diff --git a/Assets/Unheimlich_POC/Editor.meta b/Assets/Unheimlich_POC/Editor.meta
new file mode 100644
index 00000000..d3f3357d
--- /dev/null
+++ b/Assets/Unheimlich_POC/Editor.meta
@@ -0,0 +1,8 @@
+fileFormatVersion: 2
+guid: 0786eea16a39aad45a66d878d9427145
+folderAsset: yes
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/Unheimlich_POC/Editor/SceneEditPresenceTool.cs b/Assets/Unheimlich_POC/Editor/SceneEditPresenceTool.cs
new file mode 100644
index 00000000..19b4f77b
--- /dev/null
+++ b/Assets/Unheimlich_POC/Editor/SceneEditPresenceTool.cs
@@ -0,0 +1,642 @@
+using System;
+using System.IO;
+using System.Net;
+using System.Text;
+using System.Threading.Tasks;
+using UnityEditor;
+using UnityEditor.SceneManagement;
+using UnityEngine;
+using UnityEngine.SceneManagement;
+
+[InitializeOnLoad]
+public static class SceneEditPresenceTool
+{
+    private const string ServerUrl = "http://unityapi.coiriergraphics.fr/scene_presence/";
+    private const double HeartbeatInterval = 10.0;
+
+    private static string _userId;
+    private static string _projectName;
+    private static string _scenePath;
+    private static double _nextHeartbeat;
+    private static bool _offline;
+    private static string _currentEditor = "none";
+    private static bool _requestInFlight;
+
+    private const float OverlayHeight = 30f;
+    private const float OverlayMarginTop = 3f;
+    private const float OverlayOffsetX = 48f;
+    private const float OverlayBaseWidth = 420f;
+    private const float OverlayWidthScale = .70f;
+    private const float ButtonWidth = 78f;
+
+    private static string ConfigPath =>
+        Path.Combine(
+            Directory.GetParent(Application.dataPath).FullName,
+            "UserSettings",
+            "ScenePresenceUser.json"
+        );
+
+    static SceneEditPresenceTool()
+    {
+        _projectName = Directory.GetParent(Application.dataPath).Name;
+        _userId = LoadOrAskUserId();
+
+        EditorApplication.delayCall += OnStartup;
+        EditorApplication.update += OnUpdate;
+        EditorSceneManager.activeSceneChangedInEditMode += OnSceneChanged;
+        SceneView.duringSceneGui += OnSceneGui;
+    }
+
+    private static async void OnStartup()
+    {
+        if (string.IsNullOrWhiteSpace(_userId))
+            return;
+
+        var scene = SceneManager.GetActiveScene();
+        if (!string.IsNullOrEmpty(scene.path))
+        {
+            _scenePath = scene.path;
+            await OpenScene();
+        }
+    }
+
+    private static async void OnSceneChanged(Scene oldScene, Scene newScene)
+    {
+        if (string.IsNullOrWhiteSpace(_userId))
+            return;
+
+        if (!string.IsNullOrEmpty(newScene.path))
+        {
+            _scenePath = newScene.path;
+            await OpenScene();
+        }
+    }
+
+    private static async void OnUpdate()
+    {
+        if (string.IsNullOrWhiteSpace(_userId))
+            return;
+
+        if (string.IsNullOrEmpty(_scenePath))
+            return;
+
+        if (_requestInFlight)
+            return;
+
+        if (EditorApplication.timeSinceStartup < _nextHeartbeat)
+            return;
+
+        _nextHeartbeat = EditorApplication.timeSinceStartup + HeartbeatInterval;
+        await Heartbeat();
+        RepaintSceneView();
+    }
+
+    private static void OnSceneGui(SceneView sceneView)
+    {
+        Handles.BeginGUI();
+
+        float width = Mathf.Min(sceneView.position.width - (OverlayOffsetX + 16f), OverlayBaseWidth) * OverlayWidthScale;
+
+        Rect rect = new Rect(
+            OverlayOffsetX,
+            OverlayMarginTop,
+            width,
+            OverlayHeight
+        );
+
+        DrawTopBar(rect);
+
+        Handles.EndGUI();
+    }
+
+    private static void DrawTopBar(Rect rect)
+    {
+        UiState state = GetUiState();
+        string buttonLabel = state == UiState.OwnedByMe ? "Release" : "Edit";
+        bool buttonEnabled = state != UiState.Offline && !_requestInFlight;
+
+        Rect buttonRect = new Rect(
+            rect.xMax - ButtonWidth - 6f,
+            rect.y + 4f,
+            ButtonWidth,
+            rect.height - 8f
+        );
+
+        Rect textRect = new Rect(
+            rect.x + 10f,
+            rect.y,
+            rect.width - ButtonWidth - 22f,
+            rect.height
+        );
+
+        EditorGUI.DrawRect(rect, GetBackgroundColor(state));
+
+        GUIStyle textStyle = new GUIStyle(EditorStyles.label)
+        {
+            alignment = TextAnchor.MiddleLeft,
+            fontStyle = FontStyle.Bold,
+            fontSize = 11,
+            normal = { textColor = Color.white },
+            clipping = TextClipping.Clip
+        };
+
+        GUI.Label(textRect, GetMessage(state), textStyle);
+
+        Color oldColor = GUI.backgroundColor;
+        GUI.backgroundColor = GetButtonColor(state);
+
+        EditorGUI.BeginDisabledGroup(!buttonEnabled);
+        if (GUI.Button(buttonRect, buttonLabel))
+        {
+            if (state == UiState.MissingUserId)
+            {
+                AskUserIdWindow.ShowWindow(SaveUserIdAndRefresh);
+            }
+            else if (state == UiState.OwnedByMe)
+            {
+                ReleaseEditMode();
+            }
+            else
+            {
+                TakeEditMode();
+            }
+        }
+        EditorGUI.EndDisabledGroup();
+
+        GUI.backgroundColor = oldColor;
+    }
+
+    private static UiState GetUiState()
+    {
+        if (string.IsNullOrWhiteSpace(_userId))
+            return UiState.MissingUserId;
+
+        if (_offline)
+            return UiState.Offline;
+
+        if (_currentEditor == _userId)
+            return UiState.OwnedByMe;
+
+        if (!string.IsNullOrEmpty(_currentEditor) && _currentEditor != "none")
+            return UiState.OwnedByOther;
+
+        return UiState.Free;
+    }
+
+    private static string GetMessage(UiState state)
+    {
+        switch (state)
+        {
+            case UiState.MissingUserId:
+                return "User ID required";
+            case UiState.OwnedByMe:
+                return "You are editing this scene";
+            case UiState.OwnedByOther:
+                return $"{_currentEditor} is editing this scene";
+            case UiState.Offline:
+                return "Offline";
+            default:
+                return "Scene available";
+        }
+    }
+
+    private static Color GetBackgroundColor(UiState state)
+    {
+        const float alpha = 0.70f;
+
+        switch (state)
+        {
+            case UiState.MissingUserId:
+            case UiState.Offline:
+                return new Color(1.00f, 0.10f, 0.10f, alpha);
+
+            case UiState.OwnedByMe:
+                return new Color(0.22f, 0.55f, 0.28f, alpha);
+
+            case UiState.OwnedByOther:
+                return new Color(0.82f, 0.48f, 0.10f, alpha);
+
+            default:
+                return new Color(0.18f, 0.18f, 0.18f, alpha);
+        }
+    }
+
+    private static Color GetButtonColor(UiState state)
+    {
+        switch (state)
+        {
+            case UiState.Free:
+                return new Color(0.38f, 0.66f, 1.00f, 1f);
+
+            case UiState.MissingUserId:
+            case UiState.OwnedByOther:
+            case UiState.OwnedByMe:
+            case UiState.Offline:
+            default:
+                return new Color(0.22f, 0.22f, 0.22f, 1f);
+        }
+    }
+
+    private static async void TakeEditMode()
+    {
+        if (string.IsNullOrWhiteSpace(_userId))
+        {
+            AskUserIdWindow.ShowWindow(SaveUserIdAndRefresh);
+            return;
+        }
+
+        if (string.IsNullOrEmpty(_scenePath))
+            return;
+
+        EditModeRequest payload = new EditModeRequest
+        {
+            projectName = _projectName,
+            scenePath = _scenePath,
+            userId = _userId,
+            dateTime = DateTime.UtcNow.ToString("o"),
+            force = false
+        };
+
+        SetEditModeResponse result = await Request<SetEditModeResponse>("set_edit_mode.php", payload);
+        if (result == null)
+        {
+            SetOffline();
+            return;
+        }
+
+        _offline = false;
+
+        if (!result.success)
+        {
+            Debug.LogError("[ScenePresence] set_edit_mode failed.");
+            RepaintSceneView();
+            return;
+        }
+
+        if (result.granted)
+        {
+            _currentEditor = _userId;
+            RepaintSceneView();
+            return;
+        }
+
+        string ownerName = !string.IsNullOrWhiteSpace(result.occupiedBy)
+            ? result.occupiedBy
+            : (!string.IsNullOrWhiteSpace(_currentEditor) && _currentEditor != "none" ? _currentEditor : "another user");
+
+        bool forceTake = EditorUtility.DisplayDialog(
+            "Scene Already In Edit Mode",
+            $"This scene is already locked by {ownerName}.\nDo you want to take control anyway?",
+            "Take Control",
+            "Cancel"
+        );
+
+        if (!forceTake)
+            return;
+
+        payload.force = true;
+
+        SetEditModeResponse forced = await Request<SetEditModeResponse>("set_edit_mode.php", payload);
+        if (forced == null)
+        {
+            SetOffline();
+            return;
+        }
+
+        _offline = false;
+
+        if (forced.success && forced.granted)
+        {
+            _currentEditor = _userId;
+            RepaintSceneView();
+        }
+    }
+
+    private static async void ReleaseEditMode()
+    {
+        if (string.IsNullOrWhiteSpace(_userId))
+            return;
+
+        if (string.IsNullOrEmpty(_scenePath))
+            return;
+
+        ReleaseResponse result = await Request<ReleaseResponse>("release_edit_mode.php", new BaseRequest
+        {
+            projectName = _projectName,
+            scenePath = _scenePath,
+            userId = _userId,
+            dateTime = DateTime.UtcNow.ToString("o")
+        });
+
+        if (result == null)
+        {
+            SetOffline();
+            return;
+        }
+
+        _offline = false;
+        _currentEditor = "none";
+        RepaintSceneView();
+        await OpenScene();
+    }
+
+    private static async Task OpenScene()
+    {
+        OpenSceneResponse result = await Request<OpenSceneResponse>("open_scene.php", new BaseRequest
+        {
+            projectName = _projectName,
+            scenePath = _scenePath,
+            userId = _userId,
+            dateTime = DateTime.UtcNow.ToString("o")
+        });
+
+        if (result == null)
+        {
+            SetOffline();
+            return;
+        }
+
+        _offline = false;
+
+        if (result.hasEditor)
+        {
+            _currentEditor = string.IsNullOrWhiteSpace(result.editorUserId) ? "none" : result.editorUserId;
+        }
+        else
+        {
+            _currentEditor = "none";
+        }
+
+        RepaintSceneView();
+    }
+
+    private static async Task Heartbeat()
+    {
+        HeartbeatResponse result = await Request<HeartbeatResponse>("heartbeat.php", new BaseRequest
+        {
+            projectName = _projectName,
+            scenePath = _scenePath,
+            userId = _userId,
+            dateTime = DateTime.UtcNow.ToString("o")
+        });
+
+        if (result == null)
+        {
+            SetOffline();
+            return;
+        }
+
+        _offline = false;
+
+        if (result.hasEditor)
+            _currentEditor = string.IsNullOrWhiteSpace(result.editorUserId) ? "none" : result.editorUserId;
+        else
+            _currentEditor = "none";
+
+        RepaintSceneView();
+    }
+
+    private static async Task<T> Request<T>(string endpoint, object payload) where T : class
+    {
+        _requestInFlight = true;
+
+        try
+        {
+            string json = JsonUtility.ToJson(payload);
+            byte[] bytes = Encoding.UTF8.GetBytes(json);
+
+            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(ServerUrl + endpoint);
+            request.Method = "POST";
+            request.ContentType = "application/json";
+            request.Timeout = 5000;
+            request.ReadWriteTimeout = 5000;
+            request.ContentLength = bytes.Length;
+
+            using (var requestStream = await request.GetRequestStreamAsync())
+            {
+                await requestStream.WriteAsync(bytes, 0, bytes.Length);
+            }
+
+            using var response = await request.GetResponseAsync();
+            using var responseStream = response.GetResponseStream();
+            using var reader = new StreamReader(responseStream);
+            string responseJson = await reader.ReadToEndAsync();
+
+            if (string.IsNullOrWhiteSpace(responseJson))
+                return null;
+
+            if (!responseJson.TrimStart().StartsWith("{"))
+            {
+                Debug.LogError($"[ScenePresence] Non-JSON response from {endpoint}: {responseJson}");
+                return null;
+            }
+
+            //Debug.Log($"[ScenePresence] {endpoint} => {responseJson}");
+            return JsonUtility.FromJson<T>(responseJson);
+        }
+        catch (Exception ex)
+        {
+            Debug.LogError($"[ScenePresence] Request failed ({endpoint}): {ex}");
+            return null;
+        }
+        finally
+        {
+            _requestInFlight = false;
+        }
+    }
+
+    private static void SetOffline()
+    {
+        _offline = true;
+        RepaintSceneView();
+    }
+
+    private static void RepaintSceneView()
+    {
+        if (SceneView.lastActiveSceneView != null)
+            SceneView.lastActiveSceneView.Repaint();
+    }
+
+    private static string LoadOrAskUserId()
+    {
+        try
+        {
+            if (File.Exists(ConfigPath))
+            {
+                UserConfig saved = JsonUtility.FromJson<UserConfig>(File.ReadAllText(ConfigPath));
+                if (saved != null && !string.IsNullOrWhiteSpace(saved.userId))
+                    return saved.userId.Trim();
+            }
+        }
+        catch (Exception ex)
+        {
+            Debug.LogWarning($"[ScenePresence] Failed to read config: {ex.Message}");
+        }
+
+        EditorApplication.delayCall += () =>
+        {
+            AskUserIdWindow.ShowWindow(SaveUserIdAndRefresh);
+        };
+        return null;
+    }
+
+    private static void SaveUserIdAndRefresh(string userId)
+    {
+        if (string.IsNullOrWhiteSpace(userId))
+            return;
+
+        _userId = userId.Trim();
+        SaveUserId(_userId);
+
+        EditorApplication.delayCall += async () =>
+        {
+            Scene scene = SceneManager.GetActiveScene();
+            if (!string.IsNullOrEmpty(scene.path))
+            {
+                _scenePath = scene.path;
+                await OpenScene();
+            }
+
+            RepaintSceneView();
+        };
+    }
+
+    private static void SaveUserId(string userId)
+    {
+        try
+        {
+            string directory = Path.GetDirectoryName(ConfigPath);
+            if (!Directory.Exists(directory))
+                Directory.CreateDirectory(directory);
+
+            UserConfig config = new UserConfig { userId = userId };
+            File.WriteAllText(ConfigPath, JsonUtility.ToJson(config, true));
+        }
+        catch (Exception ex)
+        {
+            Debug.LogError($"[ScenePresence] Failed to save config: {ex.Message}");
+        }
+    }
+
+    [Serializable]
+    private class UserConfig
+    {
+        public string userId;
+    }
+
+    [Serializable]
+    private class BaseRequest
+    {
+        public string projectName;
+        public string scenePath;
+        public string userId;
+        public string dateTime;
+    }
+
+    [Serializable]
+    private class EditModeRequest : BaseRequest
+    {
+        public bool force;
+    }
+
+    [Serializable]
+    private class OpenSceneResponse
+    {
+        public bool success;
+        public bool hasEditor;
+        public string editorUserId;
+        public string editorDateTime;
+        public string editorServerTakenAt;
+        public bool editorOnline;
+    }
+
+    [Serializable]
+    private class HeartbeatResponse
+    {
+        public bool success;
+        public bool hasEditor;
+        public string editorUserId;
+        public bool editorOnline;
+    }
+
+    [Serializable]
+    private class SetEditModeResponse
+    {
+        public bool success;
+        public bool granted;
+        public bool forced;
+        public string occupiedBy;
+        public string editorUserId;
+    }
+
+    [Serializable]
+    private class ReleaseResponse
+    {
+        public bool success;
+        public bool released;
+    }
+
+    private enum UiState
+    {
+        MissingUserId,
+        Free,
+        OwnedByOther,
+        OwnedByMe,
+        Offline
+    }
+}
+
+public class AskUserIdWindow : EditorWindow
+{
+    private static Action<string> _onSave;
+    private static AskUserIdWindow _instance;
+
+    private string _userId = "";
+
+    public static void ShowWindow(Action<string> onSave)
+    {
+        if (_instance != null)
+        {
+            _instance.Focus();
+            return;
+        }
+
+        _onSave = onSave;
+
+        _instance = CreateInstance<AskUserIdWindow>();
+        _instance.titleContent = new GUIContent("Scene Presence Setup");
+        _instance.minSize = new Vector2(240, 60);
+        _instance.maxSize = new Vector2(240, 60);
+        _instance.ShowUtility();
+        _instance.Focus();
+    }
+
+    private void OnDestroy()
+    {
+        if (_instance == this)
+            _instance = null;
+    }
+
+    private void OnGUI()
+    {
+        GUILayout.Space(10);
+        EditorGUIUtility.labelWidth = 60;
+        _userId = EditorGUILayout.TextField("User ID", _userId);
+        GUILayout.FlexibleSpace();
+
+        using (new EditorGUILayout.HorizontalScope())
+        {
+            GUILayout.FlexibleSpace();
+
+            GUI.enabled = !string.IsNullOrWhiteSpace(_userId);
+            if (GUILayout.Button("Save", GUILayout.Width(80)))
+            {
+                _onSave?.Invoke(_userId.Trim());
+                Close();
+            }
+            GUI.enabled = true;
+        }
+
+        GUILayout.Space(10);
+    }
+}
\ No newline at end of file
diff --git a/Assets/Unheimlich_POC/Editor/SceneEditPresenceTool.cs.meta b/Assets/Unheimlich_POC/Editor/SceneEditPresenceTool.cs.meta
new file mode 100644
index 00000000..e9b69fa5
--- /dev/null
+++ b/Assets/Unheimlich_POC/Editor/SceneEditPresenceTool.cs.meta
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: d9c85ae0c5f70cc4da07f387065c0015
\ No newline at end of file