diff --git a/Endpoints/AgentEndpoint.cs b/Endpoints/AgentEndpoint.cs
index 301046c..ea3d947 100644
--- a/Endpoints/AgentEndpoint.cs
+++ b/Endpoints/AgentEndpoint.cs
@@ -1,5 +1,6 @@
 using System.Text.Json;
 using System.Threading.Tasks;
+using Gott.Extensions;
 using Gott.Models;
 using Gott.Services;
 using Microsoft.AspNetCore.Builder;
@@ -21,7 +22,8 @@ public static class AgentEndpoint
 
     private static async Task HandleList(HttpContext ctx, DatabaseService db)
     {
-        var agents = await db.GetAgents();
+        var userId = ctx.GetUserId();
+        var agents = await db.GetAgents(userId);
         await ctx.Response.WriteAsJsonAsync(agents);
     }
 
@@ -31,13 +33,14 @@ public static class AgentEndpoint
         if (string.IsNullOrEmpty(agentId)) { ctx.Response.StatusCode = 400; return; }
 
         var agent = await db.GetAgent(agentId);
-        if (agent == null) { ctx.Response.StatusCode = 404; return; }
+        if (agent == null || agent.UserId != ctx.GetUserId()) { ctx.Response.StatusCode = 404; return; }
 
         await ctx.Response.WriteAsJsonAsync(agent);
     }
 
     private static async Task HandleCreate(HttpContext ctx, DatabaseService db, ImageService imageService, MemoryService memoryService)
     {
+        var userId = ctx.GetUserId();
         var body = await JsonSerializer.DeserializeAsync<JsonElement>(ctx.Request.Body);
 
         var avatarRaw = body.TryGetProperty("avatar", out var av) ? av.GetString() : null;
@@ -48,6 +51,7 @@ public static class AgentEndpoint
 
         var agent = new AgentRecord
         {
+            UserId = userId,
             Name = body.TryGetProperty("name", out var n) ? n.GetString() ?? "Neuer Agent" : "Neuer Agent",
             Avatar = imageService.ResizeDataUrl(avatarRaw),
             Description = body.TryGetProperty("description", out var d) ? d.GetString() : null,
@@ -68,11 +72,12 @@ public static class AgentEndpoint
 
     private static async Task HandleUpdate(HttpContext ctx, DatabaseService db, ImageService imageService, MemoryService memoryService)
     {
+        var userId = ctx.GetUserId();
         var agentId = ctx.Request.RouteValues["agentId"]?.ToString();
         if (string.IsNullOrEmpty(agentId)) { ctx.Response.StatusCode = 400; return; }
 
         var agent = await db.GetAgent(agentId);
-        if (agent == null) { ctx.Response.StatusCode = 404; return; }
+        if (agent == null || agent.UserId != userId) { ctx.Response.StatusCode = 404; return; }
 
         var body = await JsonSerializer.DeserializeAsync<JsonElement>(ctx.Request.Body);
 
@@ -97,10 +102,11 @@ public static class AgentEndpoint
 
     private static async Task HandleDelete(HttpContext ctx, DatabaseService db)
     {
+        var userId = ctx.GetUserId();
         var agentId = ctx.Request.RouteValues["agentId"]?.ToString();
         if (string.IsNullOrEmpty(agentId)) { ctx.Response.StatusCode = 400; return; }
 
-        await db.DeleteAgent(agentId);
+        await db.DeleteAgent(agentId, userId);
         ctx.Response.StatusCode = 204;
     }
 }
diff --git a/Endpoints/ChatEndpoint.cs b/Endpoints/ChatEndpoint.cs
index 71747e1..4f04faf 100644
--- a/Endpoints/ChatEndpoint.cs
+++ b/Endpoints/ChatEndpoint.cs
@@ -6,6 +6,7 @@ using System.Net.Http;
 using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
+using Gott.Extensions;
 using Gott.Models;
 using Gott.Services;
 using Microsoft.AspNetCore.Builder;
@@ -50,8 +51,9 @@ public static class ChatEndpoint
         }
 
         // Agent aus Session auflösen
+        var userId = req.HttpContext.GetUserId();
         var session = await db.GetSession(sessionId);
-        if (session == null || string.IsNullOrEmpty(session.AgentId))
+        if (session == null || session.UserId != userId || string.IsNullOrEmpty(session.AgentId))
         {
             res.StatusCode = 400;
             await res.WriteAsJsonAsync(new { error = "Kein Agent ausgewählt" });
diff --git a/Endpoints/HistoryEndpoint.cs b/Endpoints/HistoryEndpoint.cs
index fa3a348..547a00c 100644
--- a/Endpoints/HistoryEndpoint.cs
+++ b/Endpoints/HistoryEndpoint.cs
@@ -1,6 +1,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using Gott.Extensions;
 using Gott.Models;
 using Gott.Services;
 using Microsoft.AspNetCore.Builder;
@@ -23,10 +24,17 @@ public static class HistoryEndpoint
         app.MapGet("/api/chains/{chainId}", HandleGetChain);
     }
 
+    private static async Task<bool> VerifySessionOwner(HttpContext ctx, DatabaseService db, string sessionId)
+    {
+        if (string.IsNullOrEmpty(sessionId)) return false;
+        var session = await db.GetSession(sessionId);
+        return session != null && session.UserId == ctx.GetUserId();
+    }
+
     private static async Task HandleHistory(HttpContext ctx, DatabaseService db)
     {
         var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
-        if (string.IsNullOrEmpty(sessionId))
+        if (string.IsNullOrEmpty(sessionId) || !await VerifySessionOwner(ctx, db, sessionId))
         {
             ctx.Response.StatusCode = 400;
             await ctx.Response.WriteAsJsonAsync(new { error = "sessionId required" });
@@ -84,7 +92,7 @@ public static class HistoryEndpoint
         var afterStr = ctx.Request.Query["afterId"].FirstOrDefault();
         var afterId = long.TryParse(afterStr, out var a) ? a : 0;
 
-        if (string.IsNullOrEmpty(sessionId))
+        if (string.IsNullOrEmpty(sessionId) || !await VerifySessionOwner(ctx, db, sessionId))
         {
             ctx.Response.StatusCode = 400;
             return;
@@ -97,7 +105,7 @@ public static class HistoryEndpoint
     private static async Task HandleArchive(HttpContext ctx, DatabaseService db)
     {
         var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
-        if (string.IsNullOrEmpty(sessionId))
+        if (string.IsNullOrEmpty(sessionId) || !await VerifySessionOwner(ctx, db, sessionId))
         {
             ctx.Response.StatusCode = 400;
             return;
@@ -115,7 +123,7 @@ public static class HistoryEndpoint
     private static async Task HandleListArchives(HttpContext ctx, DatabaseService db)
     {
         var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
-        if (string.IsNullOrEmpty(sessionId))
+        if (string.IsNullOrEmpty(sessionId) || !await VerifySessionOwner(ctx, db, sessionId))
         {
             ctx.Response.StatusCode = 400;
             return;
diff --git a/Endpoints/SessionEndpoint.cs b/Endpoints/SessionEndpoint.cs
index c883809..307b023 100644
--- a/Endpoints/SessionEndpoint.cs
+++ b/Endpoints/SessionEndpoint.cs
@@ -4,6 +4,7 @@ using System.Diagnostics;
 using System.Linq;
 using System.Text.Json;
 using System.Threading.Tasks;
+using Gott.Extensions;
 using Gott.Services;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
@@ -29,12 +30,14 @@ public static class SessionEndpoint
 
     private static async Task HandleList(HttpContext ctx, DatabaseService db)
     {
-        var sessions = await db.GetSessionsWithStats();
+        var userId = ctx.GetUserId();
+        var sessions = await db.GetSessionsWithStats(userId);
         await ctx.Response.WriteAsJsonAsync(sessions);
     }
 
     private static async Task HandleGet(HttpContext ctx, DatabaseService db)
     {
+        var userId = ctx.GetUserId();
         var sessionId = ctx.Request.RouteValues["sessionId"]?.ToString();
         if (string.IsNullOrEmpty(sessionId))
         {
@@ -42,7 +45,7 @@ public static class SessionEndpoint
             return;
         }
         var session = await db.GetSession(sessionId);
-        if (session == null)
+        if (session == null || session.UserId != userId)
         {
             ctx.Response.StatusCode = 404;
             return;
@@ -52,6 +55,7 @@ public static class SessionEndpoint
 
     private static async Task HandleCreate(HttpContext ctx, DatabaseService db, ImageService imageService)
     {
+        var userId = ctx.GetUserId();
         var body = await JsonSerializer.DeserializeAsync<JsonElement>(ctx.Request.Body);
 
         var name = body.TryGetProperty("name", out var n) ? n.GetString() : "Neue Session";
@@ -63,12 +67,13 @@ public static class SessionEndpoint
         var context = body.TryGetProperty("context", out var ctxEl) ? ctxEl.GetString() : null;
         var customCommands = body.TryGetProperty("customCommands", out var cc) && cc.ValueKind != JsonValueKind.Null ? cc.GetRawText() : null;
 
-        var session = await db.CreateSession(name, description, image, agentId, workspace, context, customCommands);
+        var session = await db.CreateSession(userId, name, description, image, agentId, workspace, context, customCommands);
         await ctx.Response.WriteAsJsonAsync(session);
     }
 
     private static async Task HandleUpdate(HttpContext ctx, DatabaseService db, ImageService imageService)
     {
+        var userId = ctx.GetUserId();
         var sessionId = ctx.Request.RouteValues["sessionId"]?.ToString();
         if (string.IsNullOrEmpty(sessionId))
         {
@@ -76,6 +81,13 @@ public static class SessionEndpoint
             return;
         }
 
+        var existing = await db.GetSession(sessionId);
+        if (existing == null || existing.UserId != userId)
+        {
+            ctx.Response.StatusCode = 404;
+            return;
+        }
+
         var body = await JsonSerializer.DeserializeAsync<JsonElement>(ctx.Request.Body);
         await db.UpdateSession(sessionId, body, imageService);
 
@@ -85,15 +97,17 @@ public static class SessionEndpoint
 
     private static async Task HandleDelete(HttpContext ctx, DatabaseService db)
     {
+        var userId = ctx.GetUserId();
         var sessionId = ctx.Request.RouteValues["sessionId"]?.ToString();
         if (string.IsNullOrEmpty(sessionId)) { ctx.Response.StatusCode = 400; return; }
 
-        await db.DeleteSession(sessionId);
+        await db.DeleteSession(sessionId, userId);
         ctx.Response.StatusCode = 204;
     }
 
     private static async Task HandleSystemPrompt(HttpContext ctx, DatabaseService db, MemoryService memoryService, SkillService skillService)
     {
+        var userId = ctx.GetUserId();
         var sessionId = ctx.Request.RouteValues["sessionId"]?.ToString();
         if (string.IsNullOrEmpty(sessionId))
         {
@@ -102,7 +116,7 @@ public static class SessionEndpoint
         }
 
         var session = await db.GetSession(sessionId);
-        if (session == null)
+        if (session == null || session.UserId != userId)
         {
             ctx.Response.StatusCode = 404;
             return;
@@ -135,11 +149,12 @@ public static class SessionEndpoint
 
     private static async Task HandleSystemPromptBlocks(HttpContext ctx, DatabaseService db, MemoryService memoryService, SkillService skillService)
     {
+        var userId = ctx.GetUserId();
         var sessionId = ctx.Request.RouteValues["sessionId"]?.ToString();
         if (string.IsNullOrEmpty(sessionId)) { ctx.Response.StatusCode = 400; return; }
 
         var session = await db.GetSession(sessionId);
-        if (session == null) { ctx.Response.StatusCode = 404; return; }
+        if (session == null || session.UserId != userId) { ctx.Response.StatusCode = 404; return; }
 
         if (string.IsNullOrEmpty(session.AgentId))
         {
@@ -165,8 +180,9 @@ public static class SessionEndpoint
         await ctx.Response.WriteAsJsonAsync(blocks.Select(b => new { b.Icon, b.Label, b.Content }));
     }
 
-    private static async Task HandleStreaming(HttpContext ctx, StreamingTracker streamingTracker)
+    private static async Task HandleStreaming(HttpContext ctx, DatabaseService db, StreamingTracker streamingTracker)
     {
+        var userId = ctx.GetUserId();
         var sessionId = ctx.Request.RouteValues["sessionId"]?.ToString();
         if (string.IsNullOrEmpty(sessionId))
         {
@@ -174,6 +190,13 @@ public static class SessionEndpoint
             return;
         }
 
+        var session = await db.GetSession(sessionId);
+        if (session == null || session.UserId != userId)
+        {
+            ctx.Response.StatusCode = 404;
+            return;
+        }
+
         var isStreaming = streamingTracker.IsStreaming(sessionId);
         var chainId = streamingTracker.GetChainId(sessionId);
         await ctx.Response.WriteAsJsonAsync(new { streaming = isStreaming, chainId });
@@ -181,6 +204,7 @@ public static class SessionEndpoint
 
     private static async Task HandleExec(HttpContext ctx, DatabaseService db)
     {
+        var userId = ctx.GetUserId();
         var sessionId = ctx.Request.RouteValues["sessionId"]?.ToString();
         if (string.IsNullOrEmpty(sessionId))
         {
@@ -189,7 +213,7 @@ public static class SessionEndpoint
         }
 
         var session = await db.GetSession(sessionId);
-        if (session == null)
+        if (session == null || session.UserId != userId)
         {
             ctx.Response.StatusCode = 404;
             return;
@@ -304,6 +328,7 @@ public static class SessionEndpoint
 
     private static async Task HandleGitStatus(HttpContext ctx, DatabaseService db)
     {
+        var userId = ctx.GetUserId();
         var sessionId = ctx.Request.RouteValues["sessionId"]?.ToString();
         if (string.IsNullOrEmpty(sessionId))
         {
@@ -312,7 +337,7 @@ public static class SessionEndpoint
         }
 
         var session = await db.GetSession(sessionId);
-        if (session == null)
+        if (session == null || session.UserId != userId)
         {
             ctx.Response.StatusCode = 404;
             return;
diff --git a/Endpoints/SkillEndpoint.cs b/Endpoints/SkillEndpoint.cs
index 242d3a9..ba7e35c 100644
--- a/Endpoints/SkillEndpoint.cs
+++ b/Endpoints/SkillEndpoint.cs
@@ -4,6 +4,7 @@ using System.IO;
 using System.Linq;
 using System.Text.Json;
 using System.Threading.Tasks;
+using Gott.Extensions;
 using Gott.Services;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
@@ -50,10 +51,17 @@ public static class SkillEndpoint
         await ctx.Response.WriteAsJsonAsync(skills);
     }
 
+    private static async Task<bool> VerifyAgentOwner(HttpContext ctx, DatabaseService db, string agentId)
+    {
+        if (string.IsNullOrEmpty(agentId)) return false;
+        var agent = await db.GetAgent(agentId);
+        return agent != null && agent.UserId == ctx.GetUserId();
+    }
+
     private static async Task HandleGetAgentSkills(HttpContext ctx, DatabaseService db, SkillService skillService)
     {
         var agentId = ctx.Request.RouteValues["agentId"]?.ToString();
-        if (string.IsNullOrEmpty(agentId)) { ctx.Response.StatusCode = 400; return; }
+        if (string.IsNullOrEmpty(agentId) || !await VerifyAgentOwner(ctx, db, agentId)) { ctx.Response.StatusCode = 400; return; }
 
         var slugs = await db.GetAgentSkills(agentId);
         var allSkills = skillService.GetAllSkills();
@@ -69,7 +77,7 @@ public static class SkillEndpoint
     private static async Task HandleSetAgentSkills(HttpContext ctx, DatabaseService db)
     {
         var agentId = ctx.Request.RouteValues["agentId"]?.ToString();
-        if (string.IsNullOrEmpty(agentId)) { ctx.Response.StatusCode = 400; return; }
+        if (string.IsNullOrEmpty(agentId) || !await VerifyAgentOwner(ctx, db, agentId)) { ctx.Response.StatusCode = 400; return; }
 
         var body = await JsonSerializer.DeserializeAsync<JsonElement>(ctx.Request.Body);
         var slugs = body.TryGetProperty("skills", out var arr)
@@ -86,7 +94,7 @@ public static class SkillEndpoint
     {
         var agentId = ctx.Request.RouteValues["agentId"]?.ToString();
         var slug = ctx.Request.RouteValues["slug"]?.ToString();
-        if (string.IsNullOrEmpty(agentId) || string.IsNullOrEmpty(slug)) { ctx.Response.StatusCode = 400; return; }
+        if (string.IsNullOrEmpty(agentId) || string.IsNullOrEmpty(slug) || !await VerifyAgentOwner(ctx, db, agentId)) { ctx.Response.StatusCode = 400; return; }
 
         await db.AddAgentSkill(agentId, slug);
         ctx.Response.StatusCode = 204;
@@ -96,7 +104,7 @@ public static class SkillEndpoint
     {
         var agentId = ctx.Request.RouteValues["agentId"]?.ToString();
         var slug = ctx.Request.RouteValues["slug"]?.ToString();
-        if (string.IsNullOrEmpty(agentId) || string.IsNullOrEmpty(slug)) { ctx.Response.StatusCode = 400; return; }
+        if (string.IsNullOrEmpty(agentId) || string.IsNullOrEmpty(slug) || !await VerifyAgentOwner(ctx, db, agentId)) { ctx.Response.StatusCode = 400; return; }
 
         await db.RemoveAgentSkill(agentId, slug);
         ctx.Response.StatusCode = 204;
diff --git a/Endpoints/WorkspaceEndpoint.cs b/Endpoints/WorkspaceEndpoint.cs
index e894a95..ac3237a 100644
--- a/Endpoints/WorkspaceEndpoint.cs
+++ b/Endpoints/WorkspaceEndpoint.cs
@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
+using Gott.Extensions;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Routing;
@@ -54,7 +55,7 @@ public static class WorkspaceEndpoint
         // Workspace aus Session holen
         var db = ctx.RequestServices.GetRequiredService<Gott.Services.DatabaseService>();
         var session = await db.GetSession(sessionId ?? "");
-        if (session == null || string.IsNullOrEmpty(session.Workspace))
+        if (session == null || session.UserId != ctx.GetUserId() || string.IsNullOrEmpty(session.Workspace))
         {
             ctx.Response.StatusCode = 400;
             await ctx.Response.WriteAsJsonAsync(new { error = "Kein Workspace konfiguriert" });
@@ -118,7 +119,7 @@ public static class WorkspaceEndpoint
 
         var db = ctx.RequestServices.GetRequiredService<Gott.Services.DatabaseService>();
         var session = await db.GetSession(sessionId ?? "");
-        if (session == null || string.IsNullOrEmpty(session.Workspace))
+        if (session == null || session.UserId != ctx.GetUserId() || string.IsNullOrEmpty(session.Workspace))
         {
             ctx.Response.StatusCode = 400;
             await ctx.Response.WriteAsJsonAsync(new { error = "Kein Workspace konfiguriert" });
@@ -176,7 +177,7 @@ public static class WorkspaceEndpoint
 
         var db = ctx.RequestServices.GetRequiredService<Gott.Services.DatabaseService>();
         var session = await db.GetSession(sessionId ?? "");
-        if (session == null || string.IsNullOrEmpty(session.Workspace))
+        if (session == null || session.UserId != ctx.GetUserId() || string.IsNullOrEmpty(session.Workspace))
         {
             ctx.Response.StatusCode = 400;
             await ctx.Response.WriteAsJsonAsync(new { error = "Kein Workspace konfiguriert" });
@@ -446,7 +447,7 @@ public static class WorkspaceEndpoint
 
         var db = ctx.RequestServices.GetRequiredService<Gott.Services.DatabaseService>();
         var session = await db.GetSession(sessionId ?? "");
-        if (session == null || string.IsNullOrEmpty(session.Workspace))
+        if (session == null || session.UserId != ctx.GetUserId() || string.IsNullOrEmpty(session.Workspace))
         {
             ctx.Response.StatusCode = 400;
             return;
diff --git a/Extensions/HttpContextExtensions.cs b/Extensions/HttpContextExtensions.cs
new file mode 100644
index 0000000..a35ab3f
--- /dev/null
+++ b/Extensions/HttpContextExtensions.cs
@@ -0,0 +1,11 @@
+using Microsoft.AspNetCore.Http;
+
+namespace Gott.Extensions;
+
+public static class HttpContextExtensions
+{
+    public static string GetUserId(this HttpContext ctx)
+    {
+        return ctx.Items["UserId"] as string;
+    }
+}
diff --git a/Models/AgentRecord.cs b/Models/AgentRecord.cs
index 17467ff..06ebce9 100644
--- a/Models/AgentRecord.cs
+++ b/Models/AgentRecord.cs
@@ -15,6 +15,7 @@ public class AgentRecord
     public bool UseIdentity { get; set; } = true;
     public bool UseUserInfo { get; set; } = true;
     public bool UseMemory { get; set; } = true;
+    public string UserId { get; set; }
     public bool IsDeleted { get; set; }
     public string CreatedAt { get; set; }
     public string UpdatedAt { get; set; }
diff --git a/Models/SessionRecord.cs b/Models/SessionRecord.cs
index b5a94db..5b5668d 100644
--- a/Models/SessionRecord.cs
+++ b/Models/SessionRecord.cs
@@ -11,6 +11,7 @@ public class SessionRecord
     public string Workspace { get; set; }
     public string Context { get; set; }
     public string CustomCommands { get; set; }
+    public string UserId { get; set; }
     public bool IsDeleted { get; set; }
     public string CreatedAt { get; set; }
     public string UpdatedAt { get; set; }
diff --git a/Services/DatabaseService.cs b/Services/DatabaseService.cs
index 5e89857..7a7d822 100644
--- a/Services/DatabaseService.cs
+++ b/Services/DatabaseService.cs
@@ -145,6 +145,10 @@ public class DatabaseService
         TryAddColumn(conn, "agents", "use_user_info", "INTEGER NOT NULL DEFAULT 1");
         TryAddColumn(conn, "agents", "use_memory", "INTEGER NOT NULL DEFAULT 1");
 
+        // User-Zuordnung
+        TryAddColumn(conn, "sessions", "user_id", "TEXT");
+        TryAddColumn(conn, "agents", "user_id", "TEXT");
+
         conn.Execute(@"
             CREATE TABLE IF NOT EXISTS agent_skills (
                 id            INTEGER PRIMARY KEY AUTOINCREMENT,
@@ -185,17 +189,17 @@ public class DatabaseService
         agent.CreatedAt = now;
         agent.UpdatedAt = now;
         await conn.ExecuteAsync(@"
-            INSERT INTO agents (agent_id, name, avatar, description, model, tool_choice, custom_commands, auto_commit, use_soul, use_identity, use_user_info, use_memory, is_deleted, created_at, updated_at)
-            VALUES (@AgentId, @Name, @Avatar, @Description, @Model, @ToolChoice, @CustomCommands, @AutoCommit, @UseSoul, @UseIdentity, @UseUserInfo, @UseMemory, 0, @CreatedAt, @UpdatedAt)
+            INSERT INTO agents (agent_id, user_id, name, avatar, description, model, tool_choice, custom_commands, auto_commit, use_soul, use_identity, use_user_info, use_memory, is_deleted, created_at, updated_at)
+            VALUES (@AgentId, @UserId, @Name, @Avatar, @Description, @Model, @ToolChoice, @CustomCommands, @AutoCommit, @UseSoul, @UseIdentity, @UseUserInfo, @UseMemory, 0, @CreatedAt, @UpdatedAt)
         ", agent);
         return agent;
     }
 
-    public async Task<IEnumerable<AgentRecord>> GetAgents()
+    public async Task<IEnumerable<AgentRecord>> GetAgents(string userId)
     {
         using var conn = CreateConnection();
         return await conn.QueryAsync<AgentRecord>(
-            "SELECT * FROM agents WHERE is_deleted = 0 ORDER BY name");
+            "SELECT * FROM agents WHERE user_id = @userId AND is_deleted = 0 ORDER BY name", new { userId });
     }
 
     public async Task<AgentRecord> GetAgent(string agentId)
@@ -215,27 +219,28 @@ public class DatabaseService
                 custom_commands = @CustomCommands, auto_commit = @AutoCommit,
                 use_soul = @UseSoul, use_identity = @UseIdentity, use_user_info = @UseUserInfo, use_memory = @UseMemory,
                 updated_at = @UpdatedAt
-            WHERE agent_id = @AgentId
+            WHERE agent_id = @AgentId AND user_id = @UserId
         ", agent);
     }
 
-    public async Task DeleteAgent(string agentId)
+    public async Task DeleteAgent(string agentId, string userId)
     {
         using var conn = CreateConnection();
         await conn.ExecuteAsync(
-            "UPDATE agents SET is_deleted = 1, updated_at = @now WHERE agent_id = @agentId",
-            new { agentId, now = DateTime.UtcNow.ToString("o") });
+            "UPDATE agents SET is_deleted = 1, updated_at = @now WHERE agent_id = @agentId AND user_id = @userId",
+            new { agentId, userId, now = DateTime.UtcNow.ToString("o") });
     }
 
     // ── Sessions ──
 
-    public async Task<SessionRecord> CreateSession(string name = null, string description = null, string image = null, string agentId = null, string workspace = null, string context = null, string customCommands = null)
+    public async Task<SessionRecord> CreateSession(string userId, string name = null, string description = null, string image = null, string agentId = null, string workspace = null, string context = null, string customCommands = null)
     {
         using var conn = CreateConnection();
         var now = DateTime.UtcNow.ToString("o");
         var session = new SessionRecord
         {
             SessionId = Guid.NewGuid().ToString("N"),
+            UserId = userId,
             Name = name,
             Description = description,
             Image = image,
@@ -247,24 +252,24 @@ public class DatabaseService
             UpdatedAt = now
         };
         await conn.ExecuteAsync(@"
-            INSERT INTO sessions (session_id, name, description, image, agent_id, workspace, context, custom_commands, created_at, updated_at)
-            VALUES (@SessionId, @Name, @Description, @Image, @AgentId, @Workspace, @Context, @CustomCommands, @CreatedAt, @UpdatedAt)
+            INSERT INTO sessions (session_id, user_id, name, description, image, agent_id, workspace, context, custom_commands, created_at, updated_at)
+            VALUES (@SessionId, @UserId, @Name, @Description, @Image, @AgentId, @Workspace, @Context, @CustomCommands, @CreatedAt, @UpdatedAt)
         ", session);
         return session;
     }
 
-    public async Task<IEnumerable<SessionRecord>> GetSessions()
+    public async Task<IEnumerable<SessionRecord>> GetSessions(string userId)
     {
         using var conn = CreateConnection();
         return await conn.QueryAsync<SessionRecord>(
-            "SELECT * FROM sessions WHERE is_deleted = 0 ORDER BY updated_at DESC");
+            "SELECT * FROM sessions WHERE user_id = @userId AND is_deleted = 0 ORDER BY updated_at DESC", new { userId });
     }
 
-    public async Task<IEnumerable<object>> GetSessionsWithStats()
+    public async Task<IEnumerable<object>> GetSessionsWithStats(string userId)
     {
         using var conn = CreateConnection();
         var sessions = await conn.QueryAsync<SessionRecord>(
-            "SELECT * FROM sessions WHERE is_deleted = 0 ORDER BY updated_at DESC");
+            "SELECT * FROM sessions WHERE user_id = @userId AND is_deleted = 0 ORDER BY updated_at DESC", new { userId });
 
         var results = new List<object>();
         foreach (var s in sessions)
@@ -341,12 +346,12 @@ public class DatabaseService
         await conn.ExecuteAsync($"UPDATE sessions SET {string.Join(", ", sets)} WHERE session_id = @sessionId", p);
     }
 
-    public async Task DeleteSession(string sessionId)
+    public async Task DeleteSession(string sessionId, string userId)
     {
         using var conn = CreateConnection();
         await conn.ExecuteAsync(
-            "UPDATE sessions SET is_deleted = 1, updated_at = @now WHERE session_id = @sessionId",
-            new { sessionId, now = DateTime.UtcNow.ToString("o") });
+            "UPDATE sessions SET is_deleted = 1, updated_at = @now WHERE session_id = @sessionId AND user_id = @userId",
+            new { sessionId, userId, now = DateTime.UtcNow.ToString("o") });
     }
 
     // ── Archives ──
@@ -657,21 +662,31 @@ public class DatabaseService
     {
         using var conn = CreateConnection();
         var count = conn.ExecuteScalar<int>("SELECT COUNT(*) FROM users");
+        string adminUserId;
         if (count == 0)
         {
+            adminUserId = Guid.NewGuid().ToString("N");
             var now = DateTime.UtcNow.ToString("o");
             conn.Execute(@"
                 INSERT INTO users (user_id, username, password_hash, display_name, created_at, updated_at)
                 VALUES (@userId, @username, @hash, @displayName, @now, @now)",
                 new
                 {
-                    userId = Guid.NewGuid().ToString("N"),
+                    userId = adminUserId,
                     username = "admin",
                     hash = auth.HashPassword("admin"),
                     displayName = "Admin",
                     now
                 });
         }
+        else
+        {
+            adminUserId = conn.ExecuteScalar<string>("SELECT user_id FROM users ORDER BY id LIMIT 1");
+        }
+
+        // Bestehende Sessions/Agents ohne User dem ersten User zuweisen
+        conn.Execute("UPDATE sessions SET user_id = @userId WHERE user_id IS NULL", new { userId = adminUserId });
+        conn.Execute("UPDATE agents SET user_id = @userId WHERE user_id IS NULL", new { userId = adminUserId });
     }
 
     public async Task<UserRecord> GetUserByUsername(string username)