Server Actions vs. API Routes: When to Use Each

Both ship with Next.js. Both can mutate data. So which one should you reach for?

Use server actions when...

• The call originates from a React component.
• You want automatic revalidatePath support.
• You do not need a public HTTP endpoint.

Use API routes when...

• You need a public REST API (this site exposes /api/blog for exactly that).
• An external client — curl, a mobile app, a webhook — needs to hit it.
• You need fine-grained HTTP semantics (status codes, headers, streaming).

My rule of thumb

If the caller is a <form> or a button, use a server action. If the caller is curl, use an API route.

This site uses both, and they share the same underlying helpers in lib/actions/blogs.ts.