Sentry React Setup

Install and configure Sentry in React projects.

Invoke This Skill When

• User asks to "add Sentry to React" or "install Sentry" in a React app
• User wants error monitoring, logging, or tracing in React
• User mentions "@sentry/react" or React error boundaries

Important: The configuration options and code samples below are examples. Always verify against docs.sentry.io before implementing, as APIs and defaults may have changed.

Install

npm install @sentry/react --save

Configure

Create instrument.js in your project root (must be imported first in your app):

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

Sentry.init({
  dsn: "YOUR_SENTRY_DSN",
  sendDefaultPii: true,
  
  // Tracing + Session Replay
  integrations: [
    Sentry.browserTracingIntegration(),
    Sentry.replayIntegration(),
  ],
  tracesSampleRate: 1.0,
  tracePropagationTargets: [/^\//, /^https:\/\/yourserver\.io\/api/],
  replaysSessionSampleRate: 0.1,
  replaysOnErrorSampleRate: 1.0,
  
  // Logs
  enableLogs: true,
});

Import First in Entry Point

// src/index.js or src/main.jsx
import "./instrument";  // Must be first!
import App from "./App";
import { createRoot } from "react-dom/client";

const root = createRoot(document.getElementById("app"));
root.render(<App />);

Error Handling

React 19+

Use error hooks with createRoot:

import { createRoot } from "react-dom/client";
import * as Sentry from "@sentry/react";

const root = createRoot(document.getElementById("app"), {
  onUncaughtError: Sentry.reactErrorHandler(),
  onCaughtError: Sentry.reactErrorHandler(),
  onRecoverableError: Sentry.reactErrorHandler(),
});

React <19

Use ErrorBoundary component:

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

<Sentry.ErrorBoundary fallback={<p>An error occurred</p>}>
  <MyComponent />
</Sentry.ErrorBoundary>

Router Integration

Router	Integration
React Router v7	Sentry.reactRouterV7BrowserTracingIntegration
React Router v6	Sentry.reactRouterV6BrowserTracingIntegration
React Router v4/v5	Sentry.reactRouterV5BrowserTracingIntegration (shared for both)
TanStack Router	See TanStack Router docs

Redux Integration (Optional)

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

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

Source Maps

Upload source maps for readable stack traces:

npx @sentry/wizard@latest -i sourcemaps

Environment Variables

SENTRY_DSN=https://xxx@o123.ingest.sentry.io/456
SENTRY_AUTH_TOKEN=sntrys_xxx  # Used by sentry-cli / source maps, not the SDK

**Note:** The SDK reads `SENTRY_DSN` automatically. If using Create React App, prefix with `REACT_APP_`; for Vite, use `VITE_`. `SENTRY_AUTH_TOKEN`/`ORG`/`PROJECT` are used by `sentry-cli` for source map uploads, not by the browser SDK.

## Verification

Add test button to trigger error:

```javascript
<button onClick={() => { throw new Error("Sentry Test Error"); }}>
  Test Sentry
</button>