Error Monitoring

A full Sentry replacement built into the Experience Platform. Errors are captured automatically and sent via protobuf. When a page crashes, users can optionally submit a comment for debug context.

Error Capture (Automatic)

The SDK hooks into:

window.onerror — runtime JS errors
window.onunhandledrejection — unhandled Promise rejections
React ErrorBoundary — React render errors (React SDK only)
fetch/XMLHttpRequest wrappers — network errors (4xx, 5xx, timeouts)

Each error captures:

Error message + stack trace
Source file, line, column
Page URL + page context
Browser context (user agent, browser, OS, screen size, device type)
Breadcrumbs (last 50 actions leading up to the error)
Session events (from tracking, for full context)
Severity: INFO, WARNING, ERROR, FATAL

Breadcrumbs

Breadcrumbs are a chronological trail of what happened before an error. The SDK maintains a ring buffer of the last 50 breadcrumbs:

Category	What's Captured
`navigation`	Page navigations (URL changes)
`click`	User clicks (element tag + text)
`console`	`console.warn` and `console.error` calls
`fetch`	HTTP requests (method, URL, status code, duration)
`xhr`	XMLHttpRequest calls (same as fetch)
`ui`	React component lifecycle errors

Example Breadcrumb Trail

10:42:01 [navigation]  → /checkout
10:42:02 [click]       → button "Add to cart"
10:42:02 [fetch]       → POST /api/cart/add → 200 (142ms)
10:42:03 [click]       → button "Proceed to payment"
10:42:03 [fetch]       → POST /api/payment/init → 500 (2301ms)
10:42:03 [console]     → Error: Payment service unavailable
10:42:03 [ERROR]       → Unhandled: PaymentError: Gateway timeout

Error Grouping (Fingerprinting)

Individual error occurrences are grouped by fingerprint to avoid drowning in duplicates. The fingerprint is computed from:

Error message (with variable parts normalized — numbers, IDs, URLs replaced with placeholders)
Top 3 stack frames (file + function name, without line numbers)
Error type (runtime, render, network)

Example: 500 users hit the same bug → 1 error group with "500 occurrences", not 500 separate errors.

Each error group tracks:

First seen / last seen timestamps
Total occurrence count
Affected profile count
Status: new → investigating → resolved → ignored
Team comments thread

User Crash Comment Flow

When a fatal error or React render failure occurs:

1. Error caught by ErrorBoundary / window.onerror
                    │
2. Error sent to Experience (without comment)
                    │
3. Crash UI displayed to user:
   ┌─────────────────────────────────────┐
   │  😔 Something went wrong            │
   │                                     │
   │  Help us fix this?                  │
   │  Tell us what you were doing:       │
   │  ┌─────────────────────────────┐    │
   │  │ I was trying to upload a    │    │
   │  │ photo and clicked save...   │    │
   │  └─────────────────────────────┘    │
   │                                     │
   │  [Send Report]    [Dismiss]         │
   └─────────────────────────────────────┘
                    │
4. If user submits comment:
   - PATCH error with user_comment
   - Comment visible in dashboard alongside stack trace
                    │
5. If user dismisses:
   - Error already sent (step 2)
   - No comment attached

Crash UI Details

Rendered by the SDK, not the app (works even when React is broken)
Falls back to native browser prompt() if the React crash UI itself fails
Styled with inline styles (no dependency on CSS that might be broken)
Non-intrusive: small panel, not a full-page takeover
Customisable: builders can provide their own fallback component

Manual Error Capture

// JS SDK
exp.captureError(new Error('Payment failed'), {
  tags: { module: 'checkout' },
  extra: { orderId: '12345' }
});
 
exp.captureMessage('Unusual cart value detected', 'warning');

// React SDK
<ErrorBoundary
  fallback={<CrashPage />}
  showCommentForm={true}
  onError={(error) => console.log(error)}
>
  <App />
</ErrorBoundary>

See the JS SDK and React SDK for full usage.

API Endpoints

Method	Path	Auth	Description
`POST`	`/api/v1/errors/ingest`	API Key	Ingest protobuf ErrorBatch
`POST`	`/api/v1/errors/ingest/json`	API Key	Ingest JSON errors (debug)
`GET`	`/api/v1/errors`	Bearer	List error groups
`GET`	`/api/v1/errors/:id`	Bearer	Error group detail
`PUT`	`/api/v1/errors/:id`	Bearer	Update status
`POST`	`/api/v1/errors/:id/comment`	Bearer	Add team comment
`GET`	`/api/v1/errors/stats`	Bearer	Error rate stats

See the full API Reference and Data Models for schemas.

Event Tracking Feature Flags