Forms & actions

A server action handles the form POST, validates it, and returns a result — no API to write.

To mutate data, export an action alongside the component. On a POST, bext runs the action server-side before re-rendering the page; whatever it returns arrives as the actionData prop.

src/app/products/new/page.tsx

export async function action({ request }) {
  const form = await request.formData();
  const name = String(form.get("name") ?? "").trim();
  if (!name) return { error: "Name is required." };
  return { ok: true, name };
}

The form is a plain <form method=\"post\"> — it works even with JavaScript off. Submit it in the preview to watch the action run and the page re-render.

WARNING

Always validate on the server inside the action — never trust client input. See server actions.