diff --git a/.github/workflows/deploy-dev.yml b/.github/workflows/deploy-dev.yml
index 0b766bff3..c4730e8c3 100644
--- a/.github/workflows/deploy-dev.yml
+++ b/.github/workflows/deploy-dev.yml
@@ -15,10 +15,16 @@ on:
         description: 'Image tag override (defaults to short SHA of HEAD)'
         required: false
         default: ''
+      allow_without_staging_smoke:
+        description: 'EMERGENCY: deploy prod even without a green staging-smoke on this SHA'
+        type: boolean
+        required: false
+        default: false
 
 permissions:
   id-token: write     # required to mint the OIDC token for google-github-actions/auth
   contents: read
+  statuses: read      # read the staging-smoke commit status for the prod-promote gate
 
 concurrency:
   group: deploy-dev
@@ -33,8 +39,39 @@ env:
   NAMESPACE: commonly-dev
 
 jobs:
+  # Prod-promote gate (Sam, 2026-10-23): no prod deploy without a green `staging-smoke`
+  # commit status on this exact SHA. Deploy Staging runs the Tier-1 UI smoke and posts that
+  # status; this job reads it and blocks the deploy if it is not success. The
+  # allow_without_staging_smoke input is the explicit emergency override.
+  require_staging_smoke:
+    name: Require green staging-smoke on this SHA
+    runs-on: ubuntu-latest
+    steps:
+      - name: Gate on the staging-smoke commit status
+        env:
+          GH_TOKEN: ${{ github.token }}
+          SHA: ${{ github.sha }}
+          REPO: ${{ github.repository }}
+          ALLOW: ${{ inputs.allow_without_staging_smoke }}
+        run: |
+          set -uo pipefail
+          if [ "$ALLOW" = "true" ]; then
+            echo "::warning title=staging-smoke gate::bypassed via allow_without_staging_smoke=true"
+            exit 0
+          fi
+          # Latest staging-smoke by created_at, tiebreak id; if a failure and a success share the
+          # newest created_at (same-second race) prefer failure, so the gate fails closed.
+          STATE=$(gh api "repos/$REPO/commits/$SHA/statuses" \
+            --jq '[.[]|select(.context=="staging-smoke")] | if length==0 then "" else ((max_by(.created_at).created_at) as $m | [.[]|select(.created_at==$m)] | (if any(.[]; .state=="failure") then "failure" else (sort_by(.id)|last|.state) end)) end' 2>/dev/null || echo "")
+          echo "staging-smoke on $SHA = ${STATE:-<none>}"
+          if [ "$STATE" != "success" ]; then
+            echo "::error title=staging-smoke gate::no green staging-smoke on $SHA (got: ${STATE:-none}). Deploy Staging on this SHA first (it runs the Tier-1 smoke and posts the status), or re-dispatch with allow_without_staging_smoke=true for an emergency."
+            exit 1
+          fi
+
   deploy:
     name: Build + push + helm upgrade
+    needs: require_staging_smoke
     runs-on: ubuntu-latest
     environment: dev
     timeout-minutes: 30
diff --git a/.github/workflows/deploy-staging.yml b/.github/workflows/deploy-staging.yml
index be270ccb2..719ccdd13 100644
--- a/.github/workflows/deploy-staging.yml
+++ b/.github/workflows/deploy-staging.yml
@@ -187,6 +187,34 @@ jobs:
           done
           if [ -n "$FAILED" ]; then echo "Deploy failed for:$FAILED"; exit 1; fi
 
+      - name: Set up Node for the Tier-1 smoke
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      # Tier-1 UI smoke (Playwright): health/ready, seeded non-admin login, /v2 home + a pod +
+      # /v2/connectors + Bring-your-own render with no console errors, left rail no horizontal
+      # scroll at 1440 & 390px. It FAILS THE JOB on red, so the staging-smoke commit status step
+      # below (which requires JOB_STATUS=success) posts failure and the prod promote path is
+      # blocked. Richer than the stranger reachability probe; it caught the FRONTEND_URL/CORS
+      # regression on 2026-10-23. Skips the hosted-agent check until staging has an LLM key.
+      - name: Tier-1 UI smoke (Playwright)
+        env:
+          SMOKE_BASE: https://staging.commonly.me
+          SMOKE_API: https://api-staging.commonly.me
+          SMOKE_EMAIL: ${{ secrets.STAGING_SMOKE_EMAIL }}
+          SMOKE_PW: ${{ secrets.STAGING_SMOKE_PW }}
+        run: |
+          set -euo pipefail
+          if [ -z "${SMOKE_EMAIL:-}" ] || [ -z "${SMOKE_PW:-}" ]; then
+            echo "::error title=Tier-1 smoke::STAGING_SMOKE_EMAIL / STAGING_SMOKE_PW repo secrets are not set"
+            exit 1
+          fi
+          cd scripts/staging-smoke
+          npm install --no-audit --no-fund --silent
+          npx playwright install --with-deps chromium
+          node staging-smoke.mjs
+
       # The stranger-path smoke drives signup -> welcome -> question -> connect
       # card against api-staging.commonly.me. Its pass/fail IS the staging-smoke
       # gate the prod promote path reads, so — unlike the dev journey, which is a
diff --git a/scripts/staging-smoke/README.md b/scripts/staging-smoke/README.md
new file mode 100644
index 000000000..076c2763c
--- /dev/null
+++ b/scripts/staging-smoke/README.md
@@ -0,0 +1,22 @@
+# Tier-1 staging smoke
+
+Fast (~1–2 min) post-deploy smoke that **gates prod promotion**: `deploy-staging.yml` runs it
+after the staging rollout, and its pass/fail feeds the `staging-smoke` commit status that
+`deploy-dev.yml` (prod) requires on the same SHA.
+
+Checks: `/api/health/ready` 200 · seeded non-admin login · `/v2` home + a pod + `/v2/connectors`
++ Bring-your-own render with no console errors · left rail no horizontal scroll at 1440 & 390px.
+The hosted-agent-answers check is skipped until staging has an LLM key (`SMOKE_HOSTED=1` to enable).
+
+## Run locally
+```
+cd scripts/staging-smoke && npm i && npx playwright install chromium
+SMOKE_EMAIL=... SMOKE_PW=... npm run smoke
+```
+
+## Env
+- `SMOKE_BASE` (default https://staging.commonly.me), `SMOKE_API` (default https://api-staging.commonly.me)
+- `SMOKE_EMAIL` / `SMOKE_PW` — a **non-admin** staging test user (in CI: secrets `STAGING_SMOKE_EMAIL` / `STAGING_SMOKE_PW`; locally a 0600 file, never printed)
+- `SMOKE_HOSTED=1` — also check a hosted-agent reply (needs a staging LLM key)
+
+Exit 0 = all green; non-zero = a blocking check failed → prod promotion must not proceed.
diff --git a/scripts/staging-smoke/package.json b/scripts/staging-smoke/package.json
new file mode 100644
index 000000000..69a5fb508
--- /dev/null
+++ b/scripts/staging-smoke/package.json
@@ -0,0 +1,8 @@
+{
+  "name": "commonly-staging-smoke",
+  "private": true,
+  "type": "module",
+  "description": "Tier-1 staging smoke — gates prod promotion (see .github/workflows/deploy-staging.yml).",
+  "scripts": { "smoke": "node staging-smoke.mjs" },
+  "dependencies": { "playwright": "1.48.2" }
+}
diff --git a/scripts/staging-smoke/staging-smoke.mjs b/scripts/staging-smoke/staging-smoke.mjs
new file mode 100644
index 000000000..36f2495f2
--- /dev/null
+++ b/scripts/staging-smoke/staging-smoke.mjs
@@ -0,0 +1,131 @@
+#!/usr/bin/env node
+// Tier-1 staging smoke — fast, gates prod promotion. Run after a deploy-staging rollout.
+// Env: SMOKE_BASE (default https://staging.commonly.me), SMOKE_API (default https://api-staging.commonly.me),
+//      SMOKE_EMAIL + SMOKE_PW (non-admin test creds; from a 0600 file / CI secrets, NEVER printed),
+//      SMOKE_HOSTED=1 to also check a hosted-agent reply (skip until staging has an LLM key).
+// Exit 0 = all green; non-zero = a blocking check failed (caller must block prod promotion).
+import { chromium } from 'playwright';
+
+const BASE = process.env.SMOKE_BASE || 'https://staging.commonly.me';
+const API  = process.env.SMOKE_API  || 'https://api-staging.commonly.me';
+const EMAIL = process.env.SMOKE_EMAIL, PW = process.env.SMOKE_PW;
+const CHECK_HOSTED = process.env.SMOKE_HOSTED === '1';
+const UA = { 'User-Agent': 'commonly-smoke/0.1' };
+const CONSOLE_ALLOW = [/favicon/i, /manifest\.json/i, /\/api\/pg\/status/i, /ResizeObserver loop/i, /Download the React DevTools/i];
+
+const results = [];
+const rec = (name, ok, detail='') => { results.push({ name, ok }); console.log(`${ok?'PASS':'FAIL'}  ${name}${detail?'  — '+detail:''}`); };
+const norm = p => (p || '').replace(/\/+$/,'') || '/';
+
+async function api(path, opts={}) {
+  const r = await fetch(`${API}${path}`, { ...opts, headers: { ...UA, ...(opts.headers||{}) } });
+  let body = null; try { body = await r.json(); } catch {}
+  return { status: r.status, body };
+}
+
+async function main() {
+  // 1) health/ready
+  try { const r = await fetch(`${API}/api/health/ready`, { headers: UA }); rec('health/ready 200', r.status === 200, `status ${r.status}`); }
+  catch (e) { rec('health/ready 200', false, e.message); }
+
+  // 2) login -> token
+  let token = null;
+  try {
+    const { status, body } = await api('/api/auth/login', { method:'POST', headers:{'Content-Type':'application/json'}, body: JSON.stringify({ email: EMAIL, password: PW }) });
+    token = body?.token || body?.accessToken || null;
+    rec('non-admin login', status === 200 && !!token, `status ${status}`);
+  } catch (e) { rec('non-admin login', false, e.message); }
+  const authH = token ? { Authorization: `Bearer ${token}` } : {};
+
+  // 3) resolve a real pod id (so /v2/pods/<id> is a true route, not the path="*" redirect to /v2)
+  let podId = null;
+  if (token) {
+    try {
+      const { body } = await api('/api/pods', { headers: authH });
+      const pods = Array.isArray(body) ? body : (body?.pods || body?.data || []);
+      if (pods.length) podId = pods[0]._id || pods[0].id;
+      if (!podId) {
+        const { body: cb } = await api('/api/pods', { method:'POST', headers:{ ...authH, 'Content-Type':'application/json' }, body: JSON.stringify({ name:'Smoke Check Pod', type:'chat', description:'tier-1 smoke render target' }) });
+        const p = cb?.pod || cb; podId = p?._id || p?.id;
+      }
+    } catch {}
+  }
+
+  const browser = await chromium.launch();
+  const ctx = await browser.newContext({ viewport: { width: 1440, height: 900 } });
+  if (token) await ctx.addInitScript(t => { try { localStorage.setItem('token', t); } catch(e){} }, token);
+
+  // 4) pages must render (http<400), with no non-allowlisted console errors, and WITHOUT redirecting
+  //    away from the requested path (a missing route falls through path="*" to /v2 and would false-pass).
+  // okLanding: a missing sub-route falls through path="*" to /v2 (or the default pod), so each
+  // page asserts it LANDED on its own path. Exception: /v2 home itself redirects to the user's
+  // default pod, so any in-app /v2* landing is fine for home.
+  const pages = [
+    ['/v2 home', '/v2', l => l.startsWith('/v2')],
+    ['/v2 pod', podId ? `/v2/pods/${podId}` : null, l => l === norm(`/v2/pods/${podId}`)],
+    ['/v2 connectors', '/v2/connectors', l => l === '/v2/connectors'],
+    ['bring-your-own', '/v2/agents/byo', l => l === '/v2/agents/byo'],
+  ];
+  for (const [label, path, okLanding] of pages) {
+    if (!path) { rec(`render ${label}`, false, 'no pod id (GET/POST /api/pods failed)'); continue; }
+    const page = await ctx.newPage();
+    const errs = [];
+    page.on('console', m => { if (m.type()==='error' && !CONSOLE_ALLOW.some(rx=>rx.test(m.text()))) errs.push(m.text().slice(0,110)); });
+    page.on('pageerror', e => errs.push('PAGEERR '+String(e.message).slice(0,110)));
+    try {
+      const resp = await page.goto(BASE+path, { waitUntil:'networkidle', timeout: 30000 });
+      await page.waitForTimeout(1500);
+      const landed = norm(new URL(page.url()).pathname);
+      const redirected = !okLanding(landed);
+      const httpOk = !resp || resp.status() < 400;
+      rec(`render ${label}`, httpOk && errs.length===0 && !redirected,
+        `http ${resp?resp.status():'?'} url=${landed}${redirected?' REDIRECTED (route missing?)':''}${errs.length?'; console: '+errs.slice(0,2).join(' | '):''}`);
+    } catch (e) { rec(`render ${label}`, false, e.message.slice(0,100)); }
+    await page.close();
+  }
+
+  // 5) no horizontal scroll. At desktop (1440) the left rail is .v2-rail__nav and MUST exist and
+  //    not overflow (TASK-363 — the Activity-badge overflow — lives here, so a missing rail fails).
+  //    At mobile (390) the desktop rail is replaced by a mobile nav, so there we assert the PAGE
+  //    itself does not h-scroll (and the rail, if present, fits).
+  {
+    const page = await ctx.newPage();
+    try {
+      await page.setViewportSize({ width: 1440, height: 900 });
+      await page.goto(BASE+'/v2', { waitUntil:'networkidle', timeout: 30000 });
+      await page.waitForTimeout(1200);
+      const r = await page.evaluate(() => {
+        const el = document.querySelector('.v2-rail__nav');
+        if (!el) return { found: false };
+        return { found: true, over: el.scrollWidth - el.clientWidth };
+      });
+      rec('rail no h-scroll @1440px', r.found === true && r.over <= 1, r.found ? `over+${r.over}` : 'RAIL NOT FOUND (.v2-rail__nav)');
+    } catch (e) { rec('rail no h-scroll @1440px', false, e.message.slice(0,100)); }
+    await page.close();
+  }
+  {
+    const page = await ctx.newPage();
+    try {
+      await page.setViewportSize({ width: 390, height: 844 });
+      await page.goto(BASE+'/v2', { waitUntil:'networkidle', timeout: 30000 });
+      await page.waitForTimeout(1200);
+      const r = await page.evaluate(() => {
+        const doc = document.documentElement;
+        const el = document.querySelector('.v2-rail__nav');
+        return { pageOver: doc.scrollWidth - doc.clientWidth, railOver: el ? (el.scrollWidth - el.clientWidth) : 0 };
+      });
+      rec('no h-scroll @390px', r.pageOver <= 1 && r.railOver <= 1, `page+${r.pageOver} rail+${r.railOver}`);
+    } catch (e) { rec('no h-scroll @390px', false, e.message.slice(0,100)); }
+    await page.close();
+  }
+
+  // 6) hosted agent answers (skip until staging has an LLM key)
+  if (CHECK_HOSTED) rec('hosted agent answers', false, 'TODO once staging LLM key is set');
+  else console.log('SKIP  hosted agent answers — staging has no LLM key yet (SMOKE_HOSTED!=1)');
+
+  await browser.close();
+  const failed = results.filter(r => !r.ok);
+  console.log(`\nSMOKE ${failed.length===0?'GREEN':'RED'} — ${results.length-failed.length}/${results.length} passed` + (failed.length?`; failing: ${failed.map(f=>f.name).join(', ')}`:''));
+  process.exit(failed.length===0 ? 0 : 1);
+}
+main().catch(e => { console.error('SMOKE_HARNESS_ERROR', e.message); process.exit(2); });