
-        // How long we wait for the previous heartbeat to clear when Start is called twice.
-        internal const int StartDrainTimeoutMs = 500;
-
         private readonly TrackDelegate _track;
         private readonly Func<DateTime> _getUtcNow;
         private readonly int _heartbeatIntervalMs;
@@ -57,7 +46,7 @@ internal string? SessionId
         internal Session(
             TrackDelegate track,
             Func<DateTime>? getUtcNow = null,
-            int heartbeatIntervalMs = HeartbeatIntervalMs)
+            int heartbeatIntervalMs = Constants.SessionHeartbeatIntervalMs)
         {
             _track = track ?? throw new ArgumentNullException(nameof(track));
             _getUtcNow = getUtcNow ?? (() => DateTime.UtcNow);
@@ -83,8 +72,8 @@ internal void Start()
                 }
             }
 
-            // Double-Start is a misuse path; StartDrainTimeoutMs caps the wait.
-            TimerDisposal.DisposeAndWait(oldTimer, TimeSpan.FromMilliseconds(StartDrainTimeoutMs));
+            // Cap the wait so a misuse Start-twice path doesn't hang.
+            TimerDisposal.DisposeAndWait(oldTimer, TimeSpan.FromMilliseconds(Constants.SessionStartDrainTimeoutMs));
 
             // Phase 2: populate new state. Re-check _disposed (may have flipped during drain).
             string sessionId;
@@ -139,7 +128,7 @@ internal void Resume()
                 // Clamp: wall-clock rewind (NTP) would otherwise over-credit engagement.
                 if (pauseDuration < TimeSpan.Zero) pauseDuration = TimeSpan.Zero;
 
-                extended = pauseDuration.TotalMilliseconds > PauseTimeoutMs;
+                extended = pauseDuration.TotalMilliseconds > Constants.SessionPauseTimeoutMs;
 
                 // Credit in both paths. End (and then Start) reset the accumulator
                 // on the extended-pause rollover so there is no double-count.
@@ -270,8 +259,7 @@ private void SafeTrack(string eventName, Dictionary<string, object> properties)
         }
 
         // Stops the timer and waits for the in-flight callback. Runs outside
-        // _lock (OnHeartbeat re-enters). HeartbeatDrainTimeoutMs caps the
-        // wait so quits don't hang. Warns on timeout.
+        // Cap the wait so quits don't hang on a re-entrant heartbeat.
         private void DrainHeartbeatTimer()
         {
             Timer? timer;
@@ -282,7 +270,7 @@ private void DrainHeartbeatTimer()
             }
             if (timer == null) return;
 
-            if (!TimerDisposal.DisposeAndWait(timer, TimeSpan.FromMilliseconds(HeartbeatDrainTimeoutMs)))
+            if (!TimerDisposal.DisposeAndWait(timer, TimeSpan.FromMilliseconds(Constants.SessionHeartbeatDrainTimeoutMs)))
             {
                 Log.Warn(AudienceLogs.SessionHeartbeatTimeout);
             }
diff --git a/src/Packages/Audience/Runtime/Events/TypedEvents.cs b/src/Packages/Audience/Runtime/Events/TypedEvents.cs
index a946d7400..6c388eaa2 100644
--- a/src/Packages/Audience/Runtime/Events/TypedEvents.cs
+++ b/src/Packages/Audience/Runtime/Events/TypedEvents.cs
@@ -84,7 +84,7 @@ public class Progression : IEvent
         public Dictionary<string, object> ToProperties()
         {
             if (Status is null)
-                throw new ArgumentException("Progression.Status is required. Set it before calling Track(IEvent).");
+                throw new ArgumentException(AudienceArgumentMessages.ProgressionStatusRequired);
 
             var props = new Dictionary<string, object>
             {
@@ -169,11 +169,11 @@ public class Resource : IEvent
         public Dictionary<string, object> ToProperties()
         {
             if (Flow is null)
-                throw new ArgumentException("Resource.Flow is required. Set it before calling Track(IEvent).");
+                throw new ArgumentException(AudienceArgumentMessages.ResourceFlowRequired);
             if (string.IsNullOrEmpty(Currency))
-                throw new ArgumentException("Resource.Currency is required. Set a non-empty string before calling Track(IEvent).");
+                throw new ArgumentException(AudienceArgumentMessages.ResourceCurrencyRequired);
             if (Amount is null)
-                throw new ArgumentException("Resource.Amount is required. Set it before calling Track(IEvent).");
+                throw new ArgumentException(AudienceArgumentMessages.ResourceAmountRequired);
 
             var props = new Dictionary<string, object>
             {
@@ -245,10 +245,9 @@ private static bool IsIso4217(string s)
         public Dictionary<string, object> ToProperties()
         {
             if (Currency == null || !IsIso4217(Currency))
-                throw new ArgumentException(
-                    $"Purchase.Currency '{Currency}' must be a three-letter uppercase ISO 4217 code");
+                throw new ArgumentException(AudienceArgumentMessages.PurchaseCurrencyInvalid(Currency));
             if (Value is null)
-                throw new ArgumentException("Purchase.Value is required. Set it before calling Track(IEvent).");
+                throw new ArgumentException(AudienceArgumentMessages.PurchaseValueRequired);
 
             var props = new Dictionary<string, object>
             {
@@ -284,7 +283,7 @@ public class MilestoneReached : IEvent
         public Dictionary<string, object> ToProperties()
         {
             if (string.IsNullOrEmpty(Name))
-                throw new ArgumentException("MilestoneReached.Name must not be null or empty");
+                throw new ArgumentException(AudienceArgumentMessages.MilestoneReachedNameRequired);
 
             return new Dictionary<string, object>
             {
diff --git a/src/Packages/Audience/Runtime/IdentityType.cs b/src/Packages/Audience/Runtime/IdentityType.cs
index 327924a5c..6d5fe1d3b 100644
--- a/src/Packages/Audience/Runtime/IdentityType.cs
+++ b/src/Packages/Audience/Runtime/IdentityType.cs
@@ -56,5 +56,18 @@ internal static class IdentityTypeExtensions
             _ => throw new System.ArgumentOutOfRangeException(nameof(type), type,
                 "Unknown IdentityType value; cast an out-of-range value."),
         };
+
+        internal static IdentityType ParseLowercaseString(string? value) =>
+            (value ?? string.Empty).ToLowerInvariant() switch
+            {
+                "passport" => IdentityType.Passport,
+                "steam" => IdentityType.Steam,
+                "epic" => IdentityType.Epic,
+                "google" => IdentityType.Google,
+                "apple" => IdentityType.Apple,
+                "discord" => IdentityType.Discord,
+                "email" => IdentityType.Email,
+                _ => IdentityType.Custom,
+            };
     }
 }
diff --git a/src/Packages/Audience/Runtime/ImmutableAudience.cs b/src/Packages/Audience/Runtime/ImmutableAudience.cs
index c9fc1a542..e08864c4e 100644
--- a/src/Packages/Audience/Runtime/ImmutableAudience.cs
+++ b/src/Packages/Audience/Runtime/ImmutableAudience.cs
@@ -27,12 +27,6 @@ public static class ImmutableAudience
         // teardown (Session.Dispose, timer drain, queue shutdown, transport
         // flush, disposes). This keeps the hold time to nanoseconds so a caller
         // arriving on a different thread is not stranded behind those budgets.
-        // How many times we retry the consent-sync PUT after a 429.
-        internal const int ConsentSyncMaxAttempts = 4;
-
-        // How long we wait before the first consent-sync retry. Doubles each time.
-        internal const int ConsentSyncBaseRetryMs = 1_000;
-
         private static AudienceConfig? _config;
         private static DiskStore? _store;
         private static EventQueue? _queue;
@@ -146,12 +140,12 @@ public static void Init(AudienceConfig config)
         {
             if (config == null) throw new ArgumentNullException(nameof(config));
             if (string.IsNullOrEmpty(config.PublishableKey))
-                throw new ArgumentException("PublishableKey is required", nameof(config));
+                throw new ArgumentException(AudienceArgumentMessages.PublishableKeyRequired, nameof(config));
 
             if (string.IsNullOrEmpty(config.PersistentDataPath))
                 config.PersistentDataPath = DefaultPersistentDataPathProvider?.Invoke();
             if (string.IsNullOrEmpty(config.PersistentDataPath))
-                throw new ArgumentException("PersistentDataPath is required", nameof(config));
+                throw new ArgumentException(AudienceArgumentMessages.PersistentDataPathRequired, nameof(config));
 
             // Normalize casing so dashboards aggregate consistently. The
             // DistributionPlatforms constants ship lowercase; a studio that
@@ -631,9 +625,8 @@ private static void SyncConsentToBackend(AudienceConfig config, ConsentLevel lev
 
             Task.Run(async () =>
             {
-                // 429 retried up to ConsentSyncMaxAttempts attempts (1s/2s/4s
-                // or Retry-After). Other non-2xx fail fast.
-                const int maxAttempts = ConsentSyncMaxAttempts;
+                // 429 retries up to Constants.ConsentSyncMaxAttempts; other non-2xx fail fast.
+                const int maxAttempts = Constants.ConsentSyncMaxAttempts;
                 var attempt = 0;
                 try
                 {
@@ -650,13 +643,13 @@ private static void SyncConsentToBackend(AudienceConfig config, ConsentLevel lev
                         if (response.StatusCode == HttpStatusCode.TooManyRequests && attempt < maxAttempts)
                         {
                             var delay = HttpRetry.ParseRetryAfter(response)
-                                ?? TimeSpan.FromMilliseconds(ConsentSyncBaseRetryMs * (1 << (attempt - 1)));
+                                ?? TimeSpan.FromMilliseconds(Constants.ConsentSyncBaseRetryMs * (1 << (attempt - 1)));
                             await Task.Delay(delay, cancellationToken).ConfigureAwait(false);
                             continue;
                         }
 
                         NotifyErrorCallback(onError, AudienceErrorCode.ConsentSyncFailed,
-                            $"Consent sync failed with status {(int)response.StatusCode}");
+                            AudienceErrorMessages.ConsentSyncFailedWithStatus((int)response.StatusCode));
                         return;
                     }
                 }
@@ -667,7 +660,7 @@ private static void SyncConsentToBackend(AudienceConfig config, ConsentLevel lev
                 catch (Exception ex)
                 {
                     NotifyErrorCallback(onError, AudienceErrorCode.ConsentSyncFailed,
-                        $"Consent sync threw: {ex.Message}");
+                        AudienceErrorMessages.ConsentSyncThrew(ex));
                 }
             });
         }
diff --git a/src/Packages/Audience/Runtime/Transport/HttpTransport.cs b/src/Packages/Audience/Runtime/Transport/HttpTransport.cs
index 2e14da13d..028da4019 100644
--- a/src/Packages/Audience/Runtime/Transport/HttpTransport.cs
+++ b/src/Packages/Audience/Runtime/Transport/HttpTransport.cs
@@ -15,17 +15,6 @@ namespace Immutable.Audience
     // Sends queued events from DiskStore to the Audience backend.
     internal sealed class HttpTransport : IDisposable
     {
-        // How long we wait for one POST before giving up.
-        // Without this, one stuck request can block everything else.
-        internal const int RequestTimeoutSeconds = 30;
-
-        // How long we wait before retrying after a failed POST. Doubles each time.
-        internal const int Backoff1stMs = 5_000;
-        internal const int Backoff2ndMs = 10_000;
-        internal const int Backoff3rdMs = 20_000;
-        internal const int Backoff4thMs = 40_000;
-        internal const int BackoffCapMs = 60_000;
-
         private readonly DiskStore _store;
         private readonly string _url;
         private readonly string _publishableKey;
@@ -59,7 +48,7 @@ internal HttpTransport(
             _client = handler != null
                 ? new HttpClient(handler, disposeHandler: false)
                 : new HttpClient();
-            _client.Timeout = TimeSpan.FromSeconds(RequestTimeoutSeconds);
+            _client.Timeout = TimeSpan.FromSeconds(Constants.MessagesRequestTimeoutSeconds);
             _getUtcNow = getUtcNow ?? (() => DateTime.UtcNow);
         }
 
@@ -81,7 +70,7 @@ internal async Task<bool> SendBatchAsync(CancellationToken ct = default)
                 // Non-IOException = unrecoverable storage failure (e.g. permissions);
                 // retry won't help. Drop the batch, report via onError.
                 _store.Delete(batch);
-                NotifyError(AudienceErrorCode.FlushFailed, $"Local storage read failed: {ex.Message}");
+                NotifyError(AudienceErrorCode.FlushFailed, AudienceErrorMessages.LocalStorageReadFailed(ex));
                 return true;
             }
 
@@ -122,7 +111,7 @@ internal async Task<bool> SendBatchAsync(CancellationToken ct = default)
                     if (rejected > 0)
                     {
                         NotifyError(AudienceErrorCode.ValidationRejected,
-                            $"Batch partially rejected: {rejected} of {batch.Count} events dropped");
+                            AudienceErrorMessages.BatchPartiallyRejected(rejected, batch.Count));
                     }
                 }
                 else if (statusCode == (int)HttpStatusCode.TooManyRequests)
@@ -149,7 +138,7 @@ internal async Task<bool> SendBatchAsync(CancellationToken ct = default)
                     _store.Delete(batch);
                     ResetBackoff();
                     NotifyError(AudienceErrorCode.ValidationRejected,
-                        FormatHttpError("Batch rejected", statusCode, rejectionBody));
+                        FormatHttpError(AudienceErrorMessages.BatchRejectedPrefix, statusCode, rejectionBody));
                 }
                 else
                 {
@@ -158,7 +147,7 @@ internal async Task<bool> SendBatchAsync(CancellationToken ct = default)
                     var serverBody = await ReadBodyForErrorAsync(response).ConfigureAwait(false);
                     RecordFailure();
                     NotifyError(AudienceErrorCode.FlushFailed,
-                        FormatHttpError("Server error, will retry", statusCode, serverBody));
+                        FormatHttpError(AudienceErrorMessages.ServerErrorWillRetryPrefix, statusCode, serverBody));
                 }
             }
             catch (OperationCanceledException) when (ct.IsCancellationRequested)
@@ -193,11 +182,11 @@ internal int BackoffMs
         private int BackoffMsLocked() => _consecutiveFailures switch
         {
             <= 0 => 0,
-            1 => Backoff1stMs,
-            2 => Backoff2ndMs,
-            3 => Backoff3rdMs,
-            4 => Backoff4thMs,
-            _ => BackoffCapMs,
+            1 => Constants.HttpBackoff1stMs,
+            2 => Constants.HttpBackoff2ndMs,
+            3 => Constants.HttpBackoff3rdMs,
+            4 => Constants.HttpBackoff4thMs,
+            _ => Constants.HttpBackoffCapMs,
         };
 
         // Earliest UTC time at which the next attempt may run.
diff --git a/src/Packages/Audience/Runtime/Utility/Log.cs b/src/Packages/Audience/Runtime/Utility/Log.cs
index 7a2c9fbf3..788f09323 100644
--- a/src/Packages/Audience/Runtime/Utility/Log.cs
+++ b/src/Packages/Audience/Runtime/Utility/Log.cs
@@ -6,7 +6,9 @@ namespace Immutable.Audience
 {
     internal static class Log
     {
-        private const string Prefix = "[ImmutableAudience]";
+        // Prepended to every SDK log line. Internal so the sample-app log adapter can strip it.
+        internal const string Prefix = "[ImmutableAudience]";
+        internal const string WarnPrefix = Prefix + " WARN:";
 
         internal static bool Enabled { get; set; }
 
@@ -20,7 +22,7 @@ internal static void Debug(string message)
         }
 
         internal static void Warn(string message) =>
-            Emit($"{Prefix} WARN: {message}");
+            Emit($"{WarnPrefix} {message}");
 
         private static void Emit(string line)
         {
@@ -43,6 +45,44 @@ private static void Emit(string line)
         }
     }
 
+    // ArgumentException messages thrown from public SDK methods.
+    internal static class AudienceArgumentMessages
+    {
+        // Init / config validation
+        internal const string PublishableKeyRequired = "PublishableKey is required";
+        internal const string PersistentDataPathRequired = "PersistentDataPath is required";
+
+        // Typed-event ToProperties validation
+        internal const string ProgressionStatusRequired = "Progression.Status is required. Set it before calling Track(IEvent).";
+        internal const string ResourceFlowRequired = "Resource.Flow is required. Set it before calling Track(IEvent).";
+        internal const string ResourceCurrencyRequired = "Resource.Currency is required. Set a non-empty string before calling Track(IEvent).";
+        internal const string ResourceAmountRequired = "Resource.Amount is required. Set it before calling Track(IEvent).";
+        internal const string PurchaseValueRequired = "Purchase.Value is required. Set it before calling Track(IEvent).";
+        internal const string MilestoneReachedNameRequired = "MilestoneReached.Name must not be null or empty";
+
+        internal static string PurchaseCurrencyInvalid(string? currency) =>
+            $"Purchase.Currency '{currency}' must be a three-letter uppercase ISO 4217 code";
+    }
+
+    // Error messages we pass to AudienceConfig.OnError.
+    internal static class AudienceErrorMessages
+    {
+        internal static string LocalStorageReadFailed(Exception ex) =>
+            $"Local storage read failed: {ex.Message}";
+
+        internal static string BatchPartiallyRejected(int rejected, int total) =>
+            $"Batch partially rejected: {rejected} of {total} events dropped";
+
+        internal const string BatchRejectedPrefix = "Batch rejected";
+        internal const string ServerErrorWillRetryPrefix = "Server error, will retry";
+
+        internal static string ConsentSyncFailedWithStatus(int statusCode) =>
+            $"Consent sync failed with status {statusCode}";
+
+        internal static string ConsentSyncThrew(Exception ex) =>
+            $"Consent sync threw: {ex.Message}";
+    }
+
     internal static class AudienceLogs
     {
         // ---- Init / config validation ----
diff --git a/src/Packages/Audience/Tests/Runtime/ConsentSyncTests.cs b/src/Packages/Audience/Tests/Runtime/ConsentSyncTests.cs
index d684622df..fdf37f599 100644
--- a/src/Packages/Audience/Tests/Runtime/ConsentSyncTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/ConsentSyncTests.cs
@@ -42,7 +42,7 @@ public void SetConsent_FiresPut_WithExpectedBodyShape()
             var put = WaitForPut(handler);
             var body = JsonReader.DeserializeObject(put.Body);
 
-            Assert.AreEqual(Constants.ConsentUrl("pk_imapik-test-key1"), put.Url);
+            Assert.AreEqual(Constants.ConsentUrl(TestDefaults.PublishableKey), put.Url);
             Assert.AreEqual(ConsentLevel.Full.ToLowercaseString(), body[ConsentBodyFields.Status]);
             Assert.AreEqual(Constants.ConsentSource, body[ConsentBodyFields.Source]);
             Assert.IsTrue(body.ContainsKey(MessageFields.AnonymousId));
@@ -165,7 +165,7 @@ public void SetConsent_429Repeated_FiresConsentSyncFailedAfterRetries()
         private AudienceConfig MakeConfig(CapturingHandler handler, ConsentLevel consent) =>
             new AudienceConfig
             {
-                PublishableKey = "pk_imapik-test-key1",
+                PublishableKey = TestDefaults.PublishableKey,
                 Consent = consent,
                 PersistentDataPath = _testDir,
                 FlushIntervalSeconds = 600,
diff --git a/src/Packages/Audience/Tests/Runtime/Core/SessionTests.cs b/src/Packages/Audience/Tests/Runtime/Core/SessionTests.cs
index ae807ef44..8c9fdec1e 100644
--- a/src/Packages/Audience/Tests/Runtime/Core/SessionTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/Core/SessionTests.cs
@@ -34,9 +34,9 @@ public void Start_FiresSessionStart_WithSessionId()
             session.Start();
 
             Assert.AreEqual(1, _events.Count);
-            Assert.AreEqual("session_start", _events[0].name);
-            Assert.IsTrue(_events[0].props.ContainsKey("sessionId"));
-            Assert.IsNotEmpty((string)_events[0].props["sessionId"]);
+            Assert.AreEqual(EventNames.SessionStart, _events[0].name);
+            Assert.IsTrue(_events[0].props.ContainsKey(EventPropertyKeys.SessionId));
+            Assert.IsNotEmpty((string)_events[0].props[EventPropertyKeys.SessionId]);
         }
 
         [Test]
@@ -62,11 +62,11 @@ public void End_FiresSessionEnd_WithDuration()
             now = now.AddSeconds(2);
             session.End();
 
-            var endEvent = _events.FirstOrDefault(e => e.name == "session_end");
+            var endEvent = _events.FirstOrDefault(e => e.name == EventNames.SessionEnd);
             Assert.IsNotNull(endEvent.props);
-            Assert.IsTrue(endEvent.props.ContainsKey("sessionId"));
-            Assert.IsTrue(endEvent.props.ContainsKey("durationSec"));
-            Assert.AreEqual(2L, (long)endEvent.props["durationSec"]);
+            Assert.IsTrue(endEvent.props.ContainsKey(EventPropertyKeys.SessionId));
+            Assert.IsTrue(endEvent.props.ContainsKey(EventPropertyKeys.DurationSec));
+            Assert.AreEqual(2L, (long)endEvent.props[EventPropertyKeys.DurationSec]);
         }
 
         [Test]
@@ -76,7 +76,7 @@ public void Dispose_FiresSessionEnd()
             session.Start();
             session.Dispose();
 
-            Assert.IsTrue(_events.Any(e => e.name == "session_end"));
+            Assert.IsTrue(_events.Any(e => e.name == EventNames.SessionEnd));
         }
 
         [Test]
@@ -85,9 +85,9 @@ public void Dispose_CalledTwice_DoesNotFireTwice()
             var session = new Session(MockTrack);
             session.Start();
             session.Dispose();
-            var count = _events.Count(e => e.name == "session_end");
+            var count = _events.Count(e => e.name == EventNames.SessionEnd);
             session.Dispose();
-            Assert.AreEqual(count, _events.Count(e => e.name == "session_end"));
+            Assert.AreEqual(count, _events.Count(e => e.name == EventNames.SessionEnd));
         }
 
         // -----------------------------------------------------------------
@@ -108,7 +108,7 @@ public void Heartbeat_FiresAfterInterval()
             void Track(string name, Dictionary<string, object> props)
             {
                 lock (gate) events.Add((name, props));
-                if (name == "session_heartbeat") heartbeatFired.Set();
+                if (name == EventNames.SessionHeartbeat) heartbeatFired.Set();
             }
 
             using var session = new Session(Track, heartbeatIntervalMs: 50);
@@ -119,10 +119,10 @@ void Track(string name, Dictionary<string, object> props)
 
             lock (gate)
             {
-                var beat = events.FirstOrDefault(e => e.name == "session_heartbeat");
+                var beat = events.FirstOrDefault(e => e.name == EventNames.SessionHeartbeat);
                 Assert.IsNotNull(beat.props, "heartbeat event should carry a properties dictionary");
-                Assert.IsTrue(beat.props.ContainsKey("sessionId"));
-                Assert.IsTrue(beat.props.ContainsKey("durationSec"));
+                Assert.IsTrue(beat.props.ContainsKey(EventPropertyKeys.SessionId));
+                Assert.IsTrue(beat.props.ContainsKey(EventPropertyKeys.DurationSec));
             }
         }
 
@@ -143,7 +143,7 @@ public void Pause_ThenResume_ShortPause_ContinuesSession()
             session.Resume();
 
             Assert.AreEqual(originalId, session.SessionId, "short pause should not change session");
-            Assert.IsFalse(_events.Any(e => e.name == "session_end"),
+            Assert.IsFalse(_events.Any(e => e.name == EventNames.SessionEnd),
                 "short pause should not fire session_end");
         }
 
@@ -158,14 +158,14 @@ public void Pause_ThenResume_LongPause_StartsNewSession()
             var id1 = session.SessionId;
 
             session.Pause();
-            now = now.AddSeconds(31); // > 30 second PauseTimeoutMs
+            now = now.AddMilliseconds(Constants.SessionPauseTimeoutMs + 1000);
             session.Resume();
 
             Assert.AreNotEqual(id1, session.SessionId,
-                "pause longer than PauseTimeoutMs should end the old session and start a new one");
-            Assert.IsTrue(_events.Any(e => e.name == "session_end"),
+                "pause longer than SessionPauseTimeoutMs should end the old session and start a new one");
+            Assert.IsTrue(_events.Any(e => e.name == EventNames.SessionEnd),
                 "old session should have fired session_end");
-            Assert.AreEqual(2, _events.Count(e => e.name == "session_start"),
+            Assert.AreEqual(2, _events.Count(e => e.name == EventNames.SessionStart),
                 "a new session_start should fire after the long pause");
         }
 
@@ -197,8 +197,8 @@ public void Pause_CalledTwice_SecondCallIsNoOp()
             now = now.AddSeconds(3); // 3s more engagement
             session.End();
 
-            var sessionEnd = _events.Last(e => e.name == "session_end");
-            var duration = (long)sessionEnd.props["durationSec"];
+            var sessionEnd = _events.Last(e => e.name == EventNames.SessionEnd);
+            var duration = (long)sessionEnd.props[EventPropertyKeys.DurationSec];
             // Wall-clock Start→End = 13s, paused from T=5 to T=10 = 5s, engaged = 8s.
             Assert.AreEqual(8L, duration,
                 "double Pause must preserve the first Pause timestamp so engagement arithmetic covers the full pause window");
@@ -245,8 +245,8 @@ public void Resume_NegativePauseDuration_ClampsAccumulatorToZero()
             now = now.AddSeconds(2); // 2 s further engagement after resume
             session.End();
 
-            var sessionEnd = _events.Last(e => e.name == "session_end");
-            var duration = (long)sessionEnd.props["durationSec"];
+            var sessionEnd = _events.Last(e => e.name == EventNames.SessionEnd);
+            var duration = (long)sessionEnd.props[EventPropertyKeys.DurationSec];
             // Wall-clock from Start to End is 10 + (-5) + 2 = 7 s. The
             // pause duration was clamped to 0, so engaged seconds = 7 - 0 = 7.
             // Without the clamp, _accumulatedPause would be -5, the
@@ -276,8 +276,8 @@ public void End_ClockRewindsSinceStart_ClampsDurationToZero()
             now = now.AddSeconds(-3); // clock rewinds after Start, no pause
             session.End();
 
-            var sessionEnd = _events.Last(e => e.name == "session_end");
-            var duration = (long)sessionEnd.props["durationSec"];
+            var sessionEnd = _events.Last(e => e.name == EventNames.SessionEnd);
+            var duration = (long)sessionEnd.props[EventPropertyKeys.DurationSec];
             Assert.AreEqual(0L, duration,
                 "negative engaged time from a wall-clock rewind must clamp to zero");
         }
@@ -305,8 +305,8 @@ public void End_ClockRewindsWhilePaused_DoesNotInflateDuration()
             now = now.AddSeconds(-5); // clock rewinds 5s while paused
             session.End();
 
-            var sessionEnd = _events.Last(e => e.name == "session_end");
-            var duration = (long)sessionEnd.props["durationSec"];
+            var sessionEnd = _events.Last(e => e.name == EventNames.SessionEnd);
+            var duration = (long)sessionEnd.props[EventPropertyKeys.DurationSec];
             Assert.LessOrEqual(duration, 5L,
                 "clock rewind while paused must not over-credit engagement past the wall-clock window");
         }
@@ -330,8 +330,8 @@ public void End_AfterShortPause_ReportsDurationMinusPause()
             now = now.AddSeconds(3);
             session.End();
 
-            var sessionEnd = _events.Last(e => e.name == "session_end");
-            var duration = (long)sessionEnd.props["durationSec"];
+            var sessionEnd = _events.Last(e => e.name == EventNames.SessionEnd);
+            var duration = (long)sessionEnd.props[EventPropertyKeys.DurationSec];
             Assert.AreEqual(7L, duration,
                 "session_end duration should exclude the 3s paused interval");
         }
@@ -352,8 +352,8 @@ public void End_WhilePaused_ExcludesInFlightPauseFromDuration()
             now = now.AddSeconds(2);
             session.End(); // ends while paused
 
-            var sessionEnd = _events.Last(e => e.name == "session_end");
-            var duration = (long)sessionEnd.props["durationSec"];
+            var sessionEnd = _events.Last(e => e.name == EventNames.SessionEnd);
+            var duration = (long)sessionEnd.props[EventPropertyKeys.DurationSec];
             Assert.AreEqual(5L, duration,
                 "session_end fired while paused should count only pre-pause engaged time");
         }
@@ -380,8 +380,8 @@ public void End_AfterExtendedPauseRollover_ReportsPrePauseDuration()
             now = now.AddSeconds(40); // 40 s paused: extended (>30 s threshold)
             session.Resume();
 
-            var sessionEnd = _events.First(e => e.name == "session_end");
-            var duration = (long)sessionEnd.props["durationSec"];
+            var sessionEnd = _events.First(e => e.name == EventNames.SessionEnd);
+            var duration = (long)sessionEnd.props[EventPropertyKeys.DurationSec];
             Assert.AreEqual(10L, duration,
                 "session_end on extended-pause rollover should report pre-pause engaged time, not wall-clock");
         }
@@ -405,8 +405,8 @@ public void Heartbeat_AfterShortPause_ReportsPauseAdjustedDuration()
             now = now.AddSeconds(2);
             session.OnHeartbeat();
 
-            var heartbeat = _events.Last(e => e.name == "session_heartbeat");
-            var duration = (long)heartbeat.props["durationSec"];
+            var heartbeat = _events.Last(e => e.name == EventNames.SessionHeartbeat);
+            var duration = (long)heartbeat.props[EventPropertyKeys.DurationSec];
             Assert.AreEqual(6L, duration,
                 "heartbeat duration should exclude the 2s paused interval");
         }
@@ -431,7 +431,7 @@ public void Start_WithoutPriorEnd_DoesNotStrandTheOldTimer()
             Assert.AreNotEqual(firstId, secondId,
                 "second Start should generate a fresh sessionId");
 
-            Assert.AreEqual(2, _events.Count(e => e.name == "session_start"),
+            Assert.AreEqual(2, _events.Count(e => e.name == EventNames.SessionStart),
                 "both session_start events should fire");
         }
 
@@ -453,7 +453,7 @@ public void Heartbeat_WhilePaused_DoesNotFire()
 
             session.OnHeartbeat();
 
-            Assert.IsFalse(_events.Any(e => e.name == "session_heartbeat"),
+            Assert.IsFalse(_events.Any(e => e.name == EventNames.SessionHeartbeat),
                 "OnHeartbeat should not emit while the session is paused");
         }
 
@@ -480,7 +480,7 @@ public void End_HeartbeatExceedsDrainBudget_LogsWarningAndContinues()
                 using var beatStarted = new ManualResetEvent(false);
                 void Track(string name, Dictionary<string, object> props)
                 {
-                    if (name == "session_heartbeat")
+                    if (name == EventNames.SessionHeartbeat)
                     {
                         beatStarted.Set();
                         // Block past the 1 s drain budget so DrainHeartbeatTimer
@@ -521,7 +521,7 @@ public void Heartbeat_AfterResume_Fires()
 
             session.OnHeartbeat();
 
-            Assert.IsTrue(_events.Any(e => e.name == "session_heartbeat"),
+            Assert.IsTrue(_events.Any(e => e.name == EventNames.SessionHeartbeat),
                 "OnHeartbeat should emit again once the session is resumed");
         }
 
@@ -545,7 +545,7 @@ public void OnHeartbeat_TrackCallbackThrows_DoesNotEscape()
             {
                 void ThrowingTrack(string name, Dictionary<string, object> props)
                 {
-                    if (name == "session_heartbeat")
+                    if (name == EventNames.SessionHeartbeat)
                         throw new InvalidOperationException("track explode");
                 }
 
@@ -557,7 +557,7 @@ void ThrowingTrack(string name, Dictionary<string, object> props)
 
                 lock (warnings)
                 {
-                    var expected = AudienceLogs.SessionTrackCallbackThrew("session_heartbeat", new InvalidOperationException());
+                    var expected = AudienceLogs.SessionTrackCallbackThrew(EventNames.SessionHeartbeat, new InvalidOperationException());
                     Assert.IsTrue(warnings.Any(w => w.Contains(expected)),
                         "SafeTrack must log a warning when the callback throws");
                 }
@@ -580,7 +580,7 @@ public void Start_TrackCallbackThrows_DoesNotEscape()
             {
                 void ThrowingTrack(string name, Dictionary<string, object> props)
                 {
-                    if (name == "session_start")
+                    if (name == EventNames.SessionStart)
                         throw new InvalidOperationException("track explode");
                 }
 
@@ -591,7 +591,7 @@ void ThrowingTrack(string name, Dictionary<string, object> props)
 
                 lock (warnings)
                 {
-                    var expected = AudienceLogs.SessionTrackCallbackThrew("session_start", new InvalidOperationException());
+                    var expected = AudienceLogs.SessionTrackCallbackThrew(EventNames.SessionStart, new InvalidOperationException());
                     Assert.IsTrue(warnings.Any(w => w.Contains(expected)),
                         "SafeTrack must log a warning when the Start callback throws");
                 }
@@ -615,7 +615,7 @@ public void End_TrackCallbackThrows_DoesNotEscape()
             {
                 void ThrowingTrack(string name, Dictionary<string, object> props)
                 {
-                    if (name == "session_end")
+                    if (name == EventNames.SessionEnd)
                         throw new InvalidOperationException("track explode");
                 }
 
@@ -627,7 +627,7 @@ void ThrowingTrack(string name, Dictionary<string, object> props)
 
                 lock (warnings)
                 {
-                    var expected = AudienceLogs.SessionTrackCallbackThrew("session_end", new InvalidOperationException());
+                    var expected = AudienceLogs.SessionTrackCallbackThrew(EventNames.SessionEnd, new InvalidOperationException());
                     Assert.IsTrue(warnings.Any(w => w.Contains(expected)),
                         "SafeTrack must log a warning when the End callback throws");
                 }
@@ -651,7 +651,7 @@ public void SafeTrack_LogWriterThrows_DoesNotEscape()
             {
                 void ThrowingTrack(string name, Dictionary<string, object> props)
                 {
-                    if (name == "session_heartbeat")
+                    if (name == EventNames.SessionHeartbeat)
                         throw new InvalidOperationException("track explode");
                 }
 
@@ -694,7 +694,7 @@ private AudienceConfig MakeConfig(ConsentLevel consent = ConsentLevel.Anonymous)
         {
             return new AudienceConfig
             {
-                PublishableKey = "pk_imapik-test-key1",
+                PublishableKey = TestDefaults.PublishableKey,
                 Consent = consent,
                 PersistentDataPath = _testDir,
                 FlushIntervalSeconds = 600,
@@ -710,7 +710,7 @@ private AudienceConfig MakeConfig(ConsentLevel consent = ConsentLevel.Anonymous)
         // masking the real signal.
         private string[] ReadQueueFiles()
         {
-            var queueDir = Path.Combine(_testDir, "imtbl_audience", "queue");
+            var queueDir = AudiencePaths.QueueDir(_testDir);
             if (!Directory.Exists(queueDir)) return Array.Empty<string>();
             return Directory.GetFiles(queueDir, AudiencePaths.QueueGlob).Select(File.ReadAllText).ToArray();
         }
@@ -810,7 +810,7 @@ public void Reset_StartsNewSession_DoesNotEmitSessionEnd()
             // Drain game_launch + session_start for the initial session so we
             // only see post-Reset events.
             ImmutableAudience.FlushQueueToDiskForTesting();
-            var queueDir = Path.Combine(_testDir, "imtbl_audience", "queue");
+            var queueDir = AudiencePaths.QueueDir(_testDir);
             foreach (var f in Directory.GetFiles(queueDir, AudiencePaths.QueueGlob)) File.Delete(f);
 
             var firstAnonymousId = Identity.Get(_testDir);
@@ -851,7 +851,7 @@ public void Reset_ConsentNone_DoesNotStartSession()
         public void SetConsent_AnonymousToNone_DoesNotEmitSessionEnd()
         {
             // Consent revocation purges the queue and disposes the session.
-            // Session.Dispose fires End → Track("session_end"), but by the
+            // Session.Dispose fires End → Track(EventNames.SessionEnd), but by the
             // time End runs the consent level has already been flipped to
             // None, so CanTrack gates the track call. No session_end event
             // should appear on disk. Regression guard: a future reorder of
diff --git a/src/Packages/Audience/Tests/Runtime/DeleteDataTests.cs b/src/Packages/Audience/Tests/Runtime/DeleteDataTests.cs
index 54233e1ce..0daa64807 100644
--- a/src/Packages/Audience/Tests/Runtime/DeleteDataTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/DeleteDataTests.cs
@@ -35,7 +35,7 @@ private AudienceConfig MakeConfig(CapturingHandler handler, ConsentLevel consent
         {
             return new AudienceConfig
             {
-                PublishableKey = "pk_imapik-test-key1",
+                PublishableKey = TestDefaults.PublishableKey,
                 Consent = consent,
                 PersistentDataPath = _testDir,
                 FlushIntervalSeconds = 600,
@@ -84,8 +84,8 @@ public void DeleteData_WithUserId_FiresDelete_WithUserIdQuery()
 
             Assert.IsNotNull(deleteRequest, "expected a DELETE request");
             StringAssert.Contains(Constants.DataPath, deleteRequest.RequestUri!.ToString());
-            StringAssert.Contains("userId=player-42", deleteRequest.RequestUri.Query);
-            Assert.IsTrue(deleteRequest.Headers.Contains("x-immutable-publishable-key"),
+            StringAssert.Contains($"{MessageFields.UserId}=player-42", deleteRequest.RequestUri.Query);
+            Assert.IsTrue(deleteRequest.Headers.Contains(Constants.PublishableKeyHeader),
                 "publishable key header must be attached");
         }
 
@@ -107,7 +107,7 @@ public void DeleteData_NoUserId_WithExistingAnonymousId_FiresDelete_WithAnonymou
                 if (r.Method == HttpMethod.Delete) { deleteRequest = r; break; }
 
             Assert.IsNotNull(deleteRequest);
-            StringAssert.Contains($"anonymousId={seeded}", deleteRequest.RequestUri!.Query);
+            StringAssert.Contains($"{MessageFields.AnonymousId}={seeded}", deleteRequest.RequestUri!.Query);
         }
 
         [Test]
diff --git a/src/Packages/Audience/Tests/Runtime/Events/MessageBuilderTests.cs b/src/Packages/Audience/Tests/Runtime/Events/MessageBuilderTests.cs
index 75b597428..e8805c9e4 100644
--- a/src/Packages/Audience/Tests/Runtime/Events/MessageBuilderTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/Events/MessageBuilderTests.cs
@@ -15,7 +15,7 @@ public void Track_RequiredFieldsPresent()
         {
             var result = MessageBuilder.Track("level_complete", "anon-1", null, PackageVersion);
 
-            Assert.AreEqual("track", result[MessageFields.Type]);
+            Assert.AreEqual(MessageTypes.Track, result[MessageFields.Type]);
             Assert.IsTrue(result.ContainsKey(MessageFields.MessageId));
             Assert.IsTrue(result.ContainsKey(MessageFields.EventTimestamp));
             Assert.IsTrue(result.ContainsKey(MessageFields.Context));
@@ -53,31 +53,34 @@ public void Track_NonNullUserId_PresentInDict()
         [Test]
         public void Identify_TypeAndIdentityFieldsPresent()
         {
-            var result = MessageBuilder.Identify("anon-42", "user-42", "steam", PackageVersion);
+            var result = MessageBuilder.Identify("anon-42", "user-42", IdentityType.Steam.ToLowercaseString(), PackageVersion);
 
-            Assert.AreEqual("identify", result[MessageFields.Type]);
+            Assert.AreEqual(MessageTypes.Identify, result[MessageFields.Type]);
             Assert.AreEqual("anon-42", result[MessageFields.AnonymousId]);
             Assert.AreEqual("user-42", result[MessageFields.UserId]);
-            Assert.AreEqual("steam", result[MessageFields.IdentityType]);
+            Assert.AreEqual(IdentityType.Steam.ToLowercaseString(), result[MessageFields.IdentityType]);
         }
 
         [Test]
         public void Alias_AllFourFieldsPresent()
         {
-            var result = MessageBuilder.Alias("from-id", "email", "to-id", "steam", PackageVersion);
+            var result = MessageBuilder.Alias(
+                "from-id", IdentityType.Email.ToLowercaseString(),
+                "to-id", IdentityType.Steam.ToLowercaseString(),
+                PackageVersion);
 
-            Assert.AreEqual("alias", result[MessageFields.Type]);
+            Assert.AreEqual(MessageTypes.Alias, result[MessageFields.Type]);
             Assert.AreEqual("from-id", result[MessageFields.FromId]);
-            Assert.AreEqual("email", result[MessageFields.FromType]);
+            Assert.AreEqual(IdentityType.Email.ToLowercaseString(), result[MessageFields.FromType]);
             Assert.AreEqual("to-id", result[MessageFields.ToId]);
-            Assert.AreEqual("steam", result[MessageFields.ToType]);
+            Assert.AreEqual(IdentityType.Steam.ToLowercaseString(), result[MessageFields.ToType]);
         }
 
         [Test]
         public void AllMessages_ContextContainsLibraryAndLibraryVersion()
         {
             var track = MessageBuilder.Track("evt", null, null, PackageVersion);
-            var identify = MessageBuilder.Identify(null, "u1", "steam", PackageVersion);
+            var identify = MessageBuilder.Identify(null, "u1", IdentityType.Steam.ToLowercaseString(), PackageVersion);
             var alias = MessageBuilder.Alias("f", "t1", "t", "t2", PackageVersion);
 
             foreach (var msg in new[] { track, identify, alias })
@@ -92,12 +95,12 @@ public void AllMessages_ContextContainsLibraryAndLibraryVersion()
         public void AllMessages_SurfaceIsUnity()
         {
             var track = MessageBuilder.Track("evt", null, null, PackageVersion);
-            var identify = MessageBuilder.Identify(null, "u1", "steam", PackageVersion);
+            var identify = MessageBuilder.Identify(null, "u1", IdentityType.Steam.ToLowercaseString(), PackageVersion);
             var alias = MessageBuilder.Alias("f", "t1", "t", "t2", PackageVersion);
 
-            Assert.AreEqual("unity", track[MessageFields.Surface]);
-            Assert.AreEqual("unity", identify[MessageFields.Surface]);
-            Assert.AreEqual("unity", alias[MessageFields.Surface]);
+            Assert.AreEqual(Constants.Surface, track[MessageFields.Surface]);
+            Assert.AreEqual(Constants.Surface, identify[MessageFields.Surface]);
+            Assert.AreEqual(Constants.Surface, alias[MessageFields.Surface]);
         }
 
         [Test]
@@ -132,9 +135,9 @@ public void AllMessages_EventTimestamp_IsRoundTripIso8601Utc()
             {
                 var ts = (string)msg[MessageFields.EventTimestamp];
                 Assert.IsTrue(
-                    DateTime.TryParseExact(ts, "o", CultureInfo.InvariantCulture,
+                    DateTime.TryParseExact(ts, Constants.IsoTimestampFormat, CultureInfo.InvariantCulture,
                         DateTimeStyles.RoundtripKind, out var parsed),
-                    $"eventTimestamp must parse as ISO 8601 round-trip ('o') format; got: '{ts}'");
+                    $"eventTimestamp must parse as ISO 8601 round-trip ('{Constants.IsoTimestampFormat}') format; got: '{ts}'");
                 Assert.AreEqual(DateTimeKind.Utc, parsed.Kind, "eventTimestamp must be UTC");
                 Assert.That(parsed, Is.GreaterThanOrEqualTo(before),
                     "eventTimestamp must be ~now, not stale");
@@ -159,7 +162,7 @@ public void AllMessages_Context_LibraryAndLibraryVersionAreNonEmptyStrings()
         private static IEnumerable<Dictionary<string, object>> EveryMessageType()
         {
             yield return MessageBuilder.Track("evt", null, null, PackageVersion);
-            yield return MessageBuilder.Identify(null, "u1", "steam", PackageVersion);
+            yield return MessageBuilder.Identify(null, "u1", IdentityType.Steam.ToLowercaseString(), PackageVersion);
             yield return MessageBuilder.Alias("f", "t1", "t", "t2", PackageVersion);
         }
     }
diff --git a/src/Packages/Audience/Tests/Runtime/Events/TypedEventTests.cs b/src/Packages/Audience/Tests/Runtime/Events/TypedEventTests.cs
index 7f4a1a250..82318087b 100644
--- a/src/Packages/Audience/Tests/Runtime/Events/TypedEventTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/Events/TypedEventTests.cs
@@ -9,7 +9,7 @@ internal class TypedEventTests
         [Test]
         public void Progression_EventName_IsProgression()
         {
-            Assert.AreEqual("progression", new Progression().EventName);
+            Assert.AreEqual(EventNames.Progression, new Progression().EventName);
         }
 
         [Test]
@@ -35,11 +35,11 @@ public void Progression_Complete_ProducesCorrectProperties()
 
             var props = evt.ToProperties();
 
-            Assert.AreEqual("complete", props["status"]);
-            Assert.AreEqual("tutorial", props["world"]);
-            Assert.AreEqual("1", props["level"]);
-            Assert.AreEqual(1500, props["score"]);
-            Assert.AreEqual(120.5f, props["durationSec"]);
+            Assert.AreEqual(ProgressionStatus.Complete.ToLowercaseString(), props[EventPropertyKeys.Status]);
+            Assert.AreEqual("tutorial", props[EventPropertyKeys.World]);
+            Assert.AreEqual("1", props[EventPropertyKeys.Level]);
+            Assert.AreEqual(1500, props[EventPropertyKeys.Score]);
+            Assert.AreEqual(120.5f, props[EventPropertyKeys.DurationSec]);
         }
 
         [Test]
@@ -47,12 +47,12 @@ public void Progression_OptionalFieldsOmitted_WhenNull()
         {
             var props = new Progression { Status = ProgressionStatus.Start }.ToProperties();
 
-            Assert.IsTrue(props.ContainsKey("status"));
-            Assert.IsFalse(props.ContainsKey("world"));
-            Assert.IsFalse(props.ContainsKey("level"));
-            Assert.IsFalse(props.ContainsKey("stage"));
-            Assert.IsFalse(props.ContainsKey("score"));
-            Assert.IsFalse(props.ContainsKey("durationSec"));
+            Assert.IsTrue(props.ContainsKey(EventPropertyKeys.Status));
+            Assert.IsFalse(props.ContainsKey(EventPropertyKeys.World));
+            Assert.IsFalse(props.ContainsKey(EventPropertyKeys.Level));
+            Assert.IsFalse(props.ContainsKey(EventPropertyKeys.Stage));
+            Assert.IsFalse(props.ContainsKey(EventPropertyKeys.Score));
+            Assert.IsFalse(props.ContainsKey(EventPropertyKeys.DurationSec));
         }
 
         [Test]
@@ -69,17 +69,17 @@ public void Resource_Source_ProducesCorrectProperties()
 
             var props = evt.ToProperties();
 
-            Assert.AreEqual("source", props["flow"]);
-            Assert.AreEqual("gold", props["currency"]);
-            Assert.AreEqual(100m, props["amount"]);
-            Assert.AreEqual("quest_reward", props["itemType"]);
-            Assert.AreEqual("main_quest_01", props["itemId"]);
+            Assert.AreEqual(ResourceFlow.Source.ToLowercaseString(), props[EventPropertyKeys.Flow]);
+            Assert.AreEqual("gold", props[EventPropertyKeys.Currency]);
+            Assert.AreEqual(100m, props[EventPropertyKeys.Amount]);
+            Assert.AreEqual("quest_reward", props[EventPropertyKeys.ItemType]);
+            Assert.AreEqual("main_quest_01", props[EventPropertyKeys.ItemId]);
         }
 
         [Test]
         public void Resource_EventName_IsResource()
         {
-            Assert.AreEqual("resource", new Resource().EventName);
+            Assert.AreEqual(EventNames.Resource, new Resource().EventName);
         }
 
         [Test]
@@ -124,12 +124,12 @@ public void Purchase_ProducesCorrectProperties()
 
             var props = evt.ToProperties();
 
-            Assert.AreEqual("USD", props["currency"]);
-            Assert.AreEqual(9.99m, props["value"]);
-            Assert.AreEqual("gem_pack_01", props["itemId"]);
-            Assert.AreEqual("Starter Gem Pack", props["itemName"]);
-            Assert.AreEqual(1, props["quantity"]);
-            Assert.AreEqual("txn_abc123", props["transactionId"]);
+            Assert.AreEqual("USD", props[EventPropertyKeys.Currency]);
+            Assert.AreEqual(9.99m, props[EventPropertyKeys.Value]);
+            Assert.AreEqual("gem_pack_01", props[EventPropertyKeys.ItemId]);
+            Assert.AreEqual("Starter Gem Pack", props[EventPropertyKeys.ItemName]);
+            Assert.AreEqual(1, props[EventPropertyKeys.Quantity]);
+            Assert.AreEqual("txn_abc123", props[EventPropertyKeys.TransactionId]);
         }
 
         [Test]
@@ -137,18 +137,18 @@ public void Purchase_OptionalFieldsOmitted_WhenNull()
         {
             var props = new Purchase { Currency = "EUR", Value = 5.00m }.ToProperties();
 
-            Assert.IsTrue(props.ContainsKey("currency"));
-            Assert.IsTrue(props.ContainsKey("value"));
-            Assert.IsFalse(props.ContainsKey("itemId"));
-            Assert.IsFalse(props.ContainsKey("itemName"));
-            Assert.IsFalse(props.ContainsKey("quantity"));
-            Assert.IsFalse(props.ContainsKey("transactionId"));
+            Assert.IsTrue(props.ContainsKey(EventPropertyKeys.Currency));
+            Assert.IsTrue(props.ContainsKey(EventPropertyKeys.Value));
+            Assert.IsFalse(props.ContainsKey(EventPropertyKeys.ItemId));
+            Assert.IsFalse(props.ContainsKey(EventPropertyKeys.ItemName));
+            Assert.IsFalse(props.ContainsKey(EventPropertyKeys.Quantity));
+            Assert.IsFalse(props.ContainsKey(EventPropertyKeys.TransactionId));
         }
 
         [Test]
         public void Purchase_EventName_IsPurchase()
         {
-            Assert.AreEqual("purchase", new Purchase().EventName);
+            Assert.AreEqual(EventNames.Purchase, new Purchase().EventName);
         }
 
         [Test]
@@ -174,14 +174,14 @@ public void MilestoneReached_ProducesCorrectProperties()
         {
             var props = new MilestoneReached { Name = "first_boss_defeated" }.ToProperties();
 
-            Assert.AreEqual("first_boss_defeated", props["name"]);
+            Assert.AreEqual("first_boss_defeated", props[EventPropertyKeys.Name]);
             Assert.AreEqual(1, props.Count);
         }
 
         [Test]
         public void MilestoneReached_EventName_IsMilestoneReached()
         {
-            Assert.AreEqual("milestone_reached", new MilestoneReached().EventName);
+            Assert.AreEqual(EventNames.MilestoneReached, new MilestoneReached().EventName);
         }
     }
 }
\ No newline at end of file
diff --git a/src/Packages/Audience/Tests/Runtime/ImmutableAudienceTests.cs b/src/Packages/Audience/Tests/Runtime/ImmutableAudienceTests.cs
index 0d397ca53..efdff3643 100644
--- a/src/Packages/Audience/Tests/Runtime/ImmutableAudienceTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/ImmutableAudienceTests.cs
@@ -38,7 +38,7 @@ private AudienceConfig MakeConfig(ConsentLevel consent = ConsentLevel.Anonymous)
         {
             return new AudienceConfig
             {
-                PublishableKey = "pk_imapik-test-key1",
+                PublishableKey = TestDefaults.PublishableKey,
                 Consent = consent,
                 PersistentDataPath = _testDir,
                 FlushIntervalSeconds = 600, // large; we flush manually in tests
@@ -179,25 +179,25 @@ public void ContextProvider_Set_MergesFieldsIntoEveryMessageContext()
         {
             ImmutableAudience.ContextProvider = () => new Dictionary<string, object>
             {
-                ["userAgent"] = "TestOS 1.0",
-                ["locale"] = "en-GB",
-                ["timezone"] = "Europe/London",
-                ["screen"] = "1920x1080",
+                [ContextKeys.UserAgent] = "TestOS 1.0",
+                [ContextKeys.Locale] = "en-GB",
+                [ContextKeys.Timezone] = "Europe/London",
+                [ContextKeys.Screen] = "1920x1080",
             };
 
             ImmutableAudience.Init(MakeConfig());
             ImmutableAudience.Track("unit_test_event");
             ImmutableAudience.Shutdown();
 
-            var queueDir = Path.Combine(_testDir, "imtbl_audience", "queue");
+            var queueDir = AudiencePaths.QueueDir(_testDir);
             var blobs = Directory.GetFiles(queueDir, AudiencePaths.QueueGlob).Select(File.ReadAllText).ToList();
 
             Assert.IsTrue(blobs.Any(b =>
-                b.Contains("\"userAgent\":\"TestOS 1.0\"") &&
-                b.Contains("\"locale\":\"en-GB\"") &&
-                b.Contains("\"timezone\":\"Europe/London\"") &&
-                b.Contains("\"screen\":\"1920x1080\"") &&
-                b.Contains("\"library\":")),
+                b.Contains($"\"{ContextKeys.UserAgent}\":\"TestOS 1.0\"") &&
+                b.Contains($"\"{ContextKeys.Locale}\":\"en-GB\"") &&
+                b.Contains($"\"{ContextKeys.Timezone}\":\"Europe/London\"") &&
+                b.Contains($"\"{ContextKeys.Screen}\":\"1920x1080\"") &&
+                b.Contains($"\"{MessageFields.Library}\":")),
                 "Enqueue should merge ContextProvider fields into msg.context alongside library/libraryVersion");
         }
 
@@ -210,21 +210,21 @@ public void ContextProvider_Set_MergesOnIdentifyPath()
             // event carries.
             ImmutableAudience.ContextProvider = () => new Dictionary<string, object>
             {
-                ["userAgent"] = "TestOS 1.0",
-                ["locale"] = "en-GB",
+                [ContextKeys.UserAgent] = "TestOS 1.0",
+                [ContextKeys.Locale] = "en-GB",
             };
 
             ImmutableAudience.Init(MakeConfig(ConsentLevel.Full));
             ImmutableAudience.Identify("player-42", IdentityType.Custom);
             ImmutableAudience.Shutdown();
 
-            var queueDir = Path.Combine(_testDir, "imtbl_audience", "queue");
+            var queueDir = AudiencePaths.QueueDir(_testDir);
             var blobs = Directory.GetFiles(queueDir, AudiencePaths.QueueGlob).Select(File.ReadAllText).ToList();
 
             Assert.IsTrue(blobs.Any(b =>
-                b.Contains("\"type\":\"identify\"") &&
-                b.Contains("\"userAgent\":\"TestOS 1.0\"") &&
-                b.Contains("\"locale\":\"en-GB\"")),
+                b.Contains($"\"{MessageFields.Type}\":\"{MessageTypes.Identify}\"") &&
+                b.Contains($"\"{ContextKeys.UserAgent}\":\"TestOS 1.0\"") &&
+                b.Contains($"\"{ContextKeys.Locale}\":\"en-GB\"")),
                 "Identify message must carry ContextProvider fields in msg.context");
         }
 
@@ -237,10 +237,10 @@ public void ContextProvider_ThrowingDelegate_SwallowsAndShipsBaseContext()
             ImmutableAudience.Track("unit_test_event");
             ImmutableAudience.Shutdown();
 
-            var queueDir = Path.Combine(_testDir, "imtbl_audience", "queue");
+            var queueDir = AudiencePaths.QueueDir(_testDir);
             var blobs = Directory.GetFiles(queueDir, AudiencePaths.QueueGlob).Select(File.ReadAllText).ToList();
 
-            Assert.IsTrue(blobs.Any(b => b.Contains("\"unit_test_event\"") && b.Contains("\"library\":")),
+            Assert.IsTrue(blobs.Any(b => b.Contains("\"unit_test_event\"") && b.Contains($"\"{MessageFields.Library}\":")),
                 "event should still ship with base context when ContextProvider throws");
         }
 
@@ -253,10 +253,10 @@ public void ContextProvider_ReturnsNull_ShipsBaseContext()
             ImmutableAudience.Track("unit_test_event");
             ImmutableAudience.Shutdown();
 
-            var queueDir = Path.Combine(_testDir, "imtbl_audience", "queue");
+            var queueDir = AudiencePaths.QueueDir(_testDir);
             var blobs = Directory.GetFiles(queueDir, AudiencePaths.QueueGlob).Select(File.ReadAllText).ToList();
 
-            Assert.IsTrue(blobs.Any(b => b.Contains("\"unit_test_event\"") && b.Contains("\"library\":")),
+            Assert.IsTrue(blobs.Any(b => b.Contains("\"unit_test_event\"") && b.Contains($"\"{MessageFields.Library}\":")),
                 "event should still ship with base context when ContextProvider returns null");
         }
 
@@ -366,9 +366,9 @@ public void Track_NullOrEmptyEventName_DoesNotEnqueue()
             foreach (var file in Directory.GetFiles(queueDir, AudiencePaths.QueueGlob))
             {
                 var msg = JsonReader.DeserializeObject(File.ReadAllText(file));
-                if ((string)msg[MessageFields.Type] != "track") continue;
+                if ((string)msg[MessageFields.Type] != MessageTypes.Track) continue;
 
-                if (!msg.TryGetValue("eventName", out var eventNameObj))
+                if (!msg.TryGetValue(MessageFields.EventName, out var eventNameObj))
                     Assert.Fail($"track message {Path.GetFileName(file)} missing eventName field");
 
                 Assert.IsNotNull(eventNameObj,
@@ -1100,7 +1100,7 @@ public void Init_FiresGameLaunch_Automatically()
             var queueDir = AudiencePaths.QueueDir(_testDir);
             var contents = Directory.GetFiles(queueDir, AudiencePaths.QueueGlob)
                 .Select(File.ReadAllText).ToList();
-            Assert.IsTrue(contents.Any(c => c.Contains("\"game_launch\"")),
+            Assert.IsTrue(contents.Any(c => c.Contains($"\"{EventNames.GameLaunch}\"")),
                 "Init should auto-fire game_launch");
         }
 
@@ -1116,7 +1116,8 @@ public void Init_GameLaunch_IncludesDistributionPlatform()
             var contents = Directory.GetFiles(queueDir, AudiencePaths.QueueGlob)
                 .Select(File.ReadAllText).ToList();
             Assert.IsTrue(contents.Any(c =>
-                c.Contains("\"game_launch\"") && c.Contains("\"steam\"")));
+                c.Contains($"\"{EventNames.GameLaunch}\"")
+                && c.Contains($"\"{GameLaunchPropertyKeys.DistributionPlatform}\":\"{DistributionPlatforms.Steam}\"")));
         }
 
         [Test]
@@ -1126,7 +1127,7 @@ public void Init_LowercasesDistributionPlatform_WhenCallerPassesMixedCase()
             config.DistributionPlatform = "Steam";
             ImmutableAudience.Init(config);
 
-            Assert.AreEqual("steam", config.DistributionPlatform,
+            Assert.AreEqual(DistributionPlatforms.Steam, config.DistributionPlatform,
                 "Init should lowercase mixed-case DistributionPlatform so dashboards aggregate consistently.");
         }
 
@@ -1137,17 +1138,17 @@ public void Init_LowercasesDistributionPlatform_WhenCallerPassesAllUpperCase()
             config.DistributionPlatform = "STEAM";
             ImmutableAudience.Init(config);
 
-            Assert.AreEqual("steam", config.DistributionPlatform);
+            Assert.AreEqual(DistributionPlatforms.Steam, config.DistributionPlatform);
         }
 
         [Test]
         public void Init_LeavesDistributionPlatformUnchanged_WhenAlreadyLowercase()
         {
             var config = MakeConfig();
-            config.DistributionPlatform = "steam";
+            config.DistributionPlatform = DistributionPlatforms.Steam;
             ImmutableAudience.Init(config);
 
-            Assert.AreEqual("steam", config.DistributionPlatform);
+            Assert.AreEqual(DistributionPlatforms.Steam, config.DistributionPlatform);
         }
 
         [Test]
@@ -1175,7 +1176,7 @@ public void Init_ConsentNone_DoesNotFireGameLaunch()
 
             var contents = Directory.GetFiles(queueDir, AudiencePaths.QueueGlob)
                 .Select(File.ReadAllText).ToList();
-            Assert.IsFalse(contents.Any(c => c.Contains("\"game_launch\"")));
+            Assert.IsFalse(contents.Any(c => c.Contains($"\"{EventNames.GameLaunch}\"")));
         }
 
         [Test]
@@ -1183,10 +1184,10 @@ public void Init_GameLaunch_IncludesLaunchContextProviderFields()
         {
             ImmutableAudience.LaunchContextProvider = () => new Dictionary<string, object>
             {
-                ["platform"] = "WindowsPlayer",
-                ["version"] = "1.2.3",
-                ["buildGuid"] = "a1b2c3d4e5f6",
-                ["unityVersion"] = "2022.3.20f1",
+                [GameLaunchPropertyKeys.Platform] = "WindowsPlayer",
+                [GameLaunchPropertyKeys.Version] = "1.2.3",
+                [GameLaunchPropertyKeys.BuildGuid] = "a1b2c3d4e5f6",
+                [GameLaunchPropertyKeys.UnityVersion] = "2022.3.20f1",
             };
 
             ImmutableAudience.Init(MakeConfig());
@@ -1195,12 +1196,12 @@ public void Init_GameLaunch_IncludesLaunchContextProviderFields()
             var queueDir = AudiencePaths.QueueDir(_testDir);
             var launchFile = Directory.GetFiles(queueDir, AudiencePaths.QueueGlob)
                 .Select(File.ReadAllText)
-                .FirstOrDefault(c => c.Contains("\"game_launch\""));
+                .FirstOrDefault(c => c.Contains($"\"{EventNames.GameLaunch}\""));
             Assert.IsNotNull(launchFile, "game_launch should have been enqueued");
-            StringAssert.Contains("\"platform\":\"WindowsPlayer\"", launchFile);
-            StringAssert.Contains("\"version\":\"1.2.3\"", launchFile);
-            StringAssert.Contains("\"buildGuid\":\"a1b2c3d4e5f6\"", launchFile);
-            StringAssert.Contains("\"unityVersion\":\"2022.3.20f1\"", launchFile);
+            StringAssert.Contains($"\"{GameLaunchPropertyKeys.Platform}\":\"WindowsPlayer\"", launchFile);
+            StringAssert.Contains($"\"{GameLaunchPropertyKeys.Version}\":\"1.2.3\"", launchFile);
+            StringAssert.Contains($"\"{GameLaunchPropertyKeys.BuildGuid}\":\"a1b2c3d4e5f6\"", launchFile);
+            StringAssert.Contains($"\"{GameLaunchPropertyKeys.UnityVersion}\":\"2022.3.20f1\"", launchFile);
         }
 
         [Test]
@@ -1208,7 +1209,7 @@ public void Init_GameLaunch_ConfigDistributionPlatformOverridesProvider()
         {
             ImmutableAudience.LaunchContextProvider = () => new Dictionary<string, object>
             {
-                ["distributionPlatform"] = "provider_value",
+                [GameLaunchPropertyKeys.DistributionPlatform] = "provider_value",
             };
 
             var config = MakeConfig();
@@ -1219,8 +1220,8 @@ public void Init_GameLaunch_ConfigDistributionPlatformOverridesProvider()
             var queueDir = AudiencePaths.QueueDir(_testDir);
             var launchFile = Directory.GetFiles(queueDir, AudiencePaths.QueueGlob)
                 .Select(File.ReadAllText)
-                .First(c => c.Contains("\"game_launch\""));
-            StringAssert.Contains("\"distributionPlatform\":\"steam\"", launchFile);
+                .First(c => c.Contains($"\"{EventNames.GameLaunch}\""));
+            StringAssert.Contains($"\"{GameLaunchPropertyKeys.DistributionPlatform}\":\"{DistributionPlatforms.Steam}\"", launchFile);
             Assert.IsFalse(launchFile.Contains("provider_value"),
                 "config.DistributionPlatform should win over the provider's value");
         }
@@ -1237,7 +1238,7 @@ public void Init_GameLaunch_ProviderThrows_StillFiresEvent()
             var queueDir = AudiencePaths.QueueDir(_testDir);
             var contents = Directory.GetFiles(queueDir, AudiencePaths.QueueGlob)
                 .Select(File.ReadAllText).ToList();
-            Assert.IsTrue(contents.Any(c => c.Contains("\"game_launch\"")),
+            Assert.IsTrue(contents.Any(c => c.Contains($"\"{EventNames.GameLaunch}\"")),
                 "game_launch must still ship when the context provider throws");
         }
 
@@ -1324,9 +1325,9 @@ public void FullToAnonymous_StripsUserIdFromQueuedTrackAndDropsIdentifyAlias()
             {
                 var msg = JsonReader.DeserializeObject(File.ReadAllText(f));
                 var type = (string)msg[MessageFields.Type];
-                Assert.AreNotEqual("identify", type, "identify must be purged on Full -> Anonymous");
-                Assert.AreNotEqual("alias", type, "alias must be purged on Full -> Anonymous");
-                if (type == "track")
+                Assert.AreNotEqual(MessageTypes.Identify, type, "identify must be purged on Full -> Anonymous");
+                Assert.AreNotEqual(MessageTypes.Alias, type, "alias must be purged on Full -> Anonymous");
+                if (type == MessageTypes.Track)
                     Assert.IsFalse(msg.ContainsKey(MessageFields.UserId), "userId must be stripped from queued track on Full -> Anonymous");
             }
         }
@@ -1344,7 +1345,7 @@ public void FullToAnonymous_FutureTracksOmitUserId()
             var queueDir = AudiencePaths.QueueDir(_testDir);
             var trackFiles = Directory.GetFiles(queueDir, AudiencePaths.QueueGlob)
                 .Select(f => JsonReader.DeserializeObject(File.ReadAllText(f)))
-                .Where(m => (string)m[MessageFields.Type] == "track"
+                .Where(m => (string)m[MessageFields.Type] == MessageTypes.Track
                             && m.ContainsKey(MessageFields.EventName)
                             && (string)m[MessageFields.EventName] == "tracked_after_downgrade")
                 .ToList();
diff --git a/src/Packages/Audience/Tests/Runtime/OfflineResilienceTests.cs b/src/Packages/Audience/Tests/Runtime/OfflineResilienceTests.cs
index b8d6f6715..b7db80763 100644
--- a/src/Packages/Audience/Tests/Runtime/OfflineResilienceTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/OfflineResilienceTests.cs
@@ -61,7 +61,7 @@ private void BlockDiskWrites()
             ImmutableAudience.FlushQueueToDiskForTesting();
             if (Directory.Exists(queueDir))
             {
-                foreach (var f in Directory.GetFiles(queueDir, "*.json")) File.Delete(f);
+                foreach (var f in Directory.GetFiles(queueDir, AudiencePaths.QueueGlob)) File.Delete(f);
                 Directory.Delete(queueDir);
             }
             File.WriteAllText(queueDir, "blocker");
diff --git a/src/Packages/Audience/Tests/Runtime/TestDefaults.cs b/src/Packages/Audience/Tests/Runtime/TestDefaults.cs
index 1a20e0cd2..a22abb42c 100644
--- a/src/Packages/Audience/Tests/Runtime/TestDefaults.cs
+++ b/src/Packages/Audience/Tests/Runtime/TestDefaults.cs
@@ -4,5 +4,8 @@ internal static class TestDefaults
     {
         internal const int FlushIntervalSeconds = 600;
         internal const int FlushSize = 1000;
+
+        // Sandbox publishable key used by every test's AudienceConfig.
+        internal const string PublishableKey = "pk_imapik-test-key1";
     }
 }
diff --git a/src/Packages/Audience/Tests/Runtime/Transport/DiskStoreTests.cs b/src/Packages/Audience/Tests/Runtime/Transport/DiskStoreTests.cs
index 96b4ef3b9..416a50931 100644
--- a/src/Packages/Audience/Tests/Runtime/Transport/DiskStoreTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/Transport/DiskStoreTests.cs
@@ -96,7 +96,7 @@ public void ReadBatch_ExcludesAndDeletesStaleFiles()
 
             // Manually plant a stale file (ticks from 31 days ago)
             var staleTime = DateTime.UtcNow.AddDays(-(Constants.StaleEventDays + 1));
-            var staleName = $"{staleTime.Ticks}_{Guid.NewGuid():N}.json";
+            var staleName = $"{staleTime.Ticks}_{Guid.NewGuid():N}{AudiencePaths.QueueFileExtension}";
             var queueDir = AudiencePaths.QueueDir(_testDir);
             File.WriteAllText(Path.Combine(queueDir, staleName), "{\"stale\":true}");
 
@@ -151,7 +151,7 @@ public void CrashRecovery_PicksUpFilesFromPreviousRun()
         {
             // Simulate a previous run by writing a file directly
             var queueDir = AudiencePaths.QueueDir(_testDir);
-            var survivingName = $"{DateTime.UtcNow.Ticks}_{Guid.NewGuid():N}.json";
+            var survivingName = $"{DateTime.UtcNow.Ticks}_{Guid.NewGuid():N}{AudiencePaths.QueueFileExtension}";
             File.WriteAllText(Path.Combine(queueDir, survivingName), "{\"survived\":true}");
 
             // Create a new DiskStore instance pointing at the same path (simulates restart)
@@ -164,10 +164,19 @@ public void CrashRecovery_PicksUpFilesFromPreviousRun()
         [Test]
         public void ApplyAnonymousDowngrade_DeletesIdentifyAndAlias_StripsUserIdFromTrack()
         {
-            _store.Write("{\"type\":\"identify\",\"anonymousId\":\"a\",\"userId\":\"u\"}");
-            _store.Write("{\"type\":\"alias\",\"fromId\":\"a\",\"toId\":\"u\"}");
-            _store.Write("{\"type\":\"track\",\"eventName\":\"x\",\"anonymousId\":\"a\",\"userId\":\"u\"}");
-            _store.Write("{\"type\":\"track\",\"eventName\":\"y\",\"anonymousId\":\"a\"}");
+            _store.Write(WireFixture.Identify(
+                (MessageFields.AnonymousId, "a"),
+                (MessageFields.UserId, "u")));
+            _store.Write(WireFixture.Alias(
+                (MessageFields.FromId, "a"),
+                (MessageFields.ToId, "u")));
+            _store.Write(WireFixture.Track(
+                (MessageFields.EventName, "x"),
+                (MessageFields.AnonymousId, "a"),
+                (MessageFields.UserId, "u")));
+            _store.Write(WireFixture.Track(
+                (MessageFields.EventName, "y"),
+                (MessageFields.AnonymousId, "a")));
 
             _store.ApplyAnonymousDowngrade();
 
@@ -178,8 +187,8 @@ public void ApplyAnonymousDowngrade_DeletesIdentifyAndAlias_StripsUserIdFromTrac
             {
                 var json = File.ReadAllText(path);
                 var msg = JsonReader.DeserializeObject(json);
-                Assert.AreEqual("track", msg["type"]);
-                Assert.IsFalse(msg.ContainsKey("userId"), "userId must be stripped from queued track messages");
+                Assert.AreEqual(MessageTypes.Track, msg[MessageFields.Type]);
+                Assert.IsFalse(msg.ContainsKey(MessageFields.UserId), "userId must be stripped from queued track messages");
             }
         }
 
@@ -218,7 +227,7 @@ public void ApplyAnonymousDowngrade_DeletesMalformedFiles()
             // Seed the queue directory with a file that is not valid JSON so the
             // downgrade cannot leave it to potentially leak identified data.
             var queueDir = AudiencePaths.QueueDir(_testDir);
-            var badName = $"{DateTime.UtcNow.Ticks}_{Guid.NewGuid():N}.json";
+            var badName = $"{DateTime.UtcNow.Ticks}_{Guid.NewGuid():N}{AudiencePaths.QueueFileExtension}";
             File.WriteAllText(Path.Combine(queueDir, badName), "{not valid json");
 
             _store.ApplyAnonymousDowngrade();
diff --git a/src/Packages/Audience/Tests/Runtime/Transport/EventQueueTests.cs b/src/Packages/Audience/Tests/Runtime/Transport/EventQueueTests.cs
index 234362ad2..0a437629c 100644
--- a/src/Packages/Audience/Tests/Runtime/Transport/EventQueueTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/Transport/EventQueueTests.cs
@@ -156,9 +156,9 @@ public void PurgeAll_ClearsMemoryAndDisk()
         {
             using var queue = new EventQueue(_store, flushIntervalSeconds: 60, flushSize: 100);
 
-            queue.Enqueue(new Dictionary<string, object> { [MessageFields.Type] = "track", [MessageFields.EventName] = "a" });
+            queue.Enqueue(new Dictionary<string, object> { [MessageFields.Type] = MessageTypes.Track, [MessageFields.EventName] = "a" });
             queue.FlushSync();
-            queue.Enqueue(new Dictionary<string, object> { [MessageFields.Type] = "track", [MessageFields.EventName] = "b" });
+            queue.Enqueue(new Dictionary<string, object> { [MessageFields.Type] = MessageTypes.Track, [MessageFields.EventName] = "b" });
 
             queue.PurgeAll();
 
diff --git a/src/Packages/Audience/Tests/Runtime/Transport/HttpTransportTests.cs b/src/Packages/Audience/Tests/Runtime/Transport/HttpTransportTests.cs
index 76b8c86f0..fa094515c 100644
--- a/src/Packages/Audience/Tests/Runtime/Transport/HttpTransportTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/Transport/HttpTransportTests.cs
@@ -49,11 +49,11 @@ public void TearDown()
         [Test]
         public async Task SendBatchAsync_200_DeletesFilesFromDisk()
         {
-            _store.Write("{\"type\":\"track\",\"eventName\":\"a\"}");
-            _store.Write("{\"type\":\"track\",\"eventName\":\"b\"}");
+            _store.Write(WireFixture.Track((MessageFields.EventName, "a")));
+            _store.Write(WireFixture.Track((MessageFields.EventName, "b")));
 
             var handler = new MockHandler(HttpStatusCode.OK, $"{{\"accepted\":2,\"{ResponseFields.Rejected}\":0}}");
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1", handler: handler);
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey, handler: handler);
 
             var sent = await transport.SendBatchAsync();
 
@@ -65,7 +65,7 @@ public async Task SendBatchAsync_200_DeletesFilesFromDisk()
         [Test]
         public async Task SendBatchAsync_200_SendsGzippedPayloadWithCorrectHeaders()
         {
-            _store.Write("{\"type\":\"track\",\"eventName\":\"test\"}");
+            _store.Write(WireFixture.Track((MessageFields.EventName, "test")));
 
             byte[]? capturedBody = null;
             string? capturedKey = null;
@@ -75,29 +75,29 @@ public async Task SendBatchAsync_200_SendsGzippedPayloadWithCorrectHeaders()
             var handler = new MockHandler(HttpStatusCode.OK, $"{{\"accepted\":1,\"{ResponseFields.Rejected}\":0}}",
                 onRequest: req =>
                 {
-                    capturedKey = string.Join("", req.Headers.GetValues("x-immutable-publishable-key"));
+                    capturedKey = string.Join("", req.Headers.GetValues(Constants.PublishableKeyHeader));
                     capturedContentType = req.Content!.Headers.ContentType!.MediaType;
                     capturedContentEncoding = string.Join("", req.Content.Headers.ContentEncoding);
                     capturedBody = req.Content.ReadAsByteArrayAsync().Result;
                 });
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1", handler: handler);
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey, handler: handler);
 
             await transport.SendBatchAsync();
 
-            Assert.AreEqual("pk_imapik-test-key1", capturedKey);
+            Assert.AreEqual(TestDefaults.PublishableKey, capturedKey);
             Assert.AreEqual(Constants.MediaTypeJson, capturedContentType);
             Assert.AreEqual(Constants.GzipEncoding, capturedContentEncoding);
 
             var decompressed = DecompressGzip(capturedBody!);
             StringAssert.StartsWith($"{{\"{ResponseFields.MessagesEnvelope}\":[", decompressed);
             StringAssert.EndsWith("]}", decompressed);
-            StringAssert.Contains("\"eventName\":\"test\"", decompressed);
+            StringAssert.Contains($"\"{MessageFields.EventName}\":\"test\"", decompressed);
         }
 #else
         [Test]
         public async Task SendBatchAsync_200_SendsPlainJsonPayloadWithoutContentEncoding()
         {
-            _store.Write("{\"type\":\"track\",\"eventName\":\"test\"}");
+            _store.Write(WireFixture.Track((MessageFields.EventName, "test")));
 
             string? capturedKey = null;
             string? capturedContentType = null;
@@ -106,33 +106,33 @@ public async Task SendBatchAsync_200_SendsPlainJsonPayloadWithoutContentEncoding
             var handler = new MockHandler(HttpStatusCode.OK, $"{{\"accepted\":1,\"{ResponseFields.Rejected}\":0}}",
                 onRequest: req =>
                 {
-                    capturedKey = string.Join("", req.Headers.GetValues("x-immutable-publishable-key"));
+                    capturedKey = string.Join("", req.Headers.GetValues(Constants.PublishableKeyHeader));
                     capturedContentType = req.Content!.Headers.ContentType!.MediaType;
                     capturedContentEncodingCount = req.Content.Headers.ContentEncoding.Count;
                     capturedBody = req.Content.ReadAsStringAsync().Result;
                 });
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1", handler: handler);
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey, handler: handler);
 
             await transport.SendBatchAsync();
 
-            Assert.AreEqual("pk_imapik-test-key1", capturedKey);
+            Assert.AreEqual(TestDefaults.PublishableKey, capturedKey);
             Assert.AreEqual(Constants.MediaTypeJson, capturedContentType);
             Assert.AreEqual(0, capturedContentEncodingCount, "no Content-Encoding header is permitted in v1");
             StringAssert.StartsWith($"{{\"{ResponseFields.MessagesEnvelope}\":[", capturedBody);
             StringAssert.EndsWith("]}", capturedBody);
-            StringAssert.Contains("\"eventName\":\"test\"", capturedBody);
+            StringAssert.Contains($"\"{MessageFields.EventName}\":\"test\"", capturedBody);
         }
 #endif
 
         [Test]
         public async Task SendBatchAsync_200_UsesCorrectUrlForTestKey()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             HttpRequestMessage? captured = null;
             var handler = new MockHandler(HttpStatusCode.OK, $"{{\"accepted\":1,\"{ResponseFields.Rejected}\":0}}",
                 onRequest: req => captured = req);
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1", handler: handler);
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey, handler: handler);
 
             await transport.SendBatchAsync();
 
@@ -142,7 +142,7 @@ public async Task SendBatchAsync_200_UsesCorrectUrlForTestKey()
         [Test]
         public async Task SendBatchAsync_200_UsesCorrectUrlForProdKey()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             HttpRequestMessage? captured = null;
             var handler = new MockHandler(HttpStatusCode.OK, $"{{\"accepted\":1,\"{ResponseFields.Rejected}\":0}}",
@@ -157,7 +157,7 @@ public async Task SendBatchAsync_200_UsesCorrectUrlForProdKey()
         [Test]
         public async Task SendBatchAsync_BaseUrlOverride_WinsOverKeyPrefix()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             HttpRequestMessage? captured = null;
             var handler = new MockHandler(HttpStatusCode.OK, $"{{\"accepted\":1,\"{ResponseFields.Rejected}\":0}}",
@@ -165,7 +165,7 @@ public async Task SendBatchAsync_BaseUrlOverride_WinsOverKeyPrefix()
             const string custom = "https://api.dev.immutable.com";
             // Test-prefixed key would resolve to Sandbox on its own; the
             // explicit override must win.
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 baseUrlOverride: custom, handler: handler);
 
             await transport.SendBatchAsync();
@@ -177,7 +177,7 @@ public async Task SendBatchAsync_BaseUrlOverride_WinsOverKeyPrefix()
         public async Task SendBatchAsync_EmptyQueue_ReturnsFalse()
         {
             var handler = new MockHandler(HttpStatusCode.OK, "{}");
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1", handler: handler);
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey, handler: handler);
 
             var sent = await transport.SendBatchAsync();
 
@@ -188,11 +188,11 @@ public async Task SendBatchAsync_EmptyQueue_ReturnsFalse()
         [Test]
         public async Task SendBatchAsync_4xx_DeletesFilesAndResetsBackoff()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var handler = new MockHandler(HttpStatusCode.BadRequest, "");
             AudienceError? reportedError = null;
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 onError: e => reportedError = e, handler: handler);
 
             await transport.SendBatchAsync();
@@ -206,11 +206,11 @@ public async Task SendBatchAsync_4xx_DeletesFilesAndResetsBackoff()
         [Test]
         public async Task SendBatchAsync_429_NoRetryAfter_KeepsFilesAndUsesExpoBackoff_NoError()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var handler = new MockHandler((HttpStatusCode)429, "");
             AudienceError? reportedError = null;
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 onError: e => reportedError = e, handler: handler, getUtcNow: _getUtcNow);
 
             await transport.SendBatchAsync();
@@ -224,7 +224,7 @@ public async Task SendBatchAsync_429_NoRetryAfter_KeepsFilesAndUsesExpoBackoff_N
         [Test]
         public async Task SendBatchAsync_429_RetryAfterDeltaSeconds_OverridesExpoBackoff()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var handler = new MockHandler(() =>
             {
@@ -232,7 +232,7 @@ public async Task SendBatchAsync_429_RetryAfterDeltaSeconds_OverridesExpoBackoff
                 resp.Headers.Add("Retry-After", "12");
                 return resp;
             });
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 handler: handler, getUtcNow: _getUtcNow);
 
             await transport.SendBatchAsync();
@@ -247,7 +247,7 @@ public async Task SendBatchAsync_429_RetryAfterHttpDate_OverridesExpoBackoff()
             // ParseRetryAfter computes the delta against DateTimeOffset.UtcNow,
             // which we can't pin from outside; assert only that a future date
             // engages the window. The seconds-form test above pins exact math.
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var handler = new MockHandler(() =>
             {
@@ -255,7 +255,7 @@ public async Task SendBatchAsync_429_RetryAfterHttpDate_OverridesExpoBackoff()
                 resp.Headers.Add("Retry-After", DateTimeOffset.UtcNow.AddSeconds(20).ToString("R"));
                 return resp;
             });
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 handler: handler, getUtcNow: _getUtcNow);
 
             await transport.SendBatchAsync();
@@ -269,7 +269,7 @@ public async Task SendBatchAsync_429_PastRetryAfterDate_FallsBackToExpoBackoff()
         {
             // Past Retry-After (clock skew or server bug) must not let
             // IsInBackoffWindow flip false and trigger instant retry.
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var handler = new MockHandler(() =>
             {
@@ -277,7 +277,7 @@ public async Task SendBatchAsync_429_PastRetryAfterDate_FallsBackToExpoBackoff()
                 resp.Headers.Add("Retry-After", DateTimeOffset.UtcNow.AddSeconds(-30).ToString("R"));
                 return resp;
             });
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 handler: handler, getUtcNow: _getUtcNow);
 
             await transport.SendBatchAsync();
@@ -289,7 +289,7 @@ public async Task SendBatchAsync_429_PastRetryAfterDate_FallsBackToExpoBackoff()
         [Test]
         public async Task SendBatchAsync_429ThenSuccess_DeliversBatchAndClearsBackoff()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var callCount = 0;
             var handler = new MockHandler(() =>
@@ -301,7 +301,7 @@ public async Task SendBatchAsync_429ThenSuccess_DeliversBatchAndClearsBackoff()
                     { Content = new StringContent($"{{\"accepted\":1,\"{ResponseFields.Rejected}\":0}}") };
             });
             AudienceError? reportedError = null;
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 onError: e => reportedError = e, handler: handler, getUtcNow: _getUtcNow);
 
             await transport.SendBatchAsync();
@@ -322,12 +322,12 @@ public async Task SendBatchAsync_200_WithRejected_DeletesFilesAndSurfacesValidat
             // per-message validation errors. The batch is deleted (retries
             // would not help) and the count is surfaced via onError so
             // studios can observe silently dropped events.
-            _store.Write("{\"type\":\"track\",\"eventName\":\"a\"}");
-            _store.Write("{\"type\":\"track\",\"eventName\":\"b\"}");
+            _store.Write(WireFixture.Track((MessageFields.EventName, "a")));
+            _store.Write(WireFixture.Track((MessageFields.EventName, "b")));
 
             var handler = new MockHandler(HttpStatusCode.OK, $"{{\"accepted\":1,\"{ResponseFields.Rejected}\":1}}");
             AudienceError? reportedError = null;
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 onError: e => reportedError = e, handler: handler);
 
             await transport.SendBatchAsync();
@@ -341,11 +341,11 @@ public async Task SendBatchAsync_200_WithRejected_DeletesFilesAndSurfacesValidat
         [Test]
         public async Task SendBatchAsync_200_ZeroRejected_DoesNotFireOnError()
         {
-            _store.Write("{\"type\":\"track\",\"eventName\":\"a\"}");
+            _store.Write(WireFixture.Track((MessageFields.EventName, "a")));
 
             var handler = new MockHandler(HttpStatusCode.OK, $"{{\"accepted\":1,\"{ResponseFields.Rejected}\":0}}");
             AudienceError? reportedError = null;
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 onError: e => reportedError = e, handler: handler);
 
             await transport.SendBatchAsync();
@@ -357,11 +357,11 @@ public async Task SendBatchAsync_200_ZeroRejected_DoesNotFireOnError()
         public async Task SendBatchAsync_200_MalformedBody_TreatsAsZeroRejected()
         {
             // Malformed diagnostic body must not block the success path.
-            _store.Write("{\"type\":\"track\",\"eventName\":\"a\"}");
+            _store.Write(WireFixture.Track((MessageFields.EventName, "a")));
 
             var handler = new MockHandler(HttpStatusCode.OK, "not-json");
             AudienceError? reportedError = null;
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 onError: e => reportedError = e, handler: handler);
 
             await transport.SendBatchAsync();
@@ -373,11 +373,11 @@ public async Task SendBatchAsync_200_MalformedBody_TreatsAsZeroRejected()
         [Test]
         public async Task SendBatchAsync_5xx_KeepsFilesAndIncreasesBackoff()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var handler = new MockHandler(HttpStatusCode.InternalServerError, "");
             AudienceError? reportedError = null;
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 onError: e => reportedError = e, handler: handler);
 
             await transport.SendBatchAsync();
@@ -392,9 +392,9 @@ public async Task SendBatchAsync_5xx_KeepsFilesAndIncreasesBackoff()
         [Test]
         public async Task BackoffMs_EscalatesOnlyAfterWindowElapsed()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
             var handler = new MockHandler(HttpStatusCode.InternalServerError, "");
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 handler: handler, getUtcNow: _getUtcNow);
 
             // Schedule: 5s → 10s → 20s → 40s → 60s cap.
@@ -426,9 +426,9 @@ public async Task BackoffMs_EscalatesOnlyAfterWindowElapsed()
         [Test]
         public async Task BackoffMs_DoesNotEscalateWhileInsidePreviousWindow()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
             var handler = new MockHandler(HttpStatusCode.InternalServerError, "");
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 handler: handler, getUtcNow: _getUtcNow);
 
             await transport.SendBatchAsync();
@@ -458,7 +458,7 @@ public async Task BackoffMs_DoesNotEscalateWhileInsidePreviousWindow()
         [Test]
         public async Task BackoffMs_ResetsAfterSuccess()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var callCount = 0;
             var handler = new MockHandler(() =>
@@ -470,7 +470,7 @@ public async Task BackoffMs_ResetsAfterSuccess()
                     : new HttpResponseMessage(HttpStatusCode.OK)
                     { Content = new StringContent($"{{\"accepted\":1,\"{ResponseFields.Rejected}\":0}}") };
             });
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 handler: handler, getUtcNow: _getUtcNow);
 
             await transport.SendBatchAsync();
@@ -489,11 +489,11 @@ public async Task BackoffMs_ResetsAfterSuccess()
         [Test]
         public async Task SendBatchAsync_NetworkError_KeepsFilesAndBacksOff()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var handler = new MockHandler(() => throw new HttpRequestException("connection refused"));
             AudienceError? reportedError = null;
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 onError: e => reportedError = e, handler: handler);
 
             await transport.SendBatchAsync();
@@ -512,11 +512,11 @@ public async Task SendBatchAsync_HttpClientTimeout_TreatedAsNetworkError()
             // guard, timeouts would be silently swallowed as "shutdown": no backoff, no error
             // callback, next cycle hot-loops. This test ensures timeouts flow through the
             // NetworkError path.
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var handler = new MockHandler(() => throw new TaskCanceledException("Request timed out"));
             AudienceError? reportedError = null;
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 onError: e => reportedError = e, handler: handler);
 
             // Pass default CancellationToken so ct.IsCancellationRequested is false; this
@@ -538,11 +538,11 @@ public async Task SendBatchAsync_CallerCancelled_Throws_DoesNotDeleteOrRecordFai
             // with the batch still on disk, and a FlushAsync loop watching
             // that return value would re-enter on the same cancelled token
             // forever: nothing ever drains, nothing ever throws.
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var handler = new MockHandler(() => throw new OperationCanceledException("simulated"));
             AudienceError? reportedError = null;
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 onError: e => reportedError = e, handler: handler);
 
             using var cts = new CancellationTokenSource();
@@ -570,11 +570,11 @@ public async Task SendBatchAsync_CallerCancelled_Throws_DoesNotDeleteOrRecordFai
         [Test]
         public async Task IsInBackoffWindow_ClearsAfterNextAttemptAtElapses()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var now = new DateTime(2026, 4, 17, 12, 0, 0, DateTimeKind.Utc);
             var handler = new MockHandler(HttpStatusCode.InternalServerError, "");
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 handler: handler, getUtcNow: () => now);
 
             await transport.SendBatchAsync();
@@ -594,10 +594,10 @@ public async Task IsInBackoffWindow_ClearsAfterNextAttemptAtElapses()
         [Test]
         public async Task SendBatchAsync_ErrorCallbackThrows_DoesNotCrash()
         {
-            _store.Write("{\"type\":\"track\"}");
+            _store.Write(WireFixture.Track());
 
             var handler = new MockHandler(HttpStatusCode.BadRequest, "");
-            using var transport = new HttpTransport(_store, "pk_imapik-test-key1",
+            using var transport = new HttpTransport(_store, TestDefaults.PublishableKey,
                 onError: _ => throw new InvalidOperationException("callback bug"),
                 handler: handler);
 
diff --git a/src/Packages/Audience/Tests/Runtime/Utility/GzipTests.cs b/src/Packages/Audience/Tests/Runtime/Utility/GzipTests.cs
index 074dd21f8..28430646f 100644
--- a/src/Packages/Audience/Tests/Runtime/Utility/GzipTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/Utility/GzipTests.cs
@@ -12,7 +12,7 @@ internal class GzipTests
         [Test]
         public void Compress_ProducesValidGzip_ThatDecompressesToOriginal()
         {
-            const string original = "{\"type\":\"track\",\"eventName\":\"test\"}";
+            var original = WireFixture.Track((MessageFields.EventName, "test"));
 
             var compressed = Gzip.Compress(original);
 
@@ -33,7 +33,9 @@ public void Compress_OutputIsSmallerThanInput_ForRealisticPayload()
             for (var i = 0; i < 20; i++)
             {
                 if (i > 0) sb.Append(',');
-                sb.Append($"{{\"type\":\"track\",\"eventName\":\"level_complete\",\"anonymousId\":\"anon-{i}\"}}");
+                sb.Append(WireFixture.Track(
+                    (MessageFields.EventName, "level_complete"),
+                    (MessageFields.AnonymousId, $"anon-{i}")));
             }
 
             sb.Append("]}");
diff --git a/src/Packages/Audience/Tests/Runtime/Utility/JsonReaderTests.cs b/src/Packages/Audience/Tests/Runtime/Utility/JsonReaderTests.cs
index e2c04407f..36ef4e543 100644
--- a/src/Packages/Audience/Tests/Runtime/Utility/JsonReaderTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/Utility/JsonReaderTests.cs
@@ -69,12 +69,12 @@ public void RoundTripViaSerializer()
         {
             var original = new Dictionary<string, object>
             {
-                [MessageFields.Type] = "track",
-                [MessageFields.EventName] = "progression",
+                [MessageFields.Type] = MessageTypes.Track,
+                [MessageFields.EventName] = EventNames.Progression,
                 [MessageFields.Properties] = new Dictionary<string, object>
                 {
-                    ["status"] = "complete",
-                    ["score"] = 1500
+                    [EventPropertyKeys.Status] = ProgressionStatus.Complete.ToLowercaseString(),
+                    [EventPropertyKeys.Score] = 1500
                 },
                 [MessageFields.AnonymousId] = "abc",
                 [MessageFields.UserId] = "76561198012345"
@@ -83,13 +83,13 @@ public void RoundTripViaSerializer()
             var serialized = Json.Serialize(original);
             var parsed = JsonReader.DeserializeObject(serialized);
 
-            Assert.AreEqual("track", parsed[MessageFields.Type]);
-            Assert.AreEqual("progression", parsed[MessageFields.EventName]);
+            Assert.AreEqual(MessageTypes.Track, parsed[MessageFields.Type]);
+            Assert.AreEqual(EventNames.Progression, parsed[MessageFields.EventName]);
             Assert.AreEqual("abc", parsed[MessageFields.AnonymousId]);
             Assert.AreEqual("76561198012345", parsed[MessageFields.UserId]);
             var props = (Dictionary<string, object>)parsed[MessageFields.Properties];
-            Assert.AreEqual("complete", props["status"]);
-            Assert.AreEqual(1500, props["score"]);
+            Assert.AreEqual(ProgressionStatus.Complete.ToLowercaseString(), props[EventPropertyKeys.Status]);
+            Assert.AreEqual(1500, props[EventPropertyKeys.Score]);
         }
 
         [Test]
diff --git a/src/Packages/Audience/Tests/Runtime/Utility/JsonTests.cs b/src/Packages/Audience/Tests/Runtime/Utility/JsonTests.cs
index 178325c91..a3abe358e 100644
--- a/src/Packages/Audience/Tests/Runtime/Utility/JsonTests.cs
+++ b/src/Packages/Audience/Tests/Runtime/Utility/JsonTests.cs
@@ -181,11 +181,11 @@ public void Serialize_RealisticEventPayload_ProducesCorrectJson()
         {
             var data = new Dictionary<string, object>
             {
-                { "type", "track" },
-                { "eventName", "level_complete" },
-                { "anonymousId", "anon-123" },
-                { "userId", null },
-                { "properties", new Dictionary<string, object>
+                { MessageFields.Type, MessageTypes.Track },
+                { MessageFields.EventName, "level_complete" },
+                { MessageFields.AnonymousId, "anon-123" },
+                { MessageFields.UserId, null },
+                { MessageFields.Properties, new Dictionary<string, object>
                     {
                         { "level", 5 },
                         { "score", 9800L },
@@ -197,9 +197,9 @@ public void Serialize_RealisticEventPayload_ProducesCorrectJson()
 
             var result = Json.Serialize(data);
 
-            StringAssert.Contains("\"type\":\"track\"", result);
-            StringAssert.Contains("\"eventName\":\"level_complete\"", result);
-            StringAssert.Contains("\"userId\":null", result);
+            StringAssert.Contains($"\"{MessageFields.Type}\":\"{MessageTypes.Track}\"", result);
+            StringAssert.Contains($"\"{MessageFields.EventName}\":\"level_complete\"", result);
+            StringAssert.Contains($"\"{MessageFields.UserId}\":null", result);
             StringAssert.Contains("\"level\":5", result);
             StringAssert.Contains("\"perfect\":true", result);
             StringAssert.Contains("\"tags\":[\"fast\",\"clean\"]", result);
diff --git a/src/Packages/Audience/Tests/Runtime/WireFixture.cs b/src/Packages/Audience/Tests/Runtime/WireFixture.cs
new file mode 100644
index 000000000..238617d78
--- /dev/null
+++ b/src/Packages/Audience/Tests/Runtime/WireFixture.cs
@@ -0,0 +1,24 @@
+using System.Collections.Generic;
+
+namespace Immutable.Audience.Tests
+{
+    // Builds JSON message envelopes from MessageFields / MessageTypes for tests.
+    internal static class WireFixture
+    {
+        internal static string Track(params (string key, object value)[] extra) =>
+            Build(MessageTypes.Track, extra);
+
+        internal static string Identify(params (string key, object value)[] extra) =>
+            Build(MessageTypes.Identify, extra);
+
+        internal static string Alias(params (string key, object value)[] extra) =>
+            Build(MessageTypes.Alias, extra);
+
+        private static string Build(string type, (string key, object value)[] extra)
+        {
+            var dict = new Dictionary<string, object> { [MessageFields.Type] = type };
+            foreach (var (key, value) in extra) dict[key] = value;
+            return Json.Serialize(dict);
+        }
+    }
+}