Bun

Learn how to manually set up Sentry in your Bun app and capture your first errors.

You need:

Choose the features you want to configure, and this guide will show you how:

Want to learn more about these features?
  • Issues (always enabled): Sentry's core error monitoring product that automatically reports errors, uncaught exceptions, and unhandled rejections. If you have something that looks like an exception, Sentry can capture it.
  • Tracing: Track software performance while seeing the impact of errors across multiple systems. For example, distributed tracing allows you to follow a request from the frontend to the backend and back.
  • Logs: Centralize and analyze your application logs to correlate them with errors and performance issues. Search, filter, and visualize log data to understand what's happening in your applications.

Use the Bun package manager to add the Sentry SDK to your application:

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bun add @sentry/bun

Sentry should be initialized as early in your app as possible. Create a file named instrument.js in the root directory of your project and add the following code:

instrument.js
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import * as Sentry from "@sentry/bun";

// Ensure to call this before importing any other modules!
Sentry.init({
  dsn: "___PUBLIC_DSN___",

  // Adds request headers and IP for users, for more info visit:
  // https://docs.sentry.io/platforms/javascript/guides/bun/configuration/options/#sendDefaultPii
  sendDefaultPii: true,
  // ___PRODUCT_OPTION_START___ performance

  // Add Performance Monitoring by setting tracesSampleRate
  // Set tracesSampleRate to 1.0 to capture 100% of transactions
  // We recommend adjusting this value in production
  // Learn more at
  // https://docs.sentry.io/platforms/javascript/configuration/options/#traces-sample-rate
  tracesSampleRate: 1.0,
  // ___PRODUCT_OPTION_END___ performance
  // ___PRODUCT_OPTION_START___ logs

  // Enable logs to be sent to Sentry
  enableLogs: true,
  // ___PRODUCT_OPTION_END___ logs
});

To make sure that Sentry initializes before any other modules, you need to preload your instrumentation file using the --preload flag. Start your app using:

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bun --preload ./instrument.js app.js

The stack traces in your Sentry errors probably won't look like your actual code without unminifying them. To fix this, upload your source maps to Sentry. The easiest way to do this is by using the Sentry Wizard:

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npx @sentry/wizard@latest -i sourcemaps

Let's test your setup and confirm that Sentry is working correctly and sending data to your Sentry project.

First, let's verify that Sentry captures errors and creates issues in your Sentry project. Add the following code snippet to your main application file, which will call an undefined function, triggering an error that Sentry will capture:

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setTimeout(() => {
  try {
    foo();
  } catch (e) {
    Sentry.captureException(e);
  }
}, 99);

To test your tracing configuration, update the previous code snippet by starting a trace to measure the time it takes for the execution of your code:

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Sentry.startSpan(
  {
    op: "test",
    name: "My First Test Transaction",
  },
  () => {
    setTimeout(() => {
      try {
        foo();
      } catch (e) {
        Sentry.captureException(e);
      }
    }, 99);
  },
);

Finally, head over to your project on Sentry.io to view the collected data (it takes a couple of moments for the data to appear).

Need help locating the captured errors in your Sentry project?
  1. Open the Issues page and select an error from the issues list to view the full details and context of this error. For more details, see this interactive walkthrough.
  2. Open the Traces page and select a trace to reveal more information about each span, its duration, and any errors. For an interactive UI walkthrough, click here.
  3. Open the Logs page and filter by service, environment, or search keywords to view log entries from your application. For an interactive UI walkthrough, click here.

At this point, you should have integrated Sentry into your Bun application, which should already be sending data to your Sentry project.

Now's a good time to customize your setup and look into more advanced topics. Our next recommended steps for you are:

Are you having problems setting up the SDK?
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