feat: add persistent COO/Assist chat as left-side primary AI interface

- New CooChat component: streaming Gemini-backed advisor chat, message
  bubbles, typing cursor animation, Shift+Enter for newlines
- New /api/projects/[projectId]/advisor streaming endpoint: builds a
  COO system prompt from project context (name, description, vision,
  repo), proxies Gemini SSE stream back to the client
- Restructured BuildHubInner layout:
    Left (340px): CooChat — persistent across all Build sections
    Inner nav (200px): Build pills + contextual items (apps, tree, surfaces)
    Main area: File viewer for Code, Layouts content, Infra content
- AgentMode removed from main view — execution surfaces via COO delegation

Made-with: Cursor

app/[workspace]/project/[projectId]/build/page.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { Suspense, useState, useEffect, useCallback } from "react";
+import { Suspense, useState, useEffect, useCallback, useRef } from "react";
 import { useParams, useSearchParams, useRouter } from "next/navigation";
 import { useSession } from "next-auth/react";
 import Link from "next/link";
@@ -812,6 +812,181 @@ function TerminalPanel({ appName }: { appName: string }) {
   );
 }
 
+// ── COO / Assist chat — persistent left-side advisor ─────────────────────────
+
+interface CooMessage {
+  id: string;
+  role: "user" | "assistant";
+  content: string;
+  streaming?: boolean;
+}
+
+const WELCOME: CooMessage = {
+  id: "welcome",
+  role: "assistant",
+  content: "Hi. I'm your product COO — I know your codebase, your goals, and what's been built. What do you need?",
+};
+
+function CooChat({ projectId, projectName }: { projectId: string; projectName: string }) {
+  const [messages, setMessages] = useState<CooMessage[]>([WELCOME]);
+  const [input, setInput] = useState("");
+  const [loading, setLoading] = useState(false);
+  const bottomRef = useRef<HTMLDivElement>(null);
+  const textareaRef = useRef<HTMLTextAreaElement>(null);
+
+  useEffect(() => {
+    bottomRef.current?.scrollIntoView({ behavior: "smooth" });
+  }, [messages]);
+
+  const send = async () => {
+    const text = input.trim();
+    if (!text || loading) return;
+    setInput("");
+
+    const userMsg: CooMessage = { id: Date.now().toString(), role: "user", content: text };
+    const assistantId = (Date.now() + 1).toString();
+    const assistantMsg: CooMessage = { id: assistantId, role: "assistant", content: "", streaming: true };
+
+    setMessages(prev => [...prev, userMsg, assistantMsg]);
+    setLoading(true);
+
+    // Build history for the API (exclude welcome message, exclude the new blank assistant placeholder)
+    const history = messages
+      .filter(m => m.id !== "welcome" && m.content)
+      .map(m => ({ role: m.role === "assistant" ? "model" as const : "user" as const, content: m.content }));
+
+    try {
+      const res = await fetch(`/api/projects/${projectId}/advisor`, {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({ message: text, history }),
+      });
+
+      if (!res.ok || !res.body) {
+        setMessages(prev => prev.map(m => m.id === assistantId
+          ? { ...m, content: "Something went wrong. Please try again.", streaming: false }
+          : m));
+        return;
+      }
+
+      const reader = res.body.getReader();
+      const decoder = new TextDecoder();
+
+      while (true) {
+        const { done, value } = await reader.read();
+        if (done) break;
+        const chunk = decoder.decode(value, { stream: true });
+        setMessages(prev => prev.map(m => m.id === assistantId
+          ? { ...m, content: m.content + chunk }
+          : m));
+      }
+
+      setMessages(prev => prev.map(m => m.id === assistantId ? { ...m, streaming: false } : m));
+    } catch {
+      setMessages(prev => prev.map(m => m.id === assistantId
+        ? { ...m, content: "Connection error. Please try again.", streaming: false }
+        : m));
+    } finally {
+      setLoading(false);
+      textareaRef.current?.focus();
+    }
+  };
+
+  return (
+    <div style={{ flex: 1, display: "flex", flexDirection: "column", overflow: "hidden" }}>
+      {/* Messages */}
+      <div style={{ flex: 1, overflow: "auto", padding: "16px 16px 8px", display: "flex", flexDirection: "column", gap: 14 }}>
+        {messages.map(msg => (
+          <div key={msg.id} style={{
+            display: "flex",
+            flexDirection: msg.role === "user" ? "row-reverse" : "row",
+            alignItems: "flex-end", gap: 8,
+          }}>
+            {msg.role === "assistant" && (
+              <span style={{ width: 22, height: 22, borderRadius: 6, background: "#1a1a1a", display: "flex", alignItems: "center", justifyContent: "center", fontSize: "0.58rem", color: "#fff", flexShrink: 0 }}>◈</span>
+            )}
+            <div style={{
+              maxWidth: "82%",
+              padding: msg.role === "user" ? "8px 12px" : "0",
+              background: msg.role === "user" ? "#f0ece4" : "transparent",
+              borderRadius: msg.role === "user" ? 12 : 0,
+              fontSize: "0.8rem",
+              color: "#1a1a1a",
+              fontFamily: "Outfit, sans-serif",
+              lineHeight: 1.6,
+              whiteSpace: "pre-wrap",
+              wordBreak: "break-word",
+            }}>
+              {msg.content || (msg.streaming ? "" : "")}
+              {msg.streaming && msg.content === "" && (
+                <span style={{ display: "inline-flex", gap: 3, alignItems: "center" }}>
+                  {[0, 1, 2].map(i => (
+                    <span key={i} style={{
+                      width: 4, height: 4, borderRadius: "50%", background: "#b5b0a6", display: "inline-block",
+                      animation: `bounce 1.2s ${i * 0.2}s ease-in-out infinite`,
+                    }} />
+                  ))}
+                </span>
+              )}
+              {msg.streaming && msg.content !== "" && (
+                <span style={{ display: "inline-block", width: 2, height: "0.9em", background: "#1a1a1a", marginLeft: 1, verticalAlign: "text-bottom", animation: "blink 1s step-end infinite" }} />
+              )}
+            </div>
+          </div>
+        ))}
+        <div ref={bottomRef} />
+      </div>
+
+      {/* Input */}
+      <div style={{ flexShrink: 0, borderTop: "1px solid #e8e4dc", padding: "10px 12px", background: "#fff" }}>
+        <div style={{ display: "flex", gap: 8, alignItems: "flex-end" }}>
+          <textarea
+            ref={textareaRef}
+            value={input}
+            onChange={e => setInput(e.target.value)}
+            onKeyDown={e => { if (e.key === "Enter" && !e.shiftKey) { e.preventDefault(); send(); } }}
+            placeholder={loading ? "Thinking…" : "Ask anything…"}
+            disabled={loading}
+            rows={2}
+            style={{
+              flex: 1, resize: "none", border: "1px solid #e8e4dc", borderRadius: 10,
+              padding: "8px 11px", fontSize: "0.8rem", fontFamily: "Outfit, sans-serif",
+              color: "#1a1a1a", outline: "none", background: loading ? "#faf8f5" : "#faf8f5",
+              lineHeight: 1.5,
+            }}
+          />
+          <button
+            onClick={send}
+            disabled={!input.trim() || loading}
+            style={{
+              width: 34, height: 34, flexShrink: 0, border: "none", borderRadius: 9,
+              background: input.trim() && !loading ? "#1a1a1a" : "#e8e4dc",
+              color: input.trim() && !loading ? "#fff" : "#b5b0a6",
+              cursor: input.trim() && !loading ? "pointer" : "default",
+              display: "flex", alignItems: "center", justifyContent: "center",
+              fontSize: "0.85rem", transition: "background 0.15s",
+            }}
+          >↑</button>
+        </div>
+        <div style={{ fontSize: "0.62rem", color: "#b5b0a6", marginTop: 5, fontFamily: "Outfit, sans-serif" }}>
+          ↵ to send · Shift+↵ new line
+        </div>
+      </div>
+
+      <style>{`
+        @keyframes bounce {
+          0%, 60%, 100% { transform: translateY(0); }
+          30% { transform: translateY(-4px); }
+        }
+        @keyframes blink {
+          0%, 100% { opacity: 1; }
+          50% { opacity: 0; }
+        }
+      `}</style>
+    </div>
+  );
+}
+
 // ── File tree (lives in sidebar B) ───────────────────────────────────────────
 
 function FileTree({ projectId, rootPath, selectedPath, onSelectFile }: {
@@ -937,26 +1112,27 @@ function BuildHubInner() {
   const [activeSurfaceId, setActiveSurfaceId] = useState<string>(activeSurfaceParam);
   const [projectName, setProjectName] = useState<string>("");
 
-  // File viewer state — lifted so FileTree (B) and FileViewer (right) share it
+  // File viewer state — shared between inner nav (tree) and viewer panel
   const [selectedFilePath, setSelectedFilePath] = useState<string | null>(null);
   const [fileContent, setFileContent] = useState<string | null>(null);
   const [fileLoading, setFileLoading] = useState(false);
   const [fileName, setFileName] = useState<string | null>(null);
 
   useEffect(() => {
-    fetch(`/api/projects/${projectId}/apps`).then(r => r.json()).then(d => setApps(d.apps ?? [])).catch(() => {});
+    fetch(`/api/projects/${projectId}/apps`)
+      .then(r => r.json())
+      .then(d => {
+        setApps(d.apps ?? []);
+        if (d.projectName) setProjectName(d.projectName);
+      }).catch(() => {});
     fetch(`/api/projects/${projectId}/design-surfaces`).then(r => r.json()).then(d => {
       const ids: string[] = d.surfaces ?? [];
       const themes: Record<string, string> = d.surfaceThemes ?? {};
       setSurfaces(ids.map(id => ({ id, label: SURFACE_LABELS[id] ?? id, lockedTheme: themes[id] })));
       if (!activeSurfaceId && ids.length > 0) setActiveSurfaceId(ids[0]);
     }).catch(() => {});
-    // Best-effort project name fetch
-    fetch(`/api/projects/${projectId}/apps`).then(r => r.json())
-      .then(d => { if (d.projectName) setProjectName(d.projectName); }).catch(() => {});
   }, [projectId]); // eslint-disable-line react-hooks/exhaustive-deps
 
-  // Clear file selection when app changes
   useEffect(() => {
     setSelectedFilePath(null);
     setFileContent(null);
@@ -986,129 +1162,119 @@ function BuildHubInner() {
   return (
     <div style={{ display: "flex", height: "100%", fontFamily: "Outfit, sans-serif", overflow: "hidden" }}>
 
-      {/* ── B: Sidebar — project header + build pills + nav + file tree ── */}
-      <div style={{ width: 260, flexShrink: 0, borderRight: "1px solid #e8e4dc", background: "#faf8f5", display: "flex", flexDirection: "column", overflow: "hidden" }}>
+      {/* ── Left: COO / Assist persistent chat ── */}
+      <div style={{ width: 340, flexShrink: 0, borderRight: "1px solid #e8e4dc", background: "#fff", display: "flex", flexDirection: "column", overflow: "hidden" }}>
 
-        {/* Project header */}
-        <div style={{ height: 48, flexShrink: 0, display: "flex", alignItems: "center", padding: "0 14px", borderBottom: "1px solid #e8e4dc", gap: 9 }}>
-          <span style={{ width: 26, height: 26, borderRadius: 7, background: "#1a1a1a", display: "flex", alignItems: "center", justifyContent: "center", fontSize: "0.68rem", color: "#fff", flexShrink: 0, fontFamily: "Outfit, sans-serif" }}>◈</span>
-          <span style={{ fontSize: "0.82rem", fontWeight: 600, color: "#1a1a1a", fontFamily: "Outfit, sans-serif", overflow: "hidden", textOverflow: "ellipsis", whiteSpace: "nowrap", flex: 1 }}>
-            {projectName || workspace}
-          </span>
-        </div>
-
-        {/* Build section pills: Code | Layouts | Infra */}
-        <div style={{ padding: "10px 12px 9px", flexShrink: 0, borderBottom: "1px solid #f0ece4" }}>
-          <div style={{ fontSize: "0.57rem", fontWeight: 700, color: "#b5b0a6", letterSpacing: "0.1em", textTransform: "uppercase", marginBottom: 7, fontFamily: "Outfit, sans-serif" }}>Build</div>
-          <div style={{ display: "flex", gap: 5 }}>
-            {(["code", "layouts", "infrastructure"] as const).map(s => (
-              <button key={s} onClick={() => setSection(s)} style={{
-                padding: "4px 10px", border: "1px solid",
-                borderRadius: 20, fontSize: "0.68rem", fontWeight: section === s ? 600 : 440,
-                cursor: "pointer", fontFamily: "Outfit, sans-serif",
-                background: section === s ? "#1a1a1a" : "transparent",
-                color: section === s ? "#fff" : "#5a5550",
-                borderColor: section === s ? "#1a1a1a" : "#e0dcd5",
-              }}>
-                {s === "code" ? "Code" : s === "layouts" ? "Layouts" : "Infra"}
-              </button>
-            ))}
-          </div>
-        </div>
-
-        {/* Code: app list + file tree */}
-        {section === "code" && (
-          <div style={{ flex: 1, display: "flex", flexDirection: "column", overflow: "hidden" }}>
-            {/* App list */}
-            <div style={{ flexShrink: 0 }}>
-              <div style={NAV_GROUP_LABEL}>Apps</div>
-              {apps.length > 0 ? apps.map(app => (
-                <NavItem key={app.name} label={app.name} indent
-                  active={activeApp === app.name}
-                  onClick={() => navigate({ section: "code", app: app.name, root: app.path })}
-                />
-              )) : (
-                <div style={{ padding: "8px 22px", fontSize: "0.74rem", color: "#b5b0a6", fontFamily: "Outfit, sans-serif" }}>No apps yet</div>
-              )}
+        {/* Advisor header */}
+        <div style={{ height: 48, flexShrink: 0, display: "flex", alignItems: "center", padding: "0 14px", borderBottom: "1px solid #e8e4dc", gap: 9, background: "#faf8f5" }}>
+          <span style={{ width: 26, height: 26, borderRadius: 7, background: "#1a1a1a", display: "flex", alignItems: "center", justifyContent: "center", fontSize: "0.68rem", color: "#fff", flexShrink: 0 }}>◈</span>
+          <div style={{ flex: 1, minWidth: 0 }}>
+            <div style={{ fontSize: "0.78rem", fontWeight: 600, color: "#1a1a1a", fontFamily: "Outfit, sans-serif", overflow: "hidden", textOverflow: "ellipsis", whiteSpace: "nowrap" }}>
+              {projectName || workspace}
             </div>
-
-            {/* File tree — appears below app list when an app is selected */}
-            {activeApp && activeRoot && (
-              <div style={{ flex: 1, display: "flex", flexDirection: "column", overflow: "hidden", borderTop: "1px solid #e8e4dc", marginTop: 6 }}>
-                <div style={{ padding: "7px 12px 4px", flexShrink: 0, display: "flex", alignItems: "center", gap: 6 }}>
-                  <span style={{ fontSize: "0.57rem", fontWeight: 700, color: "#b5b0a6", letterSpacing: "0.1em", textTransform: "uppercase", fontFamily: "Outfit, sans-serif" }}>Files</span>
-                  <span style={{ fontSize: "0.65rem", color: "#a09a90", fontFamily: "IBM Plex Mono, monospace", overflow: "hidden", textOverflow: "ellipsis", whiteSpace: "nowrap" }}>{activeApp}</span>
-                </div>
-                <FileTree
-                  projectId={projectId}
-                  rootPath={activeRoot}
-                  selectedPath={selectedFilePath}
-                  onSelectFile={handleSelectFile}
-                />
-              </div>
-            )}
+            <div style={{ fontSize: "0.6rem", color: "#a09a90", fontFamily: "Outfit, sans-serif", letterSpacing: "0.04em" }}>Assist · Your product COO</div>
           </div>
-        )}
+        </div>
 
-        {/* Layouts: surface list */}
-        {section === "layouts" && (
-          <div style={{ overflow: "auto", flex: 1 }}>
-            <div style={NAV_GROUP_LABEL}>Surfaces</div>
-            {surfaces.length > 0 ? surfaces.map(s => (
-              <NavItem key={s.id} label={SURFACE_LABELS[s.id] ?? s.id} indent
-                active={activeSurfaceId === s.id}
-                onClick={() => { setActiveSurfaceId(s.id); navigate({ section: "layouts", surface: s.id }); }}
-              />
-            )) : (
-              <div style={{ padding: "8px 22px", fontSize: "0.74rem", color: "#b5b0a6", fontFamily: "Outfit, sans-serif" }}>Not configured</div>
-            )}
-          </div>
-        )}
-
-        {/* Infrastructure: item list */}
-        {section === "infrastructure" && (
-          <div style={{ overflow: "auto", flex: 1 }}>
-            <div style={NAV_GROUP_LABEL}>Infrastructure</div>
-            {INFRA_ITEMS.map(item => (
-              <NavItem key={item.id} label={item.label} indent
-                active={activeInfra === item.id}
-                onClick={() => navigate({ section: "infrastructure", tab: item.id })}
-              />
-            ))}
-          </div>
-        )}
+        <CooChat projectId={projectId} projectName={projectName || workspace} />
       </div>
 
-      {/* ── Content ── */}
+      {/* ── Right: Build content ── */}
       <div style={{ flex: 1, display: "flex", overflow: "hidden", minWidth: 0 }}>
 
-        {/* Code: D (agent chat) + Right (file viewer) + F (terminal) */}
+        {/* Inner nav — Build section switcher + contextual items */}
+        <div style={{ width: 200, flexShrink: 0, borderRight: "1px solid #e8e4dc", background: "#faf8f5", display: "flex", flexDirection: "column", overflow: "hidden" }}>
+
+          {/* Build pills */}
+          <div style={{ padding: "10px 12px 9px", flexShrink: 0, borderBottom: "1px solid #f0ece4" }}>
+            <div style={{ fontSize: "0.57rem", fontWeight: 700, color: "#b5b0a6", letterSpacing: "0.1em", textTransform: "uppercase", marginBottom: 7, fontFamily: "Outfit, sans-serif" }}>Build</div>
+            <div style={{ display: "flex", flexDirection: "column", gap: 3 }}>
+              {(["code", "layouts", "infrastructure"] as const).map(s => (
+                <button key={s} onClick={() => setSection(s)} style={{
+                  display: "flex", alignItems: "center", gap: 8,
+                  padding: "6px 10px", border: "none", borderRadius: 7,
+                  fontSize: "0.76rem", fontWeight: section === s ? 600 : 440,
+                  cursor: "pointer", fontFamily: "Outfit, sans-serif", textAlign: "left",
+                  background: section === s ? "#f0ece4" : "transparent",
+                  color: section === s ? "#1a1a1a" : "#5a5550",
+                }}>
+                  <span style={{ fontSize: "0.65rem", opacity: 0.6 }}>
+                    {s === "code" ? "<>" : s === "layouts" ? "▢" : "⬡"}
+                  </span>
+                  {s === "code" ? "Code" : s === "layouts" ? "Layouts" : "Infrastructure"}
+                </button>
+              ))}
+            </div>
+          </div>
+
+          {/* Code: app list + file tree */}
+          {section === "code" && (
+            <div style={{ flex: 1, display: "flex", flexDirection: "column", overflow: "hidden" }}>
+              <div style={{ flexShrink: 0 }}>
+                <div style={NAV_GROUP_LABEL}>Apps</div>
+                {apps.length > 0 ? apps.map(app => (
+                  <NavItem key={app.name} label={app.name} indent
+                    active={activeApp === app.name}
+                    onClick={() => navigate({ section: "code", app: app.name, root: app.path })}
+                  />
+                )) : (
+                  <div style={{ padding: "8px 22px", fontSize: "0.74rem", color: "#b5b0a6", fontFamily: "Outfit, sans-serif" }}>No apps yet</div>
+                )}
+              </div>
+              {activeApp && activeRoot && (
+                <div style={{ flex: 1, display: "flex", flexDirection: "column", overflow: "hidden", borderTop: "1px solid #e8e4dc", marginTop: 6 }}>
+                  <div style={{ padding: "7px 12px 4px", flexShrink: 0, display: "flex", alignItems: "center", gap: 6 }}>
+                    <span style={{ fontSize: "0.57rem", fontWeight: 700, color: "#b5b0a6", letterSpacing: "0.1em", textTransform: "uppercase", fontFamily: "Outfit, sans-serif" }}>Files</span>
+                    <span style={{ fontSize: "0.62rem", color: "#a09a90", fontFamily: "IBM Plex Mono, monospace", overflow: "hidden", textOverflow: "ellipsis", whiteSpace: "nowrap" }}>{activeApp}</span>
+                  </div>
+                  <FileTree projectId={projectId} rootPath={activeRoot} selectedPath={selectedFilePath} onSelectFile={handleSelectFile} />
+                </div>
+              )}
+            </div>
+          )}
+
+          {/* Layouts: surface list */}
+          {section === "layouts" && (
+            <div style={{ overflow: "auto", flex: 1 }}>
+              <div style={NAV_GROUP_LABEL}>Surfaces</div>
+              {surfaces.length > 0 ? surfaces.map(s => (
+                <NavItem key={s.id} label={SURFACE_LABELS[s.id] ?? s.id} indent
+                  active={activeSurfaceId === s.id}
+                  onClick={() => { setActiveSurfaceId(s.id); navigate({ section: "layouts", surface: s.id }); }}
+                />
+              )) : (
+                <div style={{ padding: "8px 22px", fontSize: "0.74rem", color: "#b5b0a6", fontFamily: "Outfit, sans-serif" }}>Not configured</div>
+              )}
+            </div>
+          )}
+
+          {/* Infrastructure: item list */}
+          {section === "infrastructure" && (
+            <div style={{ overflow: "auto", flex: 1 }}>
+              <div style={NAV_GROUP_LABEL}>Infrastructure</div>
+              {INFRA_ITEMS.map(item => (
+                <NavItem key={item.id} label={item.label} indent
+                  active={activeInfra === item.id}
+                  onClick={() => navigate({ section: "infrastructure", tab: item.id })}
+                />
+              ))}
+            </div>
+          )}
+        </div>
+
+        {/* Main content panel */}
         {section === "code" && (
           <div style={{ flex: 1, display: "flex", flexDirection: "column", overflow: "hidden" }}>
-            <div style={{ flex: 1, display: "flex", overflow: "hidden" }}>
-
-              {/* D: Agent chat — main content */}
-              <div style={{ flex: 1, display: "flex", flexDirection: "column", overflow: "hidden", borderRight: "1px solid #e8e4dc", minWidth: 0 }}>
-                <AgentMode projectId={projectId} appName={activeApp} appPath={activeRoot} />
-              </div>
-
-              {/* Right: File viewer — code changes stream here */}
-              <div style={{ width: 460, flexShrink: 0, display: "flex", flexDirection: "column", overflow: "hidden" }}>
-                <FileViewer
-                  selectedPath={selectedFilePath}
-                  fileContent={fileContent}
-                  fileLoading={fileLoading}
-                  fileName={fileName}
-                  rootPath={activeRoot}
-                />
-              </div>
-            </div>
-
-            {/* F: Terminal strip */}
+            <FileViewer
+              selectedPath={selectedFilePath}
+              fileContent={fileContent}
+              fileLoading={fileLoading}
+              fileName={fileName}
+              rootPath={activeRoot}
+            />
             <TerminalPanel appName={activeApp} />
           </div>
         )}
-
         {section === "layouts" && (
           <LayoutsContent surfaces={surfaces} projectId={projectId} workspace={workspace} activeSurfaceId={activeSurfaceId} onSelectSurface={id => { setActiveSurfaceId(id); navigate({ section: "layouts", surface: id }); }} />
         )}

app/api/projects/[projectId]/advisor/route.ts

@@ -0,0 +1,152 @@
+import { NextRequest } from 'next/server';
+import { getServerSession } from 'next-auth';
+import { authOptions } from '@/lib/auth/authOptions';
+import { query } from '@/lib/db-postgres';
+
+const GOOGLE_API_KEY = process.env.GOOGLE_API_KEY ?? '';
+const MODEL = process.env.GEMINI_MODEL ?? 'gemini-2.0-flash-exp';
+const STREAM_URL = `https://generativelanguage.googleapis.com/v1beta/models/${MODEL}:streamGenerateContent?key=${GOOGLE_API_KEY}&alt=sse`;
+
+function buildSystemPrompt(projectData: Record<string, unknown>): string {
+  const name = (projectData.name as string) ?? 'this project';
+  const description = (projectData.description as string) ?? '';
+  const vision = (projectData.vision as string) ?? '';
+  const giteaRepo = (projectData.giteaRepo as string) ?? '';
+
+  return `You are the personal AI COO for "${name}" — a product assistant that thinks like a seasoned Chief Operating Officer.
+
+Your role is to be the founder's single AI interface. The founder talks to you. You figure out what needs to happen and make it clear before anything is done.
+
+## About this project
+${description ? `Description: ${description}` : ''}
+${vision ? `Vision: ${vision}` : ''}
+${giteaRepo ? `Codebase: ${giteaRepo}` : ''}
+
+## Your principles
+- You are NOT a chatbot. You are an executive partner.
+- You reason across the entire business: product, code, growth, analytics, operations.
+- You surface insights the founder hasn't asked about when they're relevant.
+- You speak in plain language. No jargon without explanation.
+- Before any work is delegated, you surface a clear plan: "Here's what I'd do: [plain language]. Want me to start?"
+- You are brief and direct. Founders are busy.
+- When something needs to be built, you describe the scope before acting.
+- When something needs analysis, you explain what you found and what it means.
+- You never ask the founder to pick a module, agent, or technical approach — you figure that out.
+
+## What you have access to (context expands over time)
+- The project codebase and commit history
+- Agent session outcomes (what's been built)
+- Analytics and deployment status
+- Market and competitor knowledge (via web search)
+- Persistent memory of decisions, preferences, patterns
+
+## Tone
+Confident, brief, thoughtful. Like a trusted advisor who has seen this before. Not overly formal, not casual. Never sycophantic — skip "Great question!" entirely.
+
+Start each conversation ready to help. If this is the user's first message, greet them briefly and ask what's on their mind.`.trim();
+}
+
+export async function POST(
+  req: NextRequest,
+  { params }: { params: Promise<{ projectId: string }> }
+) {
+  const { projectId } = await params;
+
+  const session = await getServerSession(authOptions);
+  if (!session?.user?.email) {
+    return new Response('Unauthorized', { status: 401 });
+  }
+
+  if (!GOOGLE_API_KEY) {
+    return new Response('GOOGLE_API_KEY not configured', { status: 500 });
+  }
+
+  const { message, history = [] } = await req.json() as {
+    message: string;
+    history: Array<{ role: 'user' | 'model'; content: string }>;
+  };
+
+  if (!message?.trim()) {
+    return new Response('Message required', { status: 400 });
+  }
+
+  // Load project data for context
+  let projectData: Record<string, unknown> = {};
+  try {
+    const rows = await query<{ data: Record<string, unknown> }>(
+      `SELECT p.data FROM fs_projects p
+       JOIN fs_users u ON u.id = p.user_id
+       WHERE p.id = $1 AND u.data->>'email' = $2 LIMIT 1`,
+      [projectId, session.user.email]
+    );
+    if (rows.length > 0) projectData = rows[0].data ?? {};
+  } catch { /* best-effort, proceed without context */ }
+
+  const systemPrompt = buildSystemPrompt(projectData);
+
+  // Build Gemini conversation history
+  const contents = [
+    ...history.map(h => ({
+      role: h.role,
+      parts: [{ text: h.content }],
+    })),
+    { role: 'user' as const, parts: [{ text: message }] },
+  ];
+
+  // Call Gemini streaming
+  const geminiRes = await fetch(STREAM_URL, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({
+      system_instruction: { parts: [{ text: systemPrompt }] },
+      contents,
+      generationConfig: {
+        temperature: 0.7,
+        maxOutputTokens: 1024,
+      },
+    }),
+  });
+
+  if (!geminiRes.ok) {
+    const err = await geminiRes.text();
+    return new Response(`Gemini error: ${err}`, { status: 502 });
+  }
+
+  // Proxy the SSE stream, extracting just the text deltas
+  const encoder = new TextEncoder();
+  const stream = new ReadableStream({
+    async start(controller) {
+      const reader = geminiRes.body!.getReader();
+      const decoder = new TextDecoder();
+      let buf = '';
+
+      try {
+        while (true) {
+          const { done, value } = await reader.read();
+          if (done) break;
+
+          buf += decoder.decode(value, { stream: true });
+          const lines = buf.split('\n');
+          buf = lines.pop() ?? '';
+
+          for (const line of lines) {
+            if (!line.startsWith('data: ')) continue;
+            const json = line.slice(6).trim();
+            if (!json || json === '[DONE]') continue;
+            try {
+              const chunk = JSON.parse(json);
+              const text = chunk.candidates?.[0]?.content?.parts?.[0]?.text;
+              if (text) controller.enqueue(encoder.encode(text));
+            } catch { /* skip malformed chunk */ }
+          }
+        }
+      } finally {
+        controller.close();
+      }
+    },
+  });
+
+  return new Response(stream, {
+    headers: { 'Content-Type': 'text/plain; charset=utf-8' },
+  });
+}