Introduction
What Reelay is, how it fits together, and the fastest path to your first captured error.
What is Reelay?
Reelay is an incident-response platform that captures production errors with full context, analyzes them against your source code, and helps your team resolve them in one place. Drop in an SDK and every error arrives with its stack trace, request timeline, breadcrumbs, and — for the browser — a masked session replay of the moments before it happened.
Install one SDK. Errors, context, and replay are collected automatically — no manual wiring per route.
A browser session and the backend request it triggered share one trace, so a frontend symptom links to its server-side cause.
Every event ships scrubbed of secrets by default, then routes to the right team with a durable operational record.
Quickstart
Get your first error into Reelay in under five minutes. Choose your runtime, install the SDK, and call init() once at the very start of your app.
npm install @usereelay/browser
import * as Reelay from "@usereelay/browser";Reelay.init({endpoint: "https://api.usereelay.com",token: "rlyt_live_replace_with_your_key",});
Throw a test error after init(); it should appear in your dashboard within seconds.
setTimeout(() => { throw new Error("Reelay browser test error"); }, 0);
init() once, in a module that loads first. It is safe to reference anywhere afterward — the first call wins and every later call returns that same client.Core concepts
The same five ideas underpin both SDKs. Understanding them makes the per-SDK reference below read quickly.
Each captured error becomes one event with an ID like evt_…, carrying its exception, platform, and timestamp.
The last 50 user/system actions leading to an error — clicks, navigations, console output, and fetches.
A W3C traceparent plus a session ID let one logical operation span browser and backend.
A masked rrweb recording of the ~30–60s before a browser error, uploaded only when an error occurs.
Tokens, passwords, JWTs, card numbers, and emails are redacted before anything leaves the SDK.
Events authenticate with a node API key beginning rlyt_live_, created when you add a node in the dashboard.