AuthzX + Next.js

Add authorization to your Next.js app in 5 minutes.

Install

npm install @authzx/sdk

Set up the client

Create lib/authzx.ts:

import { AuthzX } from '@authzx/sdk'

export const authzx = new AuthzX({
  apiKey: process.env.AUTHZX_API_KEY!,
})

Add your API key to .env.local:

AUTHZX_API_KEY=azx_...

Server-side check (App Router)

In a Server Component or page.tsx:

import { authzx } from '@/lib/authzx'
import { redirect } from 'next/navigation'

export default async function DocumentPage({ params }: { params: { id: string } }) {
  const userId = await getCurrentUserId() // your auth logic

  const allowed = await authzx.check(
    { id: userId },
    'read',
    { id: params.id, type: 'document' }
  )

  if (!allowed) {
    redirect('/unauthorized')
  }

  return <div>Document content</div>
}

API Route

Create app/api/documents/[id]/route.ts:

import { authzx } from '@/lib/authzx'
import { NextRequest, NextResponse } from 'next/server'

export async function GET(req: NextRequest, { params }: { params: { id: string } }) {
  const userId = req.headers.get('x-user-id')
  if (!userId) {
    return NextResponse.json({ error: 'unauthorized' }, { status: 401 })
  }

  const allowed = await authzx.check(
    { id: userId },
    'read',
    { id: params.id, type: 'document' }
  )

  if (!allowed) {
    return NextResponse.json({ error: 'forbidden' }, { status: 403 })
  }

  return NextResponse.json({ id: params.id, content: '...' })
}

Conditional UI

Check permissions and show/hide UI elements:

import { authzx } from '@/lib/authzx'

export default async function DocumentActions({ userId, docId }: Props) {
  const canEdit = await authzx.check({ id: userId }, 'write', { id: docId, type: 'document' })
  const canDelete = await authzx.check({ id: userId }, 'delete', { id: docId, type: 'document' })

  return (
    <div>
      {canEdit && <button>Edit</button>}
      {canDelete && <button>Delete</button>}
    </div>
  )
}

Using the local agent

For lower latency, run the AuthzX Agent and point the SDK to it:

export const authzx = new AuthzX({
  baseUrl: process.env.AUTHZX_URL || 'http://localhost:8181',
})

No API key needed when using the agent.

Error handling

import { AuthzXError } from '@authzx/sdk'

try {
  await authzx.check(subject, 'read', resource)
} catch (err) {
  if (err instanceof AuthzXError && err.isAuthError) {
    // Invalid API key — check your .env.local
  }
}