> ## Documentation Index
> Fetch the complete documentation index at: https://docs.prelude.so/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction to Auth

> Manage the full lifecycle of your users' authentication.

## Overview

Prelude Auth is a complete authentication API for developer teams. With this API, you can manage users, handle authentication across multiple methods, track active sessions, and maintain user profiles, all through a simple and secure REST interface.

<Note>
  To enable Prelude Auth on your account, [contact us](mailto:support@prelude.so).
</Note>

## What you can build

* **OTP login**: Authenticate users via SMS or email one-time password
* **Password authentication**: Email and password login with configurable rules
* **Social login**: OAuth with Google, Apple, Microsoft, GitHub, and Okta
* **Step-up authentication**: Add scoped, multi-step challenges for sensitive operations
* **Server tokens**: Server-to-server authentication using OAuth 2.0 client credentials
* **Session tracking**: Monitor active sessions with creation and last-seen timestamps
* **User management**: Create, retrieve, update, and delete users with unique identifiers
* **Identity verification**: Associate email addresses and phone numbers with user accounts
* **Profile management**: Store and update user profile information
* **Webhook integration**: Configure event notifications for real-time updates

Prelude Auth handles the session lifecycle for you, including token refresh and revocation, and gates sensitive operations behind step-up challenges.

### Why teams pick Prelude Auth

* **One platform, no data silos**: Prelude handles verification and authentication together, so user data carries over. Fraud signals get stronger and false positives drop.
* **Flexible step-up authentication**: Trigger scoped challenges only when needed, for sensitive operations like password changes or high-risk transactions, without disrupting the user journey.
* **Pay for what you use**: Enable only the authentication methods you need, and pay for those.

### Get started

Follow the [Integration Guide](https://docs.prelude.so/auth/documentation/integration-guide/introduction) to set up your first authentication flow in minutes.