diff --git a/app/(dashboard)/chat/page.tsx b/app/(dashboard)/chat/page.tsx
index a855f8c..3f62e52 100644
--- a/app/(dashboard)/chat/page.tsx
+++ b/app/(dashboard)/chat/page.tsx
@@ -1,339 +1,281 @@
 "use client";
 
-import { useEffect, useState, useRef } from "react";
-import { Brain, Send, MessageSquare, Plus, Trash2, Loader2, Wrench } from "lucide-react";
 import { createClient } from "@/lib/supabase/client";
-import { Button } from "poyraz-ui/atoms";
 import { useChat } from "@ai-sdk/react";
+import { DefaultChatTransport, type UIMessage } from "ai";
+import { Brain, Loader2, MessageSquare, Plus, Send, Trash2 } from "lucide-react";
+import { Button } from "poyraz-ui/atoms";
+import { useEffect, useRef, useState } from "react";
 import toast from "react-hot-toast";
 
-interface ChatSession {
+type ChatSession = {
   id: string;
   title: string;
   created_at: string;
-}
+};
 
 export default function AIChatPage() {
   const [supabase] = useState(() => createClient());
   const [sessions, setSessions] = useState<ChatSession[]>([]);
   const [activeSessionId, setActiveSessionId] = useState<string | null>(null);
+  const [input, setInput] = useState("");
   const messagesEndRef = useRef<HTMLDivElement>(null);
 
-  const [input, setInput] = useState("");
-  const { messages, append, setMessages, isLoading, stop } = useChat({
-    api: "/api/chat",
-    body: {
-      sessionId: activeSessionId
+  const { messages, sendMessage, setMessages, status, stop } = useChat({
+    transport: new DefaultChatTransport({ api: "/api/chat" }),
+    onError: (error) => {
+      console.error(error);
+      toast.error(error.message || "Yapay zeka ile iletişim kurulurken bir hata oluştu.");
     },
-    onError: (err) => {
-      console.error(err);
-      toast.error(err.message || "Yapay zeka ile iletişim kurulurken bir hata oluştu.");
-    }
   });
-
-  const handleInputChange = (e: React.ChangeEvent<HTMLTextAreaElement>) => {
-    setInput(e.target.value);
-  };
-
-  // Auto-scroll to bottom
-  const scrollToBottom = () => {
-    messagesEndRef.current?.scrollIntoView({ behavior: "smooth" });
-  };
+  const isLoading = status === "submitted" || status === "streaming";
 
   useEffect(() => {
-    scrollToBottom();
+    messagesEndRef.current?.scrollIntoView({ behavior: "smooth" });
   }, [messages]);
 
-  // 1. Fetch Sessions on mount
   useEffect(() => {
-    const fetchSessions = async () => {
-      const { data: { user } } = await supabase.auth.getUser();
+    async function fetchSessions() {
+      const {
+        data: { user },
+      } = await supabase.auth.getUser();
+
       if (!user) return;
 
       const { data } = await supabase
         .from("chat_sessions")
-        .select("*")
+        .select("id, title, created_at")
         .eq("user_id", user.id)
-        .order("updated_at", { ascending: false });
+        .order("created_at", { ascending: false });
 
       if (data) {
         setSessions(data);
-        if (data.length > 0) {
-          setActiveSessionId(data[0].id);
-        }
+        setActiveSessionId(data[0]?.id || null);
       }
-    };
-    fetchSessions();
-  }, [supabase]);
-
-  // 2. Fetch Messages when session changes
-  useEffect(() => {
-    if (!activeSessionId) {
-      setMessages([]);
-      return;
     }
 
-    const fetchMessages = async () => {
+    void fetchSessions();
+  }, [supabase]);
+
+  useEffect(() => {
+    async function fetchMessages() {
+      if (!activeSessionId) {
+        setMessages([]);
+        return;
+      }
+
       const { data } = await supabase
         .from("chat_messages")
-        .select("*")
+        .select("id, role, content")
         .eq("session_id", activeSessionId)
         .order("created_at", { ascending: true });
 
-      if (data) {
-        // Map Supabase messages to AI SDK format
-        const formattedMessages = data.map((msg: any) => ({
-          id: msg.id,
-          role: msg.role as 'user' | 'assistant' | 'system',
-          content: msg.content,
-        }));
-        setMessages(formattedMessages);
-      } else {
-        setMessages([]);
-      }
-    };
-    
-    fetchMessages();
-  }, [activeSessionId, supabase, setMessages]);
+      const formattedMessages: UIMessage[] = (data || []).map((message) => ({
+        id: message.id,
+        role: message.role as UIMessage["role"],
+        parts: [{ type: "text", text: message.content || "" }],
+      }));
 
-  const handleNewChat = async () => {
+      setMessages(formattedMessages);
+    }
+
+    void fetchMessages();
+  }, [activeSessionId, setMessages, supabase]);
+
+  async function handleNewChat() {
     setActiveSessionId(null);
     setMessages([]);
-  };
+  }
 
-  const handleDeleteSession = async (id: string, e: React.MouseEvent) => {
-    e.stopPropagation();
+  async function handleDeleteSession(id: string, event: React.MouseEvent) {
+    event.stopPropagation();
     await supabase.from("chat_sessions").delete().eq("id", id);
-    const updatedSessions = sessions.filter(s => s.id !== id);
-    setSessions(updatedSessions);
-    if (activeSessionId === id) {
-      setActiveSessionId(updatedSessions.length > 0 ? updatedSessions[0].id : null);
-      if (updatedSessions.length === 0) setMessages([]);
-    }
-  };
 
-  const customHandleSubmit = async (e: React.FormEvent) => {
-    e.preventDefault();
-    if (!(input || "").trim() || isLoading) return;
+    const nextSessions = sessions.filter((session) => session.id !== id);
+    setSessions(nextSessions);
+
+    if (activeSessionId === id) {
+      setActiveSessionId(nextSessions[0]?.id || null);
+      if (nextSessions.length === 0) setMessages([]);
+    }
+  }
+
+  async function handleSubmit(event: { preventDefault: () => void }) {
+    event.preventDefault();
+
+    const currentInput = input.trim();
+    if (!currentInput || isLoading) return;
 
     let sessionId = activeSessionId;
-    const currentInput = input || "";
     setInput("");
 
     if (!sessionId) {
-      const { data: { user } } = await supabase.auth.getUser();
+      const {
+        data: { user },
+      } = await supabase.auth.getUser();
+
       if (!user) return;
 
-      const { data: newSess } = await supabase
+      const { data: newSession } = await supabase
         .from("chat_sessions")
-        .insert({ user_id: user.id, title: currentInput.slice(0, 30) + "..." })
-        .select()
+        .insert({
+          user_id: user.id,
+          title: currentInput.length > 32 ? `${currentInput.slice(0, 32)}...` : currentInput,
+        })
+        .select("id, title, created_at")
         .single();
-      
-      if (newSess) {
-        sessionId = newSess.id;
-        setActiveSessionId(sessionId);
-        setSessions([newSess, ...sessions]);
-      } else {
-        return;
-      }
+
+      if (!newSession) return;
+
+      sessionId = newSession.id;
+      setActiveSessionId(sessionId);
+      setSessions((currentSessions) => [newSession, ...currentSessions]);
     }
 
-    // Append using AI SDK with explicit body to ensure sessionId is passed immediately
-    append({ role: 'user', content: currentInput }, { body: { sessionId } });
-  };
+    await sendMessage({ text: currentInput }, { body: { sessionId } });
+  }
 
   return (
-    <div className="flex h-[calc(100vh-6rem)] w-full overflow-hidden border border-border rounded-lg bg-background">
-      
-      {/* Sidebar - Sessions List */}
-      <div className="w-80 border-r border-border bg-muted/20 flex flex-col hidden md:flex">
-        <div className="p-4 border-b border-border flex items-center justify-between">
-          <h2 className="font-semibold text-foreground flex items-center gap-2">
+    <div className="flex h-[calc(100dvh-6rem)] w-full overflow-hidden rounded-sm border border-border bg-background">
+      <aside className="hidden w-80 flex-col border-r border-border bg-muted/20 md:flex">
+        <div className="flex items-center justify-between border-b border-border p-4">
+          <h2 className="flex items-center gap-2 font-semibold text-foreground">
             <MessageSquare className="h-4 w-4" />
-            Geçmiş Sohbetler
+            Sohbetler
           </h2>
           <Button variant="outline" size="icon" className="h-8 w-8" onClick={handleNewChat}>
             <Plus className="h-4 w-4" />
           </Button>
         </div>
-        
-        <div className="flex-1 overflow-y-auto p-3 space-y-2">
+
+        <div className="tiny-scrollbar flex-1 space-y-2 overflow-y-auto p-3">
           {sessions.length === 0 ? (
-            <div className="text-center text-sm text-muted-foreground mt-10">Henüz sohbet yok.</div>
+            <div className="mt-10 text-center text-sm text-muted-foreground">
+              Henüz sohbet yok.
+            </div>
           ) : (
-            sessions.map(session => (
-              <div 
+            sessions.map((session) => (
+              <button
                 key={session.id}
+                type="button"
                 onClick={() => setActiveSessionId(session.id)}
-                className={`group flex items-center justify-between p-3 rounded-md cursor-pointer transition-colors ${activeSessionId === session.id ? 'bg-primary/10 text-primary' : 'hover:bg-muted/50 text-foreground'}`}
+                className={`group flex w-full items-center justify-between rounded-sm p-3 text-left transition-colors ${
+                  activeSessionId === session.id
+                    ? "bg-primary/10 text-primary"
+                    : "text-foreground hover:bg-muted/50"
+                }`}
               >
-                <div className="truncate text-sm font-medium w-full pr-2">
-                  {session.title || "İsimsiz Sohbet"}
-                </div>
-                <button 
-                  onClick={(e) => handleDeleteSession(session.id, e)}
-                  className={`opacity-0 group-hover:opacity-100 p-1 hover:bg-destructive/10 hover:text-destructive rounded transition-all`}
+                <span className="truncate pr-2 text-sm font-medium">
+                  {session.title || "İsimsiz sohbet"}
+                </span>
+                <span
+                  role="button"
+                  tabIndex={0}
+                  onClick={(event) => void handleDeleteSession(session.id, event)}
+                  className="rounded-sm p-1 opacity-0 transition-all hover:bg-rose-50 hover:text-rose-600 group-hover:opacity-100"
                 >
                   <Trash2 className="h-3.5 w-3.5" />
-                </button>
-              </div>
+                </span>
+              </button>
             ))
           )}
         </div>
-      </div>
+      </aside>
 
-      {/* Main Chat Area */}
-      <div className="flex-1 flex flex-col bg-background relative">
-        {/* Chat Header */}
-        <div className="h-14 border-b border-border flex items-center justify-between px-6 bg-background/50 backdrop-blur-sm z-10">
+      <section className="flex min-w-0 flex-1 flex-col">
+        <header className="flex h-14 items-center justify-between border-b border-border px-6">
           <div className="flex items-center gap-3">
-            <div className="h-8 w-8 rounded-full bg-primary/10 flex items-center justify-center text-primary">
+            <div className="flex h-8 w-8 items-center justify-center rounded-sm bg-primary/10 text-primary">
               <Brain className="h-4 w-4" />
             </div>
             <div>
-              <h2 className="text-sm font-semibold text-foreground">Ajan Asistan</h2>
-              <p className="text-[10px] text-muted-foreground flex items-center gap-1">
-                <span className="w-1.5 h-1.5 rounded-full bg-emerald-500"></span>
-                Sisteme görev ve veri ekleyebilir
-              </p>
+              <h1 className="text-sm font-semibold text-foreground">AI Asistan</h1>
+              <p className="text-xs text-muted-foreground">Kayıtlı verilerin hakkında soru sor.</p>
             </div>
           </div>
-          <Button variant="ghost" size="icon" className="md:hidden" onClick={handleNewChat}>
+          <Button variant="outline" size="icon" className="h-8 w-8 md:hidden" onClick={handleNewChat}>
             <Plus className="h-4 w-4" />
           </Button>
-        </div>
+        </header>
 
-        {/* Messages */}
-        <div className="flex-1 overflow-y-auto p-6 space-y-6 scroll-smooth">
+        <div className="tiny-scrollbar flex-1 space-y-5 overflow-y-auto p-6">
           {messages.length === 0 ? (
-            <div className="h-full flex flex-col items-center justify-center text-center opacity-70 max-w-md mx-auto">
-              <div className="h-16 w-16 bg-primary/10 rounded-2xl flex items-center justify-center mb-6 text-primary">
-                <Brain className="h-8 w-8" />
-              </div>
-              <h3 className="text-xl font-bold text-foreground mb-2">Ajan Asistan'a Hoşgeldiniz</h3>
-              <p className="text-sm text-muted-foreground mb-4">Sadece sorularınızı cevaplamakla kalmaz, komutlarınızla projeler, görevler ve finans kayıtları da oluşturabilir.</p>
-              
-              <div className="grid grid-cols-1 sm:grid-cols-2 gap-3 w-full mt-4">
-                <Button variant="outline" className="h-auto py-3 justify-start text-left text-xs whitespace-normal" onClick={() => setInput("Bana 'Sunum hazırlığı' adında yeni bir görev ekler misin?")}>
-                  Görev Ekle
-                </Button>
-                <Button variant="outline" className="h-auto py-3 justify-start text-left text-xs whitespace-normal" onClick={() => setInput("Bugün 350 TL Yemek harcaması yaptım, kaydeder misin?")}>
-                  Harcama Ekle
-                </Button>
-                <Button variant="outline" className="h-auto py-3 justify-start text-left text-xs whitespace-normal" onClick={() => setInput("Aktif projelerimin durumunu özetler misin?")}>
-                  Projelerimi Sorgula
-                </Button>
-                <Button variant="outline" className="h-auto py-3 justify-start text-left text-xs whitespace-normal" onClick={() => setInput("Son 30 günlük finansal özetimi ver.")}>
-                  Gelir/Gider Özeti
-                </Button>
+            <div className="mx-auto flex h-full max-w-md flex-col items-center justify-center text-center">
+              <div className="mb-5 flex h-14 w-14 items-center justify-center rounded-sm bg-primary/10 text-primary">
+                <Brain className="h-7 w-7" />
               </div>
+              <h2 className="text-xl font-semibold text-foreground">Verilerine danış</h2>
+              <p className="mt-2 text-sm text-muted-foreground">
+                Görevler, projeler, müşteriler, finans ve günlük kayıtların hakkında soru sorabilirsin.
+              </p>
             </div>
           ) : (
-            messages.map((msg) => (
-              <div key={msg.id} className={`flex ${msg.role === 'user' ? 'justify-end' : 'justify-start'}`}>
-                <div className={`flex gap-3 max-w-[85%] ${msg.role === 'user' ? 'flex-row-reverse' : 'flex-row'}`}>
-                  <div className={`shrink-0 h-8 w-8 rounded-full flex items-center justify-center ${msg.role === 'user' ? 'bg-primary text-primary-foreground' : 'bg-muted border border-border text-foreground'}`}>
-                    {msg.role === 'user' ? <span className="text-xs font-bold">ME</span> : <Brain className="h-4 w-4" />}
-                  </div>
-                  
-                  <div className="flex flex-col gap-2">
-                    {msg.content && (
-                      <div className={`px-4 py-3 rounded-2xl text-sm ${msg.role === 'user' ? 'bg-primary text-primary-foreground rounded-tr-none' : 'bg-muted/50 border border-border text-foreground rounded-tl-none whitespace-pre-wrap'}`}>
-                        {msg.content}
-                      </div>
-                    )}
+            messages.map((message) => {
+              const text = getMessageText(message);
 
-                    {/* Render Tool Invocations for AI Messages */}
-                    {msg.toolInvocations && msg.toolInvocations.map((tool) => (
-                      <div key={tool.toolCallId} className="flex items-center gap-2 text-xs text-muted-foreground bg-muted/30 border border-border px-3 py-1.5 rounded-md self-start">
-                        {tool.state === 'result' ? (
-                          <>
-                            <CheckCircle2 className="h-3.5 w-3.5 text-emerald-500" />
-                            <span><span className="font-medium text-foreground">{tool.toolName}</span> aracı başarıyla çalıştırıldı.</span>
-                          </>
-                        ) : (
-                          <>
-                            <Loader2 className="h-3.5 w-3.5 animate-spin text-primary" />
-                            <span><span className="font-medium text-foreground">{tool.toolName}</span> aracı çalıştırılıyor...</span>
-                          </>
-                        )}
-                      </div>
-                    ))}
+              return (
+                <div
+                  key={message.id}
+                  className={`flex ${message.role === "user" ? "justify-end" : "justify-start"}`}
+                >
+                  <div
+                    className={`max-w-[85%] rounded-sm px-4 py-3 text-sm ${
+                      message.role === "user"
+                        ? "bg-primary text-primary-foreground"
+                        : "border border-border bg-muted/40 text-foreground"
+                    }`}
+                  >
+                    {text}
                   </div>
                 </div>
-              </div>
-            ))
-          )}
-          
-          {isLoading && messages[messages.length - 1]?.role === 'user' && (
-             <div className="flex justify-start">
-             <div className="flex gap-3 max-w-[85%] flex-row">
-               <div className="shrink-0 h-8 w-8 rounded-full bg-muted border border-border text-foreground flex items-center justify-center">
-                 <Brain className="h-4 w-4" />
-               </div>
-               <div className="px-4 py-3 rounded-2xl text-sm bg-muted/50 border border-border text-foreground rounded-tl-none flex items-center gap-2">
-                 <span className="h-2 w-2 bg-primary/50 rounded-full animate-bounce" style={{ animationDelay: '0ms' }}></span>
-                 <span className="h-2 w-2 bg-primary/50 rounded-full animate-bounce" style={{ animationDelay: '150ms' }}></span>
-                 <span className="h-2 w-2 bg-primary/50 rounded-full animate-bounce" style={{ animationDelay: '300ms' }}></span>
-               </div>
-             </div>
-           </div>
+              );
+            })
           )}
+
+          {isLoading ? (
+            <div className="flex items-center gap-2 text-sm text-muted-foreground">
+              <Loader2 className="h-4 w-4 animate-spin text-primary" />
+              Yanıt hazırlanıyor...
+            </div>
+          ) : null}
           <div ref={messagesEndRef} />
         </div>
 
-        {/* Input Area */}
-        <div className="p-4 border-t border-border bg-background">
-          <form onSubmit={customHandleSubmit} className="relative flex items-end gap-2 max-w-4xl mx-auto">
-            <div className="relative flex-1 bg-muted/30 border border-border rounded-xl flex items-center focus-within:ring-2 focus-within:ring-primary/20 focus-within:border-primary transition-all">
-              <textarea
-                value={input}
-                onChange={handleInputChange}
-                onKeyDown={(e) => {
-                  if (e.key === 'Enter' && !e.shiftKey) {
-                    e.preventDefault();
-                    customHandleSubmit(e);
-                  }
-                }}
-                placeholder="Verilerinize dayalı bir soru sorun veya görev/finans kaydı eklemesini isteyin..."
-                className="w-full bg-transparent border-none focus:outline-none focus:ring-0 resize-none py-4 pl-4 pr-12 text-sm text-foreground placeholder:text-muted-foreground min-h-[56px] max-h-[200px]"
-                rows={1}
-                disabled={isLoading}
-              />
-              <div className="absolute right-2 bottom-2 flex gap-1">
-                {isLoading ? (
-                  <Button 
-                    type="button" 
-                    variant="outline"
-                    size="icon" 
-                    className="h-10 w-10 rounded-lg bg-background text-foreground"
-                    onClick={() => stop()}
-                  >
-                    <div className="w-3 h-3 bg-current" />
-                  </Button>
-                ) : (
-                  <Button 
-                    type="submit" 
-                    size="icon" 
-                    className={`h-10 w-10 rounded-lg ${(input || "").trim() ? 'bg-primary text-primary-foreground hover:bg-primary/90' : 'bg-muted text-muted-foreground'}`}
-                    disabled={!(input || "").trim()}
-                  >
-                    <Send className="h-4 w-4 ml-0.5" />
-                  </Button>
-                )}
-              </div>
-            </div>
-          </form>
-          <div className="text-center mt-3 flex items-center justify-center gap-4 text-[10px] text-muted-foreground">
-            <span>Yapay Zeka Hatalar Yapabilir.</span>
-            <div className="flex items-center gap-1">
-              <Wrench className="h-3 w-3" />
-              <span>Veri okuma/yazma yetkisi aktiftir.</span>
-            </div>
+        <form onSubmit={handleSubmit} className="border-t border-border p-4">
+          <div className="mx-auto flex max-w-4xl items-end gap-2 rounded-sm border border-border bg-background p-2 focus-within:border-primary">
+            <textarea
+              value={input}
+              onChange={(event) => setInput(event.target.value)}
+              onKeyDown={(event) => {
+                if (event.key === "Enter" && !event.shiftKey) {
+                  event.preventDefault();
+                  void handleSubmit(event);
+                }
+              }}
+              placeholder="Örn. Bu hafta geciken işlerim neler?"
+              className="min-h-10 max-h-40 flex-1 resize-none bg-transparent px-2 py-2 text-sm outline-none placeholder:text-muted-foreground"
+              rows={1}
+              disabled={isLoading}
+            />
+            {isLoading ? (
+              <Button type="button" variant="outline" size="icon" onClick={() => void stop()}>
+                <span className="h-3 w-3 bg-current" />
+              </Button>
+            ) : (
+              <Button type="submit" size="icon" disabled={!input.trim()}>
+                <Send className="h-4 w-4" />
+              </Button>
+            )}
           </div>
-        </div>
-      </div>
+        </form>
+      </section>
     </div>
   );
 }
+
+function getMessageText(message: UIMessage) {
+  return message.parts
+    .filter((part) => part.type === "text")
+    .map((part) => part.text)
+    .join("");
+}
diff --git a/app/(dashboard)/dashboard-client.tsx b/app/(dashboard)/dashboard-client.tsx
index bada7f7..d9ef8cb 100644
--- a/app/(dashboard)/dashboard-client.tsx
+++ b/app/(dashboard)/dashboard-client.tsx
@@ -123,7 +123,7 @@ export function DashboardClient({ data }: DashboardClientProps) {
             <Plus className="h-4 w-4" />
             Hızlı Ekle
           </Button>
-          <QuickActionsSheet open={isQuickActionOpen} onOpenChange={setIsQuickActionOpen} />
+          <QuickActionsSheet isOpen={isQuickActionOpen} onClose={() => setIsQuickActionOpen(false)} />
         </div>
       </div>
 
diff --git a/app/(dashboard)/settings/page.tsx b/app/(dashboard)/settings/page.tsx
index ca2e54c..f3b16e9 100644
--- a/app/(dashboard)/settings/page.tsx
+++ b/app/(dashboard)/settings/page.tsx
@@ -1,7 +1,7 @@
 "use client";
 
 import { useEffect, useRef, useState } from "react";
-import { User, Shield, Brain, Save, Key, AlertTriangle } from "lucide-react";
+import { AlertTriangle, Blocks, Brain, Key, Save, Shield, User } from "lucide-react";
 import { updatePassword, updateProfile } from "./actions";
 import { createClient } from "@/lib/supabase/client";
 import { Button, Card, CardContent, Input, Label } from "poyraz-ui/atoms";
diff --git a/app/api/chat/route.ts b/app/api/chat/route.ts
index 5ea555b..06eab40 100644
--- a/app/api/chat/route.ts
+++ b/app/api/chat/route.ts
@@ -1,156 +1,57 @@
-import { streamText, tool } from 'ai';
-import { createOpenAI } from '@ai-sdk/openai';
-import { createGoogleGenerativeAI } from '@ai-sdk/google';
-import { z } from 'zod';
-import { createClient } from '@/lib/supabase/server';
+import { createGoogleGenerativeAI } from "@ai-sdk/google";
+import { createOpenAI } from "@ai-sdk/openai";
+import { convertToModelMessages, streamText, type UIMessage } from "ai";
+import { createClient } from "@/lib/supabase/server";
 
-export const maxDuration = 30; // Allow longer execution for tool calls
+export const maxDuration = 30;
 
-export async function POST(req: Request) {
+export async function POST(request: Request) {
   try {
     const supabase = await createClient();
-    const { data: { user } } = await supabase.auth.getUser();
+    const {
+      data: { user },
+    } = await supabase.auth.getUser();
 
     if (!user) {
-      return new Response('Yetkisiz erişim', { status: 401 });
+      return new Response("Yetkisiz erişim", { status: 401 });
     }
 
-    const { messages, sessionId, provider: clientProvider, apiKey: clientApiKey } = await req.json();
+    const body = await request.json();
+    const messages = (body.messages || []) as UIMessage[];
+    const sessionId = body.sessionId as string | undefined;
+    const latestMessage = messages[messages.length - 1];
+    const latestText = latestMessage ? getMessageText(latestMessage) : "";
+
+    if (sessionId && latestMessage?.role === "user" && latestText) {
+      await supabase.from("chat_messages").insert({
+        session_id: sessionId,
+        role: "user",
+        content: latestText,
+      });
+    }
 
-    // Read App Settings for Provider/API Key
     const { data: appSettings } = await supabase
       .from("app_settings")
-      .select("*")
+      .select("ai_provider, ai_model, api_key")
       .eq("user_id", user.id)
       .single();
 
-    const provider = clientProvider || appSettings?.ai_provider || "openai";
-    const apiKey = clientApiKey || appSettings?.api_key || "";
-
-    let model;
-    if (provider === 'gemini') {
-      const google = createGoogleGenerativeAI({ apiKey });
-      model = google('gemini-1.5-pro-latest');
-    } else if (provider === 'groq') {
-      const groq = createOpenAI({ apiKey, baseURL: 'https://api.groq.com/openai/v1' });
-      model = groq('llama-3.1-8b-instant');
-    } else {
-      const openai = createOpenAI({ apiKey });
-      model = openai('gpt-4o');
-    }
-
-    // Identify the latest user message to save to Supabase and use for RAG
-    const latestMessage = messages[messages.length - 1];
-    let ragContext = "";
-    
-    if (latestMessage && latestMessage.role === 'user' && latestMessage.content) {
-      if (sessionId) {
-        await supabase.from("chat_messages").insert({
-          session_id: sessionId,
-          role: "user",
-          content: latestMessage.content,
-        });
-      }
-
-      // Perform RAG search
-      try {
-        const { searchSimilarDocuments } = await import('@/lib/ai/embeddings');
-        const similarDocs = await searchSimilarDocuments(user.id, latestMessage.content, provider, apiKey, 3);
-        if (similarDocs && similarDocs.length > 0) {
-          ragContext = "Aşağıda kullanıcının veri tabanından sistemin otomatik bulduğu geçmiş notlar ve veriler (RAG Context) bulunmaktadır. Gerektiğinde soruları yanıtlarken bunlardan faydalan:\n\n" + similarDocs.map((doc: any) => `- ${doc.content}`).join("\n");
-        }
-      } catch (err) {
-        console.error("RAG araması başarısız:", err);
-      }
-    }
-
-    const systemPrompt = `Sen kullanıcının kişisel Freelancer İş Asistanı ve Danışmanısın. Cognis Freelancer OS içinde yaşıyorsun.
-Kullanıcının iş süreçlerini, projelerini ve finansal durumunu organize etmesine yardımcı oluyorsun.
-Gerektiğinde araçları (tools) kullanarak sistemden güncel verileri çek ve doğrudan veri ekle.
-
-${ragContext}
-
-Aşağıdaki yeteneklere sahipsin:
-- Finansal verileri listeleyebilir ve yeni finans kaydı (gelir/gider) girebilirsin.
-- Görevleri okuyabilir ve yeni görevler ekleyebilirsin.
-- Projeleri sorgulayabilir ve projelerin detaylarını/tasarım sistemini çekebilirsin.
-Kullanıcıya her zaman proaktif, kısa ve profesyonel yanıtlar ver. Türkçe dilinde cevapla.`;
+    const provider = body.provider || appSettings?.ai_provider || "openai";
+    const apiKey = body.apiKey || appSettings?.api_key || "";
+    const modelName = appSettings?.ai_model || getDefaultModel(provider);
+    const model = getModel(provider, apiKey, modelName);
+    const context = await buildUserContext(user.id);
 
     const result = streamText({
       model,
-      system: systemPrompt,
-      messages,
-      tools: {
-        getFinancialSummary: tool({
-          description: 'Son X gündeki gelir ve gider işlemlerinin listesini getirir.',
-          parameters: z.object({ days: z.number().default(30) }),
-          execute: async ({ days }) => {
-            const pastDate = new Date();
-            pastDate.setDate(pastDate.getDate() - days);
-            const { data } = await supabase.from('finance_transactions')
-              .select('type, amount, category, transaction_date')
-              .gte('transaction_date', pastDate.toISOString());
-            return data || [];
-          }
-        }),
-        listTasks: tool({
-          description: 'Kullanıcının mevcut görevlerini belirli bir duruma göre listeler.',
-          parameters: z.object({ status: z.enum(['todo', 'in_progress', 'completed', 'all']).default('all') }),
-          execute: async ({ status }) => {
-            let query = supabase.from('tasks').select('id, title, status, due_at');
-            if (status !== 'all') query = query.eq('status', status);
-            const { data } = await query.order('created_at', { ascending: false }).limit(20);
-            return data || [];
-          }
-        }),
-        createTask: tool({
-          description: 'Sisteme yeni bir görev ekler.',
-          parameters: z.object({ 
-            title: z.string().describe('Görev başlığı'), 
-            description: z.string().optional().describe('Görevin detayı') 
-          }),
-          execute: async ({ title, description }) => {
-            const { data, error } = await supabase.from('tasks')
-              .insert({ user_id: user.id, title, description, status: 'todo' })
-              .select().single();
-            if (error) return { success: false, error: error.message };
-            return { success: true, task: data };
-          }
-        }),
-        searchProjects: tool({
-          description: 'Projeleri isimlerine veya durumlarına göre listeler',
-          parameters: z.object({ status: z.enum(['active', 'planning', 'completed', 'paused', 'all']).default('active') }),
-          execute: async ({ status }) => {
-            let query = supabase.from('projects').select('id, name, status, progress, budget');
-            if (status !== 'all') query = query.eq('status', status);
-            const { data } = await query.limit(10);
-            return data || [];
-          }
-        }),
-        addFinanceTransaction: tool({
-          description: 'Sisteme yeni bir finansal kayıt (gelir veya gider) ekler.',
-          parameters: z.object({ 
-            type: z.enum(['income', 'expense']).describe('income (gelir) veya expense (gider)'), 
-            amount: z.number().describe('Tutar'), 
-            category: z.string().describe('Kategori örn. Yazılım, Yemek, Vergi vb.')
-          }),
-          execute: async ({ type, amount, category }) => {
-            const { data, error } = await supabase.from('finance_transactions')
-              .insert({ 
-                user_id: user.id, 
-                type, 
-                amount, 
-                category, 
-                transaction_date: new Date().toISOString() 
-              })
-              .select().single();
-            if (error) return { success: false, error: error.message };
-            return { success: true, transaction: data };
-          }
-        })
-      },
+      system: `Sen Cognis içindeki kişisel Freelancer OS asistanısın.
+Kullanıcının kayıtlı verileri hakkında kısa, net ve Türkçe cevap ver.
+Veri yoksa bunu açıkça söyle. Klinik, finansal veya hukuki kesin hüküm verme.
+
+Kullanıcının güncel veri özeti:
+${context}`,
+      messages: await convertToModelMessages(messages),
       onFinish: async ({ text }) => {
-        // Save assistant response to DB
         if (sessionId && text) {
           await supabase.from("chat_messages").insert({
             session_id: sessionId,
@@ -158,12 +59,91 @@ Kullanıcıya her zaman proaktif, kısa ve profesyonel yanıtlar ver. Türkçe d
             content: text,
           });
         }
-      }
+      },
     });
 
-    return result.toDataStreamResponse();
-  } catch (error: any) {
+    return result.toUIMessageStreamResponse();
+  } catch (error) {
     console.error("Chat API error:", error);
-    return new Response(error.message || "Internal Server Error", { status: 500 });
+    return new Response(error instanceof Error ? error.message : "Internal Server Error", {
+      status: 500,
+    });
   }
 }
+
+function getDefaultModel(provider: string) {
+  if (provider === "gemini") return "gemini-1.5-pro-latest";
+  if (provider === "groq") return "llama-3.1-8b-instant";
+  return "gpt-4o";
+}
+
+function getModel(provider: string, apiKey: string, modelName: string) {
+  if (provider === "gemini") {
+    return createGoogleGenerativeAI({ apiKey })(modelName);
+  }
+
+  if (provider === "groq") {
+    return createOpenAI({ apiKey, baseURL: "https://api.groq.com/openai/v1" })(modelName);
+  }
+
+  return createOpenAI({ apiKey })(modelName);
+}
+
+async function buildUserContext(userId: string) {
+  const supabase = await createClient();
+  const since = new Date();
+  since.setDate(since.getDate() - 30);
+  const sinceDate = since.toISOString().slice(0, 10);
+
+  const [{ data: tasks }, { data: projects }, { data: finance }, { data: logs }] =
+    await Promise.all([
+      supabase
+        .from("tasks")
+        .select("title, status, priority, due_at")
+        .eq("user_id", userId)
+        .order("created_at", { ascending: false })
+        .limit(20),
+      supabase
+        .from("projects")
+        .select("name, status, progress, due_date")
+        .eq("user_id", userId)
+        .order("created_at", { ascending: false })
+        .limit(12),
+      supabase
+        .from("finance_transactions")
+        .select("type, amount, currency, category, payment_status, transaction_date")
+        .eq("user_id", userId)
+        .gte("transaction_date", sinceDate)
+        .order("transaction_date", { ascending: false })
+        .limit(20),
+      supabase
+        .from("daily_logs")
+        .select("log_date, mood_score, energy_score, work_satisfaction_score, note")
+        .eq("user_id", userId)
+        .gte("log_date", sinceDate)
+        .order("log_date", { ascending: false })
+        .limit(14),
+    ]);
+
+  return [
+    formatContextList("Görevler", tasks),
+    formatContextList("Projeler", projects),
+    formatContextList("Son 30 gün finans", finance),
+    formatContextList("Son günlük kayıtlar", logs),
+  ].join("\n\n");
+}
+
+function formatContextList(title: string, rows: unknown[] | null) {
+  if (!rows || rows.length === 0) return `${title}: kayıt yok.`;
+
+  return `${title}:\n${rows
+    .map((row) => `- ${JSON.stringify(row)}`)
+    .join("\n")}`;
+}
+
+function getMessageText(message: UIMessage) {
+  return message.parts
+    .filter((part) => part.type === "text")
+    .map((part) => part.text)
+    .join("");
+}
diff --git a/app/api/create-client-user/route.ts b/app/api/create-client-user/route.ts
index fc0aaff..7804c2f 100644
--- a/app/api/create-client-user/route.ts
+++ b/app/api/create-client-user/route.ts
@@ -1,6 +1,12 @@
-import { createClient } from "@supabase/supabase-js";
 import { NextResponse } from "next/server";
 
+type SupabaseAdminUserResponse = {
+  id?: string;
+  email?: string;
+  message?: string;
+  error_description?: string;
+};
+
 export async function POST(request: Request) {
   try {
     const { email, password, client_id } = await request.json();
@@ -8,64 +14,109 @@ export async function POST(request: Request) {
     if (!email || !password || !client_id) {
       return NextResponse.json(
         { error: "Email, şifre ve müşteri ID gereklidir." },
-        { status: 400 }
+        { status: 400 },
       );
     }
 
-    // Initialize Supabase Admin client with service role key
-    const supabaseAdmin = createClient(
-      process.env.NEXT_PUBLIC_SUPABASE_URL!,
-      process.env.SUPABASE_SERVICE_ROLE_KEY!
-    );
+    const supabaseUrl = process.env.NEXT_PUBLIC_SUPABASE_URL;
+    const serviceRoleKey = process.env.SUPABASE_SERVICE_ROLE_KEY;
 
-    // 1. Create the user in auth.users
-    const { data: authData, error: authError } = await supabaseAdmin.auth.admin.createUser({
-      email,
-      password,
-      email_confirm: true,
+    if (!supabaseUrl || !serviceRoleKey) {
+      return NextResponse.json(
+        { error: "Supabase service role ayarı eksik." },
+        { status: 500 },
+      );
+    }
+
+    const userResponse = await fetch(`${supabaseUrl}/auth/v1/admin/users`, {
+      method: "POST",
+      headers: getServiceHeaders(serviceRoleKey),
+      body: JSON.stringify({
+        email,
+        password,
+        email_confirm: true,
+        app_metadata: {
+          internal_created: true,
+          role: "client",
+        },
+      }),
+    });
+    const userPayload = (await userResponse.json()) as SupabaseAdminUserResponse;
+
+    if (!userResponse.ok || !userPayload.id) {
+      return NextResponse.json(
+        {
+          error:
+            userPayload.message ||
+            userPayload.error_description ||
+            "Kullanıcı oluşturulamadı.",
+        },
+        { status: 400 },
+      );
+    }
+
+    const userId = userPayload.id;
+
+    await patchRestRow({
+      supabaseUrl,
+      serviceRoleKey,
+      table: "profiles",
+      filter: `id=eq.${encodeURIComponent(userId)}`,
+      payload: { role: "client" },
     });
 
-    if (authError || !authData.user) {
-      return NextResponse.json(
-        { error: authError?.message || "Kullanıcı oluşturulamadı." },
-        { status: 400 }
-      );
-    }
+    const clientResponse = await patchRestRow({
+      supabaseUrl,
+      serviceRoleKey,
+      table: "clients",
+      filter: `id=eq.${encodeURIComponent(client_id)}`,
+      payload: { client_auth_id: userId },
+    });
 
-    const userId = authData.user.id;
-
-    // 2. Wait for trigger to create the profile (it might take a fraction of a second, but usually synchronous in Postgres)
-    // We update the profile to set the role to 'client'
-    const { error: profileError } = await supabaseAdmin
-      .from("profiles")
-      .update({ role: "client" })
-      .eq("id", userId);
-
-    if (profileError) {
-      console.error("Profile update error:", profileError);
-      // Optional: Handle partial failure
-    }
-
-    // 3. Link the user to the client record
-    const { error: clientError } = await supabaseAdmin
-      .from("clients")
-      .update({ client_auth_id: userId })
-      .eq("id", client_id);
-
-    if (clientError) {
-      console.error("Client link error:", clientError);
+    if (!clientResponse.ok) {
       return NextResponse.json(
         { error: "Kullanıcı oluşturuldu fakat müşteri kaydıyla ilişkilendirilemedi." },
-        { status: 500 }
+        { status: 500 },
       );
     }
 
-    return NextResponse.json({ success: true, user: authData.user });
-  } catch (err: any) {
-    console.error("Create client user error:", err);
+    return NextResponse.json({ success: true, user: userPayload });
+  } catch (error) {
+    console.error("Create client user error:", error);
     return NextResponse.json(
       { error: "Sunucu tarafında beklenmeyen bir hata oluştu." },
-      { status: 500 }
+      { status: 500 },
     );
   }
 }
+
+function getServiceHeaders(serviceRoleKey: string) {
+  return {
+    apikey: serviceRoleKey,
+    authorization: `Bearer ${serviceRoleKey}`,
+    "content-type": "application/json",
+  };
+}
+
+function patchRestRow({
+  supabaseUrl,
+  serviceRoleKey,
+  table,
+  filter,
+  payload,
+}: {
+  supabaseUrl: string;
+  serviceRoleKey: string;
+  table: string;
+  filter: string;
+  payload: Record<string, unknown>;
+}) {
+  return fetch(`${supabaseUrl}/rest/v1/${table}?${filter}`, {
+    method: "PATCH",
+    headers: {
+      ...getServiceHeaders(serviceRoleKey),
+      prefer: "return=minimal",
+    },
+    body: JSON.stringify(payload),
+  });
+}
diff --git a/app/login/actions.ts b/app/login/actions.ts
index 5bb2b3c..dbff741 100644
--- a/app/login/actions.ts
+++ b/app/login/actions.ts
@@ -3,6 +3,7 @@
 import { revalidatePath } from 'next/cache'
 import { redirect } from 'next/navigation'
 import { createClient } from '@/lib/supabase/server'
+import { getFirstAdminSetupState } from '@/lib/auth/first-admin-setup'
 
 export async function login(formData: FormData) {
   const supabase = await createClient()
@@ -23,6 +24,20 @@ export async function login(formData: FormData) {
 }
 
 export async function signup(formData: FormData) {
+  const setupState = await getFirstAdminSetupState()
+
+  if (setupState.errorMessage) {
+    redirect(`/register?error=true&message=${encodeURIComponent(setupState.errorMessage)}`)
+  }
+
+  if (!setupState.available) {
+    redirect(
+      `/login?error=true&message=${encodeURIComponent(
+        'Kayıt kapalı. Bu self-host kurulumunda ilk admin hesabı zaten oluşturulmuş.',
+      )}`,
+    )
+  }
+
   const supabase = await createClient()
 
   const data = {
@@ -33,7 +48,7 @@ export async function signup(formData: FormData) {
   const { error } = await supabase.auth.signUp(data)
 
   if (error) {
-    redirect(`/login?error=true&message=${encodeURIComponent(error.message)}`)
+    redirect(`/register?error=true&message=${encodeURIComponent(error.message)}`)
   }
 
   revalidatePath('/', 'layout')
diff --git a/app/login/page.tsx b/app/login/page.tsx
index 1362112..37c3a4b 100644
--- a/app/login/page.tsx
+++ b/app/login/page.tsx
@@ -1,7 +1,8 @@
 import { login } from "@/app/login/actions";
 import { AuthPageShell } from "@/components/auth/auth-page-shell";
 import { ErrorToaster } from "@/components/error-toaster";
-import { LockKeyhole, LogIn, Mail, Search } from "lucide-react";
+import { getFirstAdminSetupState } from "@/lib/auth/first-admin-setup";
+import { LockKeyhole, LogIn, Mail } from "lucide-react";
 import Link from "next/link";
 import { Button, Input, Label } from "poyraz-ui/atoms";
 
@@ -10,7 +11,10 @@ export default async function LoginPage({
 }: {
   searchParams: Promise<{ [key: string]: string | string[] | undefined }>;
 }) {
-  const resolvedParams = await searchParams;
+  const [resolvedParams, setupState] = await Promise.all([
+    searchParams,
+    getFirstAdminSetupState(),
+  ]);
   const error = resolvedParams?.error;
   const message = resolvedParams?.message;
 
@@ -69,15 +73,19 @@ export default async function LoginPage({
         }
         secondaryAction={null}
         footer={
-          <div className="text-center text-sm">
-            Hesabın yok mu?{" "}
-            <Link
-              href="/register"
-              className="font-medium text-primary transition-colors hover:text-primary-hover"
-            >
-              Kayıt ol
-            </Link>
-          </div>
+          setupState.available ? (
+            <div className="text-center text-sm">
+              İlk kurulumu yapmadın mı?{" "}
+              <Link
+                href="/register"
+                className="font-medium text-primary transition-colors hover:text-primary-hover"
+              >
+                Admin hesabını oluştur
+              </Link>
+            </div>
+          ) : (
+            <span></span>
+          )
         }
       />
     </>
diff --git a/app/portal/revisions/page.tsx b/app/portal/revisions/page.tsx
index 25f63d9..5b88453 100644
--- a/app/portal/revisions/page.tsx
+++ b/app/portal/revisions/page.tsx
@@ -5,6 +5,14 @@ import Link from "next/link";
 import { format } from "date-fns";
 import { tr } from "date-fns/locale";
 
+type RevisionRow = {
+  id: string;
+  description: string;
+  status: string;
+  project_id: string;
+  created_at: string;
+};
+
 export default async function PortalRevisionsPage() {
   const supabase = await createClient();
   const { data: { user } } = await supabase.auth.getUser();
@@ -32,7 +40,7 @@ export default async function PortalRevisionsPage() {
 
   const projectIds = projectsData?.map(p => p.id) || [];
   
-  let revisions = [];
+  let revisions: RevisionRow[] = [];
   if (projectIds.length > 0) {
     const { data: revisionsData } = await supabase
       .from("project_revisions")
diff --git a/app/portal/tasks/page.tsx b/app/portal/tasks/page.tsx
index 7e82c3a..249880b 100644
--- a/app/portal/tasks/page.tsx
+++ b/app/portal/tasks/page.tsx
@@ -5,6 +5,16 @@ import Link from "next/link";
 import { format } from "date-fns";
 import { tr } from "date-fns/locale";
 
+type PortalTaskRow = {
+  id: string;
+  title: string;
+  status: string;
+  project_id: string;
+  created_at: string;
+  date: string | null;
+  priority: string | null;
+};
+
 export default async function PortalTasksPage() {
   const supabase = await createClient();
   const { data: { user } } = await supabase.auth.getUser();
@@ -32,7 +42,7 @@ export default async function PortalTasksPage() {
 
   const projectIds = projectsData?.map(p => p.id) || [];
   
-  let tasks = [];
+  let tasks: PortalTaskRow[] = [];
   if (projectIds.length > 0) {
     const { data: tasksData } = await supabase
       .from("tasks")
diff --git a/app/register/page.tsx b/app/register/page.tsx
index d46693b..2cc0832 100644
--- a/app/register/page.tsx
+++ b/app/register/page.tsx
@@ -1,8 +1,10 @@
 import { signup } from "@/app/login/actions";
 import { AuthPageShell } from "@/components/auth/auth-page-shell";
 import { ErrorToaster } from "@/components/error-toaster";
-import { LockKeyhole, Mail, Search, UserPlus } from "lucide-react";
+import { getFirstAdminSetupState } from "@/lib/auth/first-admin-setup";
+import { LockKeyhole, Mail, UserPlus } from "lucide-react";
 import Link from "next/link";
+import { redirect } from "next/navigation";
 import { Button, Input, Label } from "poyraz-ui/atoms";
 
 export default async function RegisterPage({
@@ -10,6 +12,20 @@ export default async function RegisterPage({
 }: {
   searchParams: Promise<{ [key: string]: string | string[] | undefined }>;
 }) {
+  const setupState = await getFirstAdminSetupState();
+
+  if (setupState.errorMessage) {
+    redirect(`/login?error=true&message=${encodeURIComponent(setupState.errorMessage)}`);
+  }
+
+  if (!setupState.available) {
+    redirect(
+      `/login?error=true&message=${encodeURIComponent(
+        "Kayıt kapalı. Bu self-host kurulumunda ilk admin hesabı zaten oluşturulmuş.",
+      )}`,
+    );
+  }
+
   const resolvedParams = await searchParams;
   const error = resolvedParams?.error;
   const message = resolvedParams?.message;
@@ -18,8 +34,8 @@ export default async function RegisterPage({
     <>
       {error && message && <ErrorToaster message={String(message)} />}
       <AuthPageShell
-        title="Kayıt ol"
-        description="Freelancer operasyon panelini kullanmak için hesabını oluştur."
+        title="İlk admin hesabını oluştur"
+        description="Bu self-host kurulumu için Cognis çalışma alanının ilk yönetici hesabını oluştur."
         form={
           <form className="space-y-6">
             <div className="space-y-4">
@@ -55,7 +71,7 @@ export default async function RegisterPage({
 
             <Button formAction={signup} className="h-11 w-full gap-2">
               <UserPlus className="h-4 w-4" />
-              Hesap oluştur
+              Admin hesabını oluştur
             </Button>
           </form>
         }
diff --git a/docs/database/0009-lock-registration-after-first-admin.md b/docs/database/0009-lock-registration-after-first-admin.md
new file mode 100644
index 0000000..3853c04
--- /dev/null
+++ b/docs/database/0009-lock-registration-after-first-admin.md
@@ -0,0 +1,34 @@
+# 0009 - Lock Registration After First Admin
+
+SQL file:
+
+`supabase/migrations/0009_lock_registration_after_first_admin.sql`
+
+## Purpose
+
+Adds the first-time setup guard for self-hosted installations.
+
+The `/register` page is only available while the system has no profile record. After the first account creates a profile, public registration is closed.
+
+## Changes
+
+- Adds `public.is_first_admin_setup_available()`.
+- Grants the function to `anon` and `authenticated` roles so the app can check setup state safely without bypassing RLS manually.
+- Replaces `public.handle_new_user()` so direct public Supabase Auth signup attempts are also rejected after the first profile exists.
+- Allows service-role/admin-created users when `raw_app_meta_data.internal_created` is `true`, so future invite/client-portal flows can still create accounts intentionally.
+
+## Behavior
+
+1. Fresh install has no `public.profiles` rows.
+2. `/register` stays open.
+3. The first signup creates an auth user and the trigger creates the first profile.
+4. The setup function starts returning `false`.
+5. `/register` redirects to `/login`.
+6. Further public signup attempts fail at the database trigger level.
+7. Admin-created internal users can still be allowed by service-role flows that set `app_metadata.internal_created = true`.
+
+## Notes
+
+- This is intended for the MVP single-admin self-host model.
+- If multi-user, client portal accounts, invites, or team members are re-enabled later, keep them behind service-role/admin-created flows instead of public signup.
+- Do not add this SQL file to `query-log.md` until it has actually been run in the target Supabase environment.
diff --git a/docs/database/query-order.md b/docs/database/query-order.md
index d29097c..5023397 100644
--- a/docs/database/query-order.md
+++ b/docs/database/query-order.md
@@ -7,6 +7,7 @@ This file is the canonical order of SQL files for database setup and migration.
 | 0001 | `supabase/schema.sql` | `docs/database/0001-initial-schema.md` | Baseline registered |
 | 0002 | `supabase/migrations/0002_add_freelancer_os_core_tables.sql` | `docs/database/0002-freelancer-os-core-tables.md` | Pending execution |
 | 0003 | `supabase/migrations/0003_add_project_planning_assets.sql` | `docs/database/0003-project-planning-assets.md` | Pending execution |
+| 0009 | `supabase/migrations/0009_lock_registration_after_first_admin.sql` | `docs/database/0009-lock-registration-after-first-admin.md` | Pending execution |
 | seed-0001 | `supabase/seeds/0001_demo_freelancer_os_data.sql` | `docs/database/seed-0001-demo-freelancer-os-data.md` | Optional demo seed, pending execution |
 
 ## How To Add The Next Query
diff --git a/lib/auth/first-admin-setup.ts b/lib/auth/first-admin-setup.ts
new file mode 100644
index 0000000..9aa8c42
--- /dev/null
+++ b/lib/auth/first-admin-setup.ts
@@ -0,0 +1,21 @@
+import { createClient } from "@/lib/supabase/server";
+
+type FirstAdminSetupState = {
+  available: boolean;
+  errorMessage?: string;
+};
+
+export async function getFirstAdminSetupState(): Promise<FirstAdminSetupState> {
+  const supabase = await createClient();
+  const { data, error } = await supabase.rpc("is_first_admin_setup_available");
+
+  if (error) {
+    return {
+      available: false,
+      errorMessage:
+        "İlk kurulum kontrolü yapılamadı. 0009 kayıt kilidi migration dosyasını çalıştırdığından emin ol.",
+    };
+  }
+
+  return { available: Boolean(data) };
+}
diff --git a/next-env.d.ts b/next-env.d.ts
index c4b7818..9edff1c 100644
--- a/next-env.d.ts
+++ b/next-env.d.ts
@@ -1,6 +1,6 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
-import "./.next/dev/types/routes.d.ts";
+import "./.next/types/routes.d.ts";
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/app/api-reference/config/typescript for more information.
diff --git a/supabase/migrations/0009_lock_registration_after_first_admin.sql b/supabase/migrations/0009_lock_registration_after_first_admin.sql
new file mode 100644
index 0000000..1bf2e1c
--- /dev/null
+++ b/supabase/migrations/0009_lock_registration_after_first_admin.sql
@@ -0,0 +1,39 @@
+-- 0009: Lock public registration after the first self-host admin account
+-- Run after: supabase/migrations/0008_add_project_progress_and_quota.sql
+
+create or replace function public.is_first_admin_setup_available()
+returns boolean
+language sql
+security definer
+set search_path = public
+as $$
+  select not exists (
+    select 1
+    from public.profiles
+    limit 1
+  );
+$$;
+
+revoke all on function public.is_first_admin_setup_available() from public;
+grant execute on function public.is_first_admin_setup_available() to anon;
+grant execute on function public.is_first_admin_setup_available() to authenticated;
+
+create or replace function public.handle_new_user()
+returns trigger
+language plpgsql
+security definer
+set search_path = public
+as $$
+begin
+  if exists (select 1 from public.profiles limit 1)
+    and coalesce(new.raw_app_meta_data->>'internal_created', 'false') <> 'true' then
+    raise exception 'Registration is closed. The first admin account already exists.';
+  end if;
+
+  insert into public.profiles (id, first_name, last_name, avatar_url)
+  values (new.id, '', '', '')
+  on conflict (id) do nothing;
+
+  return new;
+end;
+$$;