# Native Tools for the Official Sentry Node.js SDK [](https://www.npmjs.com/package/@sentry/node-native) [](https://www.npmjs.com/package/@sentry/node-native) [](https://www.npmjs.com/package/@sentry/node-native) ## Installation ```bash # Using yarn yarn add @sentry/node @sentry/node-native # Using npm npm install --save @sentry/node @sentry/node-native ``` ## `eventLoopBlockIntegration` The `eventLoopBlockIntegration` can be used to monitor for blocked event loops in all threads of a Node.js application. If you instrument your application via the Node.js `--import` flag, Sentry will be started and this instrumentation will be automatically applied to all worker threads. `instrument.mjs` ```javascript import * as Sentry from '@sentry/node'; import { eventLoopBlockIntegration } from '@sentry/node-native'; Sentry.init({ dsn: '__YOUR_DSN__', // Capture stack traces when the event loop is blocked for more than 500ms integrations: [eventLoopBlockIntegration({ threshold: 500 })], }); ``` `app.mjs` ```javascript import { Worker } from 'worker_threads'; const worker = new Worker(new URL('./worker.mjs', import.meta.url)); // This main thread will be monitored for blocked event loops ``` `worker.mjs` ```javascript // This worker thread will also be monitored for blocked event loops too ``` Start your application: ```bash node --import instrument.mjs app.mjs ``` If a thread is blocked for more than the configured threshold, stack traces will be captured for all threads and sent to Sentry.