diff --git a/tests/playwright/package-lock.json b/tests/playwright/package-lock.json
new file mode 100644
index 00000000..71b2d1bc
--- /dev/null
+++ b/tests/playwright/package-lock.json
@@ -0,0 +1,56 @@
+{
+  "name": "api-examples",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "dependencies": {
+        "playwright": "^1.60.0"
+      }
+    },
+    "node_modules/fsevents": {
+      "version": "2.3.2",
+      "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.2.tgz",
+      "integrity": "sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==",
+      "hasInstallScript": true,
+      "license": "MIT",
+      "optional": true,
+      "os": [
+        "darwin"
+      ],
+      "engines": {
+        "node": "^8.16.0 || ^10.6.0 || >=11.0.0"
+      }
+    },
+    "node_modules/playwright": {
+      "version": "1.60.0",
+      "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.60.0.tgz",
+      "integrity": "sha512-hheHdokM8cdqCb0lcE3s+zT4t4W+vvjpGxsZlDnikarzx8tSzMebh3UiFtgqwFwnTnjYQcsyMF8ei2mCO/tpeA==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "playwright-core": "1.60.0"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      },
+      "optionalDependencies": {
+        "fsevents": "2.3.2"
+      }
+    },
+    "node_modules/playwright-core": {
+      "version": "1.60.0",
+      "resolved": "https://registry.npmjs.org/playwright-core/-/playwright-core-1.60.0.tgz",
+      "integrity": "sha512-9bW6zvX/m0lEbgTKJ6YppOKx8H3VOPBMOCFh2irXFOT4BbHgrx5hPjwJYLT40Lu+4qtD36qKc/Hn56StUW57IA==",
+      "license": "Apache-2.0",
+      "bin": {
+        "playwright-core": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    }
+  }
+}
diff --git a/tests/playwright/package.json b/tests/playwright/package.json
new file mode 100644
index 00000000..f2eab146
--- /dev/null
+++ b/tests/playwright/package.json
@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "playwright": "^1.60.0"
+  }
+}
diff --git a/tests/playwright/test-results/.last-run.json b/tests/playwright/test-results/.last-run.json
new file mode 100644
index 00000000..5fca3f84
--- /dev/null
+++ b/tests/playwright/test-results/.last-run.json
@@ -0,0 +1,4 @@
+{
+  "status": "failed",
+  "failedTests": []
+}
\ No newline at end of file
diff --git a/tests/playwright/test_notebook.mjs b/tests/playwright/test_notebook.mjs
new file mode 100644
index 00000000..994a5926
--- /dev/null
+++ b/tests/playwright/test_notebook.mjs
@@ -0,0 +1,92 @@
+import { chromium } from "playwright";
+
+const URL =
+  "http://localhost:8000/lab/index.html?path=experiments/relax_structure_with_uma.ipynb";
+
+(async () => {
+  const browser = await chromium.launch({ channel: "chrome", headless: false });
+  const page = await browser.newPage();
+
+  console.log("⏳ Navigating to JupyterLite...");
+  await page.goto(URL, { waitUntil: "domcontentloaded", timeout: 60_000 });
+
+  // Wait for kernel idle
+  console.log("⏳ Waiting for Pyodide kernel...");
+  await page.waitForFunction(
+    () => {
+      const ind = document.querySelector(".jp-Notebook-ExecutionIndicator");
+      return ind?.dataset?.status === "idle" && document.querySelectorAll(".jp-CodeCell").length > 5;
+    },
+    { timeout: 120_000, polling: 2_000 }
+  );
+  console.log("✅ Kernel idle!");
+
+  // Click Restart & Run All
+  await page.locator('button[data-command="runmenu:restart-and-run-all"]').click();
+  await page.waitForTimeout(1_000);
+  try {
+    await page.locator(".jp-Dialog button", { hasText: /restart/i }).click({ timeout: 3_000 });
+    console.log("✅ Restart & Run All confirmed!");
+  } catch {
+    console.log("⚠ No dialog");
+  }
+
+  // Monitor with logging until all cells done
+  console.log("\n📊 Monitoring...");
+  const start = Date.now();
+
+  while (Date.now() - start < 300_000) {
+    await page.waitForTimeout(10_000);
+
+    const s = await page.evaluate(() => {
+      const cells = document.querySelectorAll(".jp-CodeCell");
+      let running = 0, done = 0, errors = 0;
+      cells.forEach((c) => {
+        const p = c.querySelector(".jp-InputPrompt")?.textContent?.trim() || "";
+        if (p === "[*]:") running++;
+        else if (/\[\d+\]:/.test(p)) done++;
+        if (c.querySelector(".jp-RenderedText[data-mime-type='application/vnd.jupyter.stderr']")) errors++;
+      });
+      const k = document.querySelector(".jp-Notebook-ExecutionIndicator")?.dataset?.status;
+      return { running, done, errors, total: cells.length, k };
+    });
+
+    const t = ((Date.now() - start) / 1000) | 0;
+    console.log(`  [${t}s] kernel=${s.k} running=${s.running} done=${s.done}/${s.total} errors=${s.errors}`);
+
+    if (s.k === "idle" && s.running === 0 && s.done > 0) break;
+  }
+
+  // Final report
+  console.log("\n" + "=".repeat(60));
+  const results = await page.evaluate(() =>
+    Array.from(document.querySelectorAll(".jp-CodeCell")).map((c, i) => {
+      let t = "";
+      for (const o of c.querySelectorAll(".jp-OutputArea-output")) t += o.textContent;
+      return { cell: i + 1, err: t.includes("Traceback"), out: t };
+    })
+  );
+
+  let failures = 0;
+  for (const r of results) {
+    if (r.err) {
+      failures++;
+      console.log(`Cell ${r.cell} ❌`);
+      console.log(r.out.substring(0, 1500));
+      console.log();
+    } else {
+      const preview = r.out.trim().substring(0, 120).replace(/\n/g, " | ");
+      console.log(`Cell ${r.cell} ✅${preview ? ": " + preview : ""}`);
+    }
+  }
+
+  console.log("=".repeat(60));
+  if (failures > 0) {
+    console.log(`\n⚠ ${failures} cell(s) failed`);
+    process.exitCode = 1;
+  } else {
+    console.log(`\n🎉 ALL ${results.length} CELLS PASSED!`);
+  }
+
+  await browser.close();
+})();