---
title: Introduction
description: What ZevAuth is, and what it gives you.
---

import Callout from '../../../components/Callout.astro';


ZevAuth is authentication as a service. You get sign-up, sign-in, sessions,
organizations and the screens that go with them, and you keep writing your
product instead of writing password resets.

## What you actually integrate

Three things, and you rarely need all of them at once.

**Drop-in components.** `<SignIn>`, `<SignUp>`, `<UserButton>` and
`<OrganizationSwitcher>` render complete, branded flows. They read which
sign-in methods your environment has enabled, so turning magic links on in
the console makes them appear in your app without a deploy.

**A client SDK.** Hooks and a small client for when you want your own UI.
Everything the components do is available directly.

**A REST API.** For your backend, and for anything the SDK does not cover.

## What runs where

Your users' credentials never touch your servers. They go to ours, and your
application receives a short-lived **access token**: a signed JWT you verify
with a public key. Your backend never calls us to check a token, so an outage
of ours is not an outage of yours.

<Callout type="info">
A ZevAuth access token is an ordinary JWT with an issuer, an audience and a
JWKS endpoint. If you already verify tokens from another provider, the same
library works here.
</Callout>

## Two environments, always

Every project has a **development** environment from the moment you create it,
and you add **production** when you are ready. They are completely separate:
different keys, different users, different signing keys.

Development captures the email it would have sent instead of delivering it, so
you can build a sign-up flow without an inbox and without emailing a real
person by accident.

## Where to go next

- [Quickstart](/guide/quickstart). A working sign-in in about five minutes.
- [Keys and environments](/guide/keys). Which key goes where, and why one of
  them must never reach a browser.
- [React](/sdk/react). The components and hooks in full.