How to Add Sentry Error Monitoring to Your Node.js Project with TypeScript

As a Node.js developer, you know that errors are inevitable. But what if you could catch them before your users do? That‘s where Sentry comes in.

Sentry is an open-source error tracking and monitoring platform that helps developers identify, triage, and fix issues in real-time. By adding Sentry to your Node.js project, you can:

• Get instant alerts when exceptions occur in production
• See detailed stack traces and contextual data to quickly pinpoint the root cause
• Monitor trends over time to proactively prevent future issues
• Integrate with your existing workflow and tools

In fact, organizations using Sentry have seen up to a 48% reduction in mean time to resolution (MTTR) for errors (Source).

In this guide, we‘ll walk through step-by-step how to add Sentry to a Node.js application built with TypeScript. Whether you‘re a seasoned pro or just getting started with error monitoring, this article will give you the knowledge and best practices to implement Sentry effectively.

Why Use Sentry for Node.js Error Monitoring?

Before we dive into the technical details, let‘s explore some of the key benefits of using Sentry for Node.js error monitoring:

1. Catch errors before your users do: Sentry captures and alerts you of exceptions in real-time, so you can fix them before they impact your users.

2. Get the full context: Sentry automatically captures data about the user, request, and environment to help you reproduce and fix issues faster.

3. Integrate with your workflow: Sentry integrates with popular tools like Jira, Slack, and PagerDuty, so you can triage and assign issues right from your existing workflow.

4. Monitor performance: In addition to errors, Sentry can also track performance metrics like response time and throughput to help you optimize your application.

5. Scale with ease: Sentry is designed to handle high volumes of data and can easily scale with your application as it grows.

Setting Up a Sentry Account and Project

To get started with Sentry, you‘ll need to create an account and set up a project for your Node.js application. Here‘s how:

1. Go to sentry.io and click "Sign Up" to create a new account. You can sign up with your email, GitHub, or Google account.

2. Once you‘ve created an account, you‘ll be prompted to create a new organization. An organization is a top-level container for your projects and teams.

3. After creating an organization, click "Create Project" to set up a new project for your Node.js application.

4. On the project creation page, choose "Node.js" as the platform and give your project a name.

5. Sentry will generate a unique "Data Source Name" (DSN) for your project. This is the key that your Node.js application will use to authenticate with Sentry and send error data. Make sure to copy this DSN as you‘ll need it in the next step.

Installing and Configuring the Sentry SDK

Now that you have a Sentry account and project set up, it‘s time to install and configure the Sentry SDK in your Node.js application.

1. Install the Sentry SDK package using npm:

   npm install @sentry/node @sentry/tracing

   This will install both the core Sentry SDK and the performance tracing module.

2. Import and initialize the Sentry SDK in your application‘s entry file (e.g. app.ts or server.ts):

   import * as Sentry from ‘@sentry/node‘;
   import * as Tracing from ‘@sentry/tracing‘;
   
   Sentry.init({
     dsn: ‘YOUR_DSN_HERE‘,
     integrations: [
       new Sentry.Integrations.Http({ tracing: true }),
       new Tracing.Integrations.Express({ app: yourExpressApp }),
     ],
     tracesSampleRate: 1.0,
   });

   Make sure to replace YOUR_DSN_HERE with the actual DSN for your Sentry project.

   This code initializes the Sentry SDK and sets up automatic tracing for HTTP requests and Express routes. The tracesSampleRate option determines what percentage of transactions are sent to Sentry (1.0 means 100%).

3. If you‘re using TypeScript, you‘ll need to add the Sentry types to your project:

   npm install --save-dev @sentry/types

4. By default, Sentry will capture all unhandled exceptions in your Node.js application. But you can also capture specific exceptions by wrapping them in a try/catch block and calling Sentry.captureException():

   try {
     throw new Error(‘Something went wrong‘);
   } catch (error) {
     Sentry.captureException(error);
   }

   This will send the exception to Sentry along with a stack trace and other metadata.

5. If you‘re using TypeScript, you‘ll also need to configure source maps so that Sentry can display readable stack traces. To do this, make sure your TypeScript compiler is generating source maps:

   {
     "compilerOptions": {
       "sourceMap": true
     }
   }

   Then, upload the source maps to Sentry by adding the following code to your build process:

   import * as SentryCliPlugin from ‘@sentry/webpack-plugin‘;
   
   const sentryPlugin = new SentryCliPlugin({
     release: process.env.SENTRY_RELEASE,
     include: ‘./dist‘,
     ignore: [‘node_modules‘, ‘webpack.config.js‘],
   });

   This will upload the source maps to Sentry whenever you create a new release.

Capturing Breadcrumbs and Context

In addition to capturing exceptions, Sentry can also capture "breadcrumbs" and contextual data to help you understand what led to an error.

Breadcrumbs are a trail of events that occurred prior to an exception. To capture a breadcrumb, call Sentry.addBreadcrumb():

Sentry.addBreadcrumb({
  category: ‘auth‘,
  message: ‘User logged in‘,
  level: Sentry.Severity.Info,
});

You can also attach user information to errors by configuring the Sentry scope:

Sentry.configureScope(scope => {
  scope.setUser({
    id: user.id,
    email: user.email,
  });
});

This will display the user information in the Sentry UI and allow you to search and filter errors by user attributes.

Customizing Sentry Settings

Sentry provides a number of configuration options to fine-tune your error monitoring setup. Here are a few key settings to consider:

• environment: Set the environment name (e.g. "production", "staging") to differentiate errors between different environments.

  Sentry.init({
    dsn: ‘YOUR_DSN_HERE‘,
    environment: ‘production‘,
  });

• release: Set the release version to track errors across different releases of your application.

  Sentry.init({
    dsn: ‘YOUR_DSN_HERE‘,
    release: ‘1.0.0‘,
  });

• sampleRate: Adjust the sample rate to control the percentage of errors that are sent to Sentry. This can be useful for reducing noise and controlling costs.

  Sentry.init({
    dsn: ‘YOUR_DSN_HERE‘,
    sampleRate: 0.5,
  });

  A sample rate of 0.5 means that 50% of errors will be sent to Sentry.

• beforeSend: Modify or filter errors before they are sent to Sentry. This can be used to remove sensitive data or add custom metadata.

  Sentry.init({
    dsn: ‘YOUR_DSN_HERE‘,
    beforeSend(event) {
      if (event.user) {
        delete event.user.email;
      }
      return event;
    },
  });

For more configuration options, check out the Sentry docs.

Tracking Performance with Sentry

In addition to error monitoring, Sentry can also track performance metrics for your Node.js application. This can help you identify and fix performance bottlenecks before they impact your users.

To enable performance tracking, you‘ll need to install the @sentry/tracing package and configure it in your Sentry init code:

import * as Tracing from ‘@sentry/tracing‘;

Sentry.init({
  dsn: ‘YOUR_DSN_HERE‘,
  integrations: [
    new Sentry.Integrations.Http({ tracing: true }),
    new Tracing.Integrations.Express({ app: yourExpressApp }),
  ],
  tracesSampleRate: 1.0,
});

This will automatically capture performance metrics for HTTP requests and Express routes. You can also manually instrument specific code blocks using the Sentry.startTransaction() method:

const transaction = Sentry.startTransaction({
  op: ‘task‘,
  name: ‘My Task‘,
});

try {
  // Your code here
  transaction.finish();
} catch (error) {
  transaction.finish();
  throw error;
}

Sentry will display the performance data in the "Performance" section of the UI, allowing you to see metrics like throughput, failure rate, and response time.

Best Practices for Error Monitoring with Sentry

To get the most value out of Sentry, it‘s important to follow best practices for error monitoring and triaging. Here are a few tips:

1. Prioritize errors based on impact: Focus on fixing errors that are affecting the most users or causing the most damage to your business.

2. Set up alerts: Configure Sentry to send alerts when critical errors occur or when error rates exceed a certain threshold. This will help you respond to issues faster and minimize downtime.

3. Use tags and context: Add tags and context to your errors to make them easier to search and filter. This will help you identify patterns and root causes more quickly.

4. Integrate with your workflow: Connect Sentry to your issue tracking system (e.g. Jira) and chat tools (e.g. Slack) to streamline the error resolution process.

5. Monitor trends over time: Use Sentry‘s dashboards and reports to track error trends over time. This will help you identify areas for improvement and measure the impact of your error monitoring efforts.

By following these best practices and leveraging Sentry‘s features, you can proactively identify and resolve errors before they impact your users.

Conclusion

Adding Sentry to your Node.js project with TypeScript is a powerful way to improve the stability and reliability of your application. By capturing and alerting on errors in real-time, you can fix issues faster and provide a better experience for your users.

In this guide, we‘ve covered the key steps for setting up Sentry in a Node.js project, including:

• Creating a Sentry account and project
• Installing and configuring the Sentry SDK
• Capturing breadcrumbs and context
• Customizing Sentry settings
• Tracking performance with Sentry
• Best practices for error monitoring with Sentry

By following these steps and best practices, you‘ll be well on your way to implementing effective error monitoring in your Node.js applications.

Further Reading

• Sentry Documentation
• Sentry Blog
• Sentry Community Forum