diff --git a/.github/workflows/playwright.yml b/.github/workflows/playwright.yml
new file mode 100644
index 0000000..4102267
--- /dev/null
+++ b/.github/workflows/playwright.yml
@@ -0,0 +1,85 @@
+name: playwright
+
+on:
+  pull_request:
+    paths:
+      - "ui/**"
+      - ".github/workflows/playwright.yml"
+  push:
+    branches: [main]
+    paths:
+      - "ui/**"
+      - ".github/workflows/playwright.yml"
+
+permissions: read-all
+
+concurrency:
+  group: playwright-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  e2e:
+    name: e2e (chromium)
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    timeout-minutes: 15
+    defaults:
+      run:
+        working-directory: ui
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+
+      - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+        with:
+          node-version: "22"
+          cache: "npm"
+          cache-dependency-path: ui/package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Derive Playwright version
+        id: pw
+        run: |
+          set -eu
+          ver=$(node -p "require('@playwright/test/package.json').version")
+          echo "version=$ver" >> "$GITHUB_OUTPUT"
+
+      - name: Cache Playwright browsers
+        id: pw-cache
+        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5
+        with:
+          path: ~/.cache/ms-playwright
+          key: playwright-${{ runner.os }}-${{ steps.pw.outputs.version }}
+
+      - name: Install Playwright browser (chromium)
+        if: steps.pw-cache.outputs.cache-hit != 'true'
+        run: npx playwright install --with-deps chromium
+
+      - name: Install system deps for cached browser
+        if: steps.pw-cache.outputs.cache-hit == 'true'
+        run: npx playwright install-deps chromium
+
+      - name: Run Playwright tests
+        env:
+          CI: "1"
+        run: npm run e2e
+
+      - name: Upload Playwright report
+        if: always()
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
+        with:
+          name: playwright-report
+          path: ui/playwright-report
+          retention-days: 7
+          if-no-files-found: ignore
+
+      - name: Upload failure traces
+        if: failure()
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
+        with:
+          name: playwright-traces
+          path: ui/test-results
+          retention-days: 7
+          if-no-files-found: ignore
diff --git a/.gitignore b/.gitignore
index 3d45ddc..b04805f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -39,6 +39,12 @@ ui/.vite/
 ui/coverage/
 ui/*.tsbuildinfo
 
+# Frontend — Playwright E2E artifacts (generated, never committed)
+ui/playwright-report/
+ui/test-results/
+ui/blob-report/
+ui/playwright/.cache/
+
 # Environment — never commit secrets
 .env
 .env.*
diff --git a/ui/e2e/fixtures.ts b/ui/e2e/fixtures.ts
new file mode 100644
index 0000000..e95b5c7
--- /dev/null
+++ b/ui/e2e/fixtures.ts
@@ -0,0 +1,47 @@
+import { test as base, expect, type Page } from "@playwright/test";
+
+// Match only backend paths — anchored to pathname start so Vite's dev-server
+// module requests under src/hooks/api/** are not stubbed.
+const API_PATH = /^\/api\//;
+const MCP_PATH = /^\/mcp\//;
+
+async function stubApi(page: Page) {
+  await page.route(
+    (url) => API_PATH.test(url.pathname),
+    async (route) => {
+      const path = new URL(route.request().url()).pathname;
+
+      if (/\/notes(\?|$)/.test(path) || /\/documents(\?|$)/.test(path) || /\/activity(\?|$)/.test(path)) {
+        return route.fulfill({ status: 200, contentType: "application/json", body: "[]" });
+      }
+      if (/\/stats$/.test(path)) {
+        return route.fulfill({
+          status: 200,
+          contentType: "application/json",
+          body: JSON.stringify({ notes: 0, documents: 0, entities: 0, relationships: 0 }),
+        });
+      }
+      if (/\/search/.test(path)) {
+        return route.fulfill({
+          status: 200,
+          contentType: "application/json",
+          body: JSON.stringify({ notes: [], docs: [] }),
+        });
+      }
+      return route.fulfill({ status: 200, contentType: "application/json", body: "{}" });
+    },
+  );
+  await page.route(
+    (url) => MCP_PATH.test(url.pathname),
+    (route) => route.fulfill({ status: 200, contentType: "application/json", body: "{}" }),
+  );
+}
+
+export const test = base.extend<{ stubbedPage: Page }>({
+  stubbedPage: async ({ page }, use) => {
+    await stubApi(page);
+    await use(page);
+  },
+});
+
+export { expect };
diff --git a/ui/e2e/smoke.spec.ts b/ui/e2e/smoke.spec.ts
new file mode 100644
index 0000000..cb6414e
--- /dev/null
+++ b/ui/e2e/smoke.spec.ts
@@ -0,0 +1,50 @@
+import { test, expect } from "./fixtures";
+
+// The Shell renders the primary landmark as `<main id="main">`; selecting by id
+// avoids strict-mode ambiguity with any other <main> rendered by shadcn sidebar.
+const main = (page: import("@playwright/test").Page) => page.locator("main#main");
+
+test.describe("smoke", () => {
+  test("home renders shell and main landmark", async ({ stubbedPage: page }) => {
+    await page.goto("/");
+    await expect(main(page)).toBeVisible();
+    await expect(page).toHaveTitle(/docsiq/i);
+  });
+
+  test("command palette opens with Ctrl+K and closes with Escape", async ({ stubbedPage: page }) => {
+    await page.goto("/");
+    await main(page).waitFor();
+    await page.keyboard.press("ControlOrMeta+k");
+    const palette = page.getByPlaceholder(/search notes, docs, entities/i);
+    await expect(palette).toBeVisible();
+    await page.keyboard.press("Escape");
+    await expect(palette).not.toBeVisible();
+  });
+
+  test("command palette navigates to Documents", async ({ stubbedPage: page }) => {
+    await page.goto("/");
+    await main(page).waitFor();
+    await page.keyboard.press("ControlOrMeta+k");
+    await page.getByPlaceholder(/search notes, docs, entities/i).waitFor();
+    await page.getByRole("option", { name: /^documents$/i }).click();
+    await expect(page).toHaveURL(/\/docs$/);
+  });
+
+  test("chord hotkey g,g navigates to Graph", async ({ stubbedPage: page }) => {
+    await page.goto("/");
+    await main(page).waitFor();
+    await page.keyboard.press("g");
+    await page.keyboard.press("g");
+    await expect(page).toHaveURL(/\/graph$/);
+  });
+
+  test("theme toggle switches to light and persists on reload", async ({ stubbedPage: page }) => {
+    await page.goto("/");
+    await main(page).waitFor();
+    await page.getByRole("button", { name: /change theme/i }).click();
+    await page.getByRole("menuitem", { name: /^light$/i }).click();
+    await expect(page.locator("html")).not.toHaveClass(/dark/);
+    await page.reload();
+    await expect(page.locator("html")).not.toHaveClass(/dark/);
+  });
+});
diff --git a/ui/package-lock.json b/ui/package-lock.json
index 39e94b7..9f3faa9 100644
--- a/ui/package-lock.json
+++ b/ui/package-lock.json
@@ -55,6 +55,7 @@
         "zustand": "^5.0.2"
       },
       "devDependencies": {
+        "@playwright/test": "^1.59.1",
         "@tailwindcss/vite": "^4.0.0",
         "@testing-library/jest-dom": "^6.9.1",
         "@testing-library/react": "^16.3.2",
@@ -1613,6 +1614,22 @@
         "url": "https://github.com/sponsors/Boshen"
       }
     },
+    "node_modules/@playwright/test": {
+      "version": "1.59.1",
+      "resolved": "https://registry.npmjs.org/@playwright/test/-/test-1.59.1.tgz",
+      "integrity": "sha512-PG6q63nQg5c9rIi4/Z5lR5IVF7yU5MqmKaPOe0HSc0O2cX1fPi96sUQu5j7eo4gKCkB2AnNGoWt7y4/Xx3Kcqg==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "playwright": "1.59.1"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    },
     "node_modules/@radix-ui/number": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/@radix-ui/number/-/number-1.1.1.tgz",
@@ -7407,6 +7424,53 @@
         "url": "https://github.com/sponsors/jonschlinkert"
       }
     },
+    "node_modules/playwright": {
+      "version": "1.59.1",
+      "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.59.1.tgz",
+      "integrity": "sha512-C8oWjPR3F81yljW9o5OxcWzfh6avkVwDD2VYdwIGqTkl+OGFISgypqzfu7dOe4QNLL2aqcWBmI3PMtLIK233lw==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "playwright-core": "1.59.1"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      },
+      "optionalDependencies": {
+        "fsevents": "2.3.2"
+      }
+    },
+    "node_modules/playwright-core": {
+      "version": "1.59.1",
+      "resolved": "https://registry.npmjs.org/playwright-core/-/playwright-core-1.59.1.tgz",
+      "integrity": "sha512-HBV/RJg81z5BiiZ9yPzIiClYV/QMsDCKUyogwH9p3MCP6IYjUFu/MActgYAvK0oWyV9NlwM3GLBjADyWgydVyg==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "playwright-core": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    },
+    "node_modules/playwright/node_modules/fsevents": {
+      "version": "2.3.2",
+      "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.2.tgz",
+      "integrity": "sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==",
+      "dev": true,
+      "hasInstallScript": true,
+      "license": "MIT",
+      "optional": true,
+      "os": [
+        "darwin"
+      ],
+      "engines": {
+        "node": "^8.16.0 || ^10.6.0 || >=11.0.0"
+      }
+    },
     "node_modules/postcss": {
       "version": "8.5.10",
       "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.10.tgz",
diff --git a/ui/package.json b/ui/package.json
index 46f939d..994d721 100644
--- a/ui/package.json
+++ b/ui/package.json
@@ -11,7 +11,10 @@
     "test:watch": "vitest",
     "test:coverage": "vitest run --coverage",
     "typecheck": "tsc -b --noEmit",
-    "lint": "eslint src"
+    "lint": "eslint src",
+    "e2e": "playwright test",
+    "e2e:ui": "playwright test --ui",
+    "e2e:install": "playwright install --with-deps chromium"
   },
   "dependencies": {
     "@codemirror/commands": "^6.7.0",
@@ -61,6 +64,7 @@
     "zustand": "^5.0.2"
   },
   "devDependencies": {
+    "@playwright/test": "^1.59.1",
     "@tailwindcss/vite": "^4.0.0",
     "@testing-library/jest-dom": "^6.9.1",
     "@testing-library/react": "^16.3.2",
diff --git a/ui/playwright.config.ts b/ui/playwright.config.ts
new file mode 100644
index 0000000..c47723f
--- /dev/null
+++ b/ui/playwright.config.ts
@@ -0,0 +1,35 @@
+import { defineConfig, devices } from "@playwright/test";
+
+const PORT = Number(process.env.PLAYWRIGHT_PORT ?? 5173);
+const BASE_URL = process.env.PLAYWRIGHT_BASE_URL ?? `http://localhost:${PORT}`;
+const isCI = !!process.env.CI;
+
+export default defineConfig({
+  testDir: "./e2e",
+  fullyParallel: true,
+  forbidOnly: isCI,
+  retries: isCI ? 1 : 0,
+  workers: isCI ? 2 : undefined,
+  reporter: isCI ? [["github"], ["html", { open: "never" }]] : "list",
+  timeout: 30_000,
+  expect: { timeout: 5_000 },
+  use: {
+    baseURL: BASE_URL,
+    trace: "on-first-retry",
+    screenshot: "only-on-failure",
+    video: "retain-on-failure",
+  },
+  projects: [
+    { name: "chromium", use: { ...devices["Desktop Chrome"] } },
+  ],
+  webServer: process.env.PLAYWRIGHT_SKIP_WEBSERVER
+    ? undefined
+    : {
+        command: `npm run dev -- --port ${PORT} --strictPort`,
+        url: BASE_URL,
+        reuseExistingServer: !isCI,
+        timeout: 60_000,
+        stdout: "ignore",
+        stderr: "pipe",
+      },
+});
diff --git a/ui/tsconfig.e2e.json b/ui/tsconfig.e2e.json
new file mode 100644
index 0000000..ee9d3ba
--- /dev/null
+++ b/ui/tsconfig.e2e.json
@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
+    "types": ["node"],
+    "strict": true,
+    "skipLibCheck": true,
+    "isolatedModules": true,
+    "esModuleInterop": true,
+    "resolveJsonModule": true,
+    "noEmit": true,
+    "paths": { "@/*": ["./src/*"] }
+  },
+  "include": ["e2e/**/*.ts", "playwright.config.ts"]
+}
diff --git a/ui/tsconfig.json b/ui/tsconfig.json
index 0ad4751..0b34e9b 100644
--- a/ui/tsconfig.json
+++ b/ui/tsconfig.json
@@ -2,7 +2,8 @@
   "files": [],
   "references": [
     { "path": "./tsconfig.app.json" },
-    { "path": "./tsconfig.node.json" }
+    { "path": "./tsconfig.node.json" },
+    { "path": "./tsconfig.e2e.json" }
   ],
   "compilerOptions": {
     "baseUrl": ".",
diff --git a/ui/vitest.config.ts b/ui/vitest.config.ts
index a5a3b57..370ad40 100644
--- a/ui/vitest.config.ts
+++ b/ui/vitest.config.ts
@@ -11,6 +11,7 @@ export default defineConfig({
     environment: "jsdom",
     globals: true,
     setupFiles: ["./src/setupTests.ts"],
+    exclude: ["node_modules/**", "dist/**", "e2e/**"],
     coverage: {
       reporter: ["text", "html"],
       include: [