diff --git a/.github/workflows/README.md b/.github/workflows/README.md
index 3d82b2d..eec9d91 100644
--- a/.github/workflows/README.md
+++ b/.github/workflows/README.md
@@ -11,3 +11,4 @@ This directory contains GitHub Actions workflow files that automate various task
 - [deploy-wikitree-apps.yml](deploy-wikitree-apps.yml): Manages the deployment of the application to WikiTree Apps using SFTP.
 - [node.js.yml](node.js.yml): The main Continuous Integration (CI) workflow. It installs dependencies, checks formatting, lints, builds, and runs tests across multiple Node.js versions.
 - [prober-gh-pages.yml](prober-gh-pages.yml): Reusable prober that smoke-tests the GitHub Pages deployment with GEDCOM-from-URL through the CORS proxy. Runs daily and after deploy.
+- [prober-wikitree.yml](prober-wikitree.yml): Reusable prober that smoke-tests the WikiTree direct API path on the live WikiTree deployment. Runs daily and after deploy.
diff --git a/.github/workflows/deploy-everywhere.yml b/.github/workflows/deploy-everywhere.yml
index f22d31c..9da1da9 100644
--- a/.github/workflows/deploy-everywhere.yml
+++ b/.github/workflows/deploy-everywhere.yml
@@ -21,3 +21,10 @@ jobs:
     secrets: inherit
     with:
       wait_for_propagation: true
+
+  prober-wikitree:
+    needs: deploy-wikitree-apps
+    uses: ./.github/workflows/prober-wikitree.yml
+    secrets: inherit
+    with:
+      wait_for_propagation: true
diff --git a/.github/workflows/prober-wikitree.yml b/.github/workflows/prober-wikitree.yml
new file mode 100644
index 0000000..3aa2ac8
--- /dev/null
+++ b/.github/workflows/prober-wikitree.yml
@@ -0,0 +1,77 @@
+name: Prober - WikiTree
+
+on:
+  workflow_call:
+    inputs:
+      wait_for_propagation:
+        type: boolean
+        default: false
+  workflow_dispatch:
+    inputs:
+      wait_for_propagation:
+        type: boolean
+        default: false
+  schedule:
+    - cron: '0 5 * * *'
+
+permissions:
+  contents: read
+  actions: write
+
+concurrency:
+  group: prober-${{ github.workflow }}
+  cancel-in-progress: false
+
+jobs:
+  prober:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    env:
+      SPEC: wikitree.spec.ts
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Use Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 24.x
+          cache: 'npm'
+
+      - run: npm ci
+
+      - name: Wait for deployment propagation
+        if: inputs.wait_for_propagation
+        run: sleep 180
+
+      - name: Get Playwright version
+        id: playwright-version
+        run: echo "version=$(node -p "require('@playwright/test/package.json').version")" >> $GITHUB_OUTPUT
+
+      - name: Cache Playwright Browsers
+        id: cache-playwright
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/ms-playwright
+          key: playwright-${{ runner.os }}-${{ steps.playwright-version.outputs.version }}
+
+      - name: Install Playwright System Dependencies
+        run: npx playwright install-deps chromium
+
+      - name: Install Playwright Browsers (If Not Cached)
+        if: steps.cache-playwright.outputs.cache-hit != 'true'
+        run: npx playwright install chromium
+
+      - name: Run prober
+        env:
+          PLAYWRIGHT_HTML_REPORT: playwright-report/prober
+        run: npx playwright test --config=playwright.prober.config.ts "${SPEC}"
+
+      - name: Upload Playwright report
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: prober-report-wikitree
+          path: playwright-report/
+          retention-days: 30
diff --git a/tests/probers/wikitree.spec.ts b/tests/probers/wikitree.spec.ts
new file mode 100644
index 0000000..8edb429
--- /dev/null
+++ b/tests/probers/wikitree.spec.ts
@@ -0,0 +1,34 @@
+import {expect, test} from '@playwright/test';
+
+/**
+ * Prober: WikiTree direct API
+ *
+ * Loads a known WikiTree profile (Skłodowska-2) from the app deployed on
+ * apps.wikitree.com. Because the app is on the apps.wikitree.com domain,
+ * WikiTree API calls go direct (no CORS proxy). This exercises the WikiTree
+ * direct API path and confirms the WikiTree deployment is healthy.
+ */
+test('WikiTree direct API prober', async ({page}) => {
+  await page.goto(
+    'https://apps.wikitree.com/apps/wiech13/topola-viewer/#/view?source=wikitree&indi=Sk%C5%82odowska-2',
+  );
+
+  // Wait for the app to reach SHOWING_CHART state.
+  await expect(page.locator('#content')).toBeVisible();
+
+  // Assert the expected person's name appears in the chart SVG.
+  await expect(page.locator('#chart')).toContainText('Skłodowska');
+
+  // Assert the expected person's name appears in the side panel.
+  // Scoped to div.details to avoid matching <text class="details sex"> SVG
+  // elements in the chart that also carry the "details" class.
+  await expect(page.locator('div.details')).toContainText('Skłodowska');
+
+  // Assert no fatal error is displayed (replaces chart when state is ERROR).
+  await expect(page.locator('.ui.error.message')).not.toBeVisible();
+
+  // Assert no popup error is displayed.
+  // ErrorPopup uses Semantic UI React's <Portal>, which renders at
+  // document.body level, not inside #content.
+  await expect(page.locator('.ui.errorPopup.message')).not.toBeVisible();
+});