diff --git a/craft/src/panels/sitesmith/ChatInput.tsx b/craft/src/panels/sitesmith/ChatInput.tsx
new file mode 100644
index 0000000..36d6dde
--- /dev/null
+++ b/craft/src/panels/sitesmith/ChatInput.tsx
@@ -0,0 +1,25 @@
+import React, { useState, KeyboardEvent } from 'react';
+
+interface Props { disabled?: boolean; placeholder?: string; onSend: (text: string) => void; }
+
+export const ChatInput: React.FC<Props> = ({ disabled, placeholder, onSend }) => {
+  const [v, setV] = useState('');
+  const fire = () => { const t = v.trim(); if (!t || disabled) return; onSend(t); setV(''); };
+  const onKey = (e: KeyboardEvent<HTMLTextAreaElement>) => { if (e.key === 'Enter' && !e.shiftKey) { e.preventDefault(); fire(); } };
+  return (
+    <div style={{ display: 'flex', gap: 8, padding: '8px 0' }}>
+      <textarea value={v} onChange={(e) => setV(e.target.value)} onKeyDown={onKey} rows={2} disabled={disabled}
+        placeholder={placeholder || 'Describe what you want...'}
+        style={{
+          flex: 1, background: disabled ? '#1f1f24' : '#0f0f17', color: '#e5e7eb',
+          border: '1px solid #3f3f46', borderRadius: 6, padding: 10, fontSize: 14, resize: 'none',
+        }} />
+      <button onClick={fire} disabled={disabled || v.trim() === ''}
+        style={{
+          background: disabled ? '#27272a' : '#7c3aed', color: '#fff',
+          border: 'none', padding: '0 16px', borderRadius: 6,
+          cursor: disabled ? 'not-allowed' : 'pointer', fontWeight: 500,
+        }}>→</button>
+    </div>
+  );
+};
diff --git a/craft/src/panels/sitesmith/MessageList.tsx b/craft/src/panels/sitesmith/MessageList.tsx
new file mode 100644
index 0000000..afd0f28
--- /dev/null
+++ b/craft/src/panels/sitesmith/MessageList.tsx
@@ -0,0 +1,32 @@
+import React from 'react';
+import { SitesmithMessage } from '../../types/sitesmith';
+
+export const MessageList: React.FC<{ messages: SitesmithMessage[] }> = ({ messages }) => {
+  const extract = (m: SitesmithMessage): string => {
+    if (m.role === 'user') return m.content;
+    try { const obj = JSON.parse(m.content); if (obj.type === 'ask') return obj.question; if (obj.message) return obj.message; } catch {}
+    return m.content;
+  };
+  return (
+    <div style={{ flex: 1, overflowY: 'auto', padding: '8px 0', display: 'flex', flexDirection: 'column', gap: 10 }}>
+      {messages.length === 0 && (
+        <div style={{ color: '#71717a', fontSize: 13, textAlign: 'center', padding: 30 }}>
+          Describe the site you want and Sitesmith builds it. e.g. "A two-page site for a small bakery, friendly tone, photo of cupcakes in the hero."
+        </div>
+      )}
+      {messages.map((m, i) => {
+        const isUser = m.role === 'user';
+        return (
+          <div key={i} style={{
+            alignSelf: isUser ? 'flex-end' : 'flex-start',
+            maxWidth: '80%', padding: '10px 14px', borderRadius: 10,
+            background: isUser ? '#312e81' : '#1f2937', color: '#f3f4f6',
+            fontSize: 14, whiteSpace: 'pre-wrap',
+          }}>
+            {extract(m)}
+          </div>
+        );
+      })}
+    </div>
+  );
+};
diff --git a/craft/src/panels/sitesmith/SitesmithModal.tsx b/craft/src/panels/sitesmith/SitesmithModal.tsx
new file mode 100644
index 0000000..c8d5e0f
--- /dev/null
+++ b/craft/src/panels/sitesmith/SitesmithModal.tsx
@@ -0,0 +1,94 @@
+import React, { useState } from 'react';
+import { useEditor } from '@craftjs/core';
+import { useEditorConfig } from '../../state/EditorConfigContext';
+import { useSitesmith } from '../../hooks/useSitesmith';
+import { useApplyAiResponse } from '../../utils/apply-ai-response';
+import { summarizeCanvas } from '../../utils/canvas-summary';
+import { UpgradeBanner } from './UpgradeBanner';
+import { ScopeConfirmDialog } from './ScopeConfirmDialog';
+import { MessageList } from './MessageList';
+import { ChatInput } from './ChatInput';
+import { SitesmithResponse } from '../../types/sitesmith';
+
+interface Props { onClose: () => void; }
+
+export const SitesmithModal: React.FC<Props> = ({ onClose }) => {
+  const cfg = useEditorConfig();
+  const siteId = cfg.whpConfig?.siteId ?? 0;
+  const { query } = useEditor();
+  const { summary, messages, send, loading } = useSitesmith(siteId);
+  const apply = useApplyAiResponse();
+  const [busy, setBusy] = useState(false);
+  const [pendingReplace, setPendingReplace] = useState<SitesmithResponse | null>(null);
+  const [error, setError] = useState<string | null>(null);
+
+  const canChat = summary && (summary.status === 'OK_BONUS' || summary.status === 'OK_MONTHLY');
+
+  const overlay: React.CSSProperties = { position: 'fixed', inset: 0, background: 'rgba(0,0,0,0.8)', zIndex: 9000, display: 'flex', alignItems: 'center', justifyContent: 'center' };
+  const panel:   React.CSSProperties = { background: '#0f0f17', border: '1px solid #27272a', borderRadius: 12, width: 'min(720px, 90vw)', maxHeight: '90vh', display: 'flex', flexDirection: 'column' };
+  const header:  React.CSSProperties = { display: 'flex', alignItems: 'center', justifyContent: 'space-between', padding: '14px 18px', borderBottom: '1px solid #27272a' };
+  const body:    React.CSSProperties = { flex: 1, padding: '14px 18px', overflowY: 'auto', display: 'flex', flexDirection: 'column' };
+  const footer:  React.CSSProperties = { padding: '12px 18px', borderTop: '1px solid #27272a' };
+  const closeBtn:React.CSSProperties = { background: 'transparent', color: '#a1a1aa', border: 'none', fontSize: 18, cursor: 'pointer' };
+  const errBox:  React.CSSProperties = { background: '#3b1d1d', border: '1px solid #7f1d1d', color: '#fecaca', padding: '8px 12px', borderRadius: 6, marginBottom: 10, fontSize: 13 };
+
+  const handleSend = async (text: string) => {
+    setBusy(true); setError(null);
+    try {
+      const canvas = summarizeCanvas(query.getSerializedNodes());
+      const result = await send(text, canvas);
+      if (!result.ok) { setError(result.message || 'Failed'); return; }
+      if (result.response.type === 'replace' && result.response.scope === 'site') {
+        setPendingReplace(result.response);
+        return;
+      }
+      const applied = await apply(result.response);
+      if (!applied.ok) setError(applied.message || 'Apply failed');
+    } catch (e: any) { setError(String(e?.message ?? e)); }
+    finally { setBusy(false); }
+  };
+
+  const confirmReplace = async () => {
+    if (!pendingReplace) return;
+    const r = await apply(pendingReplace);
+    setPendingReplace(null);
+    if (!r.ok) setError(r.message || 'Apply failed');
+  };
+
+  return (
+    <div role="dialog" aria-modal="true" style={overlay}>
+      <div style={panel}>
+        <div style={header}>
+          <div style={{ fontWeight: 600, color: '#fff' }}>✨ Sitesmith</div>
+          {summary && summary.enabled && (
+            <div style={{ fontSize: 12, color: '#a1a1aa' }}>
+              {summary.monthly_used} / {summary.monthly_cap} this month
+              {summary.bonus_credits > 0 && ` • +${summary.bonus_credits} bonus`}
+            </div>
+          )}
+          <button onClick={onClose} aria-label="Close" style={closeBtn}>✕</button>
+        </div>
+        <div style={body}>
+          <UpgradeBanner summary={summary} />
+          {error && <div role="alert" style={errBox}>{error}</div>}
+          {loading
+            ? <div style={{ color: '#71717a', textAlign: 'center', padding: 30 }}>Loading…</div>
+            : <MessageList messages={messages} />}
+        </div>
+        <div style={footer}>
+          <ChatInput
+            disabled={!canChat || busy}
+            placeholder={!canChat ? 'Upgrade your plan to use Sitesmith' : busy ? 'Thinking…' : 'Describe what you want…'}
+            onSend={handleSend}
+          />
+        </div>
+        <ScopeConfirmDialog
+          open={!!pendingReplace}
+          pendingMessage={pendingReplace && 'message' in pendingReplace ? (pendingReplace as any).message : undefined}
+          onConfirm={confirmReplace}
+          onCancel={() => setPendingReplace(null)}
+        />
+      </div>
+    </div>
+  );
+};
diff --git a/craft/src/panels/topbar/TopBar.tsx b/craft/src/panels/topbar/TopBar.tsx
index f347cd2..497a2eb 100644
--- a/craft/src/panels/topbar/TopBar.tsx
+++ b/craft/src/panels/topbar/TopBar.tsx
@@ -7,6 +7,7 @@ import { DeviceMode } from '../../types';
 import { TemplateModal } from './TemplateModal';
 import { HeadCodeModal } from './HeadCodeModal';
 import { SitesmithButton } from '../sitesmith/SitesmithButton';
+import { SitesmithModal } from '../sitesmith/SitesmithModal';
 
 interface TopBarProps {
   device: DeviceMode;
@@ -273,14 +274,7 @@ export const TopBar: React.FC<TopBarProps> = ({ device, onDeviceChange }) => {
       </div>
       <TemplateModal open={templateModalOpen} onClose={() => setTemplateModalOpen(false)} />
       <HeadCodeModal open={headCodeModalOpen} onClose={() => setHeadCodeModalOpen(false)} />
-      {sitesmithOpen && (
-        <div role="dialog" style={{ position: 'fixed', top: 0, left: 0, right: 0, bottom: 0, background: 'rgba(0,0,0,0.6)', zIndex: 9000, display: 'flex', alignItems: 'center', justifyContent: 'center' }}>
-          <div style={{ background: '#0f0f17', color: '#fff', padding: 32, borderRadius: 10 }}>
-            <p>SitesmithModal will land in Task 20.</p>
-            <button onClick={() => setSitesmithOpen(false)} style={{ background: '#7c3aed', color: '#fff', border: 'none', padding: '8px 14px', borderRadius: 6 }}>Close</button>
-          </div>
-        </div>
-      )}
+      {sitesmithOpen && <SitesmithModal onClose={() => setSitesmithOpen(false)} />}
     </nav>
   );
 };