sentry-react-sdk

What this skill does

> [All Skills](../../SKILL_TREE.md) > [SDK Setup](../sentry-sdk-setup/SKILL.md) > React SDK

# 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 v5/v6/v7 non-framework navigation, Redux state, or component performance

If project is React Router **Framework mode** using `@sentry/react-router`, use `sentry-react-router-framework-sdk` instead of this skill.

> **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/](https://docs.sentry.io/platforms/javascript/guides/react/) before implementing.

---

## Phase 1: Detect

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

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

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

# Detect router and framework mode hints
cat package.json | grep -E '"react-router-dom"|"react-router"|"@react-router/"|"@tanstack/react-router"|"@sentry/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 Framework mode indicators (`@sentry/react-router`, `@react-router/*`)? | Use `sentry-react-router-framework-sdk` |
| `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 v5/v6/v7 non-framework detected → configure matching router integration (see Phase 3)
- React Router Framework mode detected → switch to `sentry-react-router-framework-sdk`
- 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

```bash
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:

```typescript
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:

```tsx
// 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`:

```tsx
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`:

```tsx
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 (non-framework mode):

| 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:**

```typescript
// in instrument.ts integrations array:
import React from "react";
import {
  createRoutesFromChildren, matchRoutes,
  useLocation, useNavigationType,
} from "react-router-dom"; // or "react-router" for v7