Automate Clojure projects without setting your hair on fire
Phil Hagelberg cee9029d15
Merge pull request #2413 from aroemers/fix-duplicate-alias
9 months ago
.circleci Deploy typo and doc update. 1 year ago
bin Port TLS fix from #2405 to lein.ps1 11 months ago
doc Use `clojars` repo consistently in document 1 year ago
lein-pprint Release 1.2.0 of lein-pprint. 1 year ago
leiningen-core Update clojars cert 9 months ago
resources Exclude project-specific `profiles.clj` from version control 10 months ago
src/leiningen Update `lein change` docstring to include set command 10 months ago
test Update clojars cert 9 months ago
test_projects Exclude project-specific `profiles.clj` from version control 10 months ago
.gitattributes Added .gitattributes to avoid autocrlf for bat files 8 years ago
.gitignore Exclude project-specific `profiles.clj` from version control 10 months ago Fix gitlab mirror link. 1 year ago
COPYING tocontrol -> to control in LICENSE files 2 years ago Warn when hooks or implicit middleware is found. 1 year ago We shouldn't recommend use of outdated JDKs. 1 year ago fix broken link 7 years ago
bash_completion.bash Remove 'swank' and add missing commands to bash completion. 2 years ago
pcmpl-lein.el Clarify that pcmpl-lein.el is not part of Leiningen. 5 years ago
project.clj Bump commons-io version 11 months ago
sample.project.clj Fixed comments formatting. 1 year ago
zsh_completion.zsh Check if in a lein project before ns completion 4 years ago


Leiningen logo

"Leiningen!" he shouted. "You're insane! They're not creatures you can fight—they're an elemental—an 'act of God!' Ten miles long, two miles wide—ants, nothing but ants! And every single one of them a fiend from hell..."

Leiningen is for automating Clojure projects without setting your hair on fire.


If your preferred package manager offers a recent version of Leiningen, try that first as long as it has version 2.x.

Leiningen installs itself on the first run of the lein shell script; there is no separate install script. Follow these instructions to install Leiningen manually:

  1. Make sure you have Java installed; version 8 is recommended at this time.
  2. Download the lein script from the stable branch of this project.
  3. Place it on your $PATH. (~/bin is a good choice if it is on your path.)
  4. Set it to be executable. (chmod +x ~/bin/lein)
  5. Run it.


There is an installer which will handle downloading and placing Leiningen and its dependencies.

The manual method of putting the batch file. on your PATH and running lein self-install should still work for most users. If you have Cygwin you should be able to use the shell script above rather than the batch file.

N.B.: Avoid using a LEIN_JAR environment variable. If you have one instance of Leiningen on your PATH as well as a LEIN_JAR pointing to a different instance, there is a known problem where lein -v and lein upgrade will refer to the first instance, while usage of Leiningen, such as lein new foobar, will refer to the latter.

Basic Usage

The tutorial has a detailed walk-through of the steps involved in creating a new project, but here are the commonly-used tasks:

$ lein new [TEMPLATE] NAME # generate a new project skeleton

$ lein test [TESTS] # run the tests in the TESTS namespaces, or all tests

$ lein repl # launch an interactive REPL session

$ lein run -m my.namespace # run the -main function of a namespace

$ lein uberjar # package the project and dependencies as standalone jar

$ lein deploy clojars # publish the project to Clojars as a library

Use lein help to see a complete list. lein help $TASK shows the usage for a specific task.

You can also chain tasks together in a single command by using the do task with comma-separated tasks:

$ lein do clean, test foo.test-core, jar

Most tasks need to be run from somewhere inside a project directory to work, but some (new, help, search, version, and repl) may run from anywhere.


The project.clj file in the project root should look like this:

(defproject myproject "0.5.0-SNAPSHOT"
  :description "A project for doing things."
  :license "Eclipse Public License 1.0"
  :url ""
  :dependencies org.clojure/clojure "1.8.0"
  :plugins lein-tar "3.2.0")

The lein new task generates a project skeleton with an appropriate starting point from which you can work. See the sample.project.clj file (also available via lein help sample) for a detailed listing of configuration options.

The project.clj file can be customized further with the use of profiles.


Leiningen documentation is organized as a number of guides:




Leiningen supports plugins which may introduce new tasks. See the plugins wiki page for a full list. If a plugin is needed for successful test or build runs, (such as lein-tar) then it should be added to :plugins in project.clj, but if it's for your own convenience (such as lein-pprint) then it should be added to the :plugins list in the :user profile in ~/.lein/profiles.clj. See the profiles guide for details on how to add to your :user profile. The plugin guide explains how to write plugins.


Source Copyright © 2009-2017 Phil Hagelberg, Alex Osborne, Dan Larkin, and contributors. Distributed under the Eclipse Public License, the same as Clojure uses. See the file COPYING.

Thanks to Stuart Halloway for Lancet and Tim Dysinger for convincing me that good builds are important.

Images Copyright © 2010 Phil Hagelberg. Distributed under the Creative Commons Attribution + ShareAlike License. Full-size version available.