Packer is extensible and supports plugins that let you
create and use custom builders, provisioners, post-processors, and data sources. This page explains how to develop Packer plugins. Before you begin, we recommend reviewing the Packer documentation and the instructions for [installing external plugins](https://developer.hashicorp.com/packer/docs/plugins/install-plugins).
create and use custom builders, provisioners, post-processors, and data sources. This page explains how to develop Packer plugins. Before you begin, we recommend reviewing the Packer documentation and the instructions for [installing external plugins](/packer/docs/plugins/install).
~> **Warning** This is an advanced topic. You should have strong knowledge of Packer before you start writing plugins.