Svelte

Sentry's Svelte SDK was introduced with version 7.10.0.

If you're seeing deprecation warnings in your code, please note that we're currently working on version 8 of the JavaScript SDKs. In v8, some methods and properties will be removed or renamed. Check out the Migration docs and learn how to update your code to be compatible with v8.

Don't already have an account and Sentry project established? Head over to sentry.io, then return to this page.

Install

Sentry captures data by using an SDK within your application’s runtime.

npm install --save @sentry/svelte

Configure

Configuration should happen as early as possible in your application's lifecycle.

To use the SDK, initialize it in your Svelte entry point before bootstrapping your app. In a typical Svelte project, that is your main.js or main.ts file.

import './app.css';
import App from './App.svelte';

import * as Sentry from '@sentry/svelte';

// Initialize the Sentry SDK here
Sentry.init({
  dsn: 'https://examplePublicKey@o0.ingest.sentry.io/0',
  integrations: [Sentry.browserTracingIntegration(), Sentry.replayIntegration()],

  // Set tracesSampleRate to 1.0 to capture 100%
  // of transactions for performance monitoring.
  // We recommend adjusting this value in production
  tracesSampleRate: 1.0,

  // Set `tracePropagationTargets` to control for which URLs distributed tracing should be enabled
  tracePropagationTargets: ['localhost', /^https:\/\/yourserver\.io\/api/],

  // Capture Replay for 10% of all sessions,
  // plus for 100% of sessions with an error
  replaysSessionSampleRate: 0.1,
  replaysOnErrorSampleRate: 1.0,
});

const app = new App({
  target: document.getElementById('app'),
});

export default app;

Once you've done this, the SDK will automatically capture unhandled errors and promise rejections, and monitor performance in the client. You can also manually capture errors.

Add Readable Stack Traces to Errors

Depending on how you've set up your project, the stack traces in your Sentry errors probably don't look like your actual code.

To fix this, upload your source maps to Sentry. The easiest way to do this is to use the Sentry Wizard:

npx @sentry/wizard@latest -i sourcemaps

The wizard will guide you through the following steps:

• Logging into Sentry and selecting a project
• Installing the necessary Sentry packages
• Configuring your build tool to generate and upload source maps
• Configuring your CI to upload source maps

For more information on source maps or for more options to upload them, head over to our Source Maps documentation.

Verify

This snippet includes an intentional error, so you can test that everything is working as soon as you set it up.

<button
  type="button"
  on:click={() => {
    throw new Error('Sentry Frontend Error');
  }}
>
  Throw error
</button>;

This snippet adds a button that throws an error in a Svelte component.

To view and resolve the recorded error, log into sentry.io and open your project. Clicking on the error's title will open a page where you can see detailed information and mark it as resolved.