slim

The slim way to build Clojure.

Overview

slim is a build tool for Clojure projects that emphasizes simplicity and minimal configuration. It helps you build uberjars for applications or build and deploy jars for libraries with zero ceremony.

Features

• 🔄 Versatile Building: Can build applications (uberjar), and build and deploy libraries
• 🎯 Minimal Configuration: Uses deps.edn - no additional configuration files needed
• 🔧 Sensible Defaults: Works out of the box with minimal configs for most Clojure projects
• 📦 Minimal Dependencies: Built on top of tools.build and slipset/deps-deploy

Quick Start: Build App

Add slim to your deps.edn:

{:aliases
 {:slim {:deps {io.github.abogoyavlensky/slim {:mvn/version "LATEST"}}
         :ns-default slim.app
         :exec-args {:main-ns my-app.core}}}}

Run the build:

clojure -T:slim build

That's it! Your uberjar will be created at target/standalone.jar.

Usage

Build: App

Builds an uberjar file for an application. The minimal configuration requires only the main namespace:

{:deps {io.github.abogoyavlensky/slim {:mvn/version "LATEST"}}
 :ns-default slim.app
 :exec-args {:main-ns my-app.core}}

Custom configuration

You can customize the build with optional parameters. All available options are shown below:

{...
 :exec-args {:main-ns my-app.core
             :target-dir "custom-target"
             :uber-file "my-app.jar"
             :src-dirs ["src" "resources" "custom-src"]
             :class-dir "custom-classes"}}

• :main-ns (required) - Main namespace to compile.
• :target-dir (optional) - Target directory for build artifacts (default: "target").
• :uber-file (optional) - Name of the output uberjar (default: "target/standalone.jar").
• :src-dirs (optional) - Source directories to include (default: ["src" "resources"]).
• :class-dir (optional) - class directory (default: "target/classes").

Available commands

Command	Description
build	Builds an uberjar file with all dependencies included. The uberjar file will be created at the specified location (defaults to target/standalone.jar).

Build: Library

Builds and deploys a jar file for a library. The minimal configuration requires the library name and version. It also requires the slipset/deps-deploy dependency to deploy the library to Clojars:

{:deps {io.github.abogoyavlensky/slim {:mvn/version "LATEST"}
        slipset/deps-deploy {:mvn/version "0.2.2"}}
 :ns-default slim.lib
 :exec-args {:lib my-org/my-lib
             :version "0.1.0"}}

Install locally:

clojure -T:slim install

Run the build and deploy snapshot version:

clojure -T:slim deploy :snapshot true

or deploy release version:

clojure -T:slim deploy

That's it! Your library has been built and deployed to Clojars.

Note: You need to have CLOJARS_USERNAME and CLOJARS_PASSWORD environment variables set to your Clojars credentials.

Extended configuration

You can customize the build with optional parameters for extended metadata information in the library's pom-file.

{...
 :exec-args {:lib my-org/my-lib
             :version "0.1.0"
             :url "https://github.com/my-org/my-lib"
             :description "My awesome library"
             :developer "Your Name"
             :license {:name "Apache License 2.0"
                       :url "https://www.apache.org/licenses/LICENSE-2.0"}}}

• :lib (required) - Library name in org/lib format.
• :version (required) - Library version. The version will be used as a git tag as-is. If you want to customize it, please use the :scm option.
• :url (optional) - Project URL. It will also be used as the SCM URL. If you have a separate URL, please define a separate :scm option.
• :description (optional) - Project description.
• :developer (optional) - Developer name.
• :license (optional) - If not set, defaults to "MIT License".

Available commands

Command	Description	Options
build	Builds a jar file for the library.	:snapshot (optional) - If true, the jar will be built as a snapshot version. Default is false.
install	Builds and installs the jar to local Maven repository.	:snapshot (optional) - If true, the jar will be installed as a snapshot version. Default is false.
deploy	Builds and deploys the jar to Clojars (requires CLOJARS_USERNAME and CLOJARS_PASSWORD environment variables).	:snapshot (optional) - If true, the jar will be deployed as a snapshot version. Default is false.
tag	Creates a git tag for the library version.	:push - If true automatically pushes the newly created git tag to remote repository. Default is false.

Custom configuration

The options :url, :description, :developer, and :license are used to generate the pom-file for the library. If you need to customize the pom-file, you can pass the :pom-data option, which will take precedence over other options. An example of :pom-data:

[[:description "My awesome library"]
 [:url "https://github.com/username/lib"]
 [:licenses
  [:license
   [:name "MIT License"]
   [:url "https://opensource.org/license/mit/"]]]
 [:developers
  [:developer
   [:name "Person Name"]]]]

By default, :scm is generated using :url and :version (as tag). If you need to change your SCM repository URL or tag, you can pass the :scm option with a value:

{:url "https://github.com/username/lib"
 :connection "scm:git:git://github.com/username/lib.git"
 :developerConnection "scm:git:ssh://git@github.com/username/lib.git"
 :tag "v0.1.0}}}}}

Note: For other options, please consult the spec of the library and the definition of clojure.tools.build.api/write-pom function.

Inspired by

• build-clj
• application build guide

Alternatives

• https://github.com/liquidz/build.edn
• https://github.com/NoahTheDuke/clein

License

MIT License Copyright (c) 2025 Andrey Bogoyavlenskiy