diff --git a/.env b/.env
new file mode 100644
index 0000000..0596c6c
--- /dev/null
+++ b/.env
@@ -0,0 +1,3 @@
+VITE_SUPABASE_PROJECT_ID="mebgazuntzkcnkifftbe"
+VITE_SUPABASE_PUBLISHABLE_KEY="eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZSIsInJlZiI6Im1lYmdhenVudHprY25raWZmdGJlIiwicm9sZSI6ImFub24iLCJpYXQiOjE3Nzg3Mzg3NTMsImV4cCI6MjA5NDMxNDc1M30.lf3sYc11q9Rl7yk77rIOkacHytG_VKcOBu5kqw0CgcY"
+VITE_SUPABASE_URL="https://mebgazuntzkcnkifftbe.supabase.co"
diff --git a/.lovable/plan.md b/.lovable/plan.md
index 0cf1cc4..c6bdee8 100644
--- a/.lovable/plan.md
+++ b/.lovable/plan.md
@@ -1,96 +1,118 @@
-## Objetivo
+# Plano — Compartilhar tela do Quest 3 via link público
 
-Adicionar um botão **"Escala"** com presets de redução (1:2, 1:4, 1:8, 1:10, 1:20, 1:33, 1:50, 1:100, 1:200) e ampliação (2:1, 4:1, 10:1), disponível tanto no Viewer 2D quanto no XR. Ao mudar a escala, o app ajusta automaticamente as ferramentas que dependem de tamanho real (medições, sensibilidade do ajuste fino, snap, hover auto-detect), mantendo todos os números exibidos em **mm reais da peça**.
+Permitir que o inspetor no Quest gere um link tipo `tracksteelxr.lovable.app/watch/AB12CD`, mande no WhatsApp/email, e até 3 espectadores assistam ao vivo (vídeo + áudio do Quest) em qualquer celular ou PC.
 
-## Conceito chave
+## Como vai funcionar para o usuário
 
-- "1:N" significa: o modelo é renderizado **N vezes menor** que o real (renderScale = 1/N).
-- "N:1" significa: renderizado N vezes maior (renderScale = N).
-- Os dados do modelo continuam em mm reais. Só o `scale` aplicado ao `<group>` muda.
-- **Medições, sensibilidades, indicadores e relatório PDF continuam exibindo mm REAIS** — o app multiplica/divide pelo fator quando necessário.
+**No Quest (broadcaster):**
+1. No HUD do `/xr` aparece novo botão **"Compartilhar"** (ícone Share/Cast)
+2. Ao clicar: app gera código de 6 caracteres, mostra QR + link encurtado
+3. Botões "Copiar link" e "Compartilhar" (Web Share API → abre WhatsApp/email do sistema)
+4. Indicador vermelho 🔴 LIVE fica visível enquanto transmite, com contador de viewers
+5. Botão "Encerrar" para parar
 
-## Mudanças
+**No celular/PC (viewer):**
+1. Abre o link → tela cheia com vídeo da sessão XR
+2. Sem login, sem instalar nada
+3. Mostra "Aguardando inspetor…" se a sala não estiver ativa
+4. Read-only: só assiste
 
-### 1. Store (`useModelStore.ts`)
-
-Adicionar:
-```ts
-scaleRatio: { label: '1:1', factor: 1 }   // factor = renderScale
-setScaleRatio: (r) => void
-```
-Lista de presets exportada (label + factor).
-
-`fineTuning.scale` continua existindo para o gesto two-hand do XR; o novo `scaleRatio` é aplicado **por cima** (multiplicado) no grupo do modelo.
-
-### 2. Cálculo de medições (`addMeasurePoint`)
-
-Pontos A/B vêm em coordenadas world já escaladas. Para reportar mm reais:
-```
-distanceMM_real = distanciaWorld_mm / scaleRatio.factor
-```
-Atualizar a função `addMeasurePoint` para dividir pela escala atual antes de salvar `distanceMM`. Tooltips e PDF continuam usando o valor salvo (sem mudança).
-
-### 3. Ajuste fino (`FineTuningControls` + XRHud joystick)
-
-`POSITION_STEP` deve representar **1 mm real**. Aplicar:
-```
-worldStep = POSITION_STEP * scaleRatio.factor
-```
-Isso garante que clicar "+" desloca visualmente proporcional à escala (em escala 1:100, mexer "1 mm real" desloca 0,01 mm na cena — coerente).
-
-Mesmo tratamento para o joystick no XR (incremento por frame multiplicado por `scaleRatio.factor`).
-
-### 4. Auto-detect (hover hole/edge) e snap
-
-Os limiares de detecção de furo/aresta e raio de snap são em metros world. Multiplicar pelo `scaleRatio.factor` para que continuem capturando os mesmos elementos físicos da peça.
-
-### 5. ModelViewer
-
-No `<group>` do modelo, multiplicar o scale final:
-```
-finalScale = fineTuning.scale * scaleRatio.factor
-```
-
-### 6. UI — novo componente `ScaleSelector`
-
-Botão com ícone de régua + label atual ("1:1", "1:50"…). Ao clicar abre um Popover/Sheet com grid:
+## Arquitetura técnica
 
 ```text
-Reduzir                          Ampliar
-[1:1*] [1:2] [1:4] [1:8]         [2:1]
-[1:10] [1:20] [1:33] [1:50]      [4:1]
-[1:100] [1:200]                  [10:1]
+   Quest 3 (broadcaster)              Lovable Cloud                 Viewers (celular/PC)
+   ┌──────────────────┐         ┌─────────────────────┐         ┌──────────────────┐
+   │ /xr              │         │ Supabase Realtime   │         │ /watch/AB12CD    │
+   │ - canvas WebXR   │ ──SDP──▶│ (signaling channel) │◀──SDP── │ - <video> tag    │
+   │ - getDisplayMedia│         │ rooms table         │         │ - peer connection│
+   │ - RTCPeerConn x3 │◀════════ ICE candidates ═════════════▶  │                  │
+   └──────────────────┘         │ viewers count       │         └──────────────────┘
+            ║                   └─────────────────────┘                    ▲
+            ╚════════ WebRTC P2P media stream (vídeo H264) ════════════════╝
 ```
 
-Toast ao trocar: *"Escala 1:50 — medições e controles ajustados para mm reais"*.
+**Stack:**
+- **Lovable Cloud** (precisa habilitar): tabela `share_rooms` + canal Realtime para signaling
+- **WebRTC nativo do browser** (`RTCPeerConnection`) — sem libs pesadas
+- **Captura no Quest:** `navigator.mediaDevices.getDisplayMedia()` no browser do Quest captura a janela atual (inclui o canvas 3D). Em sessão XR imersiva, alternativa é usar `canvas.captureStream(30)` direto do canvas WebGL — funciona melhor e não precisa de prompt
+- **Sem servidor de mídia (SFU):** P2P 1→3 viewers, banda do Quest aguenta tranquilo (~2 Mbps por viewer)
 
-Inserir o componente em:
-- **`ViewerControls`** (canto dos controles flutuantes do Viewer 2D)
-- **`XRHud`** (linha de ferramentas, próximo ao toggle "Escala ON/OFF" two-hand)
+## Estrutura de arquivos
 
-### 7. MeasurementsList & FineTuningControls
+**Novos:**
+- `src/pages/Watch.tsx` — página pública do viewer (rota `/watch/:code`)
+- `src/components/ShareButton.tsx` — botão + dialog com QR/link no HUD
+- `src/lib/webrtc/broadcaster.ts` — lógica do lado Quest (cria offer, gerencia múltiplos peers)
+- `src/lib/webrtc/viewer.ts` — lógica do lado viewer (recebe offer, monta `<video>`)
+- `src/lib/webrtc/signaling.ts` — wrapper sobre Supabase Realtime para troca SDP/ICE
 
-Adicionar pequeno badge "Escala atual: 1:50" no topo dos painéis de Medições e Ajuste Fino para o usuário lembrar que os valores exibidos são mm reais.
+**Editados:**
+- `src/App.tsx` — adicionar rota `/watch/:code` (pública, fora do layout XR)
+- `src/components/XRHud.tsx` — adicionar `<ShareButton />` na toolbar
+- `src/pages/XRSession.tsx` — botão também visível fora do HUD
+- `src/stores/useModelStore.ts` — estado `shareRoom: { code, viewerCount, isLive }`
 
-## O que NÃO muda
+## Schema do banco (Lovable Cloud)
 
-- Gesto two-hand de escala (`allowScale`) continua funcionando para ajuste livre — mas se o usuário usar o preset, o gesto reseta para 1.0 e o preset assume.
-- Relatório PDF: registra a escala atual no cabeçalho.
-- Grid e checklist: sem alteração.
+```sql
+create table public.share_rooms (
+  code text primary key,           -- 6 chars, ex: 'AB12CD'
+  created_at timestamptz default now(),
+  expires_at timestamptz default now() + interval '4 hours',
+  is_active boolean default true,
+  viewer_count int default 0
+);
 
-## Arquivos tocados
+-- RLS: leitura pública (viewers precisam saber se sala existe), escrita só anon controlada
+alter table public.share_rooms enable row level security;
+create policy "anyone reads active rooms" on public.share_rooms
+  for select using (is_active and expires_at > now());
+create policy "anyone creates room" on public.share_rooms
+  for insert with check (true);
+create policy "anyone updates count" on public.share_rooms
+  for update using (true);
+```
 
-- `src/stores/useModelStore.ts` — novo estado + ajuste em `addMeasurePoint`
-- `src/components/ScaleSelector.tsx` — novo (popover com presets)
-- `src/components/ViewerControls.tsx` — incluir `<ScaleSelector />`
-- `src/components/XRHud.tsx` — incluir `<ScaleSelector />` + multiplicar passos do joystick
-- `src/components/FineTuningControls.tsx` — multiplicar passos pela escala + badge
-- `src/components/MeasurementsList.tsx` — badge da escala
-- `src/components/three/ModelViewer.tsx` — aplicar `scaleRatio.factor` no group + ajustar threshold de snap/hover
-- `src/lib/generateReport.ts` — incluir escala no cabeçalho do PDF
+Signaling propriamente dito (SDP offers/answers, ICE candidates) acontece via **Supabase Realtime broadcast channel** `room:${code}` — não persiste em tabela, é efêmero.
 
-## Validação
+## STUN/TURN
 
-- Carregar viga demo, medir uma aresta conhecida em 1:1 → trocar para 1:10 → remedir mesma aresta → valor em mm deve permanecer igual.
-- Em 1:50, clicar "+" no ajuste fino X uma vez → modelo desloca visualmente pouquíssimo (esperado), mas valor exibido sobe 1 mm.
-- No XR, joystick em 1:100 não "voa" o modelo a metros de distância.
+- **STUN público do Google** (`stun:stun.l.google.com:19302`) — grátis, resolve ~80% dos casos (NAT comum)
+- **TURN:** se inspetor estiver atrás de NAT simétrico (raro em fábrica), conexão falha. Para v1 deixamos só STUN. Se precisar TURN depois, integramos Twilio TURN (~$0,40/GB) ou Metered.ca (free tier 50GB/mês)
+
+## Captura no Quest — detalhes importantes
+
+Tem dois cenários:
+1. **Fora da sessão XR** (modo viewer 2D): `canvas.captureStream(30)` — fácil, funciona já
+2. **Dentro da sessão XR imersiva** (passthrough AR): aqui o canvas é renderizado para o display do headset, não para a tela visível. Solução: usar `XRWebGLLayer.framebuffer` e renderizar uma view extra "spectator" para um canvas offscreen que vira o stream. **Esta parte tem risco** — pode precisar fallback para `getDisplayMedia()` que pede permissão do usuário no Quest
+
+Plano: começar com cenário 1 (já cobre uso fora do AR imersivo), e cenário 2 numa segunda iteração se necessário.
+
+## Limitações honestas
+
+- **Latência:** 200-500ms (não é instantâneo, mas serve para acompanhamento)
+- **Sem áudio do microfone do Quest** na v1 (adicionar depois com `getUserMedia({audio:true})`)
+- **Sala expira em 4h** — geração de novo código se sessão durar mais
+- **Link público:** qualquer um com a URL vê. Se vazar, código pode ser revogado pelo inspetor
+- **Não grava** — só transmissão ao vivo. Gravação seria feature separada
+
+## Pré-requisito
+
+Precisa **habilitar Lovable Cloud** (atualmente o projeto não tem). Vou pedir confirmação antes de habilitar, pois cria infraestrutura backend.
+
+## Escopo desta implementação
+
+✅ Botão "Compartilhar" no HUD do XR + tela inicial
+✅ Geração de código + QR + link curto + Web Share API
+✅ Página `/watch/:code` pública com vídeo
+✅ Signaling via Supabase Realtime
+✅ WebRTC P2P 1→3 viewers
+✅ Contador de viewers em tempo real para o broadcaster
+✅ Captura via `canvas.captureStream` (cenário fora do XR imersivo)
+❌ Captura dentro da sessão XR imersiva (segunda iteração)
+❌ Áudio do mic (segunda iteração)
+❌ Chat / interação (você optou por read-only)
+❌ TURN server (só se aparecer problema de NAT)
+❌ Gravação
+
+Aprovando o plano, eu habilito o Lovable Cloud e implemento.
diff --git a/bun.lockb b/bun.lockb
index 914dae2..7907ee2 100755
Binary files a/bun.lockb and b/bun.lockb differ
diff --git a/package.json b/package.json
index e16bdb1..550048d 100644
--- a/package.json
+++ b/package.json
@@ -44,6 +44,7 @@
     "@react-three/drei": "^9.122.0",
     "@react-three/fiber": "^8.18.0",
     "@react-three/xr": "^6.6.29",
+    "@supabase/supabase-js": "^2.105.4",
     "@tanstack/react-query": "^5.83.0",
     "@types/three": "^0.160.0",
     "class-variance-authority": "^0.7.1",
@@ -55,6 +56,7 @@
     "jspdf": "^4.2.0",
     "lucide-react": "^0.462.0",
     "next-themes": "^0.3.0",
+    "qrcode.react": "^4.2.0",
     "react": "^18.3.1",
     "react-day-picker": "^8.10.1",
     "react-dom": "^18.3.1",
diff --git a/src/App.tsx b/src/App.tsx
index 00a16eb..7b72dc8 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -6,6 +6,7 @@ import { BrowserRouter, Routes, Route } from "react-router-dom";
 import Index from "./pages/Index";
 import Viewer from "./pages/Viewer";
 import XRSession from "./pages/XRSession";
+import Watch from "./pages/Watch";
 import NotFound from "./pages/NotFound";
 
 const queryClient = new QueryClient();
@@ -20,6 +21,7 @@ const App = () => (
           <Route path="/" element={<Index />} />
           <Route path="/viewer" element={<Viewer />} />
           <Route path="/xr" element={<XRSession />} />
+          <Route path="/watch/:code" element={<Watch />} />
           <Route path="*" element={<NotFound />} />
         </Routes>
       </BrowserRouter>
diff --git a/src/components/ShareButton.tsx b/src/components/ShareButton.tsx
new file mode 100644
index 0000000..1e13caa
--- /dev/null
+++ b/src/components/ShareButton.tsx
@@ -0,0 +1,196 @@
+import { useEffect, useRef, useState } from 'react';
+import { Share2, Copy, Users, X, Loader2 } from 'lucide-react';
+import { QRCodeSVG } from 'qrcode.react';
+import { Button } from '@/components/ui/button';
+import { Dialog, DialogContent, DialogHeader, DialogTitle } from '@/components/ui/dialog';
+import { startBroadcast, type BroadcasterHandle } from '@/lib/webrtc/broadcaster';
+import { toast } from 'sonner';
+
+interface ShareButtonProps {
+  variant?: 'default' | 'compact';
+}
+
+export function ShareButton({ variant = 'default' }: ShareButtonProps) {
+  const [open, setOpen] = useState(false);
+  const [starting, setStarting] = useState(false);
+  const [handle, setHandle] = useState<BroadcasterHandle | null>(null);
+  const [viewerCount, setViewerCount] = useState(0);
+  const streamRef = useRef<MediaStream | null>(null);
+
+  const link = handle ? `${window.location.origin}/watch/${handle.code}` : '';
+
+  const start = async () => {
+    setStarting(true);
+    try {
+      // Try canvas.captureStream first (works inside the page, no permission prompt)
+      const canvas = document.querySelector('canvas') as HTMLCanvasElement | null;
+      let stream: MediaStream | null = null;
+
+      if (canvas && typeof canvas.captureStream === 'function') {
+        stream = canvas.captureStream(30);
+      }
+
+      // Fallback: getDisplayMedia (asks user permission, captures the browser tab)
+      if (!stream || stream.getVideoTracks().length === 0) {
+        stream = await navigator.mediaDevices.getDisplayMedia({
+          video: { frameRate: 30 },
+          audio: false,
+        });
+      }
+
+      streamRef.current = stream;
+      const h = await startBroadcast(stream);
+      setHandle(h);
+      h.onViewerCountChange(setViewerCount);
+      toast.success(`Sala criada: ${h.code}`);
+    } catch (e) {
+      const msg = e instanceof Error ? e.message : String(e);
+      toast.error(`Falha ao iniciar transmissão: ${msg}`);
+    } finally {
+      setStarting(false);
+    }
+  };
+
+  const stop = async () => {
+    if (handle) await handle.stop();
+    if (streamRef.current) streamRef.current.getTracks().forEach((t) => t.stop());
+    streamRef.current = null;
+    setHandle(null);
+    setViewerCount(0);
+    toast.info('Transmissão encerrada');
+  };
+
+  // Cleanup on unmount
+  useEffect(() => {
+    return () => {
+      if (handle) handle.stop();
+      if (streamRef.current) streamRef.current.getTracks().forEach((t) => t.stop());
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  const copyLink = async () => {
+    await navigator.clipboard.writeText(link);
+    toast.success('Link copiado');
+  };
+
+  const shareLink = async () => {
+    if (navigator.share) {
+      try {
+        await navigator.share({
+          title: 'TrackSteelXR — Sessão ao vivo',
+          text: 'Acompanhe a inspeção ao vivo:',
+          url: link,
+        });
+      } catch {/* user cancelled */}
+    } else {
+      copyLink();
+    }
+  };
+
+  const isCompact = variant === 'compact';
+
+  return (
+    <>
+      <Button
+        variant={handle ? 'default' : 'outline'}
+        size={isCompact ? 'sm' : 'sm'}
+        className={isCompact ? 'h-8 gap-1.5 text-[10px] font-mono' : 'gap-2'}
+        onClick={() => setOpen(true)}
+        title="Compartilhar tela ao vivo"
+      >
+        <Share2 className={isCompact ? 'h-3.5 w-3.5' : 'h-4 w-4'} />
+        {handle ? (
+          <>
+            <span className="relative flex h-2 w-2">
+              <span className="animate-ping absolute inline-flex h-full w-full rounded-full bg-red-500 opacity-75" />
+              <span className="relative inline-flex rounded-full h-2 w-2 bg-red-500" />
+            </span>
+            LIVE {viewerCount > 0 && `· ${viewerCount}`}
+          </>
+        ) : (
+          'Compartilhar'
+        )}
+      </Button>
+
+      <Dialog open={open} onOpenChange={setOpen}>
+        <DialogContent className="max-w-md">
+          <DialogHeader>
+            <DialogTitle className="flex items-center gap-2 font-mono text-sm">
+              <Share2 className="h-4 w-4 text-primary" />
+              Compartilhar tela ao vivo
+            </DialogTitle>
+          </DialogHeader>
+
+          {!handle ? (
+            <div className="space-y-4">
+              <p className="text-xs text-muted-foreground leading-relaxed">
+                Gere um link público para que até 5 pessoas acompanhem sua sessão ao vivo
+                pelo celular ou PC. Não precisa de login. A sala expira em 4h.
+              </p>
+              <Button onClick={start} disabled={starting} className="w-full gap-2">
+                {starting ? (
+                  <><Loader2 className="h-4 w-4 animate-spin" /> Iniciando…</>
+                ) : (
+                  <><Share2 className="h-4 w-4" /> Gerar link de acesso</>
+                )}
+              </Button>
+            </div>
+          ) : (
+            <div className="space-y-4">
+              <div className="flex justify-center">
+                <div className="rounded-lg bg-white p-3">
+                  <QRCodeSVG value={link} size={160} level="M" />
+                </div>
+              </div>
+
+              <div className="rounded-lg border bg-muted/30 p-3 space-y-2">
+                <div className="flex items-center justify-between">
+                  <span className="font-mono text-[10px] text-muted-foreground">CÓDIGO</span>
+                  <span className="font-mono text-lg font-bold tracking-widest text-primary">
+                    {handle.code}
+                  </span>
+                </div>
+                <div className="flex items-center gap-2 rounded bg-background px-2 py-1.5 border">
+                  <input
+                    readOnly
+                    value={link}
+                    className="flex-1 bg-transparent text-[10px] font-mono outline-none"
+                  />
+                  <Button size="icon" variant="ghost" className="h-6 w-6" onClick={copyLink}>
+                    <Copy className="h-3 w-3" />
+                  </Button>
+                </div>
+              </div>
+
+              <div className="flex items-center justify-between rounded-lg border bg-muted/30 px-3 py-2">
+                <div className="flex items-center gap-2 text-xs">
+                  <Users className="h-3.5 w-3.5 text-primary" />
+                  <span className="font-mono text-[11px]">
+                    {viewerCount} {viewerCount === 1 ? 'espectador' : 'espectadores'}
+                  </span>
+                </div>
+                <div className="flex items-center gap-1.5">
+                  <span className="relative flex h-2 w-2">
+                    <span className="animate-ping absolute inline-flex h-full w-full rounded-full bg-red-500 opacity-75" />
+                    <span className="relative inline-flex rounded-full h-2 w-2 bg-red-500" />
+                  </span>
+                  <span className="font-mono text-[10px] text-red-500">LIVE</span>
+                </div>
+              </div>
+
+              <div className="grid grid-cols-2 gap-2">
+                <Button onClick={shareLink} className="gap-2">
+                  <Share2 className="h-4 w-4" /> Enviar
+                </Button>
+                <Button onClick={stop} variant="destructive" className="gap-2">
+                  <X className="h-4 w-4" /> Encerrar
+                </Button>
+              </div>
+            </div>
+          )}
+        </DialogContent>
+      </Dialog>
+    </>
+  );
+}
diff --git a/src/components/XRHud.tsx b/src/components/XRHud.tsx
index e7c9866..30d04a2 100644
--- a/src/components/XRHud.tsx
+++ b/src/components/XRHud.tsx
@@ -11,6 +11,7 @@ import { useModelStore } from '@/stores/useModelStore';
 import { InspectionChecklist } from '@/components/InspectionChecklist';
 import { ScaleSelector } from '@/components/ScaleSelector';
 import { CloudLoader } from '@/components/CloudLoader';
+import { ShareButton } from '@/components/ShareButton';
 import { toast } from 'sonner';
 
 const POSITION_STEP = 0.001;
@@ -318,6 +319,9 @@ export function XRHud({ freeMove, onToggleFreeMove, placementMode = false, onTog
               {/* Cloud loader (acessível também no AR) */}
               <CloudLoader compact />
 
+              {/* Share live screen */}
+              <ShareButton variant="compact" />
+
               <Button
                 variant={freeMove ? 'default' : 'outline'}
                 size="sm" className="h-8 gap-1.5 text-[10px] font-mono"
diff --git a/src/integrations/supabase/client.ts b/src/integrations/supabase/client.ts
new file mode 100644
index 0000000..1619b47
--- /dev/null
+++ b/src/integrations/supabase/client.ts
@@ -0,0 +1,17 @@
+// This file is automatically generated. Do not edit it directly.
+import { createClient } from '@supabase/supabase-js';
+import type { Database } from './types';
+
+const SUPABASE_URL = import.meta.env.VITE_SUPABASE_URL;
+const SUPABASE_PUBLISHABLE_KEY = import.meta.env.VITE_SUPABASE_PUBLISHABLE_KEY;
+
+// Import the supabase client like this:
+// import { supabase } from "@/integrations/supabase/client";
+
+export const supabase = createClient<Database>(SUPABASE_URL, SUPABASE_PUBLISHABLE_KEY, {
+  auth: {
+    storage: localStorage,
+    persistSession: true,
+    autoRefreshToken: true,
+  }
+});
\ No newline at end of file
diff --git a/src/integrations/supabase/types.ts b/src/integrations/supabase/types.ts
new file mode 100644
index 0000000..3d77ad6
--- /dev/null
+++ b/src/integrations/supabase/types.ts
@@ -0,0 +1,178 @@
+export type Json =
+  | string
+  | number
+  | boolean
+  | null
+  | { [key: string]: Json | undefined }
+  | Json[]
+
+export type Database = {
+  // Allows to automatically instantiate createClient with right options
+  // instead of createClient<Database, { PostgrestVersion: 'XX' }>(URL, KEY)
+  __InternalSupabase: {
+    PostgrestVersion: "14.5"
+  }
+  public: {
+    Tables: {
+      share_rooms: {
+        Row: {
+          code: string
+          created_at: string
+          expires_at: string
+          is_active: boolean
+          viewer_count: number
+        }
+        Insert: {
+          code: string
+          created_at?: string
+          expires_at?: string
+          is_active?: boolean
+          viewer_count?: number
+        }
+        Update: {
+          code?: string
+          created_at?: string
+          expires_at?: string
+          is_active?: boolean
+          viewer_count?: number
+        }
+        Relationships: []
+      }
+    }
+    Views: {
+      [_ in never]: never
+    }
+    Functions: {
+      [_ in never]: never
+    }
+    Enums: {
+      [_ in never]: never
+    }
+    CompositeTypes: {
+      [_ in never]: never
+    }
+  }
+}
+
+type DatabaseWithoutInternals = Omit<Database, "__InternalSupabase">
+
+type DefaultSchema = DatabaseWithoutInternals[Extract<keyof Database, "public">]
+
+export type Tables<
+  DefaultSchemaTableNameOrOptions extends
+    | keyof (DefaultSchema["Tables"] & DefaultSchema["Views"])
+    | { schema: keyof DatabaseWithoutInternals },
+  TableName extends DefaultSchemaTableNameOrOptions extends {
+    schema: keyof DatabaseWithoutInternals
+  }
+    ? keyof (DatabaseWithoutInternals[DefaultSchemaTableNameOrOptions["schema"]]["Tables"] &
+        DatabaseWithoutInternals[DefaultSchemaTableNameOrOptions["schema"]]["Views"])
+    : never = never,
+> = DefaultSchemaTableNameOrOptions extends {
+  schema: keyof DatabaseWithoutInternals
+}
+  ? (DatabaseWithoutInternals[DefaultSchemaTableNameOrOptions["schema"]]["Tables"] &
+      DatabaseWithoutInternals[DefaultSchemaTableNameOrOptions["schema"]]["Views"])[TableName] extends {
+      Row: infer R
+    }
+    ? R
+    : never
+  : DefaultSchemaTableNameOrOptions extends keyof (DefaultSchema["Tables"] &
+        DefaultSchema["Views"])
+    ? (DefaultSchema["Tables"] &
+        DefaultSchema["Views"])[DefaultSchemaTableNameOrOptions] extends {
+        Row: infer R
+      }
+      ? R
+      : never
+    : never
+
+export type TablesInsert<
+  DefaultSchemaTableNameOrOptions extends
+    | keyof DefaultSchema["Tables"]
+    | { schema: keyof DatabaseWithoutInternals },
+  TableName extends DefaultSchemaTableNameOrOptions extends {
+    schema: keyof DatabaseWithoutInternals
+  }
+    ? keyof DatabaseWithoutInternals[DefaultSchemaTableNameOrOptions["schema"]]["Tables"]
+    : never = never,
+> = DefaultSchemaTableNameOrOptions extends {
+  schema: keyof DatabaseWithoutInternals
+}
+  ? DatabaseWithoutInternals[DefaultSchemaTableNameOrOptions["schema"]]["Tables"][TableName] extends {
+      Insert: infer I
+    }
+    ? I
+    : never
+  : DefaultSchemaTableNameOrOptions extends keyof DefaultSchema["Tables"]
+    ? DefaultSchema["Tables"][DefaultSchemaTableNameOrOptions] extends {
+        Insert: infer I
+      }
+      ? I
+      : never
+    : never
+
+export type TablesUpdate<
+  DefaultSchemaTableNameOrOptions extends
+    | keyof DefaultSchema["Tables"]
+    | { schema: keyof DatabaseWithoutInternals },
+  TableName extends DefaultSchemaTableNameOrOptions extends {
+    schema: keyof DatabaseWithoutInternals
+  }
+    ? keyof DatabaseWithoutInternals[DefaultSchemaTableNameOrOptions["schema"]]["Tables"]
+    : never = never,
+> = DefaultSchemaTableNameOrOptions extends {
+  schema: keyof DatabaseWithoutInternals
+}
+  ? DatabaseWithoutInternals[DefaultSchemaTableNameOrOptions["schema"]]["Tables"][TableName] extends {
+      Update: infer U
+    }
+    ? U
+    : never
+  : DefaultSchemaTableNameOrOptions extends keyof DefaultSchema["Tables"]
+    ? DefaultSchema["Tables"][DefaultSchemaTableNameOrOptions] extends {
+        Update: infer U
+      }
+      ? U
+      : never
+    : never
+
+export type Enums<
+  DefaultSchemaEnumNameOrOptions extends
+    | keyof DefaultSchema["Enums"]
+    | { schema: keyof DatabaseWithoutInternals },
+  EnumName extends DefaultSchemaEnumNameOrOptions extends {
+    schema: keyof DatabaseWithoutInternals
+  }
+    ? keyof DatabaseWithoutInternals[DefaultSchemaEnumNameOrOptions["schema"]]["Enums"]
+    : never = never,
+> = DefaultSchemaEnumNameOrOptions extends {
+  schema: keyof DatabaseWithoutInternals
+}
+  ? DatabaseWithoutInternals[DefaultSchemaEnumNameOrOptions["schema"]]["Enums"][EnumName]
+  : DefaultSchemaEnumNameOrOptions extends keyof DefaultSchema["Enums"]
+    ? DefaultSchema["Enums"][DefaultSchemaEnumNameOrOptions]
+    : never
+
+export type CompositeTypes<
+  PublicCompositeTypeNameOrOptions extends
+    | keyof DefaultSchema["CompositeTypes"]
+    | { schema: keyof DatabaseWithoutInternals },
+  CompositeTypeName extends PublicCompositeTypeNameOrOptions extends {
+    schema: keyof DatabaseWithoutInternals
+  }
+    ? keyof DatabaseWithoutInternals[PublicCompositeTypeNameOrOptions["schema"]]["CompositeTypes"]
+    : never = never,
+> = PublicCompositeTypeNameOrOptions extends {
+  schema: keyof DatabaseWithoutInternals
+}
+  ? DatabaseWithoutInternals[PublicCompositeTypeNameOrOptions["schema"]]["CompositeTypes"][CompositeTypeName]
+  : PublicCompositeTypeNameOrOptions extends keyof DefaultSchema["CompositeTypes"]
+    ? DefaultSchema["CompositeTypes"][PublicCompositeTypeNameOrOptions]
+    : never
+
+export const Constants = {
+  public: {
+    Enums: {},
+  },
+} as const
diff --git a/src/lib/webrtc/broadcaster.ts b/src/lib/webrtc/broadcaster.ts
new file mode 100644
index 0000000..fa4b7f6
--- /dev/null
+++ b/src/lib/webrtc/broadcaster.ts
@@ -0,0 +1,127 @@
+import { supabase } from '@/integrations/supabase/client';
+import {
+  generateRoomCode,
+  joinSignalingChannel,
+  sendSignal,
+  ICE_SERVERS,
+  type SignalMessage,
+} from './signaling';
+import type { RealtimeChannel } from '@supabase/supabase-js';
+
+export interface BroadcasterHandle {
+  code: string;
+  stop: () => Promise<void>;
+  onViewerCountChange: (cb: (n: number) => void) => () => void;
+}
+
+const MAX_VIEWERS = 5;
+
+/**
+ * Starts broadcasting a MediaStream under a fresh room code.
+ * Returns a handle exposing the code and a stop() to teardown.
+ */
+export async function startBroadcast(stream: MediaStream): Promise<BroadcasterHandle> {
+  const code = generateRoomCode();
+
+  // Insert room
+  const { error: insErr } = await supabase.from('share_rooms').insert({ code, is_active: true });
+  if (insErr) throw new Error(`Falha ao criar sala: ${insErr.message}`);
+
+  const peers = new Map<string, RTCPeerConnection>();
+  const listeners = new Set<(n: number) => void>();
+  const notify = () => listeners.forEach((cb) => cb(peers.size));
+
+  let channel: RealtimeChannel | null = null;
+
+  const handleMessage = async (msg: SignalMessage) => {
+    if (msg.type === 'viewer-join') {
+      if (peers.size >= MAX_VIEWERS) return;
+      const pc = new RTCPeerConnection({ iceServers: ICE_SERVERS });
+      peers.set(msg.viewerId, pc);
+
+      stream.getTracks().forEach((t) => pc.addTrack(t, stream));
+
+      pc.onicecandidate = (ev) => {
+        if (ev.candidate && channel) {
+          sendSignal(channel, {
+            type: 'ice',
+            viewerId: msg.viewerId,
+            from: 'broadcaster',
+            candidate: ev.candidate.toJSON(),
+          });
+        }
+      };
+
+      pc.onconnectionstatechange = () => {
+        if (['failed', 'closed', 'disconnected'].includes(pc.connectionState)) {
+          peers.delete(msg.viewerId);
+          pc.close();
+          notify();
+          updateViewerCount(code, peers.size);
+        }
+      };
+
+      const offer = await pc.createOffer();
+      await pc.setLocalDescription(offer);
+      if (channel) {
+        sendSignal(channel, { type: 'offer', viewerId: msg.viewerId, sdp: offer });
+      }
+      notify();
+      updateViewerCount(code, peers.size);
+    } else if (msg.type === 'answer') {
+      const pc = peers.get(msg.viewerId);
+      if (pc && pc.signalingState !== 'stable') {
+        await pc.setRemoteDescription(msg.sdp);
+      }
+    } else if (msg.type === 'ice' && msg.from === 'viewer') {
+      const pc = peers.get(msg.viewerId);
+      if (pc) {
+        try {
+          await pc.addIceCandidate(msg.candidate);
+        } catch (e) {
+          console.warn('[broadcaster] addIceCandidate failed', e);
+        }
+      }
+    } else if (msg.type === 'viewer-leave') {
+      const pc = peers.get(msg.viewerId);
+      if (pc) {
+        pc.close();
+        peers.delete(msg.viewerId);
+        notify();
+        updateViewerCount(code, peers.size);
+      }
+    }
+  };
+
+  channel = joinSignalingChannel(code, handleMessage);
+
+  // Stop when the underlying stream ends
+  stream.getTracks().forEach((t) => {
+    t.addEventListener('ended', () => stop());
+  });
+
+  let stopped = false;
+  const stop = async () => {
+    if (stopped) return;
+    stopped = true;
+    peers.forEach((pc) => pc.close());
+    peers.clear();
+    notify();
+    if (channel) await supabase.removeChannel(channel);
+    await supabase.from('share_rooms').update({ is_active: false, viewer_count: 0 }).eq('code', code);
+  };
+
+  return {
+    code,
+    stop,
+    onViewerCountChange: (cb) => {
+      listeners.add(cb);
+      cb(peers.size);
+      return () => listeners.delete(cb);
+    },
+  };
+}
+
+async function updateViewerCount(code: string, n: number) {
+  await supabase.from('share_rooms').update({ viewer_count: n }).eq('code', code);
+}
diff --git a/src/lib/webrtc/signaling.ts b/src/lib/webrtc/signaling.ts
new file mode 100644
index 0000000..ab48542
--- /dev/null
+++ b/src/lib/webrtc/signaling.ts
@@ -0,0 +1,40 @@
+import { supabase } from '@/integrations/supabase/client';
+import type { RealtimeChannel } from '@supabase/supabase-js';
+
+export type SignalMessage =
+  | { type: 'viewer-join'; viewerId: string }
+  | { type: 'viewer-leave'; viewerId: string }
+  | { type: 'offer'; viewerId: string; sdp: RTCSessionDescriptionInit }
+  | { type: 'answer'; viewerId: string; sdp: RTCSessionDescriptionInit }
+  | { type: 'ice'; viewerId: string; from: 'broadcaster' | 'viewer'; candidate: RTCIceCandidateInit };
+
+export function joinSignalingChannel(
+  code: string,
+  onMessage: (msg: SignalMessage) => void,
+): RealtimeChannel {
+  const channel = supabase.channel(`share:${code}`, {
+    config: { broadcast: { self: false, ack: false } },
+  });
+
+  channel
+    .on('broadcast', { event: 'signal' }, ({ payload }) => onMessage(payload as SignalMessage))
+    .subscribe();
+
+  return channel;
+}
+
+export function sendSignal(channel: RealtimeChannel, msg: SignalMessage) {
+  return channel.send({ type: 'broadcast', event: 'signal', payload: msg });
+}
+
+export function generateRoomCode(): string {
+  const chars = 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789'; // unambiguous
+  let out = '';
+  for (let i = 0; i < 6; i++) out += chars[Math.floor(Math.random() * chars.length)];
+  return out;
+}
+
+export const ICE_SERVERS: RTCIceServer[] = [
+  { urls: 'stun:stun.l.google.com:19302' },
+  { urls: 'stun:stun1.l.google.com:19302' },
+];
diff --git a/src/lib/webrtc/viewer.ts b/src/lib/webrtc/viewer.ts
new file mode 100644
index 0000000..fd0d329
--- /dev/null
+++ b/src/lib/webrtc/viewer.ts
@@ -0,0 +1,89 @@
+import {
+  joinSignalingChannel,
+  sendSignal,
+  ICE_SERVERS,
+  type SignalMessage,
+} from './signaling';
+import type { RealtimeChannel } from '@supabase/supabase-js';
+
+export interface ViewerHandle {
+  stop: () => Promise<void>;
+}
+
+/**
+ * Connects to a broadcaster's room and renders the incoming stream into the given <video>.
+ */
+export async function joinAsViewer(
+  code: string,
+  videoEl: HTMLVideoElement,
+  onState: (s: 'connecting' | 'waiting' | 'live' | 'error', detail?: string) => void,
+): Promise<ViewerHandle> {
+  const viewerId = crypto.randomUUID();
+  let pc: RTCPeerConnection | null = null;
+  let channel: RealtimeChannel | null = null;
+
+  onState('connecting');
+
+  const handleMessage = async (msg: SignalMessage) => {
+    if (msg.type === 'offer' && msg.viewerId === viewerId) {
+      pc = new RTCPeerConnection({ iceServers: ICE_SERVERS });
+
+      pc.ontrack = (ev) => {
+        videoEl.srcObject = ev.streams[0];
+        videoEl.play().catch(() => {/* autoplay may need user gesture */});
+        onState('live');
+      };
+
+      pc.onicecandidate = (ev) => {
+        if (ev.candidate && channel) {
+          sendSignal(channel, {
+            type: 'ice',
+            viewerId,
+            from: 'viewer',
+            candidate: ev.candidate.toJSON(),
+          });
+        }
+      };
+
+      pc.onconnectionstatechange = () => {
+        if (pc && ['failed', 'disconnected'].includes(pc.connectionState)) {
+          onState('error', 'Conexão perdida');
+        }
+      };
+
+      await pc.setRemoteDescription(msg.sdp);
+      const answer = await pc.createAnswer();
+      await pc.setLocalDescription(answer);
+      if (channel) sendSignal(channel, { type: 'answer', viewerId, sdp: answer });
+    } else if (msg.type === 'ice' && msg.viewerId === viewerId && msg.from === 'broadcaster') {
+      if (pc) {
+        try {
+          await pc.addIceCandidate(msg.candidate);
+        } catch (e) {
+          console.warn('[viewer] addIceCandidate failed', e);
+        }
+      }
+    }
+  };
+
+  channel = joinSignalingChannel(code, handleMessage);
+
+  // Wait a tick for subscribe, then announce join
+  setTimeout(() => {
+    if (channel) {
+      sendSignal(channel, { type: 'viewer-join', viewerId });
+      onState('waiting');
+    }
+  }, 600);
+
+  const stop = async () => {
+    if (channel) {
+      try { sendSignal(channel, { type: 'viewer-leave', viewerId }); } catch {}
+      const { supabase } = await import('@/integrations/supabase/client');
+      await supabase.removeChannel(channel);
+    }
+    if (pc) pc.close();
+  };
+
+  return { stop };
+}
diff --git a/src/pages/Viewer.tsx b/src/pages/Viewer.tsx
index 0f3eca9..fed6695 100644
--- a/src/pages/Viewer.tsx
+++ b/src/pages/Viewer.tsx
@@ -8,6 +8,7 @@ import { InspectionChecklist } from "@/components/InspectionChecklist";
 import { FineTuningControls } from "@/components/FineTuningControls";
 import { MeasurementsList } from "@/components/MeasurementsList";
 import { ScreenshotGallery } from "@/components/ScreenshotGallery";
+import { ShareButton } from "@/components/ShareButton";
 import { useEffect } from "react";
 import { toast } from "sonner";
 import { ScrollArea } from "@/components/ui/scroll-area";
@@ -49,10 +50,13 @@ const Viewer = () => {
           </div>
         </div>
 
-        <Button className="gap-2 glow-primary" disabled={!xrSupported} onClick={handleEnterXR}>
-          <Glasses className="h-4 w-4" />
-          Entrar em Modo XR
-        </Button>
+        <div className="flex items-center gap-2">
+          <ShareButton />
+          <Button className="gap-2 glow-primary" disabled={!xrSupported} onClick={handleEnterXR}>
+            <Glasses className="h-4 w-4" />
+            Entrar em Modo XR
+          </Button>
+        </div>
       </header>
 
       <div className="flex flex-1 overflow-hidden">
diff --git a/src/pages/Watch.tsx b/src/pages/Watch.tsx
new file mode 100644
index 0000000..e9897e4
--- /dev/null
+++ b/src/pages/Watch.tsx
@@ -0,0 +1,153 @@
+import { useEffect, useRef, useState } from 'react';
+import { useParams, Link } from 'react-router-dom';
+import { Loader2, Maximize, Minimize, AlertCircle, Eye } from 'lucide-react';
+import { Button } from '@/components/ui/button';
+import { supabase } from '@/integrations/supabase/client';
+import { joinAsViewer, type ViewerHandle } from '@/lib/webrtc/viewer';
+
+type ConnState = 'checking' | 'connecting' | 'waiting' | 'live' | 'error' | 'not-found';
+
+export default function Watch() {
+  const { code = '' } = useParams();
+  const videoRef = useRef<HTMLVideoElement>(null);
+  const handleRef = useRef<ViewerHandle | null>(null);
+  const [state, setState] = useState<ConnState>('checking');
+  const [error, setError] = useState<string>('');
+  const [fullscreen, setFullscreen] = useState(false);
+
+  useEffect(() => {
+    let cancelled = false;
+
+    (async () => {
+      const { data, error: dbErr } = await supabase
+        .from('share_rooms')
+        .select('code, is_active, expires_at')
+        .eq('code', code.toUpperCase())
+        .maybeSingle();
+
+      if (cancelled) return;
+
+      if (dbErr) {
+        setError(dbErr.message);
+        setState('error');
+        return;
+      }
+      if (!data) {
+        setState('not-found');
+        return;
+      }
+
+      if (!videoRef.current) return;
+      try {
+        const handle = await joinAsViewer(code.toUpperCase(), videoRef.current, (s, detail) => {
+          setState(s as ConnState);
+          if (detail) setError(detail);
+        });
+        handleRef.current = handle;
+      } catch (e) {
+        setError(e instanceof Error ? e.message : String(e));
+        setState('error');
+      }
+    })();
+
+    return () => {
+      cancelled = true;
+      if (handleRef.current) handleRef.current.stop();
+    };
+  }, [code]);
+
+  const toggleFullscreen = async () => {
+    const el = videoRef.current;
+    if (!el) return;
+    if (document.fullscreenElement) {
+      await document.exitFullscreen();
+      setFullscreen(false);
+    } else {
+      await el.requestFullscreen();
+      setFullscreen(true);
+    }
+  };
+
+  return (
+    <div className="min-h-screen bg-background flex flex-col">
+      <header className="border-b bg-card/50 backdrop-blur px-4 py-3 flex items-center justify-between">
+        <Link to="/" className="font-mono text-sm font-bold text-foreground">
+          TrackSteel<span className="text-primary">XR</span>
+        </Link>
+        <div className="flex items-center gap-3">
+          <span className="font-mono text-[10px] text-muted-foreground">SALA</span>
+          <span className="font-mono text-sm font-bold tracking-widest text-primary">
+            {code.toUpperCase()}
+          </span>
+          {state === 'live' && (
+            <span className="flex items-center gap-1.5">
+              <span className="relative flex h-2 w-2">
+                <span className="animate-ping absolute inline-flex h-full w-full rounded-full bg-red-500 opacity-75" />
+                <span className="relative inline-flex rounded-full h-2 w-2 bg-red-500" />
+              </span>
+              <span className="font-mono text-[10px] text-red-500">AO VIVO</span>
+            </span>
+          )}
+        </div>
+      </header>
+
+      <div className="flex-1 relative bg-black flex items-center justify-center">
+        <video
+          ref={videoRef}
+          autoPlay
+          playsInline
+          muted
+          className="max-w-full max-h-full object-contain"
+        />
+
+        {(state === 'checking' || state === 'connecting' || state === 'waiting') && (
+          <div className="absolute inset-0 flex flex-col items-center justify-center gap-3 bg-black/80">
+            <Loader2 className="h-8 w-8 animate-spin text-primary" />
+            <p className="font-mono text-xs text-muted-foreground">
+              {state === 'checking' && 'Verificando sala…'}
+              {state === 'connecting' && 'Conectando…'}
+              {state === 'waiting' && 'Aguardando o inspetor iniciar…'}
+            </p>
+          </div>
+        )}
+
+        {state === 'not-found' && (
+          <div className="absolute inset-0 flex flex-col items-center justify-center gap-3 bg-black/90 px-6 text-center">
+            <AlertCircle className="h-10 w-10 text-destructive" />
+            <h2 className="font-mono text-base font-bold">Sala não encontrada</h2>
+            <p className="font-mono text-xs text-muted-foreground max-w-sm">
+              A sala <span className="text-primary">{code.toUpperCase()}</span> não existe,
+              expirou ou foi encerrada pelo inspetor.
+            </p>
+          </div>
+        )}
+
+        {state === 'error' && (
+          <div className="absolute inset-0 flex flex-col items-center justify-center gap-3 bg-black/90 px-6 text-center">
+            <AlertCircle className="h-10 w-10 text-destructive" />
+            <h2 className="font-mono text-base font-bold">Erro de conexão</h2>
+            <p className="font-mono text-xs text-muted-foreground max-w-sm">{error}</p>
+          </div>
+        )}
+
+        {state === 'live' && (
+          <Button
+            onClick={toggleFullscreen}
+            variant="outline"
+            size="icon"
+            className="absolute bottom-4 right-4 h-9 w-9 bg-card/80 backdrop-blur"
+          >
+            {fullscreen ? <Minimize className="h-4 w-4" /> : <Maximize className="h-4 w-4" />}
+          </Button>
+        )}
+      </div>
+
+      <footer className="border-t bg-card/50 backdrop-blur px-4 py-2 flex items-center justify-center gap-2">
+        <Eye className="h-3 w-3 text-muted-foreground" />
+        <span className="font-mono text-[10px] text-muted-foreground">
+          Modo somente visualização · TrackSteelXR
+        </span>
+      </footer>
+    </div>
+  );
+}
diff --git a/supabase/config.toml b/supabase/config.toml
new file mode 100644
index 0000000..10ec1db
--- /dev/null
+++ b/supabase/config.toml
@@ -0,0 +1 @@
+project_id = "mebgazuntzkcnkifftbe"
\ No newline at end of file
diff --git a/supabase/migrations/20260514124951_23703083-0333-44bc-bb04-a2eef2d65bb8.sql b/supabase/migrations/20260514124951_23703083-0333-44bc-bb04-a2eef2d65bb8.sql
new file mode 100644
index 0000000..c671f59
--- /dev/null
+++ b/supabase/migrations/20260514124951_23703083-0333-44bc-bb04-a2eef2d65bb8.sql
@@ -0,0 +1,21 @@
+create table public.share_rooms (
+  code text primary key,
+  created_at timestamptz not null default now(),
+  expires_at timestamptz not null default (now() + interval '4 hours'),
+  is_active boolean not null default true,
+  viewer_count int not null default 0
+);
+
+alter table public.share_rooms enable row level security;
+
+create policy "anyone can read active rooms"
+  on public.share_rooms for select
+  using (is_active = true and expires_at > now());
+
+create policy "anyone can create rooms"
+  on public.share_rooms for insert
+  with check (true);
+
+create policy "anyone can update rooms"
+  on public.share_rooms for update
+  using (true);
\ No newline at end of file