From 4d2ddb5beba1a10925d2d38faa322aafec932394 Mon Sep 17 00:00:00 2001
From: Meta Vens <rwvens@hotmail.com>
Date: Sun, 19 Jul 2026 09:20:40 +0100
Subject: [PATCH] Default hot body subscriptions to live delivery

---
 src/GameCult.Mesh/CultMesh.cs                   |  4 ++--
 .../docs/reliability-migration-plan.md          |  9 ++++++++-
 .../CultMeshBodyTransportTests.cs               | 17 +++++++++++++++++
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/src/GameCult.Mesh/CultMesh.cs b/src/GameCult.Mesh/CultMesh.cs
index 34b31474..567de868 100644
--- a/src/GameCult.Mesh/CultMesh.cs
+++ b/src/GameCult.Mesh/CultMesh.cs
@@ -2860,7 +2860,7 @@ namespace GameCult.Mesh
             CultNetDatabaseSubscriptionClient subscriptions,
             IEnumerable<CultMeshBodyTransportKind> supportedBodyTransports,
             CultMeshHotBodySubscription subscription,
-            CultNetDatabaseSubscriptionDeliveryMode deliveryMode = CultNetDatabaseSubscriptionDeliveryMode.ReplicateToCache)
+            CultNetDatabaseSubscriptionDeliveryMode deliveryMode = CultNetDatabaseSubscriptionDeliveryMode.Live)
         {
             if (subscriptions == null) throw new ArgumentNullException(nameof(subscriptions));
             if (supportedBodyTransports == null) throw new ArgumentNullException(nameof(supportedBodyTransports));
@@ -2883,7 +2883,7 @@ namespace GameCult.Mesh
             CultNetDatabaseSubscriptionClient subscriptions,
             CultMeshBodyPublicationResolver bodyResolver,
             CultMeshHotBodySubscription subscription,
-            CultNetDatabaseSubscriptionDeliveryMode deliveryMode = CultNetDatabaseSubscriptionDeliveryMode.ReplicateToCache)
+            CultNetDatabaseSubscriptionDeliveryMode deliveryMode = CultNetDatabaseSubscriptionDeliveryMode.Live)
         {
             if (bodyResolver == null) throw new ArgumentNullException(nameof(bodyResolver));
             return SubscribeHotBodyAsync(subscriptions, bodyResolver.SupportedTransports, subscription, deliveryMode);
diff --git a/src/GameCult.Mesh/docs/reliability-migration-plan.md b/src/GameCult.Mesh/docs/reliability-migration-plan.md
index d0594d44..3d31483b 100644
--- a/src/GameCult.Mesh/docs/reliability-migration-plan.md
+++ b/src/GameCult.Mesh/docs/reliability-migration-plan.md
@@ -924,7 +924,11 @@ latest-publication record, consumer identity, and logical body demand in one
 contract. The local `CultMeshBodyTransportService` contributes only adapters it
 can actually open, ordered shared-memory first; the server combines those
 capabilities with observed peer locality. Applications do not hand-assemble
-transport-name arrays or request one snapshot per frame.
+transport-name arrays or request one snapshot per frame. Hot-body subscriptions
+default to `Live`: their exact initial metadata is decoded for bootstrap, then
+subsequent layout/publication changes remain ephemeral notifications. Durable
+cache replication is an explicit opt-in for consumers that actually own a
+replica requirement.
 
 ### Reactive document delivery body map
 
@@ -936,6 +940,9 @@ the value; the transport and renderer own neither its persistence nor meaning.
 `CultNetDatabaseSubscriptionDeliveryMode`. `ReplicateToCache` materializes
 bootstrap and durable state before notification. `Live` validates and decodes
 the same typed payload, then notifies the subscriber without a replica write.
+High-rate body subscriptions select `Live` by default; general database
+subscriptions retain the durable default because CultMesh cannot infer their
+ownership contract.
 
 **Outputs:** both modes produce the same typed initial values and change event.
 Only durable replication mutates the consumer's CultCache.
diff --git a/tests/GameCult.Mesh.Tests/CultMeshBodyTransportTests.cs b/tests/GameCult.Mesh.Tests/CultMeshBodyTransportTests.cs
index 154ee587..11782a0a 100644
--- a/tests/GameCult.Mesh.Tests/CultMeshBodyTransportTests.cs
+++ b/tests/GameCult.Mesh.Tests/CultMeshBodyTransportTests.cs
@@ -1,5 +1,6 @@
 using System;
 using System.IO;
+using System.Linq;
 using FluentAssertions;
 using NUnit.Framework;
 using System.IO.MemoryMappedFiles;
@@ -381,6 +382,22 @@ public sealed class CultMeshBodyTransportTests
         subscription.ConsumerRuntimeId.Should().Be("eve-unity");
     }
 
+    [Test]
+    public void HotBodySubscriptionsDefaultToEphemeralLiveDelivery()
+    {
+        var overloads = typeof(CultMesh).GetMethods()
+            .Where(method => method.Name == nameof(CultMesh.SubscribeHotBodyAsync))
+            .ToArray();
+
+        overloads.Should().HaveCount(2);
+        foreach (var overload in overloads)
+        {
+            var deliveryMode = overload.GetParameters().Single(parameter =>
+                parameter.ParameterType == typeof(CultNetDatabaseSubscriptionDeliveryMode));
+            deliveryMode.DefaultValue.Should().Be(CultNetDatabaseSubscriptionDeliveryMode.Live);
+        }
+    }
+
     private static CultMeshBodyValidationRequest Request(CultMeshBodyDescriptor descriptor, DateTimeOffset now) => new()
     {
         BodyId = descriptor.BodyId,