Server Actions

Server Actions call server functions directly from components without API routes.

Basics

• Declare with "use server".

"use server";

• Called via forms or direct imports.
• Runs on the server in an isolated context.

Form handling

<form action={updateUser}>
  <input name="email" />
  <button type="submit">Save</button>
</form>

• Data is serialized automatically.
• No API route, no client fetch, no form state boilerplate.

Programmatic call

import { updateUser } from "./actions";
await updateUser({ name: "John" });

Advantages

• Less client JS, simpler mutations, full server access.

Limitations

• No browser APIs.
• Client Components still required for interactive UI.
• Cache config matters; mutations can make routes dynamic.