A simple package consists of a single Emacs Lisp source file. The file must conform to the Emacs Lisp library header conventions (see Conventional Headers for Emacs Libraries). The package’s attributes are taken from the various headers, as illustrated by the following example:
;;; superfrobnicator.el --- Frobnicate and bifurcate flanges -*- lexical-binding:t -*- ;; Copyright (C) 2022 Free Software Foundation, Inc.
;; Author: J. R. Hacker <jrh@example.com> ;; Version: 1.3 ;; Package-Requires: ((flange "1.0")) ;; Keywords: multimedia, hypermedia ;; URL: https://example.com/jrhacker/superfrobnicate … ;;; Commentary: ;; This package provides a minor mode to frobnicate and/or ;; bifurcate any flanges you desire. To activate it, just type … ;;;###autoload (define-minor-mode superfrobnicator-mode …
The name of the package is the same as the base name of the file, as written on the first line. Here, it is ‘superfrobnicator’.
The brief description is also taken from the first line. Here, it is ‘Frobnicate and bifurcate flanges’.
The version number comes from the ‘Package-Version’ header, if it exists, or from the ‘Version’ header otherwise. One or the other must be present. Here, the version number is 1.3.
If the file has a ‘;;; Commentary:’ section, this section is used as the long description. (When displaying the description, Emacs omits the ‘;;; Commentary:’ line, as well as the leading comment characters in the commentary itself.)
If the file has a ‘Package-Requires’ header, that is used as the package dependencies. In the above example, the package depends on the ‘flange’ package, version 1.0 or higher. See Conventional Headers for Emacs Libraries, for a description of the ‘Package-Requires’ header. If the header is omitted, the package has no dependencies.
The ‘Keywords’ and ‘URL’ headers are optional, but recommended.
The command describe-package uses these to add links to its
output. The ‘Keywords’ header should contain at least one
standard keyword from the finder-known-keywords list.
The file ought to also contain one or more autoload magic comments,
as explained in Packaging Basics. In the above example, a magic
comment autoloads superfrobnicator-mode.
See Creating and Maintaining Package Archives, for an explanation of how to add a single-file package to a package archive.