Integrating with Express

See Working Example

The TrackJS-Node agent provides handlers that can be injected into the Express pipeline. The request middleware should be added first to setup the context and the error middleware should be added last to catch any errors.

var express = require("express");
var TrackJS = require("trackjs-node").TrackJS;

// Install TrackJS as soon as possible
TrackJS.install({
  token: "YOUR_TOKEN"
});

var app = express()
  // the first handler should be the TrackJS request handler.
  .use(TrackJS.Handlers.expressRequestHandler())

  // ... your application logic

  // the last handler should be the TrackJS error handler.
  .use(TrackJS.Handlers.expressErrorHandler({ next: false }))

  .listen(PORT_NUMBER);

Express integration example

Request Isolation

Agent metadata and telemetry is isolated between requests. For example, a console.log message written during a request to /foo won’t appear on errors captured from /bar. This enables you to add request-specific metadata to requests.

app.get("/foo", (req, res, next) => {
  TrackJS.addMetadata({
    userStep: "1"
  });
  //...
  next();
});
app.get("/bar", (req, res, next) => {
  TrackJS.addMetadata({
    userStep: "2"
  });
  //...
  next();
});

Request-specific data