diff --git a/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HeatParts/GridHeatApi.cs b/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HeatParts/GridHeatApi.cs
new file mode 100644
index 000000000..667ab13ae
--- /dev/null
+++ b/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HeatParts/GridHeatApi.cs	
@@ -0,0 +1,139 @@
+using System;
+using System.Collections.Generic;
+using Sandbox.ModAPI;
+using VRage.Game.ModAPI;
+
+namespace Epstein_Fusion_DS.HeatParts
+{
+    /// <summary>
+    /// Copy this class into another mod and call Load() in LoadData() to use the grid heat API.
+    /// </summary>
+    public sealed class GridHeatApi
+    {
+        private const long Channel = 11920040L;
+        private const string ApiRequest = "GridHeatAPI.Request";
+
+        private Action _onReady;
+        private Dictionary<string, Delegate> _api;
+        private bool _registered;
+
+        public bool IsReady => _api != null;
+
+        public void Load(Action onReady = null)
+        {
+            if (_registered)
+                return;
+
+            _onReady = onReady;
+            _registered = true;
+            MyAPIGateway.Utilities.RegisterMessageHandler(Channel, HandleMessage);
+            MyAPIGateway.Utilities.SendModMessage(Channel, ApiRequest);
+        }
+
+        public void Unload()
+        {
+            if (!_registered)
+                return;
+
+            MyAPIGateway.Utilities.UnregisterMessageHandler(Channel, HandleMessage);
+            _registered = false;
+            _api = null;
+            _onReady = null;
+        }
+
+        public int Version()
+        {
+            var method = Get<Func<int>>("Version");
+            return method?.Invoke() ?? 0;
+        }
+
+        public bool AddHeat(IMyCubeGrid grid, float heat)
+        {
+            var method = Get<Func<IMyCubeGrid, float, bool>>("AddHeat");
+            return method != null && method(grid, heat);
+        }
+
+        public bool SetHeat(IMyCubeGrid grid, float heat)
+        {
+            var method = Get<Func<IMyCubeGrid, float, bool>>("SetHeat");
+            return method != null && method(grid, heat);
+        }
+
+        public float GetHeat(IMyCubeGrid grid)
+        {
+            var method = Get<Func<IMyCubeGrid, float>>("GetHeat");
+            return method?.Invoke(grid) ?? -1;
+        }
+
+        public float GetHeatRatio(IMyCubeGrid grid)
+        {
+            var method = Get<Func<IMyCubeGrid, float>>("GetHeatRatio");
+            return method?.Invoke(grid) ?? -1;
+        }
+
+        public float GetHeatCapacity(IMyCubeGrid grid)
+        {
+            var method = Get<Func<IMyCubeGrid, float>>("GetHeatCapacity");
+            return method?.Invoke(grid) ?? -1;
+        }
+
+        public float GetHeatDissipation(IMyCubeGrid grid)
+        {
+            var method = Get<Func<IMyCubeGrid, float>>("GetHeatDissipation");
+            return method?.Invoke(grid) ?? -1;
+        }
+
+        public float GetHeatGeneration(IMyCubeGrid grid)
+        {
+            var method = Get<Func<IMyCubeGrid, float>>("GetHeatGeneration");
+            return method?.Invoke(grid) ?? -1;
+        }
+
+        public bool SetHeatCapacity(IMyCubeGrid grid, float capacity)
+        {
+            var method = Get<Func<IMyCubeGrid, float, bool>>("SetHeatCapacity");
+            return method != null && method(grid, capacity);
+        }
+
+        public bool SetHeatDissipation(IMyCubeGrid grid, float dissipation)
+        {
+            var method = Get<Func<IMyCubeGrid, float, bool>>("SetHeatDissipation");
+            return method != null && method(grid, dissipation);
+        }
+
+        public bool SetHeatGeneration(IMyCubeGrid grid, float generation)
+        {
+            var method = Get<Func<IMyCubeGrid, float, bool>>("SetHeatGeneration");
+            return method != null && method(grid, generation);
+        }
+
+        public void SetHudVisible(bool visible)
+        {
+            Get<Action<bool>>("SetHudVisible")?.Invoke(visible);
+        }
+
+        public void SetHudOffset(float x, float y, float z)
+        {
+            Get<Action<float, float, float>>("SetHudOffset")?.Invoke(x, y, z);
+        }
+
+        private T Get<T>(string name) where T : class
+        {
+            if (_api == null || !_api.ContainsKey(name))
+                return null;
+
+            return _api[name] as T;
+        }
+
+        private void HandleMessage(object obj)
+        {
+            var api = obj as Dictionary<string, Delegate>;
+            if (api == null)
+                return;
+
+            _api = api;
+            _onReady?.Invoke();
+            _onReady = null;
+        }
+    }
+}
diff --git a/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HeatParts/GridHeatManager.cs b/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HeatParts/GridHeatManager.cs
index 34e874fc3..18c564696 100644
--- a/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HeatParts/GridHeatManager.cs	
+++ b/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HeatParts/GridHeatManager.cs	
@@ -21,6 +21,12 @@ internal class GridHeatManager
 
         public float HeatGeneration;
 
+        public float ApiHeatCapacity;
+
+        public float ApiHeatDissipation;
+
+        public float ApiHeatGeneration;
+
         public float HeatRatio = float.Epsilon;
 
         public float HeatStored;
@@ -34,7 +40,12 @@ public GridHeatManager(IMyCubeGrid grid)
 
         public MyCubeGrid Grid { get; }
 
-        public float GrossHeatDissipation => (HeatDissipation + BaseHeatDissipation) * HeatRatio;
+        public float TotalHeatCapacity => HeatCapacity + BaseHeatCapacity + ApiHeatCapacity;
+
+        public float GrossHeatDissipation => (HeatDissipation + BaseHeatDissipation + ApiHeatDissipation) * HeatRatio;
+
+        public bool HasApiHeat =>
+            ApiHeatCapacity > 0 || ApiHeatDissipation > 0 || ApiHeatGeneration != 0 || HeatStored > 0;
 
         public void UpdateTick()
         {
@@ -42,7 +53,7 @@ public void UpdateTick()
                 Update15Tick();
             _ticks++;
 
-            if (HeatCapacity + BaseHeatCapacity == 0)
+            if (TotalHeatCapacity == 0)
             {
                 HeatRatio = 1;
                 HeatStored = 0;
@@ -52,10 +63,28 @@ public void UpdateTick()
             HeatStored += (HeatGeneration - GrossHeatDissipation) / 60;
             if (HeatStored < 0)
                 HeatStored = 0;
-            else if (HeatStored > HeatCapacity + BaseHeatCapacity)
-                HeatStored = HeatCapacity + BaseHeatCapacity;
+            else if (HeatStored > TotalHeatCapacity)
+                HeatStored = TotalHeatCapacity;
+
+            HeatRatio = HeatStored / TotalHeatCapacity;
+        }
+
+        public float AddHeat(float heat)
+        {
+            return SetHeat(HeatStored + heat);
+        }
+
+        public float SetHeat(float heat)
+        {
+            if (heat < 0)
+                heat = 0;
+
+            if (TotalHeatCapacity > 0 && heat > TotalHeatCapacity)
+                heat = TotalHeatCapacity;
 
-            HeatRatio = HeatStored / (HeatCapacity + BaseHeatCapacity);
+            HeatStored = heat;
+            HeatRatio = TotalHeatCapacity > 0 ? HeatStored / TotalHeatCapacity : HeatStored > 0 ? 1 : float.Epsilon;
+            return HeatStored;
         }
 
         public void RemoveAssembly(int assemblyId)
@@ -71,7 +100,7 @@ private void Update15Tick()
             BaseHeatDissipation = 2 * (gridSize.X * gridSize.Y + gridSize.Y * gridSize.Z + gridSize.Z * gridSize.X) *
                                   BaseHeatDissipationModifier;
 
-            HeatGeneration = 0;
+            HeatGeneration = ApiHeatGeneration;
             foreach (var assemblyId in ModularApi.GetGridAssemblies(Grid))
                 HeatGeneration +=
                     ModularApi.GetAssemblyProperty<float>(assemblyId,
@@ -106,4 +135,4 @@ public void OnPartRemove(int assemblyId, IMyCubeBlock block, bool isBaseBlock)
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HeatParts/HeatManager.cs b/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HeatParts/HeatManager.cs
index d770a90f5..dbfd3efb1 100644
--- a/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HeatParts/HeatManager.cs	
+++ b/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HeatParts/HeatManager.cs	
@@ -1,31 +1,46 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using Sandbox.ModAPI;
 using VRage.Game.ModAPI;
 using VRage.ModAPI;
+using VRageMath;
 
 namespace Epstein_Fusion_DS.HeatParts
 {
     internal class HeatManager
     {
+        public const long ApiChannel = 11920040L;
+        private const string ApiRequest = "GridHeatAPI.Request";
+
         public static HeatManager I = new HeatManager();
 
         private readonly Dictionary<IMyCubeGrid, GridHeatManager> _heatSystems =
             new Dictionary<IMyCubeGrid, GridHeatManager>();
 
+        private Dictionary<string, Delegate> _api;
+
+        public bool HeatHudVisible = true;
+        public Vector3D HeatHudOffset = new Vector3D(-0.759375, -0.8, 0);
+
         public void Load()
         {
             I = this;
             MyAPIGateway.Entities.OnEntityAdd += OnEntityAdd;
             MyAPIGateway.Entities.OnEntityRemove += OnEntityRemove;
+            MyAPIGateway.Utilities.RegisterMessageHandler(ApiChannel, HandleApiRequest);
+            RegisterExistingGrids();
         }
 
         public void Unload()
         {
             MyAPIGateway.Entities.OnEntityAdd -= OnEntityAdd;
             MyAPIGateway.Entities.OnEntityRemove -= OnEntityRemove;
+            MyAPIGateway.Utilities.UnregisterMessageHandler(ApiChannel, HandleApiRequest);
             foreach (var system in _heatSystems.Values)
                 system.Unload();
+            _heatSystems.Clear();
+            _api = null;
             I = null;
         }
 
@@ -46,9 +61,14 @@ public float GetGridHeatLevel(IMyCubeGrid grid)
             return _heatSystems.GetValueOrDefault(grid, null)?.HeatRatio ?? -1;
         }
 
+        public float GetGridHeat(IMyCubeGrid grid)
+        {
+            return _heatSystems.GetValueOrDefault(grid, null)?.HeatStored ?? -1;
+        }
+
         public float GetGridHeatCapacity(IMyCubeGrid grid)
         {
-            return _heatSystems.GetValueOrDefault(grid, null)?.HeatCapacity ?? -1;
+            return _heatSystems.GetValueOrDefault(grid, null)?.TotalHeatCapacity ?? -1;
         }
 
         public float GetGridHeatDissipation(IMyCubeGrid grid)
@@ -61,13 +81,117 @@ public float GetGridHeatGeneration(IMyCubeGrid grid)
             return _heatSystems.GetValueOrDefault(grid, null)?.HeatGeneration ?? -1;
         }
 
+        public bool HasGridHeat(IMyCubeGrid grid)
+        {
+            return _heatSystems.GetValueOrDefault(grid, null)?.HasApiHeat ?? false;
+        }
+
+        public bool AddGridHeat(IMyCubeGrid grid, float heat)
+        {
+            var system = EnsureGrid(grid);
+            if (system == null)
+                return false;
+
+            system.AddHeat(heat);
+            return true;
+        }
+
+        public bool SetGridHeat(IMyCubeGrid grid, float heat)
+        {
+            var system = EnsureGrid(grid);
+            if (system == null)
+                return false;
+
+            system.SetHeat(heat);
+            return true;
+        }
+
+        public bool SetGridHeatCapacity(IMyCubeGrid grid, float capacity)
+        {
+            var system = EnsureGrid(grid);
+            if (system == null)
+                return false;
+
+            system.ApiHeatCapacity = Math.Max(0, capacity);
+            system.SetHeat(system.HeatStored);
+            return true;
+        }
+
+        public bool SetGridHeatDissipation(IMyCubeGrid grid, float dissipation)
+        {
+            var system = EnsureGrid(grid);
+            if (system == null)
+                return false;
+
+            system.ApiHeatDissipation = Math.Max(0, dissipation);
+            return true;
+        }
+
+        public bool SetGridHeatGeneration(IMyCubeGrid grid, float generation)
+        {
+            var system = EnsureGrid(grid);
+            if (system == null)
+                return false;
+
+            system.ApiHeatGeneration = generation;
+            system.HeatGeneration = generation;
+            return true;
+        }
+
+        public void SetHeatHudVisible(bool visible)
+        {
+            HeatHudVisible = visible;
+        }
+
+        public void SetHeatHudOffset(float x, float y, float z)
+        {
+            HeatHudOffset = new Vector3D(x, y, z);
+        }
+
+        private void HandleApiRequest(object obj)
+        {
+            if (!(obj is string) || (string)obj != ApiRequest)
+                return;
+
+            MyAPIGateway.Utilities.SendModMessage(ApiChannel, GetApi());
+        }
+
+        private Dictionary<string, Delegate> GetApi()
+        {
+            return _api ?? (_api = new Dictionary<string, Delegate>
+            {
+                ["Version"] = new Func<int>(() => 1),
+                ["AddHeat"] = new Func<IMyCubeGrid, float, bool>(AddGridHeat),
+                ["SetHeat"] = new Func<IMyCubeGrid, float, bool>(SetGridHeat),
+                ["GetHeat"] = new Func<IMyCubeGrid, float>(GetGridHeat),
+                ["GetHeatRatio"] = new Func<IMyCubeGrid, float>(GetGridHeatLevel),
+                ["GetHeatCapacity"] = new Func<IMyCubeGrid, float>(GetGridHeatCapacity),
+                ["GetHeatDissipation"] = new Func<IMyCubeGrid, float>(GetGridHeatDissipation),
+                ["GetHeatGeneration"] = new Func<IMyCubeGrid, float>(GetGridHeatGeneration),
+                ["SetHeatCapacity"] = new Func<IMyCubeGrid, float, bool>(SetGridHeatCapacity),
+                ["SetHeatDissipation"] = new Func<IMyCubeGrid, float, bool>(SetGridHeatDissipation),
+                ["SetHeatGeneration"] = new Func<IMyCubeGrid, float, bool>(SetGridHeatGeneration),
+                ["SetHudVisible"] = new Action<bool>(SetHeatHudVisible),
+                ["SetHudOffset"] = new Action<float, float, float>(SetHeatHudOffset),
+            });
+        }
+
+        private void RegisterExistingGrids()
+        {
+            var entities = new HashSet<IMyEntity>();
+            MyAPIGateway.Entities.GetEntities(entities, entity => entity is IMyCubeGrid && entity.Physics != null);
+
+            foreach (var entity in entities)
+                EnsureGrid((IMyCubeGrid)entity);
+        }
+
         private void OnEntityAdd(IMyEntity entity)
         {
             if (!(entity is IMyCubeGrid) || entity.Physics == null)
                 return;
             var grid = (IMyCubeGrid)entity;
 
-            _heatSystems[grid] = new GridHeatManager(grid);
+            EnsureGrid(grid);
         }
 
         private void OnEntityRemove(IMyEntity entity)
@@ -76,18 +200,32 @@ private void OnEntityRemove(IMyEntity entity)
                 return;
             var grid = (IMyCubeGrid)entity;
 
+            if (!_heatSystems.ContainsKey(grid))
+                return;
+
             _heatSystems[grid].Unload();
             _heatSystems.Remove(grid);
         }
 
         public void OnPartAdd(int assemblyId, IMyCubeBlock block, bool isBaseBlock)
         {
-            _heatSystems[block.CubeGrid].OnPartAdd(assemblyId, block, isBaseBlock);
+            EnsureGrid(block.CubeGrid)?.OnPartAdd(assemblyId, block, isBaseBlock);
         }
 
         public void OnPartRemove(int assemblyId, IMyCubeBlock block, bool isBaseBlock)
         {
-            _heatSystems[block.CubeGrid].OnPartRemove(assemblyId, block, isBaseBlock);
+            EnsureGrid(block.CubeGrid)?.OnPartRemove(assemblyId, block, isBaseBlock);
+        }
+
+        private GridHeatManager EnsureGrid(IMyCubeGrid grid)
+        {
+            if (grid == null)
+                return null;
+
+            if (!_heatSystems.ContainsKey(grid))
+                _heatSystems[grid] = new GridHeatManager(grid);
+
+            return _heatSystems[grid];
         }
     }
-}
\ No newline at end of file
+}
diff --git a/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HudHelpers/FusionWindow.cs b/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HudHelpers/FusionWindow.cs
index e677e6414..129d368ca 100644
--- a/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HudHelpers/FusionWindow.cs	
+++ b/Utility Mods/MoA Fusion Systems/Data/Scripts/ModularAssemblies/HudHelpers/FusionWindow.cs	
@@ -20,26 +20,16 @@ internal class FusionWindow : CamSpaceNode
         private readonly GlyphFormat _stdTextFormat = new GlyphFormat(color: HudConstants.HudTextColor, alignment: TextAlignment.Center, font: FontManager.GetFont("Monospace"));
         private readonly GlyphFormat _stdTextFormatInfo = new GlyphFormat(color: HudConstants.HudTextColor, textSize: 0.6f, alignment: TextAlignment.Left, font: FontManager.GetFont("Monospace"));
 
-        private static readonly Vector3D UnitTransformOffset = new Vector3D(-0.759375, -0.8, 0);
-
-        public FusionWindow(HudParentBase parent) : base(parent)
-        {
-            RotationAxis = new Vector3(0, 1, 0);
-            RotationAngle = 0.25f;
-
-            //var invert = MatrixD.CreatePerspectiveFieldOfView(MathHelper.ToRadians(90), 16 / 9d,
-            //    MyAPIGateway.Session.Camera.NearPlaneDistance, MyAPIGateway.Session.Camera.FarPlaneDistance);
-            //ModularApi.Log(Vector3D.Transform(new Vector3D(-0.0675, -0.04, -0.05), invert).ToString());
-
-            var fovMatrix = MatrixD.Invert(MatrixD.CreatePerspectiveFieldOfView(
-                MathHelper.ToRadians(MyAPIGateway.Session.Camera.FieldOfViewAngle), HudMain.AspectRatio,
-                MyAPIGateway.Session.Camera.NearPlaneDistance, MyAPIGateway.Session.Camera.FarPlaneDistance));
-
-            TransformOffset = Vector3D.Transform(UnitTransformOffset, fovMatrix);
-
-
-            _backgroundBox = new TexturedBox(this)
-            {
+        private static readonly Vector3D DefaultUnitTransformOffset = new Vector3D(-0.759375, -0.8, 0);
+
+        public FusionWindow(HudParentBase parent) : base(parent)
+        {
+            RotationAxis = new Vector3(0, 1, 0);
+            RotationAngle = 0.25f;
+            UpdateTransformOffset();
+
+            _backgroundBox = new TexturedBox(this)
+            {
                 Material = new Material("WhiteSquare", HudConstants.HudSize),
                 Size = HudConstants.HudSize,
                 Color = HudConstants.HudBackgroundColor,
@@ -105,19 +95,20 @@ public FusionWindow(HudParentBase parent) : base(parent)
         private MyEntity3DSoundEmitter _soundEmitter = null;
         private readonly MySoundPair _alertSound = new MySoundPair("ArcSoundBlockAlert2");
 
-        public void Update()
-        {
-            _ticks++;
-            var playerCockpit = MyAPIGateway.Session?.Player?.Controller?.ControlledEntity?.Entity as IMyShipController;
+        public void Update()
+        {
+            _ticks++;
+            UpdateTransformOffset();
+            var playerCockpit = MyAPIGateway.Session?.Player?.Controller?.ControlledEntity?.Entity as IMyShipController;
 
             // Pulling the current HudState is SLOOOOWWWW, so we only pull it when tab is just pressed.
             //if (MyAPIGateway.Input.IsNewKeyPressed(MyKeys.Tab))
             //    _shouldHide = MyAPIGateway.Session?.Config?.HudState != 1;
 
             // Hide HUD element if the player isn't in a cockpit
-            if (playerCockpit == null || _shouldHide)
-            {
-                if (Visible) Visible = false;
+            if (playerCockpit == null || _shouldHide || !HeatManager.I.HeatHudVisible)
+            {
+                if (Visible) Visible = false;
 
                 if (_soundEmitter != null)
                 {
@@ -154,13 +145,15 @@ public void Update()
                     reactorCount++;
                 }
             }
-            reactorIntegrity /= reactorCount;
-
-            // Hide HUD element if the grid has no fusion systems (capacity is always >0 for a fusion system)
-            if (totalFusionCapacity == 0)
-            {
-                if (Visible) Visible = false;
-                return;
+            reactorIntegrity = reactorCount > 0 ? reactorIntegrity / reactorCount : 1;
+            var hasFusion = totalFusionCapacity > 0;
+            var hasApiHeat = HeatManager.I.HasGridHeat(playerGrid);
+
+            // Hide HUD element if the grid has no fusion systems and no API-managed heat.
+            if (!hasFusion && !hasApiHeat)
+            {
+                if (Visible) Visible = false;
+                return;
             }
 
             // Show otherwise
@@ -171,19 +164,32 @@ public void Update()
             _heatBox.Width = 384 * HudConstants.HudSizeRatio.X * heatPct;
             _heatBox.Color = new Color(heatPct, 1-heatPct, 0, 0.75f);
 
-            _storBox.Width = 384 * HudConstants.HudSizeRatio.X * (totalFusionStored / totalFusionCapacity);
-
-            _infoLabelLeft.Text = new RichText
-            {
-                {(reactorIntegrity*100).ToString("N0") + "%", _stdTextFormatInfo.WithColor(reactorIntegrity > 0.6 ? Color.White : Color.Red)},
-                {" INTEGRITY - ", _stdTextFormatInfo},
-                {GetNoticeText(heatPct, reactorIntegrity), GetNoticeFormat(heatPct, reactorIntegrity)},
-            };
-
-            _heatLabel.Text = $"{heatPct*100:N0}% HEAT";
-            _storageLabel.Text = $"{(totalFusionStored / totalFusionCapacity) * 100:N0}% STOR";
-
-            if (heatPct > 0.8f)
+            if (hasFusion)
+            {
+                _storBox.Width = 384 * HudConstants.HudSizeRatio.X * (totalFusionStored / totalFusionCapacity);
+
+                _infoLabelLeft.Text = new RichText
+                {
+                    {(reactorIntegrity*100).ToString("N0") + "%", _stdTextFormatInfo.WithColor(reactorIntegrity > 0.6 ? Color.White : Color.Red)},
+                    {" INTEGRITY - ", _stdTextFormatInfo},
+                    {GetNoticeText(heatPct, reactorIntegrity), GetNoticeFormat(heatPct, reactorIntegrity)},
+                };
+
+                _storageLabel.Text = $"{(totalFusionStored / totalFusionCapacity) * 100:N0}% STOR";
+            }
+            else
+            {
+                _storBox.Width = 0;
+                _infoLabelLeft.Text = new RichText
+                {
+                    {"GRID HEAT API", _stdTextFormatInfo.WithColor(heatPct > 0.8f ? Color.Red : Color.White)},
+                };
+                _storageLabel.Text = "GRID HEAT";
+            }
+
+            _heatLabel.Text = $"{heatPct*100:N0}% HEAT";
+
+            if (heatPct > 0.8f)
             {
                 if (_soundEmitter == null)
                 {
@@ -201,10 +207,20 @@ public void Update()
                     _soundEmitter.StopSound(true);
                     _soundEmitter = null;
                 }
-            }
-        }
-
-        private int _errRemainingTicks = 0;
+            }
+        }
+
+        private void UpdateTransformOffset()
+        {
+            var fovMatrix = MatrixD.Invert(MatrixD.CreatePerspectiveFieldOfView(
+                MathHelper.ToRadians(MyAPIGateway.Session.Camera.FieldOfViewAngle), HudMain.AspectRatio,
+                MyAPIGateway.Session.Camera.NearPlaneDistance, MyAPIGateway.Session.Camera.FarPlaneDistance));
+
+            var offset = HeatManager.I?.HeatHudOffset ?? DefaultUnitTransformOffset;
+            TransformOffset = Vector3D.Transform(offset, fovMatrix);
+        }
+
+        private int _errRemainingTicks = 0;
         private float _lastIntegrityPct = 1;
         private string _lastErrText = "";
         private string GetNoticeText(float heatPct, float integrityPct)
diff --git a/Utility Mods/MoA Fusion Systems/GridHeatAPI.md b/Utility Mods/MoA Fusion Systems/GridHeatAPI.md
new file mode 100644
index 000000000..3a50ffbcc
--- /dev/null
+++ b/Utility Mods/MoA Fusion Systems/GridHeatAPI.md	
@@ -0,0 +1,45 @@
+# Grid Heat API
+
+`GridHeatApi.cs` exposes the fusion heat system as a small grid-level API other mods can call without knowing anything about fusion assemblies.
+
+## Quick Use
+
+Copy `Data/Scripts/ModularAssemblies/HeatParts/GridHeatApi.cs` into your mod and keep one instance on your session component:
+
+```csharp
+private readonly GridHeatApi _heat = new GridHeatApi();
+
+public override void LoadData()
+{
+    _heat.Load();
+}
+
+protected override void UnloadData()
+{
+    _heat.Unload();
+}
+```
+
+## Common Calls
+
+```csharp
+_heat.SetHeatCapacity(grid, 1000f);
+_heat.SetHeatDissipation(grid, 20f);
+_heat.AddHeat(grid, 75f);
+
+float heat = _heat.GetHeat(grid);
+float heatRatio = _heat.GetHeatRatio(grid);
+```
+
+`SetHeatCapacity` and `SetHeatDissipation` add API-owned capacity/dissipation on top of the heat blocks already provided by Fusion Systems. `AddHeat` and `SetHeat` are clamped to the grid's total heat capacity.
+
+## HUD Position
+
+The HUD heat bar uses the same camera-space offset as the Fusion Systems HUD. Other mods can hide or move it:
+
+```csharp
+_heat.SetHudVisible(true);
+_heat.SetHudOffset(-0.76f, -0.80f, 0f);
+```
+
+The offset values are camera-space X/Y/Z values. The default is the existing Fusion Systems position.