Page "${page}" is missing exported function "generateStaticP

Error message

Page "${page}" is missing exported function "generateStaticParams()", which is required with "output: export" config. See more info here: https://nextjs.org/docs/messages/generate-static-params

What it means

Thrown during static-path resolution in dev when output:'export' is set and an app-directory page does not export generateStaticParams. Static export requires every dynamic segment to be pre-rendered at build time, so Next.js needs the list of params; when prerenderedRoutes is undefined (no generateStaticParams exported), it throws. Triggered in getStaticPaths while coalescing static-path results.

Source

Thrown at packages/next/src/server/dev/next-dev-server.ts:889

        return pathsResult
      } finally {
        // we don't re-use workers so destroy the used one
        staticPathsWorker.end()
      }
    }
    const result = this.staticPathsCache.get(pathname)

    const nextInvoke = withCoalescedInvoke(__getStaticPaths)(
      `staticPaths-${pathname}`,
      []
    )
      .then(async (res) => {
        const { prerenderedRoutes, fallbackMode: fallback } = res.value

        if (isAppPath) {
          if (this.nextConfig.output === 'export') {
            if (!prerenderedRoutes) {
              throw new Error(
                `Page "${page}" is missing exported function "generateStaticParams()", which is required with "output: export" config. See more info here: https://nextjs.org/docs/messages/generate-static-params`
              )
            }

            if (
              !prerenderedRoutes.some((item) => item.pathname === urlPathname)
            ) {
              throw new Error(
                `Page "${page}" is missing param "${pathname}" in "generateStaticParams()", which is required with "output: export" config.`
              )
            }
          }
        }

        if (!isAppPath && this.nextConfig.output === 'export') {
          if (fallback === FallbackMode.BLOCKING_STATIC_RENDER) {
            throw new Error(
              'getStaticPaths with "fallback: blocking" cannot be used with "output: export". See more info here: https://nextjs.org/docs/advanced-features/static-html-export'

View on GitHub (pinned to 0ae8c72462)

Solutions

Add an exported async generateStaticParams() to the dynamic page that returns all params to prerender.
If the route should be fully static, provide the single param explicitly.
Remove output:'export' if dynamic/on-demand rendering is actually needed.
Ensure generateStaticParams returns an array of param objects covering every dynamic segment.

Example fix

// before: app/blog/[slug]/page.tsx with output:export, no params
export default function Page({ params }: { params: { slug: string } }) {
  return <h1>{params.slug}</h1>
}

// after
export async function generateStaticParams() {
  return [{ params: { slug: 'hello' } }, { params: { slug: 'world' } }]
}
export default function Page({ params }: { params: { slug: string } }) {
  return <h1>{params.slug}</h1>
}

Defensive patterns

Strategy: validation

Validate before calling

// Static-analysis guard: every dynamic app route needs generateStaticParams under output:export
import fs from 'fs'
import path from 'path'
function assertExportDynamicRoutesHaveGSP(appDir: string) {
  for (const file of fs.readdirSync(appDir, { withFileTypes: true, recursive: true }) as any[]) {
    if (file.isFile() && /\[.+\]/.test(file.parentPath || '') && /\.(tsx|ts|js|jsx)$/.test(file.name)) {
      const src = fs.readFileSync(path.join(file.parentPath, file.name), 'utf8')
      if (/export\s+default/.test(src) && !/generateStaticParams/.test(src)) {
        throw new Error(`${file.name}: dynamic route missing generateStaticParams (output:export)`)
      }
    }
  }
}

Prevention

When enabling output:'export', audit every app-router [param] route.
Keep generateStaticParams in sync with your data source.
Add a CI step that asserts all dynamic routes export params under export mode.

When it happens

Trigger: An app-router page (isAppPath true) under output:'export' has a dynamic route segment (e.g. app/blog/[slug]/page.tsx) but exports no generateStaticParams function. res.value.prerenderedRoutes is undefined, hitting the throw at line 889.

Common situations: Adding output:'export' to next.config while having dynamic app-router routes. Converting a pages-router project to app router and forgetting generateStaticParams. Newly adding a [param] route after enabling static export.

Related errors

AI-assisted analysis of vercel/next.js@0ae8c72462 (2026-08-06). Data as JSON: /api/errors/2e4d6755babf3783. Report an issue: GitHub.