Error & crash tracking

Nohmo captures errors and crashes automatically — it's on by default, no setup required. Because every error is just an event, it carries the same session and device context as everything else: the Errors page groups errors by signature and shows the exact journey leading up to each crash — the pages, screens, clicks and taps right before it broke.

What's captured

Event	Platform	Trigger
JS_ERROR	Web + RN	Uncaught exceptions and unhandled promise rejections
HTTP_ERROR	Web	Failed fetch/XHR requests (4xx/5xx) and resource 404s
APP_CRASH	React Native	Fatal JS crashes and native crashes — reported on next launch

Native crashes (React Native)

The JS error handler can't see crashes that happen in native code. Nohmo installs native crash handlers too — no extra packages, it's built into the SDK. A crashing process can't do network I/O, so the crash is written to disk and reported as an APP_CRASH on the next launch, attributed back to the session it happened in.

Platform	Catches
Android	Uncaught Java/Kotlin exceptions (any thread)
iOS	Objective-C exceptions, plus Swift fatalError, force-unwraps, and memory crashes (signal handlers)

Configuration

Error capture is enabled by default. To turn it off, set autoErrors: false:

tsx

// React / Next.js / React Native
<NohmoProvider projectId="..." apiKey="..." options={{ autoErrors: false }}>
  <YourApp />
</NohmoProvider>

For the plain HTML / script-tag build, add data-errors="false":

html

<script
  src="https://cdn.jsdelivr.net/npm/nohmo@latest/dist/n.min.js"
  data-project="proj_xxxx"
  data-api-key="pk_xxxx"
  data-errors="false"
  defer
></script>

Where it shows up

Errors page

Errors are grouped by signature with occurrence counts, affected users and devices, and a sample stack trace. Open one to see every occurrence.

Journey to the crash

Each occurrence shows the session timeline up to the moment it broke — what the user did right before the error, so you can reproduce it.

Real-time alerts

Add an Event Match webhook (Settings → Webhooks) on JS_ERROR or APP_CRASH to get notified the instant errors happen.

Privacy & scope

Captured errors are bounded for safety: messages are truncated, query strings are stripped from request URLs, and Nohmo never reports failures of its own tracking endpoint. Stack traces are raw / unsymbolicatedfor now (dSYM & ProGuard mapping are planned).

Native capture covers uncaught JVM exceptions (Android) and Objective-C exceptions + signal crashes (iOS). Android NDK/C++ crashes, ANRs, and out-of-memory terminations are not captured in this version.

Note: Error tracking is on by default on every platform — you don't need to add anything to start seeing errors in your dashboard.