Clikt (pronounced "clicked") is a multiplatform Kotlin library that makes writing command line interfaces simple and intuitive. It's the "Command Line Interface for Kotlin".

It is designed to make the process of writing command line tools effortless while supporting a wide variety of use cases and allowing advanced customization when needed.

Clikt has:

• arbitrary nesting of commands
• composable, type safe parameter values
• generation of help output and shell autocomplete scripts
• multiplatform packages for JVM, Node.js, and native Linux, Windows and macOS

What does it look like? Here's a complete example of a simple Clikt program:

class Hello : CliktCommand() {
    val count: Int by option().int().default(1).help("Number of greetings")
    val name: String by option().prompt("Your name").help("The person to greet")

    override fun run() {
        repeat(count) {
            echo("Hello $name!")
        }
    }
}

fun main(args: Array<String>) = Hello().main(args)

And here's what it looks like when run:

The help page is generated for you:

Errors are also taken care of:

Documentation

The full documentation can be found on the website.

There are also a number of sample applications. You can run them with the included runsample script.

Installation

Clikt is distributed through Maven Central.

dependencies {
   implementation("com.github.ajalt.clikt:clikt:5.1.0")

   // optional support for rendering markdown in help messages
   implementation("com.github.ajalt.clikt:clikt-markdown:5.1.0")
}

There is also a smaller core module available. See the docs for details.

If you're using Maven instead of Gradle, use <artifactId>clikt-jvm</artifactId>

Multiplatform

Clikt supports most multiplatform targets. See the docs for more information about functionality supported on each target. You'll need to use Gradle 6 or newer.

Snapshots

repositories {
    maven {
        url = uri("https://central.sonatype.com/repository/maven-snapshots/")
    }
}

License

Copyright 2018 AJ Alt

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.