> ## Documentation Index
> Fetch the complete documentation index at: https://auth0.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Extensibility Overview

> Extend and tailor authentication to fit your business with pro-code to no-code tools that go beyond the out-of-the-box experience.

> **[Actions](https://auth0.com/docs/customize/actions/actions-overview.md)**
>
> Actions are secure, tenant-specific, versioned functions written in Node.js that execute at certain points within the Auth0 platform.
>
> Use Actions to customize and extend Auth0’s capabilities with custom logic.

> **[Events](https://auth0.com/docs/customize/events.md)**
>
> Events are real-time notifications about specific actions that have occurred within your Auth0 tenant.
>
> Use event streams to orchestrate asynchronous changes in Auth0 and forward them for external processing, or receive events as a Server-Sent Events (SSE) stream with the Events API.

> **[Extensions](https://auth0.com/docs/customize/extensions.md)**
>
> Extensions are official and third-party add-ons that let you install applications or run commands and scripts.
>
> Use extensions to expand the functionality of the Auth0 base product.

> **[Forms](https://auth0.com/docs/customize/forms.md)**
>
> Forms is a visual editor for customizable forms that add additional steps to identity flows.
>
> Use Flows to visually build the server-side logic executed within Forms and collect information, and store secrets in the vault to authenticate requests to APIs and external services.

> **[Integrations](https://auth0.com/docs/customize/integrations.md)**
>
> The Auth0 Marketplace contains third-party identity solutions that integrate with Auth0 products.
>
> Browse and enable additional applications and tools to reduce implementation time with Auth0-reviewed integrations that you can trust.

> **[Rules & Hooks](https://auth0.com/docs/customize/rules.md)**
>
> Rules are JavaScript functions that execute when a user authenticates to your application. Hooks are JavaScript functions that execute at selected extensibility points in the Auth0 platform.
>
>  **Rules and Hooks are approaching End of Life (EOL).**