diff --git a/app/shared/src/chatview/components/AgentGroup.rendering.test.tsx b/app/shared/src/chatview/components/AgentGroup.rendering.test.tsx
index 9900f277a..235b9c953 100644
--- a/app/shared/src/chatview/components/AgentGroup.rendering.test.tsx
+++ b/app/shared/src/chatview/components/AgentGroup.rendering.test.tsx
@@ -254,3 +254,31 @@ describe('AgentGroup rendering', () => {
     }
   });
 });
+
+describe('AgentGroup fenced code (#1971)', () => {
+  it('renders agent fenced code bubbles as code blocks', () => {
+    const item: TranscriptAgentItem = {
+      id: 'agent-fenced',
+      agent: 'Hub Agent',
+      role: 'agent',
+      time: '',
+      rows: [],
+      standaloneRows: [],
+      runs: [],
+      parts: [
+        {
+          type: 'bubble',
+          text: 'Here is a fenced code sample:\n```python\ndef greet():\n    return 42\n```\n',
+          blockId: 'hub-message-m2',
+        },
+      ],
+      bubbles: ['Here is a fenced code sample:\n```python\ndef greet():\n    return 42\n```\n'],
+    };
+
+    const { container, getByText } = render(<AgentGroup item={item} chatMode="dm" />);
+
+    expect(getByText('Here is a fenced code sample:')).toBeInTheDocument();
+    expect(container.textContent).toContain('return 42');
+    expect(container.querySelectorAll('pre, code, [class*="codeBlockWrapper"]').length).toBeGreaterThan(0);
+  });
+});
diff --git a/app/shared/src/chatview/components/UserMessage.rendering.test.tsx b/app/shared/src/chatview/components/UserMessage.rendering.test.tsx
index 315fe882d..2f7aa8326 100644
--- a/app/shared/src/chatview/components/UserMessage.rendering.test.tsx
+++ b/app/shared/src/chatview/components/UserMessage.rendering.test.tsx
@@ -185,3 +185,19 @@ describe('UserMessage attachments (#1957)', () => {
     expect(bubble!.children).toHaveLength(2);
   });
 });
+
+describe('UserMessage fenced code (#1971)', () => {
+  it('renders Hub-delivered fenced code as a code block, not plain text', () => {
+    const item: TranscriptUserItem = {
+      type: 'user',
+      name: 'partner',
+      text: 'partner fenced probe\n```python\nprint("hello fenced")\n```\n',
+    };
+
+    const { container, getByText } = render(<UserMessage item={item} chatMode="dm" />);
+
+    expect(getByText('partner fenced probe')).toBeInTheDocument();
+    expect(getByText('print("hello fenced")')).toBeInTheDocument();
+    expect(container.querySelectorAll('pre, code, [class*="codeBlockWrapper"]').length).toBeGreaterThan(0);
+  });
+});
diff --git a/app/shared/src/chatview/pipeline-integration.test.ts b/app/shared/src/chatview/pipeline-integration.test.ts
index aa6f1a4c3..29e28f7a1 100644
--- a/app/shared/src/chatview/pipeline-integration.test.ts
+++ b/app/shared/src/chatview/pipeline-integration.test.ts
@@ -1404,3 +1404,45 @@ describe('Cross-pipeline: Edge + Hub blocks mixed in same TranscriptItem[]', ()
     }
   })
 })
+
+describe('Pipeline: Hub fenced-code content survives normalization (#1971)', () => {
+  it('keeps fence structure from snake_case REST messages through blocks and items', () => {
+    const fenced = 'Here is a fenced code sample:\n```python\nprint("hello")\n```\n'
+    const blocks = normalizeHubMessagesToTranscript([
+      {
+        id: 'm1',
+        session_id: 'hub-session-1',
+        seq_id: 1,
+        sender_type: 'user',
+        sender_id: 'partner-1',
+        content_type: 'text',
+        content: JSON.stringify({ text: fenced }),
+      },
+      {
+        id: 'm2',
+        session_id: 'hub-session-1',
+        seq_id: 2,
+        sender_type: 'agent',
+        sender_id: 'agent-1',
+        content_type: 'text',
+        content: JSON.stringify({ text: fenced }),
+      },
+    ])
+
+    expect(blocks).toHaveLength(2)
+    for (const block of blocks) {
+      expect(block.kind).toBe('text')
+      if (block.kind === 'text') {
+        expect(block.text).toContain('```python')
+        expect(block.text).toContain('print("hello")')
+      }
+    }
+
+    const items = blocksToTranscriptItems(blocks)
+    const agentItem = items.find((item) => isTranscriptAgentItem(item))
+    expect(agentItem).toBeDefined()
+    if (agentItem && isTranscriptAgentItem(agentItem)) {
+      expect(agentItem.bubbles.some((bubble) => bubble.includes('```python'))).toBe(true)
+    }
+  })
+})
diff --git a/app/shared/src/ui/Markdown.test.tsx b/app/shared/src/ui/Markdown.test.tsx
index 6ec7a5709..0cca6146e 100644
--- a/app/shared/src/ui/Markdown.test.tsx
+++ b/app/shared/src/ui/Markdown.test.tsx
@@ -338,3 +338,13 @@ describe('markdown table header stickiness (codeg parity)', () => {
     expect(thRule).toMatch(/z-index:\s*var\(--z-base\);/);
   });
 });
+
+describe('fenced code baseline (#1971)', () => {
+  test('renders fenced code blocks with their exact source', () => {
+    const container = renderMarkdown('Here is a fenced code sample:\n```python\nprint("hello")\n```\n');
+    const codeText = container.textContent ?? '';
+    expect(codeText).toContain('print("hello")');
+    expect(container.querySelectorAll('pre, code').length).toBeGreaterThan(0);
+    expect(codeText).not.toContain('```');
+  });
+});
diff --git a/app/web/package.json b/app/web/package.json
index f02e2ed29..528a61242 100644
--- a/app/web/package.json
+++ b/app/web/package.json
@@ -14,7 +14,7 @@
     "test:e2e:smoke": "playwright test --config playwright.config.ts --project=chromium smoke.spec.ts",
     "test:e2e:real": "playwright test --config playwright.real.config.ts",
     "test:e2e:chat-flow": "playwright test --config playwright.config.ts --project=chromium chat-flow-contract.spec.ts",
-    "test:e2e:stubbed-hub": "playwright test --config playwright.config.ts --project=chromium chat-flow-contract.spec.ts web-stubbed-hub-replay-smoke.spec.ts task-contract.spec.ts",
+    "test:e2e:stubbed-hub": "playwright test --config playwright.config.ts --project=chromium chat-flow-contract.spec.ts web-stubbed-hub-replay-smoke.spec.ts web-stubbed-hub-fenced-code.spec.ts task-contract.spec.ts",
     "test:e2e:approved-real-stub": "pnpm test:e2e:stubbed-hub",
     "test:visual:chat-flow": "node scripts/manual-chat-flow-check.mjs",
     "visual:qa:shell": "node scripts/visual-qa-shell.mjs",
diff --git a/app/web/src/__e2e__/web-stubbed-hub-fenced-code.spec.ts b/app/web/src/__e2e__/web-stubbed-hub-fenced-code.spec.ts
new file mode 100644
index 000000000..7c403c898
--- /dev/null
+++ b/app/web/src/__e2e__/web-stubbed-hub-fenced-code.spec.ts
@@ -0,0 +1,125 @@
+import { expect, test, type Route } from '@playwright/test';
+
+// #1971 contract: Hub-delivered text messages whose body contains fenced
+// code must render as code blocks in the Web transcript, for both human
+// (partner) and agent senders, using the real REST shapes (snake_case
+// session id, jsonb string content with a `text` field).
+const HUB_ORIGIN_HOST = 'hub.test.invalid';
+
+const HUMAN_FENCED = 'partner fenced probe\n```python\nprint("hello fenced")\n```\n';
+const AGENT_FENCED = 'Here is a fenced code sample:\n```python\ndef greet():\n    return 42\n```\n';
+
+function corsHeaders(): Record<string, string> {
+  return {
+    'access-control-allow-origin': '*',
+    'access-control-allow-headers': 'authorization,content-type',
+    'access-control-allow-methods': 'GET,POST,PATCH,PUT,DELETE,OPTIONS',
+  };
+}
+
+function fulfill(data: unknown) {
+  return {
+    status: 200,
+    contentType: 'application/json',
+    body: JSON.stringify({ code: 'ok', data }),
+    headers: corsHeaders(),
+  };
+}
+
+test.describe('Web stubbed Hub fenced-code transcript (#1971)', () => {
+  test('renders fenced code blocks from Hub history for human and agent senders', async ({ page }) => {
+    await page.addInitScript(() => {
+      window.localStorage.setItem('agenthub.workbench.dataMode', 'approved-real');
+      window.sessionStorage.setItem('agenthub_hub_token', 'stubbed-hub-token');
+      window.sessionStorage.setItem('agenthub_token_source', 'hub');
+      window.sessionStorage.setItem('agenthub_hub_user', JSON.stringify({
+        userId: 'user-fenced',
+        username: 'fenced',
+      }));
+    });
+
+    await page.route('**/*', async (route: Route) => {
+      const request = route.request();
+      const url = new URL(request.url());
+
+      if (url.host !== HUB_ORIGIN_HOST) {
+        if (url.host === 'fonts.googleapis.com' || url.host === 'fonts.gstatic.com') {
+          return route.fulfill({ status: 200, contentType: 'text/css', body: '' });
+        }
+        return route.continue();
+      }
+
+      if (request.method() === 'OPTIONS') {
+        return route.fulfill({ status: 204, headers: corsHeaders() });
+      }
+
+      const p = url.pathname;
+      if (p === '/client/auth/me') {
+        return route.fulfill(fulfill({ id: 'user-fenced', username: 'fenced', nickname: 'Fenced', avatar_url: '' }));
+      }
+      if (p === '/client/sessions') {
+        return route.fulfill(fulfill([{
+          session_id: 'session-fenced',
+          type: 'private',
+          name: 'Fenced code probe',
+          member_count: 2,
+          unread_count: 0,
+        }]));
+      }
+      if (p === '/client/sessions/session-fenced/messages') {
+        return route.fulfill(fulfill([
+          {
+            id: 'msg-fenced-1',
+            session_id: 'session-fenced',
+            seq_id: 1,
+            sender_type: 'user',
+            sender_id: 'partner-1',
+            content_type: 'text',
+            content: JSON.stringify({ text: HUMAN_FENCED }),
+            created_at: '2026-08-25T06:00:00Z',
+          },
+          {
+            id: 'msg-fenced-2',
+            session_id: 'session-fenced',
+            seq_id: 2,
+            sender_type: 'agent',
+            sender_id: 'agent-fenced',
+            content_type: 'text',
+            content: JSON.stringify({ text: AGENT_FENCED }),
+            created_at: '2026-08-25T06:01:00Z',
+          },
+        ]));
+      }
+      if (p === '/client/sessions/session-fenced/pins') {
+        return route.fulfill(fulfill([]));
+      }
+      if (p === '/client/contacts' || p === '/client/notifications') {
+        return route.fulfill(fulfill([]));
+      }
+      // Any other Hub call fails closed so missing stubs surface loudly.
+      return route.fulfill({
+        status: 404,
+        contentType: 'application/json',
+        body: JSON.stringify({ code: 'not_stubbed', path: p }),
+        headers: corsHeaders(),
+      });
+    });
+
+    await page.goto('/');
+
+    await expect(page.getByTestId('agenthub-workbench')).toHaveAttribute('data-page', 'chat');
+    // Preamble text of both messages renders.
+    await expect(page.getByText('partner fenced probe')).toBeVisible();
+    await expect(page.getByText('Here is a fenced code sample:')).toBeVisible();
+    // The fenced code bodies render inside code-block containers (the
+    // Markdown CodeBlock wrapper in dev builds carries a readable
+    // `codeBlockWrapper` CSS-module class; the lazy highlighter or its
+    // <pre><code> fallback both live inside that wrapper).
+    const humanBlock = page.locator('[class*="codeBlockWrapper"]', { hasText: 'print("hello fenced")' });
+    await expect(humanBlock).toBeVisible();
+    const agentBlock = page.locator('[class*="codeBlockWrapper"]', { hasText: 'return 42' });
+    await expect(agentBlock).toBeVisible();
+    // The preamble paragraph and the code block are distinct nodes.
+    await expect(page.getByText('print("hello fenced")')).toBeVisible();
+  });
+});