Sentry React SDK

Opinionated wizard that scans your React project and guides you through complete Sentry setup.

Invoke This Skill When

• User asks to "add Sentry to React" or "set up Sentry" in a React app
• User wants error monitoring, tracing, session replay, profiling, or logging in React
• User mentions @sentry/react, React Sentry SDK, or Sentry error boundaries
• User wants to monitor React Router navigation, Redux state, or component performance

Note: SDK versions and APIs below reflect current Sentry docs at time of writing (@sentry/react ≥8.0.0). Always verify against docs.sentry.io/platforms/javascript/guides/react/ before implementing.

---

Phase 1: Detect

Run these commands to understand the project before making any recommendations:

# Detect React version
cat package.json | grep -E '"react"|"react-dom"'

# Check for existing Sentry
cat package.json | grep '"@sentry/'

# Detect router
cat package.json | grep -E '"react-router-dom"|"@tanstack/react-router"'

# Detect state management
cat package.json | grep -E '"redux"|"@reduxjs/toolkit"'

# Detect build tool
ls vite.config.ts vite.config.js webpack.config.js craco.config.js 2>/dev/null
cat package.json | grep -E '"vite"|"react-scripts"|"webpack"'

# Detect logging libraries
cat package.json | grep -E '"pino"|"winston"|"loglevel"'

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

What to determine:

Question	Impact
React 19+?	Use reactErrorHandler() hook pattern
React <19?	Use Sentry.ErrorBoundary
@sentry/react already present?	Skip install, go straight to feature config
react-router-dom v5 / v6 / v7?	Determines which router integration to use
@tanstack/react-router?	Use tanstackRouterBrowserTracingIntegration()
Redux in use?	Recommend createReduxEnhancer()
Vite detected?	Source maps via sentryVitePlugin
CRA (react-scripts)?	Source maps via @sentry/webpack-plugin in CRACO
Backend directory found?	Trigger Phase 4 cross-link suggestion

---

Phase 2: Recommend

Present a concrete recommendation based on what you found. Don't ask open-ended questions — lead with a proposal:

Recommended (core coverage):

• ✅ Error Monitoring — always; captures unhandled errors, React error boundaries, React 19 hooks
• ✅ Tracing — React SPAs benefit from page load, navigation, and API call tracing
• ✅ Session Replay — recommended for user-facing apps; records sessions around errors

Optional (enhanced observability):

• ⚡ Logging — structured logs via Sentry.logger.*; recommend when structured log search is needed
• ⚡ Profiling — JS Self-Profiling API (⚠️ experimental; requires cross-origin isolation headers)

Recommendation logic:

Feature	Recommend when...
Error Monitoring	Always — non-negotiable baseline
Tracing	Always for React SPAs — page load + navigation spans are high-value
Session Replay	User-facing app, login flows, or checkout pages
Logging	App needs structured log search or log-to-trace correlation
Profiling	Performance-critical app; server sends Document-Policy: js-profiling header

React-specific extras:

• React 19 detected → set up reactErrorHandler() on createRoot
• React Router detected → configure matching router integration (see Phase 3)
• Redux detected → add createReduxEnhancer() to Redux store
• Vite detected → configure sentryVitePlugin for source maps (essential for readable stack traces)

Propose: "I recommend setting up Error Monitoring + Tracing + Session Replay. Want me to also add Logging or Profiling?"

---

Phase 3: Guide

Install

npm install @sentry/react --save

Create src/instrument.ts

Sentry must initialize before any other code runs. Put Sentry.init() in a dedicated sidecar file:

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

Sentry.init({
  dsn: import.meta.env.VITE_SENTRY_DSN, // Adjust per build tool (see table below)
  environment: import.meta.env.MODE,
  release: import.meta.env.VITE_APP_VERSION, // inject at build time

  sendDefaultPii: true,

  integrations: [
    Sentry.browserTracingIntegration(),
    Sentry.replayIntegration({
      maskAllText: true,
      blockAllMedia: true,
    }),
  ],

  // Tracing
  tracesSampleRate: 1.0, // lower to 0.1–0.2 in production
  tracePropagationTargets: ["localhost", /^https:\/\/yourapi\.io/],

  // Session Replay
  replaysSessionSampleRate: 0.1,
  replaysOnErrorSampleRate: 1.0,

  enableLogs: true,
});

DSN environment variable by build tool:

Build Tool	Variable Name	Access in code
Vite	VITE_SENTRY_DSN	import.meta.env.VITE_SENTRY_DSN
Create React App	REACT_APP_SENTRY_DSN	process.env.REACT_APP_SENTRY_DSN
Custom webpack	SENTRY_DSN	process.env.SENTRY_DSN

Entry Point Setup

Import instrument.ts as the very first import in your entry file:

// src/main.tsx (Vite) or src/index.tsx (CRA/webpack)
import "./instrument";              // ← MUST be first

import { StrictMode } from "react";
import { createRoot } from "react-dom/client";
import App from "./App";

createRoot(document.getElementById("root")!).render(
  <StrictMode>
    <App />
  </StrictMode>
);

React Version-Specific Error Handling

React 19+ — use reactErrorHandler() on createRoot:

import { reactErrorHandler } from "@sentry/react";

createRoot(document.getElementById("root")!, {
  onUncaughtError: reactErrorHandler(),
  onCaughtError: reactErrorHandler(),
  onRecoverableError: reactErrorHandler(),
}).render(<App />);

React <19 — wrap your app in Sentry.ErrorBoundary:

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

createRoot(document.getElementById("root")!).render(
  <Sentry.ErrorBoundary fallback={<p>Something went wrong</p>} showDialog>
    <App />
  </Sentry.ErrorBoundary>
);

Use <Sentry.ErrorBoundary> for any sub-tree that should catch errors independently (route sections, widgets, etc.).

Router Integration

Configure the matching integration for your router:

Router	Integration	Notes
React Router v7	reactRouterV7BrowserTracingIntegration	useEffect, useLocation, useNavigationType, createRoutesFromChildren, matchRoutes from react-router
React Router v6	reactRouterV6BrowserTracingIntegration	useEffect, useLocation, useNavigationType, createRoutesFromChildren, matchRoutes from react-router-dom
React Router v5	reactRouterV5BrowserTracingIntegration	Wrap routes in withSentryRouting(Route)
TanStack Router	tanstackRouterBrowserTracingIntegration(router)	Pass router instance — no hooks required
No router / custom	browserTracingIntegration()	Names transactions by URL path

React Router v6/v7 setup:

// in instrument.ts integrations array:
import React from "react";
import {
  createRoutesFromChildren, matchRoutes,
  useLocation, useNavigationType,
} from "react-router-dom"; // or "react-router" for v7
import * as Sentry from "@sentry/react";
import { reactRouterV6BrowserTracingIntegration } from "@sentry/react";
import { createBrowserRouter } from "react-router-dom";

// Option A — createBrowserRouter (recommended for v6.4+):
const sentryCreateBrowserRouter = Sentry.wrapCreateBrowserRouterV6(createBrowserRouter);
const router = sentryCreateBrowserRouter([...routes]);

// Option B — createBrowserRouter for React Router v7:
// const sentryCreateBrowserRouter = Sentry.wrapCreateBrowserRouterV7(createBrowserRouter);

// Option C — integration with hooks (v6 without data APIs):
Sentry.init({
  integrations: [
    reactRouterV6BrowserTracingIntegration({
      useEffect: React.useEffect,
      useLocation,
      useNavigationType,
      matchRoutes,
      createRoutesFromChildren,
    }),
  ],
});

TanStack Router setup:

import { tanstackRouterBrowserTracingIntegration } from "@sentry/react";

// Pass your TanStack router instance:
Sentry.init({
  integrations: [tanstackRouterBrowserTracingIntegration(router)],
});

Redux Integration (when detected)

import * as Sentry from "@sentry/react";
import { configureStore } from "@reduxjs/toolkit";

const store = configureStore({
  reducer: rootReducer,
  enhancers: (getDefaultEnhancers) =>
    getDefaultEnhancers().concat(Sentry.createReduxEnhancer()),
});

Source Maps Setup (strongly recommended)

Without source maps, stack traces show minified code. Set up the build plugin to upload source maps automatically:

Vite (vite.config.ts):

import { defineConfig } from "vite";
import react from "@vitejs/plugin-react";
import { sentryVitePlugin } from "@sentry/vite-plugin";

export default defineConfig({
  build: { sourcemap: "hidden" },
  plugins: [
    react(),
    sentryVitePlugin({
      org: process.env.SENTRY_ORG,
      project: process.env.SENTRY_PROJECT,
      authToken: process.env.SENTRY_AUTH_TOKEN,
    }),
  ],
});

Add to .env (never commit):

SENTRY_AUTH_TOKEN=sntrys_...
SENTRY_ORG=my-org-slug
SENTRY_PROJECT=my-project-slug

Create React App (via CRACO):

npm install @craco/craco @sentry/webpack-plugin --save-dev

// craco.config.js
const { sentryWebpackPlugin } = require("@sentry/webpack-plugin");

module.exports = {
  webpack: {
    plugins: {
      add: [
        sentryWebpackPlugin({
          org: process.env.SENTRY_ORG,
          project: process.env.SENTRY_PROJECT,
          authToken: process.env.SENTRY_AUTH_TOKEN,
        }),
      ],
    },
  },
};

For Each Agreed Feature

Walk through features one at a time. Load the reference file, follow its steps, verify before moving on:

Feature	Reference	Load when...
Error Monitoring	${SKILL_ROOT}/references/error-monitoring.md	Always (baseline)
Tracing	${SKILL_ROOT}/references/tracing.md	SPA navigation / API call tracing
Session Replay	${SKILL_ROOT}/references/session-replay.md	User-facing app
Logging	${SKILL_ROOT}/references/logging.md	Structured log search / log-to-trace
Profiling	${SKILL_ROOT}/references/profiling.md	Performance-critical app
React Features	${SKILL_ROOT}/references/react-features.md	Redux, component tracking, source maps, integrations catalog

For each feature: Read ${SKILL_ROOT}/references/<feature>.md, follow steps exactly, verify it works.

---

Configuration Reference

Key Sentry.init() Options

Option	Type	Default	Notes
dsn	string	—	Required. SDK disabled when empty
environment	string	"production"	e.g., "staging", "development"
release	string	—	e.g., "my-app@1.0.0" or git SHA — links errors to releases
sendDefaultPii	boolean	false	Includes IP addresses and request headers
tracesSampleRate	number	—	0–1; 1.0 in dev, 0.1–0.2 in prod
tracesSampler	function	—	Per-transaction sampling; overrides rate
tracePropagationTargets	(string|RegExp)[]	—	Outgoing URLs that receive distributed tracing headers
replaysSessionSampleRate	number	—	Fraction of all sessions recorded
replaysOnErrorSampleRate	number	—	Fraction of error sessions recorded
enableLogs	boolean	false	Enable Sentry.logger.* API
attachStacktrace	boolean	false	Stack traces on captureMessage() calls
maxBreadcrumbs	number	100	Breadcrumbs stored per event
debug	boolean	false	Verbose SDK output to console
tunnel	string	—	Proxy URL to bypass ad blockers

React Compatibility Matrix

React Version	Error handling approach	SDK minimum
React 19+	reactErrorHandler() on createRoot	@sentry/react ≥8.0.0
React 16–18	Sentry.ErrorBoundary component	@sentry/react ≥7.0.0
React 16	componentDidCatch class boundaries	@sentry/react ≥6.0.0

---

Verification

Trigger test events to confirm Sentry is receiving data:

// Add a temporary test button anywhere in your app
import * as Sentry from "@sentry/react";

function SentryTest() {
  return (
    <>
      <button onClick={() => { throw new Error("Sentry React test error"); }}>
        Test Error
      </button>
      <button onClick={() => Sentry.captureMessage("Sentry test message", "info")}>
        Test Message
      </button>
    </>
  );
}

Check the Sentry dashboard:

• Issues → error appears within seconds
• Traces → page load and navigation transactions visible
• Replays → session recording visible after page interaction
• Logs → structured log entries if logging enabled

Set debug: true in Sentry.init() and check the browser console if nothing appears.

---

Phase 4: Cross-Link

After completing React setup, check for a companion backend missing Sentry coverage:

ls ../backend ../server ../api ../go ../python 2>/dev/null
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 2>/dev/null | grep '<artifactId>' | head -3

If a backend exists without Sentry configured, suggest the matching skill:

Backend detected	Suggest skill
Go (go.mod)	sentry-go-sdk
Python (requirements.txt, pyproject.toml)	sentry-python-sdk
Ruby (Gemfile)	sentry-ruby-sdk
Java (pom.xml, build.gradle)	Use @sentry/java — see docs.sentry.io/platforms/java/
Node.js (Express, Fastify)	Use @sentry/node — see docs.sentry.io/platforms/javascript/guides/express/

---

Troubleshooting

Issue	Solution
Events not appearing	Set debug: true, check DSN, open browser console for SDK errors
Source maps not working	Build in production mode (npm run build); verify SENTRY_AUTH_TOKEN is set
Minified stack traces	Source maps not uploading — check plugin config and auth token
instrument.ts not running first	Verify it's the first import in entry file before React/app imports
React 19 errors not captured	Confirm reactErrorHandler() is passed to all three createRoot options
React <19 errors not captured	Ensure <Sentry.ErrorBoundary> wraps the component tree
Router transactions named <unknown>	Add router integration matching your router version
tracePropagationTargets not matching	Check regex escaping; default is localhost and your DSN origin only
Session replay not recording	Confirm replayIntegration() is in init; check replaysSessionSampleRate
Redux actions not in breadcrumbs	Add Sentry.createReduxEnhancer() to store enhancers
Ad blockers dropping events	Set tunnel: "/sentry-tunnel" and add server-side relay endpoint
High replay storage costs	Lower replaysSessionSampleRate; keep replaysOnErrorSampleRate: 1.0
Profiling not working	Verify Document-Policy: js-profiling header is set on document responses