# Detect Next.js version and existing Sentry
cat package.json | grep -E '"next"|"@sentry/'

# Detect router type (App Router vs Pages Router)
ls src/app app src/pages pages 2>/dev/null

# Check for existing Sentry config files
ls instrumentation.ts instrumentation-client.ts sentry.server.config.ts sentry.edge.config.ts 2>/dev/null
ls src/instrumentation.ts src/instrumentation-client.ts 2>/dev/null

# Check next.config
ls next.config.ts next.config.js next.config.mjs 2>/dev/null

# Check for existing error boundaries
find . -name "global-error.tsx" -o -name "_error.tsx" 2>/dev/null | grep -v node_modules

# Check build tool
cat package.json | grep -E '"turbopack"|"webpack"'

# Check for logging libraries
cat package.json | grep -E '"pino"|"winston"|"bunyan"'

# Check for companion backend
ls ../backend ../server ../api 2>/dev/null
cat ../go.mod ../requirements.txt ../Gemfile 2>/dev/null | head -3

npm install @sentry/nextjs --save

import * as Sentry from "@sentry/nextjs";

Sentry.init({
  dsn: process.env.NEXT_PUBLIC_SENTRY_DSN ?? "___PUBLIC_DSN___",

  sendDefaultPii: true,

  // 100% in dev, 10% in production
  tracesSampleRate: process.env.NODE_ENV === "development" ? 1.0 : 0.1,

  // Session Replay: 10% of all sessions, 100% of sessions with errors
  replaysSessionSampleRate: 0.1,
  replaysOnErrorSampleRate: 1.0,

  enableLogs: true,

  integrations: [
    Sentry.replayIntegration(),
    // Optional: user feedback widget
    // Sentry.feedbackIntegration({ colorScheme: "system" }),
  ],
});

// Hook into App Router navigation transitions (App Router only)
export const onRouterTransitionStart = Sentry.captureRouterTransitionStart;

import * as Sentry from "@sentry/nextjs";

Sentry.init({
  dsn: process.env.SENTRY_DSN ?? "___DSN___",

  sendDefaultPii: true,
  tracesSampleRate: process.env.NODE_ENV === "development" ? 1.0 : 0.1,

  // Attach local variable values to stack frames
  includeLocalVariables: true,

  enableLogs: true,
});

import * as Sentry from "@sentry/nextjs";

Sentry.init({
  dsn: process.env.SENTRY_DSN ?? "___DSN___",

  sendDefaultPii: true,
  tracesSampleRate: process.env.NODE_ENV === "development" ? 1.0 : 0.1,

  enableLogs: true,
});

import * as Sentry from "@sentry/nextjs";

export async function register() {
  if (process.env.NEXT_RUNTIME === "nodejs") {
    await import("./sentry.server.config");
  }

  if (process.env.NEXT_RUNTIME === "edge") {
    await import("./sentry.edge.config");
  }
}

// Automatically captures all unhandled server-side request errors
// Requires @sentry/nextjs >= 8.28.0
export const onRequestError = Sentry.captureRequestError;

"use client";

import * as Sentry from "@sentry/nextjs";
import NextError from "next/error";
import { useEffect } from "react";

export default function GlobalError({
  error,
}: {
  error: Error & { digest?: string };
}) {
  useEffect(() => {
    Sentry.captureException(error);
  }, [error]);

  return (
    <html>
      <body>
        <NextError statusCode={0} />
      </body>
    </html>
  );
}

import * as Sentry from "@sentry/nextjs";
import type { NextPageContext } from "next";
import NextErrorComponent from "next/error";

type ErrorProps = { statusCode: number };

export default function CustomError({ statusCode }: ErrorProps) {
  return <NextErrorComponent statusCode={statusCode} />;
}

CustomError.getInitialProps = async (ctx: NextPageContext) => {
  await Sentry.captureUnderscoreErrorException(ctx);
  return NextErrorComponent.getInitialProps(ctx);
};

import type { NextConfig } from "next";
import { withSentryConfig } from "@sentry/nextjs";

const nextConfig: NextConfig = {
  // your existing Next.js config
};

export default withSentryConfig(nextConfig, {
  org: "___ORG_SLUG___",
  project: "___PROJECT_SLUG___",

  // Source map upload auth token (see Source Maps section below)
  authToken: process.env.SENTRY_AUTH_TOKEN,

  // Upload wider set of client source files for better stack trace resolution
  widenClientFileUpload: true,

  // Create a proxy API route to bypass ad-blockers
  tunnelRoute: "/monitoring",

  // Suppress non-CI output
  silent: !process.env.CI,
});

// middleware.ts
export const config = {
  matcher: [
    // Exclude monitoring route, Next.js internals, and static files
    "/((?!monitoring|_next/static|_next/image|favicon.ico).*)",
  ],
};

# .env.sentry-build-plugin  (gitignore this file)
SENTRY_AUTH_TOKEN=sntrys_eyJ...

SENTRY_AUTH_TOKEN=sntrys_eyJ...
SENTRY_ORG=my-org        # optional if set in next.config
SENTRY_PROJECT=my-project # optional if set in next.config

.env.sentry-build-plugin

withSentryConfig(nextConfig, {
  org: "my-org",
  project: "my-project",
  authToken: process.env.SENTRY_AUTH_TOKEN, // reads from .env.sentry-build-plugin or CI env
  widenClientFileUpload: true,
});

// Add temporarily to a server action or API route, then remove
import * as Sentry from "@sentry/nextjs";

throw new Error("Sentry test error — delete me");
// or
Sentry.captureException(new Error("Sentry test error — delete me"));

# Check for backend services in adjacent directories
ls ../backend ../server ../api ../services 2>/dev/null

# Check for backend language indicators
cat ../go.mod 2>/dev/null | head -3
cat ../requirements.txt ../pyproject.toml 2>/dev/null | head -3
cat ../Gemfile 2>/dev/null | head -3
cat ../pom.xml ../build.gradle 2>/dev/null | head -3