Star us on GitHub

Next.js App Router Guide

npm install @highlight-run/next
Client instrumentation

This sections adds session replay and frontend error monitoring to Highlight. This implementation requires React 17 or greater.

  • Add HighlightInit to your layout.tsx file.
// app/layout.tsx import { CONSTANTS } from '../constants' import { HighlightInit } from '@highlight-run/next/client' export default function RootLayout({ children }: { children: React.ReactNode }) { return ( <> <HighlightInit // excludedHostnames={['localhost']} projectId={CONSTANTS.NEXT_PUBLIC_HIGHLIGHT_PROJECT_ID} serviceName="my-nextjs-frontend" tracingOrigins networkRecording={{ enabled: true, recordHeadersAndBody: true }} debug /> <html lang="en"> <body>{children}</body> </html> </> ) }
Add React ErrorBoundary (optional)

Optionally add a React Error Boundary.

You can wrap the root of your app in layout.tsx with the <ErrorBoundary />, or you can wrap individual parts of your React tree.

// components/error-boundary.tsx 'use client' import { ErrorBoundary as HighlightErrorBoundary } from '@highlight-run/next/client' export function ErrorBoundary({ children }: { children: React.ReactNode }) { return <HighlightErrorBoundary showDialog>{children}</HighlightErrorBoundary> }
Validate client implementation
  • Render this example component somewhere in your client application to see it in action.

Omit the ErrorBoundary wrapper if you haven't created it yet.

// app/app-router-test/page.tsx // http://localhost:3000/app-router-test 'use client' import { useEffect, useState } from 'react' import { ErrorBoundary } from '../../components/error-boundary' export default function ErrorButtons() { const [isErrored, setIsErrored] = useState(false) return ( <div style={{ display: 'grid', gridTemplateColumns: '20rem', gridGap: '1rem', padding: '2rem', }} > <ErrorBoundary> <button onClick={() => { throw new Error('Threw client-side Error') }} > Throw client-side onClick error </button> <ThrowerOfErrors isErrored={isErrored} setIsErrored={setIsErrored} /> <button onClick={() => setIsErrored(true)}>Trigger error boundary</button> <button onClick={async () => { throw new Error('an async error occurred') }} > Trigger promise error </button> </ErrorBoundary> </div> ) } function ThrowerOfErrors({ isErrored, setIsErrored, }: { isErrored: boolean setIsErrored: (isErrored: boolean) => void }) { useEffect(() => { if (isErrored) { setIsErrored(false) throw new Error('Threw useEffect error') } }, [isErrored, setIsErrored]) return null }
Enable server-side tracing

We use experimental.instrumentationHook to capture Next.js's automatic instrumentation. This method captures detailed API route tracing as well as server-side errors.

  • Enable experimental.instrumentationHook in next.config.js.
// next.config.mjs import { withHighlightConfig } from '@highlight-run/next/config' const nextConfig = { experimental: { instrumentationHook: true, }, webpack(config, options) { if (options.isServer) { config.ignoreWarnings = [{ module: /highlight-(run\/)?node/ }] } return config }, // ...additional config } export default withHighlightConfig(nextConfig)
  • Call registerHighlight in instrumentation.ts or src/instrumentation.ts if you're using a /src folder. Make sure that instrumentation.ts is a sibling of your pages folder.
// instrumentation.ts or src/instrumentation.ts import { CONSTANTS } from './constants' export async function register() { const { registerHighlight } = await import('@highlight-run/next/server') registerHighlight({ projectID: CONSTANTS.NEXT_PUBLIC_HIGHLIGHT_PROJECT_ID, serviceName: 'my-nextjs-backend', }) }
Catch server-side render (SSR) errors

App Router uses app/error.tsx to send server-side render errors to the client. We can catch and consume those errors with a custom error page.

This will captures any server-rendered error, including those generated from React Server Components, as sometimes identified with the 'use server' directive.

All SSR error will display as client errors on your Highlight dashboard.

We don't call H.init in this example because we injected <HighlightInit /> into the layout using app/layout.tsx.

// app/error.tsx 'use client' // Error components must be Client Components import { appRouterSsrErrorHandler, AppRouterErrorProps, } from '@highlight-run/next/ssr' export default appRouterSsrErrorHandler( ({ error, reset }: AppRouterErrorProps) => { console.error(error) return ( <div> <h2>Something went wrong!</h2> <button onClick={ () => reset() // Attempt to recover by trying to re-render the segment } > Try again </button> </div> ) }, )
Validate SSR error capture
  • Copy the following code into app/app-router-ssr/page.tsx.
  • Build and start your production app with npm run build && npm run start.
  • Once you've validated that the error is caught and sent to, don't forget to ctrl + c to kill npm run start and restart with npm run dev.
// app/app-router-ssr/page.tsx 'use server' type Props = { searchParams: { error?: string } } export default async function SsrPage({ searchParams }: Props) { if (typeof searchParams.error !== "undefined") { throw new Error( '๐ŸŽ‰ SSR Error with use-server: src/app-router/ssr/page.tsx', ) } return ( <div> <h1>App Router SSR with use-server: Success</h1> <p>The random number is {Math.random()}</p> <p>The date is {new Date().toLocaleTimeString()}</p> </div> ) }
Validate server actions
  • Copy the following code into app/server-actions/page.tsx.
  • Navigate to to validate that the error was captured.
export default function Page() { async function createInvoice(formData: FormData) { 'use server' if (formData.get('isError')) { throw new Error( '๐ŸŒ‹ Server action error: src/app/server-actions/page.tsx', ) } '๐ŸŽ‰ Server action success: src/app/server-actions/page.tsx', ) } return ( <form action={createInvoice} style={{ padding: '1rem' }}> <div style={{ display: 'flex', gap: '1rem' }}> <label>Throw error</label> <input type="checkbox" name="isError" defaultChecked /> <button>Submit form</button> </div> </form> ) }
Skip localhost tracking

We do not recommend enabling this while integrating Highlight for the first time because it will prevent you from validating that your local build can send data to Highlight.

In the case that you don't want local sessions sent to Highlight, the excludedHostnames prop accepts an array of partial or full hostnames. For example, if you pass in excludedHostnames={['localhost', 'staging]}, you'll block localhost on all ports, and

Alternatively, you could manually call H.start() and H.stop() to manage invocation on your own.

// components/custom-highlight-start.tsx 'use client' import { H } from '@highlight-run/next/client' import { useEffect } from 'react' export function CustomHighlightStart() { useEffect(() => { const shouldStartHighlight = window.location.hostname === '' if (shouldStartHighlight) { H.start() return () => { H.stop() } } }) return null }
// app/layout.tsx <HighlightInit manualStart projectId={CONSTANTS.NEXT_PUBLIC_HIGHLIGHT_PROJECT_ID} serviceName="my-nextjs-frontend" /> <CustomHighlightStart />
API route instrumentation


Each App Router route must be wrapped individually.

  • Add @highlight-run/node to experimental.serverComponentsExternalPackages in your next.config.js.
// next.config.js const nextConfig = { experimental: { serverComponentsExternalPackages: ['@highlight-run/node'], }, } module.exports = nextConfig
  • Create a file to export your AppRouterHighlight wrapper function:
// utils/app-router-highlight.config.ts: import { AppRouterHighlight } from '@highlight-run/next/server' import { CONSTANTS } from '../constants' export const withAppRouterHighlight = AppRouterHighlight({ projectID: CONSTANTS.NEXT_PUBLIC_HIGHLIGHT_PROJECT_ID, })
  • Wrap your /app functions with withAppRouterHighlight:
// app/nodejs-app-router-test/route.ts import { NextRequest } from 'next/server' import { withAppRouterHighlight } from '../../utils/app-router-highlight.config' export const GET = withAppRouterHighlight(async function GET(request: NextRequest) {'Here: app/nodejs-app-router-test/route.ts') if (request.url?.includes('error')) { throw new Error('Error: app/nodejs-app-router-test (App Router)') } else { return new Response('Success: app/nodejs-app-router-test') } })
  • Add highlightMiddleware to enable cookie-based session tracking
// middleware.ts import type { NextRequest } from 'next/server' import { NextResponse } from 'next/server' import { highlightMiddleware } from '@highlight-run/next/server' export function middleware(request: NextRequest) { highlightMiddleware(request) return }
  • Run your app in dev mode with npm run dev.
  • Copy/paste the above code snippet into /app/api/nodejs-app-router-test.ts and hit the endpoint in your browser or with curl to watch it work.
curl http://localhost:3000/nodejs-app-router-test?error