04 · Server Actions ("use server")

Mutation entry points: adapt UI input, call entity actions, trigger revalidation.

Mental Model

Server Actions are the mutation boundary callable from the UI.
They orchestrate: validate → authorize → call entity action → revalidate.
No Prisma here; data authority stays in entity actions.

File Classification

Layer: Mutation boundary

Directive: "use server"

Runtime: Server

Prisma: ❌ Never

Calls: Entity actions for writes

Revalidation: ✅ Explicit

Canonical Example

"use server";


import { createProject } from "./actions/createProject";

import { getSession } from "@/auth";

import { revalidatePath } from "next/cache";


export async function createProjectAction(formData: FormData) {

  const session = await getSession();

  if (!session) throw new Error("Unauthorized"); // security


  await createProject(formData, session.user.id);

  revalidatePath("/projects"); // perf

}

Server vs Entity Actions (Quick)

Server Action: callable by UI, no Prisma, orchestrates + revalidates.
Entity Action: owns Prisma, validation, authorization; not called by UI directly.
Keep mutations thin at server-action layer; keep rules/DB in entity actions.