---
description: |
  Packer is extensible, allowing you to write new builders without having to
  modify the core source code of Packer itself. Documentation for creating new
  builders is covered in the custom builders page of the Packer plugin section.
layout: docs
page_title: Custom - Builders
sidebar_title: Custom
---

# Custom Builder

Packer is extensible, allowing you to write new builders without having to
modify the core source code of Packer itself. Documentation for creating new
builders is covered in the [custom
builders](/docs/extending/custom-builders) page of the Packer plugin
section.