How do you write API tests in Playwright?

Playwright's request client shares configuration with the UI projects, including baseURL and extra headers. That makes it convenient to create data over the API and then verify the behaviour through the browser, or to test endpoints on their own.

test("creates an order", async ({ request }) => {
  const response = await request.post("/api/orders", {
    data: { sku: "SKU-1", quantity: 2 },
  });

  expect(response.status()).toBe(201);

  const order = await response.json();
  expect(order).toMatchObject({ sku: "SKU-1", quantity: 2 });
});

What the request fixture gives you

• get, post, put, patch, delete and head helpers
• Automatic JSON serialization through the data option
• Shared baseURL, headers and cookies from the project config
• expect(response).toBeOK() for a 2xx check
• A way to create or clean up data without going through the UI

const created = await request.post("/api/invoices", {
  data: { total: 120 },
});
const invoice = await created.json();

await page.goto("/invoices/" + invoice.id);
await expect(page.getByText("120")).toBeVisible();

await request.delete("/api/invoices/" + invoice.id);

The request fixture does not share cookies with the page fixture by default. If a test needs both an authenticated API call and an authenticated browser, either log in through the API and pass the state to the context, or use page.request, which shares the page's cookie jar.