Express

Add @sentry/node as a dependency:

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npm install --save @sentry/node

Sentry should be initialized as early in your app as possible:

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import express from "express";
import * as Sentry from "@sentry/node";

// or using CommonJS
// const express = require('express');
// const Sentry = require('@sentry/node');

const app = express();

Sentry.init({ dsn: "https://examplePublicKey@o0.ingest.sentry.io/0" });

// The request handler must be the first middleware on the app
app.use(Sentry.Handlers.requestHandler());

// All controllers should live here
app.get("/", function rootHandler(req, res) {
  res.end("Hello world!");
});

// The error handler must be before any other error middleware and after all controllers
app.use(Sentry.Handlers.errorHandler());

// Optional fallthrough error handler
app.use(function onError(err, req, res, next) {
  // The error id is attached to `res.sentry` to be returned
  // and optionally displayed to the user for support.
  res.statusCode = 500;
  res.end(res.sentry + "\n");
});

app.listen(3000);

You can verify the Sentry integration by creating a route that will throw an error:

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app.get("/debug-sentry", function mainHandler(req, res) {
  throw new Error("My first Sentry error!");
});

requestHandler accepts some options that let you decide what data should be included in the event sent to Sentry.

Possible options are:

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// keys to be extracted from req
request?: boolean | string[]; // default: true = ['cookies', 'data', 'headers', 'method', 'query_string', 'url']

// server name
serverName?: boolean; // default: true

// generate transaction name
//   path == request.path (eg. "/foo")
//   methodPath == request.method + request.path (eg. "GET|/foo")
//   handler == function name (eg. "fooHandler")
transaction?: boolean | 'path' | 'methodPath' | 'handler'; // default: true = 'methodPath'

// keys to be extracted from req.user
user?: boolean | string[]; // default: true = ['id', 'username', 'email']

// client ip address
ip?: boolean; // default: false

// node version
version?: boolean; // default: true

// timeout for fatal route errors to be delivered
flushTimeout?: number; // default: undefined

For example, if you want to skip the server name and add just user, you would use requestHandler like this:

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app.use(
  Sentry.Handlers.requestHandler({
    serverName: false,
    user: ["email"],
  })
);

By default, errorHandler will capture only errors with a status code of 500 or higher. If you want to change it, provide it with the shouldHandleError callback, which accepts middleware errors as its argument and decides, whether an error should be sent or not, by returning an appropriate boolean value.

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app.use(
  Sentry.Handlers.errorHandler({
    shouldHandleError(error) {
      // Capture all 404 and 500 errors
      if (error.status === 404 || error.status === 500) {
        return true;
      }
      return false;
    },
  })
);

If you use TypeScript, you need to cast our handlers to express specific types. They are fully compatible, so the only things you need to change are:

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// from
const express = require('express');
// to
import * as express from 'express';


// from
app.use(Sentry.Handlers.requestHandler());
// to
app.use(Sentry.Handlers.requestHandler() as express.RequestHandler);


// from
app.use(Sentry.Handlers.errorHandler());
// to
app.use(Sentry.Handlers.errorHandler() as express.ErrorRequestHandler);

Monitor Performance

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npm install --save @sentry/node @sentry/tracing

It’s possible to add tracing to all popular frameworks; however, we only provide pre-written handlers for Express.

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const Sentry = require("@sentry/node");
const Tracing = require("@sentry/tracing");
const express = require("express");
const app = express();

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  integrations: [
    // enable HTTP calls tracing
    new Sentry.Integrations.Http({ tracing: true }),
    // enable Express.js middleware tracing
    new Tracing.Integrations.Express({
      // to trace all requests to the default router
      app,
      // alternatively, you can specify the routes you want to trace:
      // router: someRouter,
    }),
  ],

  // We recommend adjusting this value in production, or using tracesSampler
  // for finer control
  tracesSampleRate: 1.0,
});

// RequestHandler creates a separate execution context using domains, so that every
// transaction/span/breadcrumb is attached to its own Hub instance
app.use(Sentry.Handlers.requestHandler());
// TracingHandler creates a trace for every incoming request
app.use(Sentry.Handlers.tracingHandler());

// the rest of your app

app.use(Sentry.Handlers.errorHandler());
app.listen(3000);

Spans are instrumented for the following operations within a transaction:

  • HTTP requests made with request
  • get calls using native http and https modules
  • Middleware (Express.js only)

Troubleshooting

When capturing errors locally, ensure that your project's data filter for filtering localhost events is toggled off:

express data filters

This ensures that errors produced by your browser (such as errors produced by HTTP methods) are properly captured.