--- 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_current: 'docs-builders-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.html) page of the Packer plugin section.