diff --git a/apps/worker/src/lib/export.test.ts b/apps/worker/src/lib/export.test.ts
new file mode 100644
index 0000000..3fdbd13
--- /dev/null
+++ b/apps/worker/src/lib/export.test.ts
@@ -0,0 +1,51 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
+import { downloadExport } from './export';
+import { setToken } from './auth-storage';
+
+describe('downloadExport', () => {
+  beforeEach(() => {
+    localStorage.clear();
+    // jsdom does not implement the object-URL API; stub it so the download path runs.
+    URL.createObjectURL = vi.fn(() => 'blob:mock-url');
+    URL.revokeObjectURL = vi.fn();
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+    vi.unstubAllGlobals();
+  });
+
+  it('fetches the CSV with the bearer token and triggers an object-URL download', async () => {
+    setToken('tok');
+    const clickSpy = vi.spyOn(HTMLAnchorElement.prototype, 'click').mockImplementation(() => {});
+    const fetchMock = vi.fn().mockResolvedValue(new Response('a,b\n1,2\n', { status: 200 }));
+    vi.stubGlobal('fetch', fetchMock);
+
+    await downloadExport();
+
+    expect(fetchMock).toHaveBeenCalledTimes(1);
+    const [url, init] = fetchMock.mock.calls[0];
+    expect(url).toBe('http://localhost:3000/api/export');
+    expect(new Headers(init.headers).get('Authorization')).toBe('Bearer tok');
+    expect(URL.createObjectURL).toHaveBeenCalledTimes(1);
+    expect(clickSpy).toHaveBeenCalledTimes(1);
+    expect(URL.revokeObjectURL).toHaveBeenCalledWith('blob:mock-url');
+  });
+
+  it('sends no Authorization header when there is no token', async () => {
+    vi.spyOn(HTMLAnchorElement.prototype, 'click').mockImplementation(() => {});
+    const fetchMock = vi.fn().mockResolvedValue(new Response('x', { status: 200 }));
+    vi.stubGlobal('fetch', fetchMock);
+
+    await downloadExport();
+
+    const [, init] = fetchMock.mock.calls[0];
+    expect(new Headers(init.headers).has('Authorization')).toBe(false);
+  });
+
+  it('throws when the response is not ok', async () => {
+    vi.stubGlobal('fetch', vi.fn().mockResolvedValue(new Response(null, { status: 401 })));
+
+    await expect(downloadExport()).rejects.toThrow('Kan de export niet openen');
+  });
+});
diff --git a/apps/worker/src/screens/History.test.tsx b/apps/worker/src/screens/History.test.tsx
index 9a2567c..d9e7139 100644
--- a/apps/worker/src/screens/History.test.tsx
+++ b/apps/worker/src/screens/History.test.tsx
@@ -120,4 +120,80 @@ describe('History', () => {
     await user.click(screen.getByRole('button', { name: 'Exporteer CSV' }));
     expect(mockedDownloadExport).toHaveBeenCalledTimes(1);
   });
+
+  it('shows an error message when the export fails', async () => {
+    const user = userEvent.setup();
+    mockedDownloadExport.mockRejectedValueOnce(new Error('boom'));
+    renderHistory();
+
+    await user.click(screen.getByRole('button', { name: 'Exporteer CSV' }));
+    expect(await screen.findByText(/Kan de export niet openen/)).toBeInTheDocument();
+  });
+
+  it('formats a sub-minute duration as just seconds', async () => {
+    mockedApiFetch.mockResolvedValue([session({ duration_seconds: 45 })]);
+    renderHistory();
+
+    const card = (await screen.findByText('Frezen')).closest('.session-card') as HTMLElement;
+    expect(card.textContent).toContain('45s');
+    expect(card.textContent).not.toContain('m 45s');
+  });
+
+  it('renders 0s when duration_seconds is null', async () => {
+    mockedApiFetch.mockResolvedValue([session({ duration_seconds: null })]);
+    renderHistory();
+
+    const card = (await screen.findByText('Frezen')).closest('.session-card') as HTMLElement;
+    expect(card.textContent).toContain('0s');
+  });
+
+  it('falls back to "Onbekende handeling" when the activity name is null', async () => {
+    mockedApiFetch.mockResolvedValue([session({ activity_name: undefined })]);
+    renderHistory();
+
+    expect(await screen.findByText('Onbekende handeling')).toBeInTheDocument();
+  });
+
+  it('omits the type pill when insole_type is null', async () => {
+    mockedApiFetch.mockResolvedValue([session({ insole_type: null })]);
+    renderHistory();
+
+    const card = (await screen.findByText('Frezen')).closest('.session-card') as HTMLElement;
+    expect(card.textContent).not.toContain('Kurk');
+  });
+
+  it('renders sessions in the order the API returns them (newest-first)', async () => {
+    mockedApiFetch.mockResolvedValue([
+      session({ id: 2, activity_name: 'Frezen' }),
+      session({ id: 1, activity_name: 'Zagen' }),
+    ]);
+    const { container } = renderHistory();
+
+    await screen.findByText('Frezen');
+    const names = [...container.querySelectorAll('.session-name')].map((el) => el.textContent);
+    expect(names).toEqual(['Frezen', 'Zagen']);
+  });
+
+  it('shows neither the empty state nor cards while loading', () => {
+    mockedApiFetch.mockReturnValue(new Promise<never>(() => {}));
+    const { container } = renderHistory();
+
+    expect(screen.queryByText('Nog geen opgeslagen sessies.')).not.toBeInTheDocument();
+    expect(container.querySelectorAll('.session-card')).toHaveLength(0);
+  });
+
+  it('lifecycle: renders a completed paused session, then export calls the download path', async () => {
+    const user = userEvent.setup();
+    mockedApiFetch.mockResolvedValue([
+      session({ status: 'completed', duration_seconds: 3661, paused_seconds: 125 }),
+    ]);
+    renderHistory();
+
+    const card = (await screen.findByText('Frezen')).closest('.session-card') as HTMLElement;
+    expect(card.textContent).toContain('1h 1m');
+    expect(card.textContent).toContain('Pauze 2m 5s');
+
+    await user.click(screen.getByRole('button', { name: 'Exporteer CSV' }));
+    expect(mockedDownloadExport).toHaveBeenCalledTimes(1);
+  });
 });
diff --git a/docs/reference/domain-test-checklist.md b/docs/reference/domain-test-checklist.md
index 8fa1e55..634f17c 100644
--- a/docs/reference/domain-test-checklist.md
+++ b/docs/reference/domain-test-checklist.md
@@ -283,3 +283,31 @@ Guaranteed behaviors:
 > implemented** in the current code (there is no global 401 interceptor; `apiFetch` throws
 > `ApiError` and callers surface it via React Query). Left as-is (missing feature, not a defect);
 > not tested and not filed as a bug.
+
+## History — worker client
+
+Src covered (worker `apps/worker`): `src/screens/History.tsx` and `src/lib/export.ts` — both at
+100% stmts/branch/funcs/lines. No `c8 ignore`s needed.
+
+Guaranteed behaviors:
+
+- History renders the Dutch header (`Geschiedenis`) and the `Exporteer CSV` button.
+- Sessions render in the order the API returns them (`GET /api/sessions` is newest-first), one
+  `.session-card` per session, showing the activity name and its formatted duration.
+- `formatDuration` renders the legacy format: `Hh Mm` when hours are present (`3661 → 1h 1m`),
+  `Mm Ss` when only minutes (`125 → 2m 5s`), and just seconds under a minute (`45 → 45s`); a null
+  `duration_seconds` renders `0s`.
+- A card falls back to `"Onbekende handeling"` when `activity_name` is absent, omits the insole-type
+  pill when `insole_type` is null, and uses the singular noun (`inlegzool`) only for a pair count of
+  1 (`inlegzolen` otherwise).
+- A `Pauze <duration>` line shows only when `paused_seconds > 0` (absent when it is 0).
+- The empty state (`Nog geen opgeslagen sessies.`) shows only once loading has finished and there are
+  no sessions; while the query is still loading, neither the empty state nor any cards render.
+- Clicking `Exporteer CSV` calls `downloadExport`; when it rejects, the card surfaces the
+  `Kan de export niet openen` error message instead of throwing.
+- `downloadExport` (`src/lib/export.ts`): fetches `GET /api/export` with the bearer token when one is
+  stored (no `Authorization` header when there is none), then triggers a client-side download via an
+  object URL (`createObjectURL` → anchor `click` → `revokeObjectURL`); it throws
+  `"Kan de export niet openen"` when the response is not ok.
+- Lifecycle (`src/screens/History.test.tsx`): the list renders a completed session showing both its
+  worked duration and its `Pauze` line, then the export action invokes the download path.