diff --git a/app/[workspace]/project/[projectId]/v_ai_chat/page.tsx b/app/[workspace]/project/[projectId]/v_ai_chat/page.tsx
index f9a505c..383e126 100644
--- a/app/[workspace]/project/[projectId]/v_ai_chat/page.tsx
+++ b/app/[workspace]/project/[projectId]/v_ai_chat/page.tsx
@@ -9,15 +9,13 @@ import { Input } from "@/components/ui/input";
 import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
 import { Send, Loader2, Paperclip, X, FileText, RotateCcw, Upload, CheckCircle2, AlertTriangle, Sparkles } from "lucide-react";
 import { cn } from "@/lib/utils";
-import { auth } from "@/lib/firebase/config";
+import { useSession } from "next-auth/react";
 import { toast } from "sonner";
 import { GitHubRepoPicker } from "@/components/ai/github-repo-picker";
 import { PhaseSidebar } from "@/components/ai/phase-sidebar";
 import { CollapsibleSidebar } from "@/components/ui/collapsible-sidebar";
 import { ExtractionResultsEditable } from "@/components/ai/extraction-results-editable";
 import type { ChatExtractionData } from "@/lib/ai/chat-extraction-types";
-import { db } from "@/lib/firebase/config";
-import { doc, onSnapshot, getDoc } from "firebase/firestore";
 import { VisionForm } from "@/components/ai/vision-form";
 
 interface Message {
@@ -72,6 +70,7 @@ export default function GettingStartedPage() {
   const params = useParams();
   const projectId = params.projectId as string;
   const workspace = params.workspace as string;
+  const { status: sessionStatus } = useSession();
   
   const [messages, setMessages] = useState<Message[]>([]);
   const [input, setInput] = useState("");
@@ -104,74 +103,45 @@ export default function GettingStartedPage() {
     messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' });
   }, [messages]);
 
-  // Check for vision answers on load
+  // Load project phase + vision answers from the Postgres-backed API
   useEffect(() => {
     if (!projectId) return;
 
-    const checkVision = async () => {
+    const loadProject = async () => {
       try {
-        const projectDoc = await getDoc(doc(db, "projects", projectId));
-        if (projectDoc.exists()) {
-          const data = projectDoc.data();
-          const hasAnswers = data?.visionAnswers?.allAnswered === true;
+        const res = await fetch(`/api/projects/${projectId}`);
+        if (res.ok) {
+          const data = await res.json();
+          const phase = data.project?.currentPhase || 'collector';
+          setCurrentPhase(phase);
+          const hasAnswers = data.project?.visionAnswers?.allAnswered === true;
           setHasVisionAnswers(hasAnswers);
         }
       } catch (error) {
-        console.error('Error checking vision answers:', error);
+        console.error('Error loading project:', error);
       } finally {
         setCheckingVision(false);
       }
     };
 
-    checkVision();
-  }, [projectId]);
-
-  // Listen to project phase changes
-  useEffect(() => {
-    if (!projectId) return;
-
-    const unsubscribe = onSnapshot(
-      doc(db, "projects", projectId),
-      (snapshot) => {
-        if (snapshot.exists()) {
-          const data = snapshot.data();
-          const phase = data?.currentPhase || "collector";
-          setCurrentPhase(phase);
-          
-          // Update vision answers status
-          const hasAnswers = data?.visionAnswers?.allAnswered === true;
-          setHasVisionAnswers(hasAnswers);
-        }
-      }
-    );
-
-    return () => unsubscribe();
+    loadProject();
   }, [projectId]);
 
   // Initialize with AI welcome message
   useEffect(() => {
-    if (!isInitialized && projectId) {
-      const unsubscribe = auth.onAuthStateChanged(async (user) => {
-        if (!user) {
-          // Not signed in, trigger AI welcome
+    if (!isInitialized && projectId && sessionStatus !== 'loading') {
+      const initialize = async () => {
+        if (sessionStatus === 'unauthenticated') {
           setIsLoading(false);
           setIsInitialized(true);
-          setTimeout(() => {
-            sendChatMessage("Hello");
-          }, 500);
+          setTimeout(() => sendChatMessage("Hello"), 500);
           return;
         }
 
-        // User is signed in, load conversation history first
+        // Signed in via NextAuth — load conversation history
         try {
-          const token = await user.getIdToken();
-          
           // Fetch existing conversation history
-          const historyResponse = await fetch(`/api/ai/conversation?projectId=${projectId}`, {
-            headers: {
-              'Authorization': `Bearer ${token}`,
-            },
-          });
+          const historyResponse = await fetch(`/api/ai/conversation?projectId=${projectId}`);
           
           let existingMessages: Message[] = [];
           
@@ -231,11 +201,11 @@ export default function GettingStartedPage() {
           setIsLoading(false);
           setIsInitialized(true);
         }
-      });
+      };
 
-      return () => unsubscribe();
+      initialize();
     }
-  }, [projectId, isInitialized]);
+  }, [projectId, isInitialized, sessionStatus]);
 
   const sendChatMessage = async (messageContent: string) => {
     const content = messageContent.trim();
@@ -251,24 +221,10 @@ export default function GettingStartedPage() {
     setIsSending(true);
 
     try {
-      const user = auth.currentUser;
-      if (!user) {
-        toast.error('Please sign in to continue');
-        setIsSending(false);
-        return;
-      }
-
-      const token = await user.getIdToken();
       const response = await fetch('/api/ai/chat', {
         method: 'POST',
-        headers: {
-          'Authorization': `Bearer ${token}`,
-          'Content-Type': 'application/json',
-        },
-        body: JSON.stringify({
-          projectId,
-          message: content,
-        }),
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ projectId, message: content }),
       });
 
       if (!response.ok) {
@@ -392,21 +348,8 @@ export default function GettingStartedPage() {
     }
 
     try {
-      const user = auth.currentUser;
-      if (!user) {
-        toast.error('Please sign in to reset chat');
-        return;
-      }
-
-      const token = await user.getIdToken();
-      
-      const response = await fetch('/api/ai/conversation/reset', {
-        method: 'POST',
-        headers: {
-          'Authorization': `Bearer ${token}`,
-          'Content-Type': 'application/json',
-        },
-        body: JSON.stringify({ projectId }),
+      const response = await fetch(`/api/ai/conversation?projectId=${projectId}`, {
+        method: 'DELETE',
       });
 
       if (response.ok) {
@@ -433,20 +376,9 @@ export default function GettingStartedPage() {
       setExtractionStatus("importing");
       setExtractionError(null);
 
-      const user = auth.currentUser;
-      if (!user) {
-        toast.error("Please sign in to import chats");
-        setIsImporting(false);
-        return;
-      }
-
-      const token = await user.getIdToken();
       const importResponse = await fetch(`/api/projects/${projectId}/knowledge/import-ai-chat`, {
         method: "POST",
-        headers: {
-          "Content-Type": "application/json",
-          Authorization: `Bearer ${token}`,
-        },
+        headers: { "Content-Type": "application/json" },
         body: JSON.stringify({
           title: extractForm.title || "Imported AI chat",
           provider: extractForm.provider,
diff --git a/app/api/ai/chat/route.ts b/app/api/ai/chat/route.ts
index 7e474b0..f18e6cf 100644
--- a/app/api/ai/chat/route.ts
+++ b/app/api/ai/chat/route.ts
@@ -2,8 +2,7 @@ import { NextResponse } from 'next/server';
 import { z } from 'zod';
 import { GeminiLlmClient } from '@/lib/ai/gemini-client';
 import type { LlmClient } from '@/lib/ai/llm-client';
-import { getAdminDb } from '@/lib/firebase/admin';
-import { FieldValue } from 'firebase-admin/firestore';
+import { query } from '@/lib/db-postgres';
 import { MODE_SYSTEM_PROMPTS, ChatMode } from '@/lib/ai/chat-modes';
 import { resolveChatMode } from '@/lib/server/chat-mode-resolver';
 import {
@@ -48,37 +47,30 @@ interface ChatRequestBody {
   overrideMode?: ChatMode;
 }
 
+const ENSURE_CONV_TABLE = `
+  CREATE TABLE IF NOT EXISTS chat_conversations (
+    project_id text PRIMARY KEY,
+    messages    jsonb NOT NULL DEFAULT '[]',
+    updated_at  timestamptz NOT NULL DEFAULT NOW()
+  )
+`;
+
 async function appendConversation(
   projectId: string,
-  messages: Array<{ role: 'user' | 'assistant'; content: string }>,
+  newMessages: Array<{ role: 'user' | 'assistant'; content: string }>,
 ) {
-  const adminDb = getAdminDb();
-  const docRef = adminDb.collection('chat_conversations').doc(projectId);
+  await query(ENSURE_CONV_TABLE);
+  const now = new Date().toISOString();
+  const stamped = newMessages.map((m) => ({ ...m, createdAt: now }));
 
-  await adminDb.runTransaction(async (tx) => {
-    const snapshot = await tx.get(docRef);
-    const existing = (snapshot.exists ? (snapshot.data()?.messages as unknown[]) : []) ?? [];
-
-     const now = new Date().toISOString();
-
-    const newMessages = messages.map((m) => ({
-      role: m.role,
-      content: m.content,
-      // Use a simple ISO string for message timestamps to avoid FieldValue
-      // restrictions inside arrays.
-      createdAt: now,
-    }));
-
-    tx.set(
-      docRef,
-      {
-        projectId,
-        messages: [...existing, ...newMessages],
-        updatedAt: FieldValue.serverTimestamp(),
-      },
-      { merge: true },
-    );
-  });
+  await query(
+    `INSERT INTO chat_conversations (project_id, messages, updated_at)
+     VALUES ($1, $2::jsonb, NOW())
+     ON CONFLICT (project_id) DO UPDATE
+       SET messages   = chat_conversations.messages || $2::jsonb,
+           updated_at = NOW()`,
+    [projectId, JSON.stringify(stamped)]
+  );
 }
 
 export async function POST(request: Request) {
@@ -91,13 +83,15 @@ export async function POST(request: Request) {
       return NextResponse.json({ error: 'projectId and message are required' }, { status: 400 });
     }
 
-    // Verify project exists
-    const adminDb = getAdminDb();
-    const projectSnapshot = await adminDb.collection('projects').doc(projectId).get();
-    if (!projectSnapshot.exists) {
+    // Verify project exists in Postgres
+    const projectRows = await query<{ data: any }>(
+      `SELECT data FROM fs_projects WHERE id = $1 LIMIT 1`,
+      [projectId]
+    );
+    if (projectRows.length === 0) {
       return NextResponse.json({ error: 'Project not found' }, { status: 404 });
     }
-    const projectData = projectSnapshot.data() ?? {};
+    const projectData = projectRows[0].data ?? {};
 
     // Resolve chat mode (uses new resolver)
     const resolvedMode = body.overrideMode ?? await resolveChatMode(projectId);
@@ -138,12 +132,13 @@ ${context.sessionHistory.totalSessions > 0 ? `- Complete Cursor session history
 
 Use this context to provide specific, grounded responses. The session history shows your complete conversation history with the user - use it to understand what has been built and discussed.`;
 
-    // Load existing conversation history
-    const conversationDoc = await adminDb.collection('chat_conversations').doc(projectId).get();
-    const conversationData = conversationDoc.exists ? conversationDoc.data() : null;
-    const conversationHistory = Array.isArray(conversationData?.messages) 
-      ? conversationData.messages 
-      : [];
+    // Load existing conversation history from Postgres
+    await query(ENSURE_CONV_TABLE);
+    const convRows = await query<{ messages: any[] }>(
+      `SELECT messages FROM chat_conversations WHERE project_id = $1`,
+      [projectId]
+    );
+    const conversationHistory: any[] = convRows[0]?.messages ?? [];
 
     // Build full message context (history + current message)
     const messages = [
@@ -251,10 +246,14 @@ Use this context to provide specific, grounded responses. The session history sh
       if (Object.keys(updates).length > 0) {
         updates['visionAnswers.updatedAt'] = new Date().toISOString();
         
-        await adminDb.collection('projects').doc(projectId).set(updates, { merge: true })
-          .catch((error) => {
-            console.error('[ai/chat] Failed to store vision answers', error);
-          });
+        await query(
+          `UPDATE fs_projects
+           SET data = data || $1::jsonb
+           WHERE id = $2`,
+          [JSON.stringify({ visionAnswers: updates }), projectId]
+        ).catch((error) => {
+          console.error('[ai/chat] Failed to store vision answers', error);
+        });
       }
     }
 
@@ -326,12 +325,17 @@ Use this context to provide specific, grounded responses. The session history sh
         timestamp: new Date().toISOString(),
       };
 
-      // Persist to project phaseData
-      await adminDb.collection('projects').doc(projectId).set(
-        {
-          'phaseData.phaseHandoffs.collector': handoff,
-        },
-        { merge: true }
+      // Persist to project phaseData in Postgres
+      await query(
+        `UPDATE fs_projects
+         SET data = jsonb_set(
+           data,
+           '{phaseData,phaseHandoffs,collector}',
+           $1::jsonb,
+           true
+         )
+         WHERE id = $2`,
+        [JSON.stringify(handoff), projectId]
       ).catch((error) => {
         console.error('[ai/chat] Failed to persist collector handoff', error);
       });
@@ -348,9 +352,12 @@ Use this context to provide specific, grounded responses. The session history sh
         console.log(`[AI Chat] Collector complete - triggering backend extraction`);
         
         // Mark collector as complete
-        await adminDb.collection('projects').doc(projectId).update({
-          'phaseData.collectorCompletedAt': new Date().toISOString(),
-        }).catch((error) => {
+        await query(
+          `UPDATE fs_projects
+           SET data = jsonb_set(data, '{phaseData,collectorCompletedAt}', $1::jsonb, true)
+           WHERE id = $2`,
+          [JSON.stringify(new Date().toISOString()), projectId]
+        ).catch((error) => {
           console.error('[ai/chat] Failed to mark collector complete', error);
         });
         
@@ -397,44 +404,32 @@ Use this context to provide specific, grounded responses. The session history sh
         console.log(`[AI Chat] Extraction review complete - transitioning to vision phase`);
         
         // Mark extraction review as complete and transition to vision
-        await adminDb.collection('projects').doc(projectId).update({
-          currentPhase: 'vision',
-          phaseStatus: 'in_progress',
-          'phaseData.extractionReviewCompletedAt': new Date().toISOString(),
-        }).catch((error) => {
+        await query(
+          `UPDATE fs_projects
+           SET data = data
+             || '{"currentPhase":"vision","phaseStatus":"in_progress"}'::jsonb
+             || jsonb_build_object('phaseData',
+                  (data->'phaseData') || jsonb_build_object(
+                    'extractionReviewCompletedAt', $1::text
+                  )
+                )
+           WHERE id = $2`,
+          [new Date().toISOString(), projectId]
+        ).catch((error) => {
           console.error('[ai/chat] Failed to transition to vision phase', error);
         });
       }
     }
 
-    // Save conversation history
-    const newConversationHistory = [
-      ...conversationHistory,
-      {
-        role: 'user' as const,
-        content: message,
-        createdAt: new Date().toISOString(),
-      },
-      {
-        role: 'assistant' as const,
-        content: reply.reply,
-        createdAt: new Date().toISOString(),
-      },
-    ];
-
-    await adminDb.collection('chat_conversations').doc(projectId).set(
-      {
-        projectId,
-        userId: projectData.userId,
-        messages: newConversationHistory,
-        updatedAt: new Date().toISOString(),
-      },
-      { merge: true }
-    ).catch((error) => {
+    // Save conversation history to Postgres
+    await appendConversation(projectId, [
+      { role: 'user', content: message },
+      { role: 'assistant', content: reply.reply },
+    ]).catch((error) => {
       console.error('[ai/chat] Failed to save conversation history', error);
     });
 
-    console.log(`[AI Chat] Conversation history saved (${newConversationHistory.length} total messages)`);
+    console.log(`[AI Chat] Conversation history saved (+2 messages)`);
 
     // Determine which artifacts were used
     const artifactsUsed = determineArtifactsUsed(context);
diff --git a/app/api/ai/conversation/route.ts b/app/api/ai/conversation/route.ts
index b4a03ed..823d900 100644
--- a/app/api/ai/conversation/route.ts
+++ b/app/api/ai/conversation/route.ts
@@ -1,12 +1,20 @@
 import { NextResponse } from 'next/server';
-import { getAdminDb } from '@/lib/firebase/admin';
+import { query } from '@/lib/db-postgres';
+
+const ENSURE_TABLE = `
+  CREATE TABLE IF NOT EXISTS chat_conversations (
+    project_id text PRIMARY KEY,
+    messages    jsonb NOT NULL DEFAULT '[]',
+    updated_at  timestamptz NOT NULL DEFAULT NOW()
+  )
+`;
 
 type StoredMessageRole = 'user' | 'assistant';
 
 type ConversationMessage = {
   role: StoredMessageRole;
   content: string;
-  createdAt?: { _seconds: number; _nanoseconds: number };
+  createdAt?: string;
 };
 
 type ConversationResponse = {
@@ -19,36 +27,43 @@ export async function GET(request: Request) {
     const projectId = (url.searchParams.get('projectId') ?? '').trim();
 
     if (!projectId) {
-      return NextResponse.json(
-        { error: 'projectId is required' },
-        { status: 400 },
-      );
+      return NextResponse.json({ error: 'projectId is required' }, { status: 400 });
     }
 
-    const adminDb = getAdminDb();
-    const docRef = adminDb.collection('chat_conversations').doc(projectId);
-    const snapshot = await docRef.get();
+    await query(ENSURE_TABLE);
 
-    if (!snapshot.exists) {
-      const empty: ConversationResponse = { messages: [] };
-      return NextResponse.json(empty);
-    }
-
-    const data = snapshot.data() as { messages?: ConversationMessage[] };
-    const messages = Array.isArray(data.messages) ? data.messages : [];
+    const rows = await query<{ messages: ConversationMessage[] }>(
+      `SELECT messages FROM chat_conversations WHERE project_id = $1`,
+      [projectId]
+    );
 
+    const messages: ConversationMessage[] = rows[0]?.messages ?? [];
     const response: ConversationResponse = { messages };
     return NextResponse.json(response);
   } catch (error) {
-    console.error('[ai/conversation] Failed to load conversation', error);
-    return NextResponse.json(
-      {
-        error: 'Failed to load conversation',
-        details: error instanceof Error ? error.message : String(error),
-      },
-      { status: 500 },
-    );
+    console.error('[GET /api/ai/conversation] Error:', error);
+    return NextResponse.json({ messages: [] });
   }
 }
 
+export async function DELETE(request: Request) {
+  try {
+    const url = new URL(request.url);
+    const projectId = (url.searchParams.get('projectId') ?? '').trim();
 
+    if (!projectId) {
+      return NextResponse.json({ error: 'projectId is required' }, { status: 400 });
+    }
+
+    await query(ENSURE_TABLE);
+    await query(
+      `DELETE FROM chat_conversations WHERE project_id = $1`,
+      [projectId]
+    );
+
+    return NextResponse.json({ ok: true });
+  } catch (error) {
+    console.error('[DELETE /api/ai/conversation] Error:', error);
+    return NextResponse.json({ error: 'Failed to reset conversation' }, { status: 500 });
+  }
+}
diff --git a/app/auth/page.tsx b/app/auth/page.tsx
index 68c2dda..3674d76 100644
--- a/app/auth/page.tsx
+++ b/app/auth/page.tsx
@@ -43,4 +43,3 @@ export default function AuthPage() {
     </Suspense>
   );
 }
-
diff --git a/lib/server/chat-context.ts b/lib/server/chat-context.ts
index 63772c6..d0028a3 100644
--- a/lib/server/chat-context.ts
+++ b/lib/server/chat-context.ts
@@ -5,7 +5,7 @@
  * building a compact context object for LLM consumption.
  */
 
-import { getAdminDb } from '@/lib/firebase/admin';
+import { query } from '@/lib/db-postgres';
 import { retrieveRelevantChunks } from '@/lib/server/vector-memory';
 import { embedText } from '@/lib/ai/embeddings';
 import {
@@ -121,15 +121,16 @@ export async function buildProjectContextForChat(
   } = options;
 
   try {
-    const adminDb = getAdminDb();
-
-    // Load project document
-    const projectSnapshot = await adminDb.collection('projects').doc(projectId).get();
-    if (!projectSnapshot.exists) {
+    // Load project from Postgres
+    const projectRows = await query<{ data: any }>(
+      `SELECT data FROM fs_projects WHERE id = $1 LIMIT 1`,
+      [projectId]
+    );
+    if (projectRows.length === 0) {
       throw new Error(`Project ${projectId} not found`);
     }
 
-    const projectData = projectSnapshot.data() ?? {};
+    const projectData = projectRows[0].data ?? {};
 
     // Load summaries in parallel
     const [knowledgeSummary, extractionSummary] = await Promise.all([
diff --git a/lib/server/chat-mode-resolver.ts b/lib/server/chat-mode-resolver.ts
index 16e0b1f..ff67b08 100644
--- a/lib/server/chat-mode-resolver.ts
+++ b/lib/server/chat-mode-resolver.ts
@@ -1,190 +1,91 @@
 /**
  * Chat Mode Resolution Logic
- * 
+ *
  * Determines which chat mode (collector, extraction_review, vision, mvp, marketing, general)
- * should be active based on project state.
+ * should be active based on project state stored in Postgres.
  */
 
-import { getAdminDb } from '@/lib/firebase/admin';
+import { query } from '@/lib/db-postgres';
 import type { ChatMode } from '@/lib/ai/chat-modes';
 
 /**
- * Resolve the appropriate chat mode for a project
- * 
- * Logic:
- * 1. No knowledge_items → collector_mode
- * 2. Has knowledge but no extractions → collector_mode (needs to run extraction)
- * 3. Has extractions but no canonicalProductModel → extraction_review_mode
- * 4. Has canonicalProductModel but no mvpPlan → vision_mode
- * 5. Has mvpPlan but no marketingPlan → mvp_mode
- * 6. Has marketingPlan → marketing_mode
- * 7. Otherwise → general_chat_mode
- * 
- * @param projectId - Firestore project ID
- * @returns The appropriate chat mode
+ * Resolve the appropriate chat mode for a project using Postgres (fs_projects).
  */
 export async function resolveChatMode(projectId: string): Promise<ChatMode> {
   try {
-    const adminDb = getAdminDb();
+    const rows = await query<{ data: any }>(
+      `SELECT data FROM fs_projects WHERE id = $1 LIMIT 1`,
+      [projectId]
+    );
 
-    // Load project data
-    const projectSnapshot = await adminDb.collection('projects').doc(projectId).get();
-    if (!projectSnapshot.exists) {
-      throw new Error(`Project ${projectId} not found`);
-    }
-
-    const projectData = projectSnapshot.data() ?? {};
-    const phaseData = (projectData.phaseData ?? {}) as Record<string, any>;
-
-    // Check for knowledge_items (top-level collection)
-    const knowledgeSnapshot = await adminDb
-      .collection('knowledge_items')
-      .where('projectId', '==', projectId)
-      .limit(1)
-      .get();
-
-    const hasKnowledge = !knowledgeSnapshot.empty;
-
-    // Check for chat_extractions (top-level collection)
-    const extractionsSnapshot = await adminDb
-      .collection('chat_extractions')
-      .where('projectId', '==', projectId)
-      .limit(1)
-      .get();
-
-    const hasExtractions = !extractionsSnapshot.empty;
-
-    // Apply resolution logic
-    // PRIORITY: Check explicit phase transitions FIRST (overrides knowledge checks)
-    if (projectData.currentPhase === 'extraction_review' || projectData.currentPhase === 'analyzed') {
-      return 'extraction_review_mode';
-    }
-    
-    if (projectData.currentPhase === 'vision') {
-      return 'vision_mode';
-    }
-    
-    if (projectData.currentPhase === 'mvp') {
-      return 'mvp_mode';
-    }
-    
-    if (projectData.currentPhase === 'marketing') {
-      return 'marketing_mode';
-    }
-
-    if (!hasKnowledge) {
+    if (rows.length === 0) {
+      console.warn(`[Chat Mode Resolver] Project ${projectId} not found`);
       return 'collector_mode';
     }
 
-    if (hasKnowledge && !hasExtractions) {
-      return 'collector_mode'; // Has knowledge but needs extraction
-    }
+    const projectData = rows[0].data ?? {};
+    const phaseData = (projectData.phaseData ?? {}) as Record<string, any>;
+    const currentPhase: string = projectData.currentPhase ?? 'collector';
 
-    // Fallback: Has extractions but no canonicalProductModel
-    if (hasExtractions && !phaseData.canonicalProductModel) {
-      return 'extraction_review_mode';
-    }
+    // Explicit phase overrides
+    if (currentPhase === 'extraction_review' || currentPhase === 'analyzed') return 'extraction_review_mode';
+    if (currentPhase === 'vision') return 'vision_mode';
+    if (currentPhase === 'mvp') return 'mvp_mode';
+    if (currentPhase === 'marketing') return 'marketing_mode';
 
-    if (phaseData.canonicalProductModel && !phaseData.mvpPlan) {
-      return 'vision_mode';
-    }
-
-    if (phaseData.mvpPlan && !phaseData.marketingPlan) {
-      return 'mvp_mode';
-    }
-
-    if (phaseData.marketingPlan) {
-      return 'marketing_mode';
-    }
+    // Derive from phase artifacts
+    if (!phaseData.canonicalProductModel) return 'collector_mode';
+    if (!phaseData.mvpPlan) return 'vision_mode';
+    if (!phaseData.marketingPlan) return 'mvp_mode';
+    if (phaseData.marketingPlan) return 'marketing_mode';
 
     return 'general_chat_mode';
   } catch (error) {
     console.error('[Chat Mode Resolver] Failed to resolve mode:', error);
-    // Default to collector on error
     return 'collector_mode';
   }
 }
 
 /**
- * Get a summary of knowledge_items for context building
+ * Summarise knowledge items for context building.
+ * Uses Postgres fs_knowledge_items if available, otherwise returns empty.
  */
-export async function summarizeKnowledgeItems(
-  projectId: string
-): Promise<{
+export async function summarizeKnowledgeItems(projectId: string): Promise<{
   totalCount: number;
   bySourceType: Record<string, number>;
   recentTitles: string[];
 }> {
   try {
-    const adminDb = getAdminDb();
-    const snapshot = await adminDb
-      .collection('knowledge_items')
-      .where('projectId', '==', projectId)
-      .orderBy('createdAt', 'desc')
-      .limit(20)
-      .get();
+    const rows = await query<{ data: any }>(
+      `SELECT data FROM fs_knowledge_items WHERE project_id = $1 ORDER BY created_at DESC LIMIT 20`,
+      [projectId]
+    );
 
-    const totalCount = snapshot.size;
     const bySourceType: Record<string, number> = {};
     const recentTitles: string[] = [];
 
-    snapshot.docs.forEach((doc) => {
-      const data = doc.data();
-      const sourceType = data.sourceType ?? 'unknown';
+    for (const row of rows) {
+      const d = row.data ?? {};
+      const sourceType = d.sourceType ?? 'unknown';
       bySourceType[sourceType] = (bySourceType[sourceType] ?? 0) + 1;
+      if (d.title && recentTitles.length < 5) recentTitles.push(d.title);
+    }
 
-      if (data.title && recentTitles.length < 5) {
-        recentTitles.push(data.title);
-      }
-    });
-
-    return { totalCount, bySourceType, recentTitles };
-  } catch (error) {
-    console.error('[Chat Mode Resolver] Failed to summarize knowledge:', error);
+    return { totalCount: rows.length, bySourceType, recentTitles };
+  } catch {
+    // Table may not exist for older deployments — return empty
     return { totalCount: 0, bySourceType: {}, recentTitles: [] };
   }
 }
 
 /**
- * Get a summary of chat_extractions for context building
+ * Summarise extractions for context building.
+ * Returns empty defaults — extractions not yet migrated to Postgres.
  */
-export async function summarizeExtractions(
-  projectId: string
-): Promise<{
+export async function summarizeExtractions(projectId: string): Promise<{
   totalCount: number;
   avgConfidence: number;
   avgCompletion: number;
 }> {
-  try {
-    const adminDb = getAdminDb();
-    const snapshot = await adminDb
-      .collection('chat_extractions')
-      .where('projectId', '==', projectId)
-      .get();
-
-    if (snapshot.empty) {
-      return { totalCount: 0, avgConfidence: 0, avgCompletion: 0 };
-    }
-
-    let sumConfidence = 0;
-    let sumCompletion = 0;
-    let count = 0;
-
-    snapshot.docs.forEach((doc) => {
-      const data = doc.data();
-      sumConfidence += data.overallConfidence ?? 0;
-      sumCompletion += data.overallCompletion ?? 0;
-      count++;
-    });
-
-    return {
-      totalCount: count,
-      avgConfidence: count > 0 ? sumConfidence / count : 0,
-      avgCompletion: count > 0 ? sumCompletion / count : 0,
-    };
-  } catch (error) {
-    console.error('[Chat Mode Resolver] Failed to summarize extractions:', error);
-    return { totalCount: 0, avgConfidence: 0, avgCompletion: 0 };
-  }
+  return { totalCount: 0, avgConfidence: 0, avgCompletion: 0 };
 }
-