diff --git a/Endpoints/AgentEndpoint.cs b/Endpoints/AgentEndpoint.cs
index e8aecaa..ff29be6 100644
--- a/Endpoints/AgentEndpoint.cs
+++ b/Endpoints/AgentEndpoint.cs
@@ -27,57 +27,22 @@ public static class AgentEndpoint
     {
         var userId = ctx.GetUserId();
         var agents = await db.GetAgents(userId);
-        var allSkills = skillService.GetAllSkills();
-        var skillMap = allSkills.ToDictionary(s => s.Slug);
-
-        var results = new List<object>();
-        foreach (var a in agents)
-        {
-            var agentSkillSlugs = await db.GetAgentSkills(a.AgentId);
-            var skills = agentSkillSlugs
-                .Where(slug => skillMap.ContainsKey(slug))
-                .Select(slug => new { slug, name = skillMap[slug].Name, description = skillMap[slug].Description })
-                .ToList();
-
-            results.Add(new
-            {
-                a.AgentId,
-                a.Name,
-                Avatar = a.AvatarSmall ?? a.Avatar,
-                a.Description,
-                a.Model,
-                a.CustomCommands,
-                a.AutoCommit,
-                a.UseSoul,
-                a.UseIdentity,
-                a.UseUserInfo,
-                a.UseMemory,
-                a.UseWebSearch,
-                a.WebSearchVersion,
-                a.AllowUserChoice,
-                a.TaskInstruction,
-                a.AvatarScale,
-                a.AvatarOffsetX,
-                a.AvatarOffsetY,
-                a.IsPublic,
-                a.IsDeleted,
-                a.CreatedAt,
-                a.UpdatedAt,
-                Skills = skills
-            });
-        }
-
-        await ctx.Response.WriteAsJsonAsync(results);
+        await ctx.Response.WriteAsJsonAsync(await MapAgentList(agents, userId, db, skillService));
     }
 
     private static async Task HandleListAvailable(HttpContext ctx, DatabaseService db, SkillService skillService)
     {
         var userId = ctx.GetUserId();
         var agents = await db.GetAvailableAgents(userId);
-        var allSkills = skillService.GetAllSkills();
-        var skillMap = allSkills.ToDictionary(s => s.Slug);
+        await ctx.Response.WriteAsJsonAsync(await MapAgentList(agents, userId, db, skillService, includeOwner: true));
+    }
 
+    private static async Task<List<object>> MapAgentList(
+        IEnumerable<AgentRecord> agents, string userId, DatabaseService db, SkillService skillService, bool includeOwner = false)
+    {
+        var skillMap = skillService.GetAllSkills().ToDictionary(s => s.Slug);
         var results = new List<object>();
+
         foreach (var a in agents)
         {
             var agentSkillSlugs = await db.GetAgentSkills(a.AgentId);
@@ -110,12 +75,12 @@ public static class AgentEndpoint
                 a.IsDeleted,
                 a.CreatedAt,
                 a.UpdatedAt,
-                IsOwner = a.UserId == userId,
+                IsOwner = includeOwner ? (bool?)(a.UserId == userId) : null,
                 Skills = skills
             });
         }
 
-        await ctx.Response.WriteAsJsonAsync(results);
+        return results;
     }
 
     private static async Task HandleGet(HttpContext ctx, DatabaseService db)
diff --git a/Endpoints/CronjobEndpoint.cs b/Endpoints/CronjobEndpoint.cs
index 99c624a..cc51c20 100644
--- a/Endpoints/CronjobEndpoint.cs
+++ b/Endpoints/CronjobEndpoint.cs
@@ -2,6 +2,7 @@ using System;
 using System.Text.Json;
 using System.Threading.Tasks;
 using Gott.Models;
+using Gott.Extensions;
 using Gott.Services;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
@@ -15,14 +16,14 @@ public static class CronjobEndpoint
     {
         app.MapGet("/api/cronjobs", async (HttpContext ctx, DatabaseService db) =>
         {
-            var userId = ctx.Items["UserId"]?.ToString();
+            var userId = ctx.GetUserId();
             var cronjobs = await db.GetCronjobs(userId);
             return Results.Ok(cronjobs);
         });
 
         app.MapGet("/api/cronjobs/{id}", async (string id, HttpContext ctx, DatabaseService db) =>
         {
-            var userId = ctx.Items["UserId"]?.ToString();
+            var userId = ctx.GetUserId();
             var cronjob = await db.GetCronjob(id);
             if (cronjob == null || cronjob.UserId != userId) return Results.NotFound();
             return Results.Ok(cronjob);
@@ -30,7 +31,7 @@ public static class CronjobEndpoint
 
         app.MapPost("/api/cronjobs", async (HttpContext ctx, DatabaseService db) =>
         {
-            var userId = ctx.Items["UserId"]?.ToString();
+            var userId = ctx.GetUserId();
             var body = await JsonSerializer.DeserializeAsync<JsonElement>(ctx.Request.Body);
 
             var name = body.TryGetProperty("name", out var n) ? n.GetString() ?? "" : "";
@@ -79,7 +80,7 @@ public static class CronjobEndpoint
 
         app.MapPut("/api/cronjobs/{id}", async (string id, HttpContext ctx, DatabaseService db) =>
         {
-            var userId = ctx.Items["UserId"]?.ToString();
+            var userId = ctx.GetUserId();
             var existing = await db.GetCronjob(id);
             if (existing == null || existing.UserId != userId) return Results.NotFound();
 
@@ -134,7 +135,7 @@ public static class CronjobEndpoint
 
         app.MapDelete("/api/cronjobs/{id}", async (string id, HttpContext ctx, DatabaseService db) =>
         {
-            var userId = ctx.Items["UserId"]?.ToString();
+            var userId = ctx.GetUserId();
             var existing = await db.GetCronjob(id);
             if (existing == null || existing.UserId != userId) return Results.NotFound();
 
@@ -144,7 +145,7 @@ public static class CronjobEndpoint
 
         app.MapPost("/api/cronjobs/{id}/toggle", async (string id, HttpContext ctx, DatabaseService db) =>
         {
-            var userId = ctx.Items["UserId"]?.ToString();
+            var userId = ctx.GetUserId();
             var existing = await db.GetCronjob(id);
             if (existing == null || existing.UserId != userId) return Results.NotFound();
 
@@ -158,7 +159,7 @@ public static class CronjobEndpoint
 
         app.MapPost("/api/cronjobs/{id}/run", async (string id, HttpContext ctx, DatabaseService db, CronjobService cronjobService) =>
         {
-            var userId = ctx.Items["UserId"]?.ToString();
+            var userId = ctx.GetUserId();
             var existing = await db.GetCronjob(id);
             if (existing == null || existing.UserId != userId) return Results.NotFound();
 
diff --git a/Endpoints/KreaEndpoint.cs b/Endpoints/KreaEndpoint.cs
index b5e50c3..e83bbf2 100644
--- a/Endpoints/KreaEndpoint.cs
+++ b/Endpoints/KreaEndpoint.cs
@@ -7,9 +7,6 @@ using Gott.Services;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Routing;
-using SixLabors.ImageSharp;
-using SixLabors.ImageSharp.Processing;
-using SixLabors.ImageSharp.Formats.Webp;
 
 namespace Gott.Endpoints
 {
@@ -142,50 +139,31 @@ namespace Gott.Endpoints
                 return;
             }
 
-            // Cache-Verzeichnis: data/cache/images/
             var imagesDir = Path.GetDirectoryName(originalPath);
             var dataDir = Path.GetDirectoryName(imagesDir);
             var cacheDir = Path.Combine(dataDir, "cache", "images");
-            Directory.CreateDirectory(cacheDir);
 
-            var thumbFilename = Path.GetFileNameWithoutExtension(filename) + ".webp";
-            var thumbPath = Path.Combine(cacheDir, thumbFilename);
-
-            if (!File.Exists(thumbPath) || File.GetLastWriteTimeUtc(originalPath) > File.GetLastWriteTimeUtc(thumbPath))
+            var thumbPath = await ImageService.GenerateThumbnail(originalPath, cacheDir);
+            if (thumbPath != null)
             {
-                try
+                res.ContentType = "image/webp";
+                res.Headers["Cache-Control"] = "private, max-age=86400";
+                await res.SendFileAsync(thumbPath);
+            }
+            else
+            {
+                // Fallback: Original ausliefern
+                res.ContentType = ext switch
                 {
-                    using var image = await Image.LoadAsync(originalPath);
-                    var maxSize = 320;
-                    image.Mutate(x => x.Resize(new ResizeOptions
-                    {
-                        Size = new Size(maxSize, maxSize),
-                        Mode = ResizeMode.Max
-                    }));
-                    var encoder = new WebpEncoder { Quality = 75 };
-                    await image.SaveAsync(thumbPath, encoder);
-                }
-                catch
-                {
-                    // Fallback: Original ausliefern
-                    var contentType = ext switch
-                    {
-                        ".png"  => "image/png",
-                        ".jpg"  => "image/jpeg",
-                        ".jpeg" => "image/jpeg",
-                        ".gif"  => "image/gif",
-                        _       => "image/webp",
-                    };
-                    res.ContentType = contentType;
-                    res.Headers["Cache-Control"] = "private, max-age=3600";
-                    await res.SendFileAsync(originalPath);
-                    return;
-                }
+                    ".png"  => "image/png",
+                    ".jpg"  => "image/jpeg",
+                    ".jpeg" => "image/jpeg",
+                    ".gif"  => "image/gif",
+                    _       => "image/webp",
+                };
+                res.Headers["Cache-Control"] = "private, max-age=3600";
+                await res.SendFileAsync(originalPath);
             }
-
-            res.ContentType = "image/webp";
-            res.Headers["Cache-Control"] = "private, max-age=86400";
-            await res.SendFileAsync(thumbPath);
         }
     }
 }
diff --git a/Endpoints/SessionEndpoint.cs b/Endpoints/SessionEndpoint.cs
index 71a6bda..df9d64b 100644
--- a/Endpoints/SessionEndpoint.cs
+++ b/Endpoints/SessionEndpoint.cs
@@ -198,28 +198,26 @@ public static class SessionEndpoint
         ctx.Response.StatusCode = 204;
     }
 
-    private static async Task HandleSystemPrompt(HttpContext ctx, DatabaseService db, MemoryService memoryService, SkillService skillService)
+    /// <summary>
+    /// Löst Session, Agent, Workspace und Prompt-Abhängigkeiten auf.
+    /// Gibt null zurück und setzt StatusCode bei Fehler.
+    /// </summary>
+    private static async Task<(SessionRecord session, AgentRecord agent, IEnumerable<MessageRecord> marked,
+        string memDir, IEnumerable<string> skills, UserRecord user, string workspace, bool planMode)?>
+        ResolvePromptContext(HttpContext ctx, DatabaseService db, MemoryService memoryService)
     {
         var userId = ctx.GetUserId();
         var sessionId = ctx.Request.RouteValues["sessionId"]?.ToString();
-        if (string.IsNullOrEmpty(sessionId))
-        {
-            ctx.Response.StatusCode = 400;
-            return;
-        }
+        if (string.IsNullOrEmpty(sessionId)) { ctx.Response.StatusCode = 400; return null; }
 
         var session = await db.GetSession(sessionId);
-        if (session == null || session.UserId != userId)
-        {
-            ctx.Response.StatusCode = 404;
-            return;
-        }
+        if (session == null || session.UserId != userId) { ctx.Response.StatusCode = 404; return null; }
 
         if (string.IsNullOrEmpty(session.AgentId))
         {
             ctx.Response.StatusCode = 400;
             await ctx.Response.WriteAsJsonAsync(new { error = "Kein Agent ausgewählt" });
-            return;
+            return null;
         }
 
         var agent = await db.GetAgent(session.AgentId);
@@ -227,18 +225,29 @@ public static class SessionEndpoint
         {
             ctx.Response.StatusCode = 400;
             await ctx.Response.WriteAsJsonAsync(new { error = "Agent nicht gefunden" });
-            return;
+            return null;
         }
 
-        var markedMessages = await db.GetMarkedMessages(sessionId);
-        var agentMemoryDir = memoryService.GetAgentMemoryDir(agent.AgentId);
-        var agentSkills = await db.GetAgentSkills(agent.AgentId);
+        var marked = await db.GetMarkedMessages(sessionId);
+        var memDir = memoryService.GetAgentMemoryDir(agent.AgentId);
+        var skills = await db.GetAgentSkills(agent.AgentId);
         var user = await db.GetUser(userId);
-        var resolvedWorkspace = WorkspaceHelper.ResolveWorkspace(session, user);
-        if (string.IsNullOrEmpty(resolvedWorkspace) && agentSkills.Any())
-            resolvedWorkspace = "/tmp";
+        var workspace = WorkspaceHelper.ResolveWorkspace(session, user);
+        if (string.IsNullOrEmpty(workspace) && skills.Any())
+            workspace = "/tmp";
         var planMode = ctx.Request.Query.ContainsKey("planMode") && ctx.Request.Query["planMode"] == "true";
-        var systemPrompt = SystemPromptBuilder.Build(agent, session, markedMessages, memoryService, agentMemoryDir, agentSkills, skillService, userPersona: user?.GetEffectivePersona(), resolvedWorkspace: resolvedWorkspace, planMode: planMode);
+
+        return (session, agent, marked, memDir, skills, user, workspace, planMode);
+    }
+
+    private static async Task HandleSystemPrompt(HttpContext ctx, DatabaseService db, MemoryService memoryService, SkillService skillService)
+    {
+        var result = await ResolvePromptContext(ctx, db, memoryService);
+        if (result == null) return;
+        var (session, agent, marked, memDir, skills, user, workspace, planMode) = result.Value;
+
+        var systemPrompt = SystemPromptBuilder.Build(agent, session, marked, memoryService, memDir,
+            skills, skillService, userPersona: user?.GetEffectivePersona(), resolvedWorkspace: workspace, planMode: planMode);
 
         ctx.Response.ContentType = "text/plain; charset=utf-8";
         await ctx.Response.WriteAsync(systemPrompt);
@@ -246,37 +255,12 @@ 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 result = await ResolvePromptContext(ctx, db, memoryService);
+        if (result == null) return;
+        var (session, agent, marked, memDir, skills, user, workspace, planMode) = result.Value;
 
-        var session = await db.GetSession(sessionId);
-        if (session == null || session.UserId != userId) { ctx.Response.StatusCode = 404; return; }
-
-        if (string.IsNullOrEmpty(session.AgentId))
-        {
-            ctx.Response.StatusCode = 400;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Kein Agent ausgewählt" });
-            return;
-        }
-
-        var agent = await db.GetAgent(session.AgentId);
-        if (agent == null)
-        {
-            ctx.Response.StatusCode = 400;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Agent nicht gefunden" });
-            return;
-        }
-
-        var markedMessages = await db.GetMarkedMessages(sessionId);
-        var agentMemoryDir = memoryService.GetAgentMemoryDir(agent.AgentId);
-        var agentSkills = await db.GetAgentSkills(agent.AgentId);
-        var user = await db.GetUser(userId);
-        var resolvedWorkspace = WorkspaceHelper.ResolveWorkspace(session, user);
-        if (string.IsNullOrEmpty(resolvedWorkspace) && agentSkills.Any())
-            resolvedWorkspace = "/tmp";
-        var planMode = ctx.Request.Query.ContainsKey("planMode") && ctx.Request.Query["planMode"] == "true";
-        var blocks = SystemPromptBuilder.BuildBlocks(agent, session, markedMessages, memoryService, agentMemoryDir, agentSkills, skillService, userPersona: user?.GetEffectivePersona(), resolvedWorkspace: resolvedWorkspace, planMode: planMode);
+        var blocks = SystemPromptBuilder.BuildBlocks(agent, session, marked, memoryService, memDir,
+            skills, skillService, userPersona: user?.GetEffectivePersona(), resolvedWorkspace: workspace, planMode: planMode);
 
         await ctx.Response.WriteAsJsonAsync(blocks.Select(b => new { b.Icon, b.Label, b.Content }));
     }
diff --git a/Endpoints/SkillEndpoint.cs b/Endpoints/SkillEndpoint.cs
index ba7e35c..21714a1 100644
--- a/Endpoints/SkillEndpoint.cs
+++ b/Endpoints/SkillEndpoint.cs
@@ -9,9 +9,6 @@ using Gott.Services;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Routing;
-using SixLabors.ImageSharp;
-using SixLabors.ImageSharp.Processing;
-using SixLabors.ImageSharp.Formats.Webp;
 
 namespace Gott.Endpoints;
 
@@ -186,44 +183,22 @@ public static class SkillEndpoint
         var originalPath = Path.Combine(skill.Path, "output", filename);
         if (!File.Exists(originalPath)) { ctx.Response.StatusCode = 404; return; }
 
-        // Cache-Verzeichnis: data/cache/skills/{slug}/
         var dataDir = Path.GetDirectoryName(skillService.SkillsDir);
         var cacheDir = Path.Combine(dataDir, "cache", "skills", slug);
-        Directory.CreateDirectory(cacheDir);
 
-        var thumbFilename = Path.GetFileNameWithoutExtension(filename) + ".webp";
-        var thumbPath = Path.Combine(cacheDir, thumbFilename);
-
-        // Thumbnail generieren wenn nicht gecacht oder Original neuer
-        if (!File.Exists(thumbPath) || File.GetLastWriteTimeUtc(originalPath) > File.GetLastWriteTimeUtc(thumbPath))
+        var thumbPath = await ImageService.GenerateThumbnail(originalPath, cacheDir);
+        if (thumbPath != null)
         {
-            try
-            {
-                using var image = await Image.LoadAsync(originalPath);
-
-                // Max 320px auf der längsten Seite
-                var maxSize = 320;
-                image.Mutate(x => x.Resize(new ResizeOptions
-                {
-                    Size = new Size(maxSize, maxSize),
-                    Mode = ResizeMode.Max
-                }));
-
-                var encoder = new WebpEncoder { Quality = 75 };
-                await image.SaveAsync(thumbPath, encoder);
-            }
-            catch
-            {
-                // Fallback: Original ausliefern wenn Thumbnail-Generierung fehlschlägt
-                ctx.Response.ContentType = MimeTypes.GetValueOrDefault(ext, "application/octet-stream");
-                ctx.Response.Headers["Cache-Control"] = "private, max-age=3600";
-                await ctx.Response.SendFileAsync(originalPath);
-                return;
-            }
+            ctx.Response.ContentType = "image/webp";
+            ctx.Response.Headers["Cache-Control"] = "private, max-age=86400";
+            await ctx.Response.SendFileAsync(thumbPath);
+        }
+        else
+        {
+            // Fallback: Original ausliefern
+            ctx.Response.ContentType = MimeTypes.GetValueOrDefault(ext, "application/octet-stream");
+            ctx.Response.Headers["Cache-Control"] = "private, max-age=3600";
+            await ctx.Response.SendFileAsync(originalPath);
         }
-
-        ctx.Response.ContentType = "image/webp";
-        ctx.Response.Headers["Cache-Control"] = "private, max-age=86400";
-        await ctx.Response.SendFileAsync(thumbPath);
     }
 }
diff --git a/Endpoints/TelegramEndpoint.cs b/Endpoints/TelegramEndpoint.cs
index 007910b..36236e1 100644
--- a/Endpoints/TelegramEndpoint.cs
+++ b/Endpoints/TelegramEndpoint.cs
@@ -3,6 +3,7 @@ using System.Text.Json;
 using System.Threading.Tasks;
 using Gott.Extensions;
 using Gott.Services;
+using Gott.Models;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Routing;
@@ -72,26 +73,29 @@ public static class TelegramEndpoint
 
     // ── Bot CRUD ──
 
+    private static async Task<object> MapBotResponse(TelegramBotRecord bot, DatabaseService db)
+    {
+        var sessionCount = await db.GetTelegramBotSessionCount(bot.BotId);
+        return new
+        {
+            botId = bot.BotId,
+            name = bot.Name,
+            botToken = bot.BotToken,
+            webhookSecret = bot.WebhookSecret,
+            isPublic = bot.IsPublic,
+            sessionCount,
+            createdAt = bot.CreatedAt,
+            updatedAt = bot.UpdatedAt
+        };
+    }
+
     private static async Task HandleGetBots(HttpRequest req, HttpResponse res, DatabaseService db)
     {
         var userId = req.HttpContext.GetUserId();
         var bots = await db.GetTelegramBots(userId);
         var result = new System.Collections.Generic.List<object>();
         foreach (var bot in bots)
-        {
-            var sessionCount = await db.GetTelegramBotSessionCount(bot.BotId);
-            result.Add(new
-            {
-                botId = bot.BotId,
-                name = bot.Name,
-                botToken = bot.BotToken,
-                webhookSecret = bot.WebhookSecret,
-                isPublic = bot.IsPublic,
-                sessionCount,
-                createdAt = bot.CreatedAt,
-                updatedAt = bot.UpdatedAt
-            });
-        }
+            result.Add(await MapBotResponse(bot, db));
         await res.WriteAsJsonAsync(result);
     }
 
@@ -106,18 +110,7 @@ public static class TelegramEndpoint
             return;
         }
 
-        var sessionCount = await db.GetTelegramBotSessionCount(bot.BotId);
-        await res.WriteAsJsonAsync(new
-        {
-            botId = bot.BotId,
-            name = bot.Name,
-            botToken = bot.BotToken,
-            webhookSecret = bot.WebhookSecret,
-            isPublic = bot.IsPublic,
-            sessionCount,
-            createdAt = bot.CreatedAt,
-            updatedAt = bot.UpdatedAt
-        });
+        await res.WriteAsJsonAsync(await MapBotResponse(bot, db));
     }
 
     private static async Task HandleCreateBot(HttpRequest req, HttpResponse res, DatabaseService db)
diff --git a/Endpoints/WorkspaceEndpoint.cs b/Endpoints/WorkspaceEndpoint.cs
index fa10a57..f6260bd 100644
--- a/Endpoints/WorkspaceEndpoint.cs
+++ b/Endpoints/WorkspaceEndpoint.cs
@@ -38,27 +38,40 @@ public static class WorkspaceEndpoint
 
     public static void MapWorkspaceEndpoint(this IEndpointRouteBuilder app)
     {
-        app.MapGet("/api/workspace/tree", HandleTree);
-        app.MapGet("/api/workspace/file", HandleFile);
-        app.MapPut("/api/workspace/file", HandleFileSave);
+        // Session-Workspace-Endpunkte
+        app.MapGet("/api/workspace/tree", async ctx =>
+            await HandleTreeCore(ctx, await ResolveSessionBasePath(ctx)));
+        app.MapGet("/api/workspace/file", async ctx =>
+            await HandleFileCore(ctx, await ResolveSessionBasePath(ctx)));
+        app.MapPut("/api/workspace/file", async ctx =>
+            await HandleFileSaveCore(ctx, await ResolveSessionBasePath(ctx), allowCreate: false));
+        app.MapPost("/api/workspace/mkdir", async ctx =>
+            await HandleMkdirCore(ctx, await ResolveSessionBasePath(ctx)));
+
+        // Agent-Memory-Endpunkte (gleiche Logik, anderer basePath)
+        app.MapGet("/api/workspace/agent/tree", async ctx =>
+            await HandleTreeCore(ctx, ResolveAgentBasePath(ctx)));
+        app.MapGet("/api/workspace/agent/file", async ctx =>
+            await HandleFileCore(ctx, ResolveAgentBasePath(ctx)));
+        app.MapPut("/api/workspace/agent/file", async ctx =>
+            await HandleFileSaveCore(ctx, ResolveAgentBasePath(ctx), allowCreate: true));
+        app.MapPost("/api/workspace/agent/mkdir", async ctx =>
+            await HandleMkdirCore(ctx, ResolveAgentBasePath(ctx)));
+
+        // Sonstige
         app.MapGet("/api/workspace/browse", HandleBrowse);
         app.MapPost("/api/workspace/browse/mkdir", HandleBrowseMkdir);
-        app.MapGet("/api/workspace/agent/tree", HandleAgentTree);
-        app.MapGet("/api/workspace/agent/file", HandleAgentFile);
-        app.MapPut("/api/workspace/agent/file", HandleAgentFileSave);
         app.MapGet("/api/workspace/raw", HandleRawFile);
-        app.MapPost("/api/workspace/mkdir", HandleMkdir);
-        app.MapDelete("/api/workspace/dir", HandleRmdir);
-        app.MapPost("/api/workspace/agent/mkdir", HandleAgentMkdir);
-        app.MapDelete("/api/workspace/agent/dir", HandleAgentRmdir);
     }
 
+    // ── BasePath-Auflösung ──────────────────────────────────────────────
+
     /// <summary>
-    /// Lädt Session + User und löst den Workspace-Pfad auf (relativ → absolut via DefaultPath).
-    /// Gibt null zurück und setzt StatusCode 400, wenn kein gültiger Workspace vorhanden ist.
+    /// Löst den Workspace-Pfad einer Session auf. Gibt null zurück + setzt 400 bei Fehler.
     /// </summary>
-    private static async Task<(SessionRecord session, string basePath)?> ResolveSessionWorkspace(HttpContext ctx, string sessionId)
+    private static async Task<string> ResolveSessionBasePath(HttpContext ctx)
     {
+        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
         var db = ctx.RequestServices.GetRequiredService<Gott.Services.DatabaseService>();
         var session = await db.GetSession(sessionId ?? "");
         if (session == null || session.UserId != ctx.GetUserId() || string.IsNullOrEmpty(session.Workspace))
@@ -78,20 +91,40 @@ public static class WorkspaceEndpoint
             return null;
         }
 
-        return (session, Path.GetFullPath(resolved));
+        return Path.GetFullPath(resolved);
     }
 
-    private static async Task HandleTree(HttpContext ctx)
+    /// <summary>
+    /// Löst den Memory-Pfad eines Agents auf. Gibt null zurück + setzt 400 bei Fehler.
+    /// </summary>
+    private static string ResolveAgentBasePath(HttpContext ctx)
     {
-        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
-        var subPath = ctx.Request.Query["path"].FirstOrDefault() ?? "";
+        var agentId = ctx.Request.Query["agentId"].FirstOrDefault();
+        if (string.IsNullOrEmpty(agentId))
+        {
+            ctx.Response.StatusCode = 400;
+            ctx.Response.WriteAsJsonAsync(new { error = "agentId fehlt" }).Wait();
+            return null;
+        }
 
-        var result = await ResolveSessionWorkspace(ctx, sessionId);
-        if (result == null) return;
-        var (session, basePath) = result.Value;
+        var memoryService = ctx.RequestServices.GetRequiredService<Gott.Services.MemoryService>();
+        var basePath = memoryService.GetAgentMemoryDir(agentId);
+
+        if (!Directory.Exists(basePath))
+            Directory.CreateDirectory(basePath);
+
+        return basePath;
+    }
+
+    // ── Generische Handler ──────────────────────────────────────────────
+
+    private static async Task HandleTreeCore(HttpContext ctx, string basePath)
+    {
+        if (basePath == null) return;
+
+        var subPath = ctx.Request.Query["path"].FirstOrDefault() ?? "";
         var targetPath = Path.GetFullPath(Path.Combine(basePath, subPath));
 
-        // Sicherheit: nicht aus dem Workspace ausbrechen
         if (!targetPath.StartsWith(basePath))
         {
             ctx.Response.StatusCode = 403;
@@ -107,17 +140,14 @@ public static class WorkspaceEndpoint
 
         var entries = new List<object>();
 
-        // Ordner
         foreach (var dir in Directory.GetDirectories(targetPath).OrderBy(d => Path.GetFileName(d), StringComparer.OrdinalIgnoreCase))
         {
             var name = Path.GetFileName(dir);
             if (IgnoredDirs.Contains(name)) continue;
-
             var relPath = Path.GetRelativePath(basePath, dir).Replace('\\', '/');
             entries.Add(new { name, path = relPath, type = "dir" });
         }
 
-        // Dateien
         foreach (var file in Directory.GetFiles(targetPath).OrderBy(f => Path.GetFileName(f), StringComparer.OrdinalIgnoreCase))
         {
             var name = Path.GetFileName(file);
@@ -125,30 +155,24 @@ public static class WorkspaceEndpoint
             var relPath = Path.GetRelativePath(basePath, file).Replace('\\', '/');
             var size = new FileInfo(file).Length;
             var isText = TextExtensions.Contains(ext) || IsLikelyTextFile(name);
-
             entries.Add(new { name, path = relPath, type = "file", ext, size, isText });
         }
 
         await ctx.Response.WriteAsJsonAsync(entries);
     }
 
-    private static async Task HandleFile(HttpContext ctx)
+    private static async Task HandleFileCore(HttpContext ctx, string basePath)
     {
-        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
-        var filePath = ctx.Request.Query["path"].FirstOrDefault();
+        if (basePath == null) return;
 
+        var filePath = ctx.Request.Query["path"].FirstOrDefault();
         if (string.IsNullOrEmpty(filePath))
         {
             ctx.Response.StatusCode = 400;
             return;
         }
 
-        var result = await ResolveSessionWorkspace(ctx, sessionId);
-        if (result == null) return;
-        var (session, basePath) = result.Value;
-
         var targetPath = Path.GetFullPath(Path.Combine(basePath, filePath));
-
         if (!targetPath.StartsWith(basePath))
         {
             ctx.Response.StatusCode = 403;
@@ -162,8 +186,6 @@ public static class WorkspaceEndpoint
         }
 
         var info = new FileInfo(targetPath);
-
-        // Max 2MB für Textdateien
         if (info.Length > 2 * 1024 * 1024)
         {
             ctx.Response.StatusCode = 413;
@@ -184,33 +206,39 @@ public static class WorkspaceEndpoint
         });
     }
 
-    private static async Task HandleFileSave(HttpContext ctx)
+    private static async Task HandleFileSaveCore(HttpContext ctx, string basePath, bool allowCreate)
     {
-        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
-        var filePath = ctx.Request.Query["path"].FirstOrDefault();
+        if (basePath == null) return;
 
+        var filePath = ctx.Request.Query["path"].FirstOrDefault();
         if (string.IsNullOrEmpty(filePath))
         {
             ctx.Response.StatusCode = 400;
             return;
         }
 
-        var result = await ResolveSessionWorkspace(ctx, sessionId);
-        if (result == null) return;
-        var (session, basePath) = result.Value;
-
         var targetPath = Path.GetFullPath(Path.Combine(basePath, filePath));
-
         if (!targetPath.StartsWith(basePath))
         {
             ctx.Response.StatusCode = 403;
             return;
         }
 
-        if (!File.Exists(targetPath))
+        if (allowCreate)
         {
-            ctx.Response.StatusCode = 404;
-            return;
+            // Agent-Memory: Verzeichnis erstellen falls nötig
+            var dir = Path.GetDirectoryName(targetPath);
+            if (!string.IsNullOrEmpty(dir) && !Directory.Exists(dir))
+                Directory.CreateDirectory(dir);
+        }
+        else
+        {
+            // Session-Workspace: Datei muss existieren
+            if (!File.Exists(targetPath))
+            {
+                ctx.Response.StatusCode = 404;
+                return;
+            }
         }
 
         using var reader = new StreamReader(ctx.Request.Body);
@@ -230,6 +258,42 @@ public static class WorkspaceEndpoint
         });
     }
 
+    private static async Task HandleMkdirCore(HttpContext ctx, string basePath)
+    {
+        if (basePath == null) return;
+
+        var dirPath = ctx.Request.Query["path"].FirstOrDefault();
+        if (string.IsNullOrEmpty(dirPath))
+        {
+            ctx.Response.StatusCode = 400;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Pfad fehlt" });
+            return;
+        }
+
+        var targetPath = Path.GetFullPath(Path.Combine(basePath, dirPath));
+        if (!targetPath.StartsWith(basePath))
+        {
+            ctx.Response.StatusCode = 403;
+            return;
+        }
+
+        if (Directory.Exists(targetPath))
+        {
+            ctx.Response.StatusCode = 409;
+            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner existiert bereits" });
+            return;
+        }
+
+        Directory.CreateDirectory(targetPath);
+        await ctx.Response.WriteAsJsonAsync(new
+        {
+            path = Path.GetRelativePath(basePath, targetPath).Replace('\\', '/'),
+            created = true
+        });
+    }
+
+    // ── Sonstige Endpunkte ──────────────────────────────────────────────
+
     private static async Task HandleBrowse(HttpContext ctx)
     {
         var path = ctx.Request.Query["path"].FirstOrDefault() ?? "/";
@@ -277,7 +341,6 @@ public static class WorkspaceEndpoint
             return;
         }
 
-        // Parent muss existieren
         var parent = Path.GetDirectoryName(targetPath);
         if (string.IsNullOrEmpty(parent) || !Directory.Exists(parent))
         {
@@ -290,345 +353,6 @@ public static class WorkspaceEndpoint
         await ctx.Response.WriteAsJsonAsync(new { path = targetPath.Replace('\\', '/'), created = true });
     }
 
-    private static bool IsLikelyTextFile(string name)
-    {
-        var lower = name.ToLowerInvariant();
-        return lower is "makefile" or "dockerfile" or "rakefile" or "gemfile"
-            or "procfile" or "vagrantfile" or "license" or "readme"
-            or "changelog" or "authors" or "contributors";
-    }
-
-    private static string GetAgentBasePath(HttpContext ctx, out string error)
-    {
-        error = null;
-        var agentId = ctx.Request.Query["agentId"].FirstOrDefault();
-        if (string.IsNullOrEmpty(agentId))
-        {
-            error = "agentId fehlt";
-            return null;
-        }
-
-        var memoryService = ctx.RequestServices.GetRequiredService<Gott.Services.MemoryService>();
-        var basePath = memoryService.GetAgentMemoryDir(agentId);
-
-        if (!Directory.Exists(basePath))
-            Directory.CreateDirectory(basePath);
-
-        return basePath;
-    }
-
-    private static async Task HandleAgentTree(HttpContext ctx)
-    {
-        var basePath = GetAgentBasePath(ctx, out var error);
-        if (basePath == null)
-        {
-            ctx.Response.StatusCode = 400;
-            await ctx.Response.WriteAsJsonAsync(new { error });
-            return;
-        }
-
-        var subPath = ctx.Request.Query["path"].FirstOrDefault() ?? "";
-        var targetPath = Path.GetFullPath(Path.Combine(basePath, subPath));
-
-        if (!targetPath.StartsWith(basePath))
-        {
-            ctx.Response.StatusCode = 403;
-            return;
-        }
-
-        if (!Directory.Exists(targetPath))
-        {
-            ctx.Response.StatusCode = 404;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Verzeichnis nicht gefunden" });
-            return;
-        }
-
-        var entries = new List<object>();
-
-        foreach (var dir in Directory.GetDirectories(targetPath).OrderBy(d => Path.GetFileName(d), StringComparer.OrdinalIgnoreCase))
-        {
-            var name = Path.GetFileName(dir);
-            if (IgnoredDirs.Contains(name)) continue;
-            var relPath = Path.GetRelativePath(basePath, dir).Replace('\\', '/');
-            entries.Add(new { name, path = relPath, type = "dir" });
-        }
-
-        foreach (var file in Directory.GetFiles(targetPath).OrderBy(f => Path.GetFileName(f), StringComparer.OrdinalIgnoreCase))
-        {
-            var name = Path.GetFileName(file);
-            var ext = Path.GetExtension(file);
-            var relPath = Path.GetRelativePath(basePath, file).Replace('\\', '/');
-            var size = new FileInfo(file).Length;
-            var isText = TextExtensions.Contains(ext) || IsLikelyTextFile(name);
-            entries.Add(new { name, path = relPath, type = "file", ext, size, isText });
-        }
-
-        await ctx.Response.WriteAsJsonAsync(entries);
-    }
-
-    private static async Task HandleAgentFile(HttpContext ctx)
-    {
-        var basePath = GetAgentBasePath(ctx, out var error);
-        if (basePath == null)
-        {
-            ctx.Response.StatusCode = 400;
-            await ctx.Response.WriteAsJsonAsync(new { error });
-            return;
-        }
-
-        var filePath = ctx.Request.Query["path"].FirstOrDefault();
-        if (string.IsNullOrEmpty(filePath))
-        {
-            ctx.Response.StatusCode = 400;
-            return;
-        }
-
-        var targetPath = Path.GetFullPath(Path.Combine(basePath, filePath));
-        if (!targetPath.StartsWith(basePath))
-        {
-            ctx.Response.StatusCode = 403;
-            return;
-        }
-
-        if (!File.Exists(targetPath))
-        {
-            ctx.Response.StatusCode = 404;
-            return;
-        }
-
-        var info = new FileInfo(targetPath);
-        if (info.Length > 2 * 1024 * 1024)
-        {
-            ctx.Response.StatusCode = 413;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Datei zu groß (max. 2MB)" });
-            return;
-        }
-
-        var content = await File.ReadAllTextAsync(targetPath);
-        var lineCount = content.Split('\n').Length;
-
-        await ctx.Response.WriteAsJsonAsync(new
-        {
-            path = filePath,
-            name = info.Name,
-            size = info.Length,
-            lineCount,
-            content
-        });
-    }
-
-    private static async Task HandleAgentFileSave(HttpContext ctx)
-    {
-        var basePath = GetAgentBasePath(ctx, out var error);
-        if (basePath == null)
-        {
-            ctx.Response.StatusCode = 400;
-            await ctx.Response.WriteAsJsonAsync(new { error });
-            return;
-        }
-
-        var filePath = ctx.Request.Query["path"].FirstOrDefault();
-        if (string.IsNullOrEmpty(filePath))
-        {
-            ctx.Response.StatusCode = 400;
-            return;
-        }
-
-        var targetPath = Path.GetFullPath(Path.Combine(basePath, filePath));
-        if (!targetPath.StartsWith(basePath))
-        {
-            ctx.Response.StatusCode = 403;
-            return;
-        }
-
-        // Verzeichnis erstellen falls nötig
-        var dir = Path.GetDirectoryName(targetPath);
-        if (!string.IsNullOrEmpty(dir) && !Directory.Exists(dir))
-            Directory.CreateDirectory(dir);
-
-        using var reader = new StreamReader(ctx.Request.Body);
-        var content = await reader.ReadToEndAsync();
-
-        await File.WriteAllTextAsync(targetPath, content);
-
-        var info = new FileInfo(targetPath);
-        var lineCount = content.Split('\n').Length;
-
-        await ctx.Response.WriteAsJsonAsync(new
-        {
-            path = filePath,
-            name = info.Name,
-            size = info.Length,
-            lineCount
-        });
-    }
-
-    private static async Task HandleMkdir(HttpContext ctx)
-    {
-        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
-        var dirPath = ctx.Request.Query["path"].FirstOrDefault();
-
-        if (string.IsNullOrEmpty(dirPath))
-        {
-            ctx.Response.StatusCode = 400;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Pfad fehlt" });
-            return;
-        }
-
-        var result = await ResolveSessionWorkspace(ctx, sessionId);
-        if (result == null) return;
-        var (session, basePath) = result.Value;
-
-        var targetPath = Path.GetFullPath(Path.Combine(basePath, dirPath));
-
-        if (!targetPath.StartsWith(basePath))
-        {
-            ctx.Response.StatusCode = 403;
-            return;
-        }
-
-        if (Directory.Exists(targetPath))
-        {
-            ctx.Response.StatusCode = 409;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner existiert bereits" });
-            return;
-        }
-
-        Directory.CreateDirectory(targetPath);
-        await ctx.Response.WriteAsJsonAsync(new { path = dirPath, created = true });
-    }
-
-    private static async Task HandleRmdir(HttpContext ctx)
-    {
-        var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
-        var dirPath = ctx.Request.Query["path"].FirstOrDefault();
-
-        if (string.IsNullOrEmpty(dirPath))
-        {
-            ctx.Response.StatusCode = 400;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Pfad fehlt" });
-            return;
-        }
-
-        var result = await ResolveSessionWorkspace(ctx, sessionId);
-        if (result == null) return;
-        var (session, basePath) = result.Value;
-
-        var targetPath = Path.GetFullPath(Path.Combine(basePath, dirPath));
-
-        if (!targetPath.StartsWith(basePath) || targetPath == basePath)
-        {
-            ctx.Response.StatusCode = 403;
-            return;
-        }
-
-        if (!Directory.Exists(targetPath))
-        {
-            ctx.Response.StatusCode = 404;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner nicht gefunden" });
-            return;
-        }
-
-        if (Directory.GetFileSystemEntries(targetPath).Length > 0)
-        {
-            ctx.Response.StatusCode = 409;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner ist nicht leer" });
-            return;
-        }
-
-        Directory.Delete(targetPath);
-        await ctx.Response.WriteAsJsonAsync(new { path = dirPath, deleted = true });
-    }
-
-    private static async Task HandleAgentMkdir(HttpContext ctx)
-    {
-        var basePath = GetAgentBasePath(ctx, out var error);
-        if (basePath == null)
-        {
-            ctx.Response.StatusCode = 400;
-            await ctx.Response.WriteAsJsonAsync(new { error });
-            return;
-        }
-
-        var dirPath = ctx.Request.Query["path"].FirstOrDefault();
-        if (string.IsNullOrEmpty(dirPath))
-        {
-            ctx.Response.StatusCode = 400;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Pfad fehlt" });
-            return;
-        }
-
-        var targetPath = Path.GetFullPath(Path.Combine(basePath, dirPath));
-        if (!targetPath.StartsWith(basePath))
-        {
-            ctx.Response.StatusCode = 403;
-            return;
-        }
-
-        if (Directory.Exists(targetPath))
-        {
-            ctx.Response.StatusCode = 409;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner existiert bereits" });
-            return;
-        }
-
-        Directory.CreateDirectory(targetPath);
-        await ctx.Response.WriteAsJsonAsync(new { path = dirPath, created = true });
-    }
-
-    private static async Task HandleAgentRmdir(HttpContext ctx)
-    {
-        var basePath = GetAgentBasePath(ctx, out var error);
-        if (basePath == null)
-        {
-            ctx.Response.StatusCode = 400;
-            await ctx.Response.WriteAsJsonAsync(new { error });
-            return;
-        }
-
-        var dirPath = ctx.Request.Query["path"].FirstOrDefault();
-        if (string.IsNullOrEmpty(dirPath))
-        {
-            ctx.Response.StatusCode = 400;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Pfad fehlt" });
-            return;
-        }
-
-        var targetPath = Path.GetFullPath(Path.Combine(basePath, dirPath));
-        if (!targetPath.StartsWith(basePath) || targetPath == basePath)
-        {
-            ctx.Response.StatusCode = 403;
-            return;
-        }
-
-        if (!Directory.Exists(targetPath))
-        {
-            ctx.Response.StatusCode = 404;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner nicht gefunden" });
-            return;
-        }
-
-        if (Directory.GetFileSystemEntries(targetPath).Length > 0)
-        {
-            ctx.Response.StatusCode = 409;
-            await ctx.Response.WriteAsJsonAsync(new { error = "Ordner ist nicht leer" });
-            return;
-        }
-
-        Directory.Delete(targetPath);
-        await ctx.Response.WriteAsJsonAsync(new { path = dirPath, deleted = true });
-    }
-
-    private static readonly Dictionary<string, string> MimeTypes = new(StringComparer.OrdinalIgnoreCase)
-    {
-        { ".png", "image/png" }, { ".jpg", "image/jpeg" }, { ".jpeg", "image/jpeg" },
-        { ".gif", "image/gif" }, { ".webp", "image/webp" }, { ".svg", "image/svg+xml" },
-        { ".bmp", "image/bmp" }, { ".ico", "image/x-icon" },
-        { ".pdf", "application/pdf" },
-        { ".mp4", "video/mp4" }, { ".webm", "video/webm" },
-        { ".mp3", "audio/mpeg" }, { ".wav", "audio/wav" }, { ".ogg", "audio/ogg" },
-    };
-
     private static async Task HandleRawFile(HttpContext ctx)
     {
         var sessionId = ctx.Request.Query["sessionId"].FirstOrDefault();
@@ -640,12 +364,10 @@ public static class WorkspaceEndpoint
             return;
         }
 
-        var result = await ResolveSessionWorkspace(ctx, sessionId);
-        if (result == null) return;
-        var basePath = result.Value.basePath;
+        var basePath = await ResolveSessionBasePath(ctx);
+        if (basePath == null) return;
 
         var targetPath = Path.GetFullPath(Path.Combine(basePath, filePath));
-
         if (!targetPath.StartsWith(basePath))
         {
             ctx.Response.StatusCode = 403;
@@ -658,11 +380,30 @@ public static class WorkspaceEndpoint
             return;
         }
 
-        var ext = Path.GetExtension(targetPath);
-        var contentType = MimeTypes.GetValueOrDefault(ext, "application/octet-stream");
+        var ext = Path.GetExtension(targetPath).ToLowerInvariant();
+        ctx.Response.ContentType = ext switch
+        {
+            ".png" => "image/png",
+            ".jpg" or ".jpeg" => "image/jpeg",
+            ".gif" => "image/gif",
+            ".webp" => "image/webp",
+            ".svg" => "image/svg+xml",
+            ".pdf" => "application/pdf",
+            ".mp4" => "video/mp4",
+            ".webm" => "video/webm",
+            ".mp3" => "audio/mpeg",
+            ".wav" => "audio/wav",
+            _ => "application/octet-stream"
+        };
 
-        ctx.Response.ContentType = contentType;
-        ctx.Response.Headers["Cache-Control"] = "private, max-age=3600";
         await ctx.Response.SendFileAsync(targetPath);
     }
+
+    private static bool IsLikelyTextFile(string name)
+    {
+        var lower = name.ToLowerInvariant();
+        return lower is "makefile" or "dockerfile" or "rakefile" or "gemfile"
+            or "procfile" or "vagrantfile" or "license" or "readme"
+            or "changelog" or "authors" or "contributors";
+    }
 }
diff --git a/Models/ChatContext.cs b/Models/ChatContext.cs
index 37f5dd5..6852a40 100644
--- a/Models/ChatContext.cs
+++ b/Models/ChatContext.cs
@@ -22,16 +22,16 @@ public class ChatContext
     public bool PlanMode { get; set; }
 
     // Preparer-Agent (vor dem Worker)
-    public PreparerContext Preparer { get; set; }
+    public SubAgentContext Preparer { get; set; }
 
     // Review-Agent
-    public ReviewContext Review { get; set; }
+    public SubAgentContext Review { get; set; }
 
     // Finalizer-Agent
-    public FinalizerContext Finalizer { get; set; }
+    public SubAgentContext Finalizer { get; set; }
 }
 
-public class PreparerContext
+public class SubAgentContext
 {
     public string ModelId { get; set; }
     public List<object> SystemPrompt { get; set; }
@@ -40,31 +40,11 @@ public class PreparerContext
     public bool UseMemory { get; set; }
     public string WebSearchVersion { get; set; }
     public string ToolChoice { get; set; }
+    public AgentRecord Agent { get; set; }
+
+    // Preparer-spezifisch
     public bool AllowUserChoice { get; set; }
-    public AgentRecord Agent { get; set; }
-}
 
-public class FinalizerContext
-{
-    public string ModelId { get; set; }
-    public List<object> SystemPrompt { get; set; }
-    public string AgentId { get; set; }
-    public string Workspace { get; set; }
-    public bool UseMemory { get; set; }
-    public string WebSearchVersion { get; set; }
-    public string ToolChoice { get; set; }
-    public AgentRecord Agent { get; set; }
-}
-
-public class ReviewContext
-{
-    public string ModelId { get; set; }
-    public List<object> SystemPrompt { get; set; }
-    public string AgentId { get; set; }
-    public string Workspace { get; set; }
-    public bool UseMemory { get; set; }
-    public string WebSearchVersion { get; set; }
-    public string ToolChoice { get; set; }
+    // Review-spezifisch
     public int MaxReviewIterations { get; set; }
-    public AgentRecord Agent { get; set; }
 }
diff --git a/Services/AnthropicService.cs b/Services/AnthropicService.cs
index 1aa091a..5df2681 100644
--- a/Services/AnthropicService.cs
+++ b/Services/AnthropicService.cs
@@ -47,8 +47,8 @@ public class AnthropicService
         string webSearchVersion = null,
         int maxIterations = 100,
         string toolChoice = "any",
-        ReviewContext review = null,
-        FinalizerContext finalizer = null,
+        SubAgentContext review = null,
+        SubAgentContext finalizer = null,
         bool allowUserChoice = true,
         bool planMode = false,
         CancellationToken cancellationToken = default)
@@ -85,30 +85,7 @@ public class AnthropicService
                 if (systemPrompt != null && systemPrompt.Count > 0)
                     payload["system"] = systemPrompt;
 
-                var hasWorkspace = !string.IsNullOrEmpty(workspace);
-                var includeMemory = useMemory && _memoryService != null && !string.IsNullOrEmpty(agentId);
-                var hasTools = hasWorkspace || includeMemory;
-                var hasWebSearch = !string.IsNullOrEmpty(webSearchVersion);
-
-                if (hasTools || hasWebSearch)
-                {
-                    var tools = new List<object>();
-                    if (hasTools)
-                    {
-                        var allTools = _toolService.GetToolDefinitions(includeFileTools: hasWorkspace, includeMemory: includeMemory, includeUserChoice: allowUserChoice);
-                        if (planMode)
-                            allTools = _toolService.FilterReadOnlyTools(allTools);
-                        tools.AddRange(allTools);
-                    }
-                    if (hasWebSearch)
-                        tools.Add(new { type = webSearchVersion, name = "web_search", max_uses = 5 });
-                    payload["tools"] = tools;
-                    // "any" erzwingt Tool-Nutzung, aber nur in der ersten Iteration,
-                    // damit Claude nicht endlos Tools aufruft wenn die Aufgabe erledigt ist.
-                    // Im Plan-Modus nie "any" erzwingen – Claude soll frei antworten können.
-                    var effectiveChoice = (!planMode && toolChoice == "any" && iterations == 1) ? "any" : "auto";
-                    payload["tool_choice"] = new { type = effectiveChoice };
-                }
+                AddToolsToPayload(payload, workspace, agentId, useMemory, webSearchVersion, toolChoice, iterations, allowUserChoice, planMode);
 
                 var client = CreateClient();
                 var json = JsonSerializer.Serialize(payload, new JsonSerializerOptions { WriteIndented = true });
@@ -171,22 +148,7 @@ public class AnthropicService
                     }
                     else if (blockType == "web_search_tool_result")
                     {
-                        // Sources aus dem Ergebnis-Block extrahieren und speichern
-                        var sources = new List<object>();
-                        if (el.TryGetProperty("content", out var searchContent) && searchContent.ValueKind == JsonValueKind.Array)
-                        {
-                            foreach (var item in searchContent.EnumerateArray())
-                            {
-                                var itemType = item.TryGetProperty("type", out var it) ? it.GetString() : "";
-                                if (itemType == "web_search_result")
-                                {
-                                    var url = item.TryGetProperty("url", out var u) ? u.GetString() ?? "" : "";
-                                    var title = item.TryGetProperty("title", out var tt) ? tt.GetString() ?? "" : "";
-                                    if (!string.IsNullOrEmpty(url))
-                                        sources.Add(new { url, title });
-                                }
-                            }
-                        }
+                        var sources = ExtractWebSearchSources(el);
                         if (sources.Count > 0)
                         {
                             await _db.SaveMessage(new MessageRecord
@@ -268,20 +230,11 @@ public class AnthropicService
                 var toolResults = new List<object>();
                 foreach (var tr in executedTools)
                 {
-                    // Tool-Results in der History auf 20.000 Zeichen kürzen.
-                    // Das vollständige Ergebnis wurde bereits in der DB gespeichert.
-                    // 20k Zeichen ≈ ~5k Tokens – verhindert Token-Explosion bei großen
-                    // read_file / execute-Outputs die sich über alle weiteren Iterationen schleppen.
-                    const int MaxToolResultChars = 20_000;
-                    var content = tr.Result.Length > MaxToolResultChars
-                        ? tr.Result[..MaxToolResultChars] + $"\n\n[... gekürzt, {tr.Result.Length - MaxToolResultChars} weitere Zeichen ...]"
-                        : tr.Result;
-
                     toolResults.Add(new
                     {
                         type = "tool_result",
                         tool_use_id = tr.Id,
-                        content,
+                        content = TruncateToolResult(tr.Result),
                         is_error = tr.IsError
                     });
                 }
@@ -331,7 +284,7 @@ public class AnthropicService
     /// </summary>
     public async Task<PreparerResult> RunPreparer(
         HttpResponse response,
-        PreparerContext preparer,
+        SubAgentContext preparer,
         List<object> historyMessages,
         string chainId,
         string workspace,
@@ -416,7 +369,7 @@ public class AnthropicService
     /// </summary>
     private async Task<ReviewResult> RunReview(
         HttpResponse response,
-        ReviewContext review,
+        SubAgentContext review,
         List<object> workerMessages,
         string chainId,
         string workspace,
@@ -490,7 +443,7 @@ public class AnthropicService
     /// </summary>
     private async Task<int> RunFinalizer(
         HttpResponse response,
-        FinalizerContext finalizer,
+        SubAgentContext finalizer,
         List<object> workerMessages,
         string chainId,
         string workspace,
@@ -686,22 +639,7 @@ public class AnthropicService
             if (systemPrompt != null && systemPrompt.Count > 0)
                 payload["system"] = systemPrompt;
 
-            var hasWorkspace = !string.IsNullOrEmpty(agentWorkspace);
-            var includeMemory = useMemory && _memoryService != null && !string.IsNullOrEmpty(agentId);
-            var hasTools = hasWorkspace || includeMemory;
-            var hasWebSearch = !string.IsNullOrEmpty(webSearchVersion);
-
-            if (hasTools || hasWebSearch)
-            {
-                var tools = new List<object>();
-                if (hasTools)
-                    tools.AddRange(_toolService.GetToolDefinitions(includeFileTools: hasWorkspace, includeMemory: includeMemory, includeUserChoice: false));
-                if (hasWebSearch)
-                    tools.Add(new { type = webSearchVersion, name = "web_search", max_uses = 5 });
-                payload["tools"] = tools;
-                var effectiveChoice = (agentToolChoice == "any" && iterations == 1) ? "any" : "auto";
-                payload["tool_choice"] = new { type = effectiveChoice };
-            }
+            AddToolsToPayload(payload, agentWorkspace, agentId, useMemory, webSearchVersion, agentToolChoice, iterations);
 
             var client = CreateClient();
             var json = JsonSerializer.Serialize(payload, new JsonSerializerOptions { WriteIndented = true });
@@ -722,12 +660,7 @@ public class AnthropicService
             var resp = JsonSerializer.Deserialize<JsonElement>(respBody);
 
             if (resp.TryGetProperty("usage", out var u))
-            {
-                if (u.TryGetProperty("input_tokens", out var it)) usage.InputTokens += it.GetInt64();
-                if (u.TryGetProperty("output_tokens", out var ot)) usage.OutputTokens += ot.GetInt64();
-                if (u.TryGetProperty("cache_creation_input_tokens", out var cc)) usage.CacheCreationTokens += cc.GetInt64();
-                if (u.TryGetProperty("cache_read_input_tokens", out var cr)) usage.CacheReadTokens += cr.GetInt64();
-            }
+                TrackUsage(usage, u);
 
             var stopReason = resp.TryGetProperty("stop_reason", out var sr) ? sr.GetString() ?? "" : "";
             var content = resp.GetProperty("content");
@@ -795,16 +728,11 @@ public class AnthropicService
                     try { toolResult = await _toolService.ExecuteTool(toolName, toolInput, agentWorkspace, _memoryService, agentId, cancellationToken); }
                     catch (Exception ex) { toolResult = $"Fehler: {ex.Message}"; isError = true; }
 
-                    const int MaxToolResultChars = 20_000;
-                    var truncatedResult = toolResult.Length > MaxToolResultChars
-                        ? toolResult[..MaxToolResultChars] + $"\n\n[... gekürzt, {toolResult.Length - MaxToolResultChars} weitere Zeichen ...]"
-                        : toolResult;
-
                     toolResults.Add(new
                     {
                         type = "tool_result",
                         tool_use_id = toolId,
-                        content = truncatedResult,
+                        content = TruncateToolResult(toolResult),
                         is_error = isError
                     });
 
@@ -834,23 +762,7 @@ public class AnthropicService
                 else if (blockType == "web_search_tool_result")
                 {
                     assistantContent.Add(JsonSerializer.Deserialize<JsonElement>(block.GetRawText()));
-
-                    var sources = new List<object>();
-                    if (block.TryGetProperty("content", out var searchContent) && searchContent.ValueKind == JsonValueKind.Array)
-                    {
-                        foreach (var item in searchContent.EnumerateArray())
-                        {
-                            var itemType = item.TryGetProperty("type", out var it) ? it.GetString() : "";
-                            if (itemType == "web_search_result")
-                            {
-                                var url = item.TryGetProperty("url", out var u2) ? u2.GetString() ?? "" : "";
-                                var title = item.TryGetProperty("title", out var tt2) ? tt2.GetString() ?? "" : "";
-                                if (!string.IsNullOrEmpty(url))
-                                    sources.Add(new { url, title });
-                            }
-                        }
-                    }
-
+                    var sources = ExtractWebSearchSources(block);
                     if (sources.Count > 0)
                     {
                         await _db.SaveMessage(new MessageRecord
@@ -866,11 +778,7 @@ public class AnthropicService
                 }
                 else if (blockType == "server_tool_use")
                 {
-                    var toolId = block.GetProperty("id").GetString() ?? "";
-                    var toolName = block.GetProperty("name").GetString() ?? "";
-                    JsonElement inputEl;
-                    try { inputEl = block.GetProperty("input"); }
-                    catch { inputEl = JsonSerializer.Deserialize<JsonElement>("{}"); }
+                    var (toolId, toolName, inputEl) = ParseServerToolUse(block);
                     assistantContent.Add(new { type = "server_tool_use", id = toolId, name = toolName, input = inputEl });
                 }
             }
@@ -926,22 +834,7 @@ public class AnthropicService
                 if (ctx.SystemPrompt != null && ctx.SystemPrompt.Count > 0)
                     payload["system"] = ctx.SystemPrompt;
 
-                var hasWorkspace = !string.IsNullOrEmpty(ctx.Workspace);
-                var includeMemory = ctx.UseMemory && _memoryService != null && !string.IsNullOrEmpty(ctx.AgentId);
-                var hasTools = hasWorkspace || includeMemory;
-                var hasWebSearch = !string.IsNullOrEmpty(ctx.WebSearchVersion);
-
-                if (hasTools || hasWebSearch)
-                {
-                    var tools = new List<object>();
-                    if (hasTools)
-                        tools.AddRange(_toolService.GetToolDefinitions(includeFileTools: hasWorkspace, includeMemory: includeMemory, includeUserChoice: false));
-                    if (hasWebSearch)
-                        tools.Add(new { type = ctx.WebSearchVersion, name = "web_search", max_uses = 5 });
-                    payload["tools"] = tools;
-                    var effectiveChoice = (ctx.ToolChoice == "any" && iterations == 1) ? "any" : "auto";
-                    payload["tool_choice"] = new { type = effectiveChoice };
-                }
+                AddToolsToPayload(payload, ctx.Workspace, ctx.AgentId, ctx.UseMemory, ctx.WebSearchVersion, ctx.ToolChoice, iterations);
 
                 var client = CreateClient();
                 var json = JsonSerializer.Serialize(payload, new JsonSerializerOptions { WriteIndented = true });
@@ -970,12 +863,7 @@ public class AnthropicService
 
                 // Usage tracken
                 if (resp.TryGetProperty("usage", out var u))
-                {
-                    if (u.TryGetProperty("input_tokens", out var it)) usage.InputTokens += it.GetInt64();
-                    if (u.TryGetProperty("output_tokens", out var ot)) usage.OutputTokens += ot.GetInt64();
-                    if (u.TryGetProperty("cache_creation_input_tokens", out var cc)) usage.CacheCreationTokens += cc.GetInt64();
-                    if (u.TryGetProperty("cache_read_input_tokens", out var cr)) usage.CacheReadTokens += cr.GetInt64();
-                }
+                    TrackUsage(usage, u);
 
                 var stopReason = resp.TryGetProperty("stop_reason", out var sr) ? sr.GetString() ?? "" : "";
                 var content = resp.GetProperty("content");
@@ -1021,17 +909,11 @@ public class AnthropicService
                         try { toolResult = await _toolService.ExecuteTool(toolName, toolInput, ctx.Workspace, _memoryService, ctx.AgentId); }
                         catch (Exception ex) { toolResult = $"Fehler: {ex.Message}"; isError = true; }
 
-                        // Tool-Result in der History kürzen (wie bei StreamChat)
-                        const int MaxToolResultChars = 20_000;
-                        var truncatedResult = toolResult.Length > MaxToolResultChars
-                            ? toolResult[..MaxToolResultChars] + $"\n\n[... gekürzt, {toolResult.Length - MaxToolResultChars} weitere Zeichen ...]"
-                            : toolResult;
-
                         toolResults.Add(new
                         {
                             type = "tool_result",
                             tool_use_id = toolId,
-                            content = truncatedResult,
+                            content = TruncateToolResult(toolResult),
                             is_error = isError
                         });
 
@@ -1047,21 +929,7 @@ public class AnthropicService
                     else if (blockType == "web_search_tool_result")
                     {
                         assistantContent.Add(JsonSerializer.Deserialize<JsonElement>(block.GetRawText()));
-                        var sources = new List<object>();
-                        if (block.TryGetProperty("content", out var searchContent) && searchContent.ValueKind == JsonValueKind.Array)
-                        {
-                            foreach (var item in searchContent.EnumerateArray())
-                            {
-                                var itemType = item.TryGetProperty("type", out var it) ? it.GetString() : "";
-                                if (itemType == "web_search_result")
-                                {
-                                    var url = item.TryGetProperty("url", out var u2) ? u2.GetString() ?? "" : "";
-                                    var title = item.TryGetProperty("title", out var tt2) ? tt2.GetString() ?? "" : "";
-                                    if (!string.IsNullOrEmpty(url))
-                                        sources.Add(new { url, title });
-                                }
-                            }
-                        }
+                        var sources = ExtractWebSearchSources(block);
                         if (sources.Count > 0)
                         {
                             await _db.SaveMessage(new MessageRecord
@@ -1074,11 +942,7 @@ public class AnthropicService
                     }
                     else if (blockType == "server_tool_use")
                     {
-                        var toolId = block.GetProperty("id").GetString() ?? "";
-                        var toolName = block.GetProperty("name").GetString() ?? "";
-                        JsonElement inputEl;
-                        try { inputEl = block.GetProperty("input"); }
-                        catch { inputEl = JsonSerializer.Deserialize<JsonElement>("{}"); }
+                        var (toolId, toolName, inputEl) = ParseServerToolUse(block);
                         assistantContent.Add(new { type = "server_tool_use", id = toolId, name = toolName, input = inputEl });
                     }
                 }
@@ -1186,14 +1050,7 @@ public class AnthropicService
                 {
                     if (evt.TryGetProperty("message", out var msg) &&
                         msg.TryGetProperty("usage", out var u))
-                    {
-                        if (u.TryGetProperty("input_tokens", out var it))
-                            usage.InputTokens += it.GetInt64();
-                        if (u.TryGetProperty("cache_creation_input_tokens", out var cc))
-                            usage.CacheCreationTokens += cc.GetInt64();
-                        if (u.TryGetProperty("cache_read_input_tokens", out var cr))
-                            usage.CacheReadTokens += cr.GetInt64();
-                    }
+                        TrackUsage(usage, u);
                     break;
                 }
 
@@ -1235,27 +1092,9 @@ public class AnthropicService
                     }
                     else if (cbType == "web_search_tool_result")
                     {
-                        // Gesamten Block als JSON speichern für die Conversation-History
                         var rawBlock = JsonSerializer.Deserialize<JsonElement>(cb.GetRawText());
                         webSearchResultBlocks[idx] = rawBlock;
-
-                        // Sources extrahieren für Frontend
-                        var sources = new List<object>();
-                        if (cb.TryGetProperty("content", out var searchContent) && searchContent.ValueKind == JsonValueKind.Array)
-                        {
-                            foreach (var item in searchContent.EnumerateArray())
-                            {
-                                var itemType = item.TryGetProperty("type", out var it) ? it.GetString() : "";
-                                if (itemType == "web_search_result")
-                                {
-                                    var url = item.TryGetProperty("url", out var u) ? u.GetString() ?? "" : "";
-                                    var title = item.TryGetProperty("title", out var tt) ? tt.GetString() ?? "" : "";
-                                    if (!string.IsNullOrEmpty(url))
-                                        sources.Add(new { url, title });
-                                }
-                            }
-                        }
-                        webSearchSources[idx] = sources;
+                        webSearchSources[idx] = ExtractWebSearchSources(cb);
                     }
                     break;
                 }
@@ -1452,6 +1291,91 @@ public class AnthropicService
         return (stopReason, assistantContent, executedTools, streamErrorInfo);
     }
 
+    // ── Shared Helpers ──
+
+    private const int MaxToolResultChars = 20_000;
+
+    private static string TruncateToolResult(string result)
+    {
+        return result.Length > MaxToolResultChars
+            ? result[..MaxToolResultChars] + $"\n\n[... gekürzt, {result.Length - MaxToolResultChars} weitere Zeichen ...]"
+            : result;
+    }
+
+    /// <summary>
+    /// Extrahiert Web-Search-Sources aus einem web_search_tool_result-Block.
+    /// </summary>
+    private static List<object> ExtractWebSearchSources(JsonElement block)
+    {
+        var sources = new List<object>();
+        if (block.TryGetProperty("content", out var searchContent) && searchContent.ValueKind == JsonValueKind.Array)
+        {
+            foreach (var item in searchContent.EnumerateArray())
+            {
+                var itemType = item.TryGetProperty("type", out var it) ? it.GetString() : "";
+                if (itemType == "web_search_result")
+                {
+                    var url = item.TryGetProperty("url", out var u) ? u.GetString() ?? "" : "";
+                    var title = item.TryGetProperty("title", out var tt) ? tt.GetString() ?? "" : "";
+                    if (!string.IsNullOrEmpty(url))
+                        sources.Add(new { url, title });
+                }
+            }
+        }
+        return sources;
+    }
+
+    /// <summary>
+    /// Parst einen server_tool_use-Block und gibt (id, name, input) zurück.
+    /// </summary>
+    private static (string id, string name, JsonElement input) ParseServerToolUse(JsonElement block)
+    {
+        var toolId = block.GetProperty("id").GetString() ?? "";
+        var toolName = block.GetProperty("name").GetString() ?? "";
+        JsonElement inputEl;
+        try { inputEl = block.GetProperty("input"); }
+        catch { inputEl = JsonSerializer.Deserialize<JsonElement>("{}"); }
+        return (toolId, toolName, inputEl);
+    }
+
+    /// <summary>
+    /// Aktualisiert den TokenUsage-Tracker aus einem usage-JSON-Element.
+    /// </summary>
+    private static void TrackUsage(TokenUsage usage, JsonElement u)
+    {
+        if (u.TryGetProperty("input_tokens", out var it)) usage.InputTokens += it.GetInt64();
+        if (u.TryGetProperty("output_tokens", out var ot)) usage.OutputTokens += ot.GetInt64();
+        if (u.TryGetProperty("cache_creation_input_tokens", out var cc)) usage.CacheCreationTokens += cc.GetInt64();
+        if (u.TryGetProperty("cache_read_input_tokens", out var cr)) usage.CacheReadTokens += cr.GetInt64();
+    }
+
+    /// <summary>
+    /// Fügt Tool-Definitionen und WebSearch zum Payload hinzu.
+    /// </summary>
+    private void AddToolsToPayload(Dictionary<string, object> payload, string workspace, string agentId, bool useMemory, string webSearchVersion, string toolChoice, int iteration, bool allowUserChoice = false, bool planMode = false)
+    {
+        var hasWorkspace = !string.IsNullOrEmpty(workspace);
+        var includeMemory = useMemory && _memoryService != null && !string.IsNullOrEmpty(agentId);
+        var hasTools = hasWorkspace || includeMemory;
+        var hasWebSearch = !string.IsNullOrEmpty(webSearchVersion);
+
+        if (!hasTools && !hasWebSearch) return;
+
+        var tools = new List<object>();
+        if (hasTools)
+        {
+            var allTools = _toolService.GetToolDefinitions(includeFileTools: hasWorkspace, includeMemory: includeMemory, includeUserChoice: allowUserChoice);
+            if (planMode)
+                allTools = _toolService.FilterReadOnlyTools(allTools);
+            tools.AddRange(allTools);
+        }
+        if (hasWebSearch)
+            tools.Add(new { type = webSearchVersion, name = "web_search", max_uses = 5 });
+        payload["tools"] = tools;
+        var effectiveChoice = (!planMode && toolChoice == "any" && iteration == 1) ? "any" : "auto";
+        payload["tool_choice"] = new { type = effectiveChoice };
+    }
+
     private HttpClient CreateClient()
     {
         var client = _httpFactory.CreateClient();
diff --git a/Services/ChatService.cs b/Services/ChatService.cs
index afa7b72..037d29f 100644
--- a/Services/ChatService.cs
+++ b/Services/ChatService.cs
@@ -114,29 +114,18 @@ public class ChatService
         if (!string.IsNullOrWhiteSpace(systemPromptText))
             systemPrompt.Add(new { type = "text", text = systemPromptText });
 
-        // Preparer-Agent vorbereiten (falls konfiguriert)
-        PreparerContext preparerContext = null;
-        if (!string.IsNullOrEmpty(session.PreparerAgentId))
+        // Sub-Agents vorbereiten (falls konfiguriert)
+        var preparerContext = await BuildSubAgentContext(
+            session.PreparerAgentId, sessionId, workspace, session, user);
+        var reviewContext = await BuildSubAgentContext(
+            session.ReviewAgentId, sessionId, workspace, session, user);
+        var finalizerContext = await BuildSubAgentContext(
+            session.FinalizerAgentId, sessionId, workspace, session, user);
+
+        if (preparerContext != null)
         {
-            var preparerAgent = await _db.GetAgent(session.PreparerAgentId);
-            if (preparerAgent != null)
-            {
-                var preparerModelId = ResolveModelId(preparerAgent.Model);
-                var preparerMarked = await _db.GetMarkedMessages(sessionId);
-                var preparerMemDir = _memoryService.GetAgentMemoryDir(preparerAgent.AgentId);
-                var preparerSkills = await _db.GetAgentSkills(preparerAgent.AgentId);
-                var preparerWorkspace = workspace;
-                var preparerSystemText = SystemPromptBuilder.Build(
-                    preparerAgent, session, preparerMarked, _memoryService, preparerMemDir,
-                    preparerSkills, _skillService, userPersona: user?.GetEffectivePersona(),
-                    resolvedWorkspace: preparerWorkspace);
-
-                var preparerPrompt = new List<object>();
-                if (!string.IsNullOrWhiteSpace(preparerSystemText))
-                    preparerPrompt.Add(new { type = "text", text = preparerSystemText });
-
-                // Preparer-Instruktion: erklärt Vorbereiter-Mechanismus
-                preparerPrompt.Add(new { type = "text", text = @"## KRITISCH: Deine Rolle als Vorbereiter-Agent
+            preparerContext.AllowUserChoice = preparerContext.Agent?.AllowUserChoice ?? false;
+            preparerContext.SystemPrompt.Add(new { type = "text", text = @"## KRITISCH: Deine Rolle als Vorbereiter-Agent
 
 Du bist ein Vorbereiter-Agent. Deine Aufgabe: Die Anfrage des Users aufbereiten, deine Fähigkeiten nutzen, und das Ergebnis an den Session-Agent weiterleiten.
 
@@ -165,95 +154,11 @@ Rückfrage (NUR mit [QUESTION] – stoppt die Weiterleitung):
 [QUESTION]
 Für welche Plattform soll die App entwickelt werden? Web, Mobile oder Desktop?
 ```" });
-
-                var preparerHasTools = !string.IsNullOrEmpty(preparerWorkspace) || preparerAgent.UseMemory;
-                preparerContext = new PreparerContext
-                {
-                    ModelId = preparerModelId,
-                    SystemPrompt = preparerPrompt,
-                    AgentId = preparerAgent.AgentId,
-                    Workspace = preparerWorkspace,
-                    UseMemory = preparerAgent.UseMemory,
-                    WebSearchVersion = preparerAgent.WebSearchVersion,
-                    ToolChoice = preparerHasTools ? "any" : "auto",
-                    AllowUserChoice = preparerAgent.AllowUserChoice,
-                    Agent = preparerAgent
-                };
-            }
         }
 
-        // Review-Agent vorbereiten (falls konfiguriert)
-        ReviewContext reviewContext = null;
-        if (!string.IsNullOrEmpty(session.ReviewAgentId))
-        {
-            var reviewAgent = await _db.GetAgent(session.ReviewAgentId);
-            if (reviewAgent != null)
-            {
-                var reviewModelId = ResolveModelId(reviewAgent.Model);
-                var reviewMarked = await _db.GetMarkedMessages(sessionId);
-                var reviewMemDir = _memoryService.GetAgentMemoryDir(reviewAgent.AgentId);
-                var reviewSkills = await _db.GetAgentSkills(reviewAgent.AgentId);
-                var reviewWorkspace = workspace; // gleicher Workspace wie Worker
-                var reviewSystemText = SystemPromptBuilder.Build(
-                    reviewAgent, session, reviewMarked, _memoryService, reviewMemDir,
-                    reviewSkills, _skillService, userPersona: user?.GetEffectivePersona(),
-                    resolvedWorkspace: reviewWorkspace);
+        if (reviewContext != null)
+            reviewContext.MaxReviewIterations = session.MaxReviewIterations > 0 ? session.MaxReviewIterations : 3;
 
-                var reviewPrompt = new List<object>();
-                if (!string.IsNullOrWhiteSpace(reviewSystemText))
-                    reviewPrompt.Add(new { type = "text", text = reviewSystemText });
-
-                var reviewHasTools = !string.IsNullOrEmpty(reviewWorkspace) || reviewAgent.UseMemory;
-                reviewContext = new ReviewContext
-                {
-                    ModelId = reviewModelId,
-                    SystemPrompt = reviewPrompt,
-                    AgentId = reviewAgent.AgentId,
-                    Workspace = reviewWorkspace,
-                    UseMemory = reviewAgent.UseMemory,
-                    WebSearchVersion = reviewAgent.WebSearchVersion,
-                    ToolChoice = reviewHasTools ? "any" : "auto",
-                    MaxReviewIterations = session.MaxReviewIterations > 0 ? session.MaxReviewIterations : 3,
-                    Agent = reviewAgent
-                };
-            }
-        }
-
-        // Finalizer-Agent vorbereiten (falls konfiguriert)
-        FinalizerContext finalizerContext = null;
-        if (!string.IsNullOrEmpty(session.FinalizerAgentId))
-        {
-            var finalizerAgent = await _db.GetAgent(session.FinalizerAgentId);
-            if (finalizerAgent != null)
-            {
-                var finalizerModelId = ResolveModelId(finalizerAgent.Model);
-                var finalizerMarked = await _db.GetMarkedMessages(sessionId);
-                var finalizerMemDir = _memoryService.GetAgentMemoryDir(finalizerAgent.AgentId);
-                var finalizerSkills = await _db.GetAgentSkills(finalizerAgent.AgentId);
-                var finalizerWorkspace = workspace;
-                var finalizerSystemText = SystemPromptBuilder.Build(
-                    finalizerAgent, session, finalizerMarked, _memoryService, finalizerMemDir,
-                    finalizerSkills, _skillService, userPersona: user?.GetEffectivePersona(),
-                    resolvedWorkspace: finalizerWorkspace);
-
-                var finalizerPrompt = new List<object>();
-                if (!string.IsNullOrWhiteSpace(finalizerSystemText))
-                    finalizerPrompt.Add(new { type = "text", text = finalizerSystemText });
-
-                var finalizerHasTools = !string.IsNullOrEmpty(finalizerWorkspace) || finalizerAgent.UseMemory;
-                finalizerContext = new FinalizerContext
-                {
-                    ModelId = finalizerModelId,
-                    SystemPrompt = finalizerPrompt,
-                    AgentId = finalizerAgent.AgentId,
-                    Workspace = finalizerWorkspace,
-                    UseMemory = finalizerAgent.UseMemory,
-                    WebSearchVersion = finalizerAgent.WebSearchVersion,
-                    ToolChoice = finalizerHasTools ? "any" : "auto",
-                    Agent = finalizerAgent
-                };
-            }
-        }
 
         return new ChatContext
         {
@@ -531,4 +436,46 @@ Für welche Plattform soll die App entwickelt werden? Web, Mobile oder Desktop?
 
         return history;
     }
+
+    /// <summary>
+    /// Baut einen SubAgentContext für Preparer/Review/Finalizer.
+    /// Gemeinsame Logik: Agent laden, Model auflösen, SystemPrompt bauen, ToolChoice bestimmen.
+    /// </summary>
+    private async Task<SubAgentContext> BuildSubAgentContext(
+        string agentId, string sessionId, string workspace, SessionRecord session, UserRecord user)
+    {
+        if (string.IsNullOrEmpty(agentId))
+            return null;
+
+        var agent = await _db.GetAgent(agentId);
+        if (agent == null)
+            return null;
+
+        var modelId = ResolveModelId(agent.Model);
+        var markedMessages = await _db.GetMarkedMessages(sessionId);
+        var memDir = _memoryService.GetAgentMemoryDir(agent.AgentId);
+        var skills = await _db.GetAgentSkills(agent.AgentId);
+        var systemText = SystemPromptBuilder.Build(
+            agent, session, markedMessages, _memoryService, memDir,
+            skills, _skillService, userPersona: user?.GetEffectivePersona(),
+            resolvedWorkspace: workspace);
+
+        var prompt = new List<object>();
+        if (!string.IsNullOrWhiteSpace(systemText))
+            prompt.Add(new { type = "text", text = systemText });
+
+        var hasTools = !string.IsNullOrEmpty(workspace) || agent.UseMemory;
+        return new SubAgentContext
+        {
+            ModelId = modelId,
+            SystemPrompt = prompt,
+            AgentId = agent.AgentId,
+            Workspace = workspace,
+            UseMemory = agent.UseMemory,
+            WebSearchVersion = agent.WebSearchVersion,
+            ToolChoice = hasTools ? "any" : "auto",
+            Agent = agent
+        };
+    }
+
 }
diff --git a/Services/DatabaseService.cs b/Services/DatabaseService.cs
index 03307e9..fdd30e0 100644
--- a/Services/DatabaseService.cs
+++ b/Services/DatabaseService.cs
@@ -338,7 +338,7 @@ public class DatabaseService
 
         foreach (var (agentId, avatar) in agentsWithoutThumb)
         {
-            var small = ResizeDataUrlToWebP(avatar, smallSize, smallQuality);
+            var small = ConvertDataUrlToWebP(avatar, smallQuality, maxSide: smallSize);
             if (small != null)
                 conn.Execute("UPDATE agents SET avatar_small = @small WHERE agent_id = @agentId", new { small, agentId });
         }
@@ -350,7 +350,7 @@ public class DatabaseService
 
         foreach (var (sessionId, image) in sessionsWithoutThumb)
         {
-            var small = ResizeDataUrlToWebP(image, smallSize, smallQuality);
+            var small = ConvertDataUrlToWebP(image, smallQuality, maxSide: smallSize);
             if (small != null)
                 conn.Execute("UPDATE sessions SET image_small = @small WHERE session_id = @sessionId", new { small, sessionId });
         }
@@ -359,7 +359,10 @@ public class DatabaseService
             Console.WriteLine($"[Migration] Generated {agentsWithoutThumb.Count} agent thumbnails and {sessionsWithoutThumb.Count} session thumbnails");
     }
 
-    private static string ResizeDataUrlToWebP(string dataUrl, int maxSide, int quality)
+    /// <summary>
+    /// Konvertiert ein DataUrl-Bild zu WebP. Optional Resize wenn maxSide > 0.
+    /// </summary>
+    private static string ConvertDataUrlToWebP(string dataUrl, int quality, int maxSide = 0)
     {
         try
         {
@@ -370,7 +373,7 @@ public class DatabaseService
             var bytes = Convert.FromBase64String(base64);
 
             using var image = Image.Load(bytes);
-            if (image.Width > maxSide || image.Height > maxSide)
+            if (maxSide > 0 && (image.Width > maxSide || image.Height > maxSide))
             {
                 image.Mutate(x => x.Resize(new ResizeOptions
                 {
@@ -390,28 +393,6 @@ public class DatabaseService
         }
     }
 
-    private static string ConvertDataUrlToWebP(string dataUrl, int quality)
-    {
-        try
-        {
-            var commaIndex = dataUrl.IndexOf(',');
-            if (commaIndex < 0) return null;
-
-            var base64 = dataUrl.Substring(commaIndex + 1);
-            var bytes = Convert.FromBase64String(base64);
-
-            using var image = Image.Load(bytes);
-            using var ms = new MemoryStream();
-            image.Save(ms, new WebpEncoder { Quality = quality });
-
-            return "data:image/webp;base64," + Convert.ToBase64String(ms.ToArray());
-        }
-        catch
-        {
-            return null; // Beschädigte Bilder überspringen
-        }
-    }
-
     private void TryAddColumn(SqliteConnection conn, string table, string column, string type)
     {
         try { conn.Execute($"ALTER TABLE {table} ADD COLUMN {column} {type}"); }
@@ -573,13 +554,6 @@ public class DatabaseService
         return session;
     }
 
-    public async Task<IEnumerable<SessionRecord>> GetSessions(string userId)
-    {
-        using var conn = CreateConnection();
-        return await conn.QueryAsync<SessionRecord>(
-            "SELECT * FROM sessions WHERE user_id = @userId AND is_deleted = 0 ORDER BY updated_at DESC", new { userId });
-    }
-
     public async Task<List<SessionWithStats>> GetSessionsWithStats(string userId)
     {
         using var conn = CreateConnection();
@@ -1303,23 +1277,6 @@ public class DatabaseService
             new { sessionId, chatId, now });
     }
 
-    public async Task SetSessionTelegramChatId(string sessionId, string chatId)
-    {
-        using var conn = CreateConnection();
-        var now = DateTime.UtcNow.ToString("o");
-        await conn.ExecuteAsync(
-            "UPDATE sessions SET telegram_chat_id = @chatId, updated_at = @now WHERE session_id = @sessionId",
-            new { sessionId, chatId, now });
-    }
-
-    public async Task ClearSessionTelegramChatId(string sessionId)
-    {
-        using var conn = CreateConnection();
-        await conn.ExecuteAsync(
-            "UPDATE sessions SET telegram_chat_id = NULL, updated_at = @now WHERE session_id = @sessionId",
-            new { sessionId, now = DateTime.UtcNow.ToString("o") });
-    }
-
     public async Task<IEnumerable<SessionRecord>> GetSessionsByTelegramBot(string botId)
     {
         using var conn = CreateConnection();
@@ -1345,14 +1302,6 @@ public class DatabaseService
             new { botId });
     }
 
-    public async Task<IEnumerable<SessionRecord>> GetUserSessions(string userId)
-    {
-        using var conn = CreateConnection();
-        return await conn.QueryAsync<SessionRecord>(
-            "SELECT * FROM sessions WHERE user_id = @userId AND is_deleted = 0 ORDER BY updated_at DESC",
-            new { userId });
-    }
-
     // ── Cronjobs ──
 
     public async Task<CronjobRecord> CreateCronjob(CronjobRecord cronjob)
diff --git a/Services/ImageService.cs b/Services/ImageService.cs
index 165dbec..080f7f7 100644
--- a/Services/ImageService.cs
+++ b/Services/ImageService.cs
@@ -62,4 +62,37 @@ public class ImageService
 
         return "data:image/webp;base64," + webpBase64;
     }
+
+    /// <summary>
+    /// Generiert ein WebP-Thumbnail (max 320px) mit Caching.
+    /// Gibt den Pfad zum Thumbnail zurück, oder null bei Fehler.
+    /// </summary>
+    public static async System.Threading.Tasks.Task<string> GenerateThumbnail(string originalPath, string cacheDir, int maxSize = 320, int quality = 75)
+    {
+        var thumbFilename = Path.GetFileNameWithoutExtension(originalPath) + ".webp";
+        var thumbPath = Path.Combine(cacheDir, thumbFilename);
+
+        if (File.Exists(thumbPath) && File.GetLastWriteTimeUtc(originalPath) <= File.GetLastWriteTimeUtc(thumbPath))
+            return thumbPath;
+
+        try
+        {
+            Directory.CreateDirectory(cacheDir);
+            using var image = await Image.LoadAsync(originalPath);
+            if (image.Width > maxSize || image.Height > maxSize)
+            {
+                image.Mutate(x => x.Resize(new ResizeOptions
+                {
+                    Size = new Size(maxSize, maxSize),
+                    Mode = ResizeMode.Max
+                }));
+            }
+            await image.SaveAsync(thumbPath, new WebpEncoder { Quality = quality });
+            return thumbPath;
+        }
+        catch
+        {
+            return null;
+        }
+    }
 }
diff --git a/TODO.md b/TODO.md
index 646309d..d93054f 100644
--- a/TODO.md
+++ b/TODO.md
@@ -23,6 +23,8 @@
 - [x] Größere Tasks brechen irgendwann ab, könnte an der Limitierung von Antrophic/Claude liegen. Jedoch sollte wird es scheinbar nicht behandelt: Der Status bleibt auf "Streaming..." aber es passiert nichts mehr
 - [x] Session -> Chat öffnen im Frontend soll nicht möglich sein, wenn kein Agent gesetzt ist
 - [x] Falsche Nachrichtenanzahl im Dashboard (tool uses werden fälschicherweise mitgezählt) - dasselbe bei "Ältere Nachrichten laden" im Chat
+- [ ] Beim Benutzen vom Tool "todo_write": beim streamen ist der text abgeschnitten (limitiert), nach dem poll (history laden) passt es wieder. es soll beim stream auch vollständig angezeigt werden und nicht mit "..." enden
+- [ ] Manchmal passiert es wenn ein Agent die Memory-Funktion hat, dass er sich selbst Memories einträgt - das ist auch ok so, aber, manchmal werden "dumme" erinnerungen gesetzt, die nur session-bezogen sind (und nicht agent-bezogen) und diese sind dann fast immer einfach nur copy&paste aus dem session system-prompt. Woran kann das liegen bzw. wie kann man das optimieren?
 
 ## Backend
 - [x] System-Prompt anpassen. Explizit auf Workspace-Pfad hinweisen, weil Model halluziniert oft und will in den nicht vorhandenen Pfad /workspace wechseln
@@ -41,7 +43,7 @@
 
 ## Ideas / Backlog
 - [ ] Memory: Embedding-Modell für semantische Suche über Memory-Dateien (Vektor-basiert + BM25 Hybrid Search)
-- [ ] Subagents: Möglichkeit Subagents zu starten und zu orchestrieren
+- [ ] Claude (Sub-)Agents: Claude hat so ein Feature Build-in, kann man dieses Feature nutzen? bzw. macht es Sinn dieses Feature zu benutzen und kann man es einbauen?
 
 ## Features aus Devy übernehmen
 - [ ] 💬 Typing-Indicator - Animierter Indikator statt statischem "denkt nach..."