diff --git a/Aetheria.State.Verify/Program.cs b/Aetheria.State.Verify/Program.cs
index 8454487d4..57f54f0da 100644
--- a/Aetheria.State.Verify/Program.cs
+++ b/Aetheria.State.Verify/Program.cs
@@ -5787,13 +5787,13 @@ static void RequireTradeCargoSelectorUseEveSurface(string root)
     var requiredSymbols = new[]
     {
         "RenderCargoSelectorSurface(",
-        "_cargoSelectorSurfaceModel = ComposeTradeCargoSelectorSurface();",
+        "_cargoSelectorSurfaceModel = BuildTradeCargoSelectorSurfaceModel();",
         "HandleCargoSelectorSurfaceCommand(",
         "AetheriaEveUnitySurfaceHost.RenderRuntime(",
         "AetheriaEveUnitySurfaceHost.Hide(_cargoSelectorSurfaceDocument)",
-        "AetheriaRuntimeTradeCargoSelectorSurfaceBuilder.Build(_cargoSelectorSurfaceModel.State)",
-        "ComposeTradeCargoSelectorSurface(",
-        "AetheriaRuntimeTradeCargoSelectorSurfaceBuilder.Compose(",
+        "_cargoSelectorSurfaceModel.Document",
+        "BuildTradeCargoSelectorSurfaceModel(",
+        "AetheriaRuntimeTradeCargoSelectorSurfaceBuilder.Build(",
         "_cargoSelectorSurfaceModel?.TryResolve(command.Command, out var selection) == true",
         "ApplyCargoSelection(",
         "new AetheriaRuntimeTradeCargoModelOption(",
@@ -5847,6 +5847,9 @@ static void RequireTradeCargoSelectorUseEveSurface(string root)
         "BuildCargoSelectionCommands(",
         "ProjectTradeCargoSelectorSurfaceState(",
         "ProjectTradeCargoSelectorSurface(",
+        "ComposeTradeCargoSelectorSurface(",
+        "_cargoSelectorSurfaceModel.State",
+        "AetheriaRuntimeTradeCargoSelectorSurfaceBuilder.Compose(",
         "_cargoSelectorSurfaceProjection",
         "AetheriaRuntimeObservedDockingState",
         "ResolveClient().State.CurrentDocking()",
@@ -5906,8 +5909,9 @@ static void RequireTradeCargoSelectorUseEveSurface(string root)
         "AetheriaRuntimeTradeCargoTargetKind",
         "AetheriaRuntimeTradeCargoSelection",
         "AetheriaRuntimeTradeCargoSelectorSurfaceModel",
+        "public AetheriaRuntimeSurfaceDocument Document { get; }",
         "public static string ShipBayCommand(",
-        "public static AetheriaRuntimeTradeCargoSelectorSurfaceModel Compose(",
+        "public static AetheriaRuntimeTradeCargoSelectorSurfaceModel Build(",
         "public bool TryResolve(string command, out AetheriaRuntimeTradeCargoSelection selection)",
         "public static AetheriaRuntimeSurfaceDocument Build(",
         "providerKind: \"trade.menu\"",
@@ -5922,6 +5926,13 @@ static void RequireTradeCargoSelectorUseEveSurface(string root)
             "Shared runtime trade cargo selector surface builder no longer owns the trade cargo-selector shell contract: " +
             string.Join(", ", missingBuilderSymbols));
     }
+
+    if (tradeCargoSelectorSurfaceBuilder.Contains("public AetheriaRuntimeTradeCargoSelectorSurfaceState State { get; }", StringComparison.Ordinal) ||
+        tradeCargoSelectorSurfaceBuilder.Contains("public static AetheriaRuntimeTradeCargoSelectorSurfaceModel Compose(", StringComparison.Ordinal))
+    {
+        throw new InvalidOperationException(
+            "Shared runtime trade cargo selector builder must return a model with a finished surface document; do not re-expose Compose or a public State handoff.");
+    }
 }
 
 static void RequireTradeFilterAndRowActionsUseEveSurface(string root)
diff --git a/Assets/Scripts/UI/Menu/TradeMenu.cs b/Assets/Scripts/UI/Menu/TradeMenu.cs
index 667b5e69c..6f72fd20f 100644
--- a/Assets/Scripts/UI/Menu/TradeMenu.cs
+++ b/Assets/Scripts/UI/Menu/TradeMenu.cs
@@ -1136,13 +1136,13 @@ public class TradeMenu : MonoBehaviour
 
     private void RenderCargoSelectorSurface()
     {
-        _cargoSelectorSurfaceModel = ComposeTradeCargoSelectorSurface();
+        _cargoSelectorSurfaceModel = BuildTradeCargoSelectorSurfaceModel();
 
         _cargoSelectorSurfaceDocument = AetheriaEveUnitySurfaceHost.RenderRuntime(
             transform,
             _cargoSelectorSurfaceDocument,
             "Aetheria Trade Cargo Selector Surface",
-            AetheriaRuntimeTradeCargoSelectorSurfaceBuilder.Build(_cargoSelectorSurfaceModel.State),
+            _cargoSelectorSurfaceModel.Document,
             HandleCargoSelectorSurfaceCommand,
             _cargoSelectorSurfaceChrome);
     }
@@ -1200,7 +1200,7 @@ public class TradeMenu : MonoBehaviour
         };
     }
 
-    private AetheriaRuntimeTradeCargoSelectorSurfaceModel ComposeTradeCargoSelectorSurface()
+    private AetheriaRuntimeTradeCargoSelectorSurfaceModel BuildTradeCargoSelectorSurfaceModel()
     {
         var targets = new List<AetheriaRuntimeTradeCargoModelOption>();
         var stationRefit = ResolveStationRefit();
@@ -1228,7 +1228,7 @@ public class TradeMenu : MonoBehaviour
                 target.BayIndex,
                 IsTargetCargoBayKey(target.EntityKey, target.BayIndex))));
 
-        return AetheriaRuntimeTradeCargoSelectorSurfaceBuilder.Compose(
+        return AetheriaRuntimeTradeCargoSelectorSurfaceBuilder.Build(
             _targetCargoLabel ?? "",
             targets,
             DateTime.UtcNow.ToString("O"));
diff --git a/Packages/org.gamecult.aetheria.state/Runtime/AetheriaRuntimeTradeCargoSelectorSurfaceBuilder.cs b/Packages/org.gamecult.aetheria.state/Runtime/AetheriaRuntimeTradeCargoSelectorSurfaceBuilder.cs
index 2a8442ea0..324f34162 100644
--- a/Packages/org.gamecult.aetheria.state/Runtime/AetheriaRuntimeTradeCargoSelectorSurfaceBuilder.cs
+++ b/Packages/org.gamecult.aetheria.state/Runtime/AetheriaRuntimeTradeCargoSelectorSurfaceBuilder.cs
@@ -98,17 +98,18 @@ namespace GameCult.Aetheria.State.Verse
     public sealed class AetheriaRuntimeTradeCargoSelectorSurfaceModel
     {
         public AetheriaRuntimeTradeCargoSelectorSurfaceModel(
-            AetheriaRuntimeTradeCargoSelectorSurfaceState state,
+            AetheriaRuntimeSurfaceDocument document,
             IReadOnlyDictionary<string, AetheriaRuntimeTradeCargoSelection> selections)
         {
-            State = state ?? new AetheriaRuntimeTradeCargoSelectorSurfaceState(
-                "",
-                Array.Empty<AetheriaRuntimeTradeCargoTargetOption>(),
-                "");
+            Document = document ?? AetheriaRuntimeTradeCargoSelectorSurfaceBuilder.Build(
+                new AetheriaRuntimeTradeCargoSelectorSurfaceState(
+                    "",
+                    Array.Empty<AetheriaRuntimeTradeCargoTargetOption>(),
+                    ""));
             Selections = selections ?? new Dictionary<string, AetheriaRuntimeTradeCargoSelection>(StringComparer.Ordinal);
         }
 
-        public AetheriaRuntimeTradeCargoSelectorSurfaceState State { get; }
+        public AetheriaRuntimeSurfaceDocument Document { get; }
         public IReadOnlyDictionary<string, AetheriaRuntimeTradeCargoSelection> Selections { get; }
 
         public bool TryResolve(string command, out AetheriaRuntimeTradeCargoSelection selection)
@@ -128,7 +129,7 @@ namespace GameCult.Aetheria.State.Verse
             return $"{SurfaceId}.ship_{shipIndex}_bay_{bayIndex}";
         }
 
-        public static AetheriaRuntimeTradeCargoSelectorSurfaceModel Compose(
+        public static AetheriaRuntimeTradeCargoSelectorSurfaceModel Build(
             string currentTarget,
             IEnumerable<AetheriaRuntimeTradeCargoModelOption> targets,
             string updatedAtUtc)
@@ -165,12 +166,12 @@ namespace GameCult.Aetheria.State.Verse
                     target.BayIndex);
             }
 
-            return new AetheriaRuntimeTradeCargoSelectorSurfaceModel(
-                new AetheriaRuntimeTradeCargoSelectorSurfaceState(
-                    currentTarget,
-                    options,
-                    updatedAtUtc),
-                selections);
+            var state = new AetheriaRuntimeTradeCargoSelectorSurfaceState(
+                currentTarget,
+                options,
+                updatedAtUtc);
+
+            return new AetheriaRuntimeTradeCargoSelectorSurfaceModel(Build(state), selections);
         }
 
         public static AetheriaRuntimeSurfaceDocument Build(