Error "generateStaticParams()" so it cannot be used with "output: export" config.

[PedrooMota]

Summary

I can't build my project, because it gives the following error:

Page "/api/auth/[...nextauth]" is missing "generateStaticParams()" so it cannot be used with "output: export" config.

Even using use client or export const dynamic = 'force-static' in route.ts, my build still gives this error

I checked other discussions, but none of them solved my problem. If anyone knows what to do, I would be grateful.

versions used were:

1. next: 13.5.4
2. next-auth: 4.23.2

Additional information

No response

Example

No response

[icyJoseph]

Right, so if I make the assumption that you are using /api to create Route Handlers, and also use export mode, then I have to tell you that you are trying to combine two different things.

export mode builds a static HTML site, only HTML+JS+CSS to be sent by a "static files server" down to a browser, but the "static file server" doesn't do any other handling, in fact, you have to provide yourself, usually hosting providers do that.

To use Route handlers, you need a Node.js runtime running the Next.js Server (with next start). This is why the compiler wants you to define generateStaticParams so that it can try to build those during next build, and put them into the static HTML output.

[jeffreyschultz]

I need this ability because we have two deployment footprints. One is hosted within a container that is running nextjs server where next-auth is handling authentication, and another that is being hosted within nginx, where nginx is handling authentication as part of a more complex deployment.

Is there a way to turn off the API Routes for mode: export because when that is set, I don't need the API route functionality? All of my APIs are deployed separately, and this was purely for securing the webapp when serving with nextjs.

I guess the question would ultimately be, do I need to be using the App Router, and just go back to the Page Router?

[airtonix]

It has no server whatsoever.

clarification:

It has no runtime server, but it definitely is still a server... just one that only serves static assets matched from disk (and it has some restrictive ideals about what file extensions get served as what mimetype)

[airtonix]

@jeffreyschultz In your case I'd modify your build step so it deletes the app/api directory before making a build

[Tosinkoa]

@icyJoseph Pls what can I do in a case where I have [...nextauth] and I am trying to do a build. I've added all my credential logic to my app using next auth, and I need to know if I would have to remove next auth, or there is a workaround to this.

[RjMatic]

i also encounter this error, i'm about to change my career

[jsuryakt]

TL;DR: The error fires when generateStaticParams() returns [], not when it's actually missing. The fix is to ensure it always returns at least one param.

I hit this on Next.js 16.2.4 with output: "export" and Turbopack. My generateStaticParams fetched from a remote API that was returning HTTP 500, so the catch block returned []. The error message led me down a hours-long rabbit hole inspecting compiled Turbopack chunks, thinking the export was being tree-shaken.

What actually happens:

generateStaticParams returns [] → Next.js treats it as "missing" → misleading error

Minimal fix — always return at least one param:

export async function generateStaticParams() {
  try {
    const res = await fetch(`${process.env.API_URL}/posts`);
    if (!res.ok) return [{ slug: "placeholder" }];
    const posts: { slug: string }[] = await res.json();
    if (posts.length === 0) return [{ slug: "placeholder" }];
    return posts.map((p) => ({ slug: p.slug }));
  } catch {
    return [{ slug: "placeholder" }];
  }
}

The page component handles unknown slugs with notFound(), so /blog/placeholder just renders a 404 — harmless.

Suggestion: The error message should differentiate between "function not exported" vs "function returned empty array." Something like:

Error: "generateStaticParams()" for page "/blog/[slug]" returned an empty array.
With "output: export", at least one param must be generated. If this route has
no content yet, return a placeholder value or remove the dynamic route.

[DaCameraGirl]

This error is a fundamental incompatibility between output: 'export' and any Route Handler (API route) in Next.js App Router. Here's a clear explanation and all the solutions.

Root Cause

output: 'export' produces a completely static HTML/CSS/JS site — there is no Node.js server at runtime. Route Handlers (files named route.ts in app/api/...) require a running Node.js server to handle requests. These two things are mutually exclusive.

Next Auth uses a catch-all route handler at /api/auth/[...nextauth]/route.ts, which requires server execution. Static exports can't include this.

Solution 1: Remove/Exclude the API Routes from the Export

If your API routes (like next-auth) live on a separate server or you're handling auth differently in production, exclude them from the build:

// next.config.ts
const nextConfig = {
  output: 'export',
}

Then delete or move app/api/auth/[...nextauth]/route.ts out of the project before running next build. The static export won't need it if auth is handled externally.

Solution 2: Use a Separate Server for Auth (Most Common Pattern)

For a fully static site that still needs authentication, handle auth at a different layer:

• Auth.js v5 (next-auth v5) supports JWT-only mode without a server — tokens are stored in cookies and validated client-side or at edge middleware level
• Deploy your auth server separately (e.g., a standalone Node.js API or an auth provider like Auth0, Clerk, Supabase Auth)
• Use Middleware in Next.js to protect routes — middleware runs at the edge and works with static exports:

// middleware.ts
import { auth } from 'next-auth'

export default auth((req) => {
  if (!req.auth && req.nextUrl.pathname !== '/login') {
    return Response.redirect(new URL('/login', req.url))
  }
})

export const config = {
  matcher: ['/((?!api|_next/static|_next/image|favicon.ico).*)'],
}

Note: Middleware works with output: 'export' when deployed to a platform that supports edge functions (Vercel, Cloudflare Pages). It does NOT work for local file-based exports served via a CDN.

Solution 3: Don't Use output: 'export' — Use Server Deployment

If you need both:

• Next Auth (server-side sessions)
• Dynamic API routes

...then output: 'export' is the wrong choice. Remove it and deploy with next start or any Node.js-compatible platform (Vercel, Railway, Fly.io, etc.):

// next.config.ts
const nextConfig = {
  // Remove 'output: export'
  // output: 'export', <-- delete this line
}

Solution 4: generateStaticParams Returns Empty Array (Different Bug)

If your error is on a non-API dynamic route (not next-auth), and generateStaticParams returns an empty array at build time, Next.js can't statically generate those pages. Fix:

export async function generateStaticParams() {
  const results = await fetchSlugs()
  
  // Guard: never return empty array with output: export
  if (results.length === 0) {
    return [{ slug: 'placeholder' }]
  }
  
  return results.map((item) => ({ slug: item.slug }))
}

Quick Decision Tree

Do you need next-auth server sessions?
├── Yes → Remove output: 'export', deploy to Node.js server
└── No  → Can you use JWT cookies + middleware auth?
    ├── Yes → Use auth middleware only, remove /api/auth route
    └── No  → Use external auth provider (Clerk, Auth0, Supabase)

For most apps using output: 'export' + auth, Solution 2 with next-auth v5 JWT mode + middleware is the cleanest path forward.

[reziferdiansyah]

This error happens because output: "export"` generates a fully static site.

If you use a dynamic route like:

app/blog/[slug]/page.tsx`

Next.js must know all possible slug values at build time. You can fix it by adding generateStaticParams():
`export async function generateStaticParams() {
  const posts = await getPosts()

  return posts.map((post) => ({
    slug: post.slug,
  }))
}`

Example:
`return [
  { slug: "post-1" },
  { slug: "post-2" },
  { slug: "post-3" },
]`

But if your route depends on data that is only available at runtime, then output: "export" is not suitable.

In that case, remove this from next.config.js:
`output: "export"`

and deploy using a Next.js server runtime such as Vercel, Node.js, Docker, or AWS EC2.

Summary:

Use output: "export" only when all dynamic params are known at build time.
Use generateStaticParams() for dynamic routes.
Remove output: "export" if you need runtime dynamic routes.

Static export cannot generate unknown dynamic routes at request time.