Express error alerts and on-call with Pagerless

Set up

npm i pagerless

import { pagerlessErrorHandler } from "pagerless/express";

// after your routes, before your own error handler
app.use(pagerlessErrorHandler());

It passes every error on with next(err), so your own handler still runs.

5xx and unknown errors from your routes.
Reports 5xx and crashes only, never 4xx, and leaves the response, logs and error exactly as they were.
On Node it also starts the SDK: uncaught errors and unhandled rejections, status and latency per route, failing outbound calls (Stripe, OpenAI, Supabase and others named), a heartbeat every 60 seconds and a deploy marker.

It still reports crashes, 5xx counts and failing calls. The error handler adds the errors Express catches itself, with their stack.

Updated October 22, 2026.