Logo of AppSignal

Menu
Documentation navigation

Express

The AppSignal for Node.js integration for Express.js (express) v4.0.0+.

Installation

Add both the @appsignal/nodejs and @appsignal/express packages to your package.json. Then, run yarn install/npm install.

You can also add these packages to your package.json on the command line:

1
2
yarn add @appsignal/nodejs @appsignal/express
npm install --save @appsignal/nodejs @appsignal/express

You can then import and use the package in your app.

Usage

Middleware

The module includes middleware for automatically instrumenting the routes of your application.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
const { Appsignal } = require("@appsignal/nodejs")

const appsignal = new Appsignal({
  active: true,
  name: "<YOUR APPLICATION NAME>",
  apiKey: "<YOUR API KEY>"
})

const express = require("express")
const { expressMiddleware } = require("@appsignal/express")

const app = express()

// ADD THIS AFTER ANY OTHER EXPRESS MIDDLEWARE, BUT BEFORE ANY ROUTES!
app.use(expressMiddleware(appsignal))

Error Handler

The module also contains a middleware for catching any errors passed to next().

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
const { Appsignal } = require("@appsignal/nodejs")

const appsignal = new Appsignal({
  active: true,
  name: "<YOUR APPLICATION NAME>"
  apiKey: "<YOUR API KEY>"
})

const express = require("express")
const { expressErrorHandler } = require("@appsignal/express")

const app = express()

// ADD THIS AFTER ANY OTHER EXPRESS MIDDLEWARE, AND AFTER ANY ROUTES!
app.use(expressErrorHandler(appsignal))

An example Express app, containing usage of all of our middleware and custom instrumentation can be found here.

We'd like to set cookies, read why.