Inputs

• Required env (server-only): TRANSLOADIT_KEY, TRANSLOADIT_SECRET
• Optional env: TRANSLOADIT_SMARTCDN_WORKSPACE, TRANSLOADIT_SMARTCDN_TEMPLATE, TRANSLOADIT_SMARTCDN_INPUT

For local dev, put these in .env.local. Never expose TRANSLOADIT_SECRET to the browser.

Install

npm i @transloadit/utils

Implement (App Router)

Pick the root:

• If your project has src/app, use src/app/...
• Else use app/...

1) Server route: sign Smart CDN URLs

Create app/api/smartcdn/route.ts (or src/app/api/smartcdn/route.ts if you use src/):

import { NextResponse } from 'next/server'
import { getSignedSmartCdnUrl } from '@transloadit/utils/node'

export const runtime = 'nodejs'

function reqEnv(name: string): string {
  const v = process.env[name]
  if (!v) throw new Error(`Missing required env var: ${name}`)
  return v
}

export async function GET() {
  try {
    const authKey = reqEnv('TRANSLOADIT_KEY')
    const authSecret = reqEnv('TRANSLOADIT_SECRET')

    const workspace = process.env.TRANSLOADIT_SMARTCDN_WORKSPACE || 'demo'
    const template = process.env.TRANSLOADIT_SMARTCDN_TEMPLATE || 'serve-preview'
    const input = process.env.TRANSLOADIT_SMARTCDN_INPUT || 'example.jpg'

    const url = getSignedSmartCdnUrl({ workspace, template, input, authKey, authSecret })

    return NextResponse.json({ url, workspace, template, input })
  } catch (err) {
    const message = err instanceof Error ? err.message : 'Unknown error'
    return NextResponse.json({ error: message }, { status: 500 })
  }
}

2) Optional: a tiny demo page

Create app/smartcdn/page.tsx (or src/app/smartcdn/page.tsx):

import SmartCdnDemo from './smartcdn-demo'

export default function SmartCdnPage() {
  return (
    <main style={{ padding: 24 }}>
      <h1 style={{ fontSize: 20, fontWeight: 600 }}>Smart CDN Signed URL</h1>
      <SmartCdnDemo />
    </main>
  )
}

Create app/smartcdn/smartcdn-demo.tsx (or src/app/smartcdn/smartcdn-demo.tsx):

'use client'

import { useEffect, useState } from 'react'

export default function SmartCdnDemo() {
  const [payload, setPayload] = useState<unknown>(null)

  useEffect(() => {
    let cancelled = false
    fetch('/api/smartcdn', { cache: 'no-store' })
      .then(async (res) => res.json())
      .then((json) => {
        if (!cancelled) setPayload(json)
      })
      .catch((err) => {
        if (!cancelled) setPayload({ error: String(err) })
      })
    return () => {
      cancelled = true
    }
  }, [])

  return (
    <pre data-testid="smartcdn-json">
      {payload ? JSON.stringify(payload, null, 2) : '(loading)'}
    </pre>
  )
}

Quick Check

• Start dev server, then open /smartcdn or fetch /api/smartcdn.
• Expect JSON including a url and your { workspace, template, input }.

References (Internal)

• Working reference implementation: https://github.com/transloadit/skills/tree/main/scenarios/integrate-asset-delivery-with-transloadit-smartcdn-in-nextjs

Tested with (see the scenario lockfile for the exact versions):

• Next.js 16.1.6 (App Router)
• React 19.2.3
• @transloadit/utils 4.3.0 (Smart CDN signing)