> For the complete documentation index, see [llms.txt](https://kmlaucow.gitbook.io/authgear/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://kmlaucow.gitbook.io/authgear/readme.md).

# Authgear Docs

**Authgear** is an authentication server for web and mobile apps. It is highly customizable yet comes with sensible defaults. It is built on top of [OpenID Connect (OIDC) standard](https://openid.net/connect/), making it very easy to integrate. It supports single sign-on (SSO) via integration with popular providers such as Google, Apple, and Azure Active Directory (AD). It also supports logging in via email address and phone number with one-time password or traditional password with strong password policy. Multiple factor authentication with time-based one-time password or out-out-band one-time password is available out of the box. Users can manage their sessions in the web-based settings page. Authgear, together with popular reverse proxies such as Nginx, can work as the authentication proxy for your other services.