MELPA

MELPA is a growing collection of package.el-compatible Emacs Lisp packages built automatically on our server from the upstream source code using simple recipes. (Think of it as a server-side version of el-get, or even Homebrew.)

Packages are updated at intervals throughout the day.

To browse available packages, check out the archive index page.

Adding packages is as simple as submitting a new recipe as a pull request; read on for details.

Table of Contents

• Usage
• Contributing
• Recipe Format
• Build Scripts
• API
• Mirrors
• About

Usage

To use the MELPA repository, you'll need an Emacs with package.el. Emacs 24 has package.el bundled with it, and there's also a version you can use with Emacs 23.

Enable installation of packages from MELPA by adding an entry to package-archives after (require 'package) and before the call to package-initialize in your init.el or .emacs file:

(require 'package)
(let* ((no-ssl (and (memq system-type '(windows-nt ms-dos))
                    (not (gnutls-available-p))))
       (proto (if no-ssl "http" "https")))
  (when no-ssl (warn "\
Your version of Emacs does not support SSL connections,
which is unsafe because it allows man-in-the-middle attacks.
There are two things you can do about this warning:
1. Install an Emacs version that does support SSL and be safe.
2. Remove this warning from your init file so you won't see it again."))
  ;; Comment/uncomment these two lines to enable/disable MELPA and MELPA Stable as desired
  (add-to-list 'package-archives (cons "melpa" (concat proto "://melpa.org/packages/")) t)
  ;;(add-to-list 'package-archives (cons "melpa-stable" (concat proto "://stable.melpa.org/packages/")) t)
  (when (< emacs-major-version 24)
    ;; For important compatibility libraries like cl-lib
    (add-to-list 'package-archives (cons "gnu" (concat proto "://elpa.gnu.org/packages/")))))
(package-initialize)

Then just use M-x package-list-packages to browse and install packages from MELPA and elsewhere.

Note that you'll need to run M-x package-refresh-contents or M-x package-list-packages to ensure that Emacs has fetched the MELPA package list before you can install packages with M-x package-install or similar.

Instead of the messy code above, you can of course use something like the following instead:

(require 'package)
(add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/") t)
(package-initialize)

Before doing so you should understand what it does though. To make sure of that, you should read the official documentation from the Emacs manual. Also note that the calls to require and package-initialize may be unnecessary depending on the Emacs version you use.

MELPA Stable

Packages in MELPA are built directly from the latest package source code in the upstream repositories, but we also build and publish packages corresponding to the latest tagged code in those repositories, where version tags exist. These packages are published in a separate package archive called MELPA Stable. Most users should prefer MELPA over MELPA Stable.

Some notes:

• If you leave the original MELPA server in your package-archives then by default you will get the development versions of packages and not the stable ones, because the development versions are higher.

• If your Emacs has the variables package-pinned-packages (available in 24.4 and later) and/or package-archive-priorities, you can customize or modify those variables as needed.

• You can use the package-filter.el package which we provide.

• You will probably want to remove all packages and then reinstall them. Any packages you already have installed from MELPA will never get "updated" to the stable version because of the way version numbering is handled.

Note that the MELPA maintainers do not use MELPA Stable themselves, and do not particularly recommend its use.

Contributing

See the CONTRIBUTING.org document.

Recipe Format

Packages are specified by files in the recipes directory. You can contribute a new package by adding a new file under recipes using the following form ([...] denotes optional or conditional values),

(<package-name>
 :fetcher [git|github|gitlab|hg|bitbucket]
 [:url "<repo url>"]
 [:repo "github-gitlab-or-bitbucket-user/repo-name"]
 [:commit "commit"]
 [:branch "branch"]
 [:version-regexp "<regexp>"]
 [:files ("<file1>" ...)])

• package-name a lisp symbol that has the same name as the package being specified.

• :fetcher specifies the type of repository that :url or :repo points to. Melpa supports git, github, gitlab, hg (Mercurial), and bitbucket. The bitbucket fetcher derives from hg, so you have to use git for Git repositories hosted on Bitbucket.

• :url specifies the URL of the version control repository. required for the git, and hg fetchers.

• :repo specifies the github/gitlab/bitbucket repository and is of the form user/repo-name. required for the github, gitlab, and bitbucket fetchers.

• :commit specifies the commit of the git repo to checkout. The value will be passed to git reset in a repo where upstream is the original repository. Can therefore be either a SHA, if pointing at a specific commit, or a full ref prefixed with "origin/". Only used by the git-based fetchers.

• :branch specifies the branch of the git repo to use. This is like :commit, but it adds the "origin/" prefix automatically.

• :version-regexp is a regular expression for extracting a version-string from the repository tags. The default matches typical version tags such as 1.0, R16 or v4.3.5, so you should not override it unless necessary. For an unusual tag like "OTP-18.1.5", we might add :version-regexp "[^0-9]*\\(.*\\)" to strip the "OTP-" prefix. The captured portion of the regexp must be parseable by Emacs' version-to-list function.

• :files optional property specifying the elisp and info files used to build the package. Please do not override this if the default value (below) is adequate, which it should usually be:

    ("*.el" "*.el.in" "dir"
     "*.info" "*.texi" "*.texinfo"
     "doc/dir" "doc/*.info" "doc/*.texi" "doc/*.texinfo"
     (:exclude ".dir-locals.el" "test.el" "tests.el" "*-test.el" "*-tests.el"))
  

  This option is necessary when there are multiple packages in the repository and thus the package should only be built from a subset of .el files. For example, elisp test files should not normally be packaged. Any file specified at any path in the repository is copied to the root of the package. More complex options are available, submit an Issue if the specified package requires more complex file specification.

  If the package merely requires some additional files, for example for bundling external dependencies, but is otherwise fine with the defaults, it's recommended to use :defaults as the very first element of this list, which causes the default value shown above to be prepended to the specified file list.

  Note that elisp in subdirectories is never included by default, so you might find it convenient to separate auxiliiary files such as tests into subdirectories to keep packaging simple.

Example: Single File Repository

smex is a repository that contains two files:

• README.markdown
• smex.el

Since there is only one .el file, this package only needs the :url and :fetcher specified,

(smex :repo "nonsequitur/smex" :fetcher github)

Example: Multiple Packages in one Repository

Assume we have a repository containing three libraries mypackage.el, helm-mypackage.el, and persp-mypackage.el. The latter two libraries are optional and users who don't want to use the packages helm and/or perspective should not be forced to install them just so they can install mypackage. These libraries should therefore be distributed as separate packages.

The three packages have to be declared in three separate files recipes/mypackage, recipes/helm-mypackage, and recipes/persp-mypackage:

(mypackage :repo "someuser/mypackage"
           :fetcher github
           :files ("mypackage.el"))

(helm-mypackage :repo "someuser/mypackage"
                :fetcher github
                :files ("helm-mypackage.el"))

(persp-mypackage :repo "someuser/mypackage"
                 :fetcher github
                 :files ("persp-mypackage.el"))

Example: Multiple Files in Multiple Directories

There are special cases where creation of the package comes from many different sub-directories in the repository and the destination sub-directories need to be explicitly set.

Consider the flymake-perlcritic recipe,

(flymake-perlcritic :repo "illusori/emacs-flymake-perlcritic"
                    :fetcher github
                    :files ("*.el" ("bin" "bin/flymake_perlcritic")))

which will result in a package structure of,

flymake-perlcritic-YYYMMDD
|-- bin
|   `-- flymake_perlcritic
|-- flymake-perlcritic-pkg.el
`-- flymake-perlcritic.el

Notice that specifying an entry in :files that is a list takes the first element to be the destination directory. These can be embedded further, such as the following---hypothetical---entry for :files,

("*.el" ("snippets"
         ("html-mode" "snippets/html-mode/*")
         ("python-mode" "snippets/python-mode/*")))

which would result in a package with *.el in something like,

package-YYYYMMDD
|-- snippets
|   |-- html-mode
|   |   |-- div
|   |   `-- html
|   `-- python-mode
|       |-- for
|       `-- main
`-- package.el

But a better solution, given that we probably want to copy the entire snippets directory to the root of the package, we could just specify that directory. Consider the pony-mode recipe,

(pony-mode
 :repo "davidmiller/pony-mode"
 :fetcher github
 :files ("src/*.el" "snippets"))

which generates the package,

pony-mode-YYYYMMDD
|-- pony-mode-pkg.el
|-- pony-mode.el
|-- pony-tpl.el
`-- snippets
    |-- html-mode
    |   |-- bl
    |   |-- ex
    |   |-- for
    |   |-- if
    |   |-- loa
    |   |-- sup
    |   |-- testc
    |   `-- {{
    `-- python-mode
        |-- auth-view
        |-- bn
        |-- model
        |-- modelform
        |-- render-to
        |-- testc
        `-- view

Build Scripts

Building MELPA is all based around using the Makefile included in the root repository directory. Described below are the actions that accepted by the Makefile.

• all -- Builds all packages under the recipes/ directory and compiles the index.html file for the melpa website.

• recipes/<NAME> -- Build individual recipe <NAME>. Built packages are put in the packages/ folder with version corresponding to the date of the latest commit that modified at least one of the files specified by the recipe; given according to the %Y%m%d format.

• json -- build all JSON files.

• archive.json -- construct the archive.json file that will contain a JSON object of all compiled packages.

• recipes.json -- construct the recipes.json file containing a JSON object of all packages available for building.

• clean -- clean everything.

• html -- build index.html.

• clean-working -- remove all repositories that have been checked out to the working/ directory.

• clean-packages -- remove all compiled packages from the packages directory.

• clean-json -- remove all JSON files.

Note that these scripts require an Emacs with package.el installed, such as Emacs 24. If you have an older version of Emacs, you can get a suitable package.el here.

API

All repository code is contained in the file package-build/package-build.el. That code is maintained in a separate repository: the version in the MELPA repository is imported using git subtree.

Functions

• (package-build-all) : build packages for all recipes in the directory specified by package-build-recipes-dir.

• (package-build-archive NAME) : interactive elisp function to build a single archive. NAME is a symbol for the package to be built. Packages are staged in the directory specified by package-build-working-dir and built packages are placed in the directory specified by package-build-archive-dir. Packages are versioned based on the most recent commit date to package files based on commits to upstream package repository. For multi-file packages, the file <NAME>-pkg.el is automatically generated and contains description, version, and requires information determined by searching <NAME>-pkg.el, <NAME>.el, and <NAME>-pkg.el.in, if they exist in the repository.

Variables

• package-build-working-dir : Staging area containing package repositories and package directories being built.

• package-build-archive-dir : Location to store archive-contents and any built packages.

• package-build-recipes-dir : Directory containing MELPA compatible recipes. See Recipe Format section for more details.

Configuration

Packages end up in the packages/ directory by default. This can be configured using the package-build-archive-dir variable.

Repositories are checked out to the working/ directory by default. This can be configured using the package-build-working-dir variable.

Mirrors

Official mirrors are available (with many thanks to mirrorservice.org) so that if melpa.org is down, packages can still be installed. The following are the HTTP/HTTPS URLs to use in package-archives for MELPA and MELPA Stable respectively:

• http://www.mirrorservice.org/sites/melpa.org/packages/
• https://www.mirrorservice.org/sites/melpa.org/packages/
• http://www.mirrorservice.org/sites/stable.melpa.org/packages/
• https://www.mirrorservice.org/sites/stable.melpa.org/packages/

Only the packages are mirrored, not the web site front-end itself.

We are NOT responsible for the contents of any UNOFFICIAL mirror of our packages.

About

MELPA is Milkypostman's ELPA or Milkypostman's Experimental Lisp Package Archive if you're not into the whole brevity thing.