Everything you need to create awesome command line interfaces

Usage no npm install needed!

<script type="module">
  import cliKit from '';



A command line application toolkit for Node.js.

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  • Command line parsing
  • Support for dynamic command hierarchies
  • Auto-generated help
  • CLI template engine
  • External CLI extensions
  • Client and server for remote CLI session such as xterm.js
  • Automatic Node.js version enforcement


npm install cli-kit --save


import CLI from 'cli-kit';

(async () => {
    const { argv, _ } = await new CLI({
        options: {
            '-f, --force': 'use the force',
            '--timeout [value]': {
                desc: 'the timeout duration',
                type: 'int'

    console.log('options:', argv);
    console.log('args:', _);


In cli-kit, commands and options are grouped into "contexts". The main CLI instance defines the "global context". Each command defines a new context. Each context can have its own commands, options, and arguments. What you end up with is a hierarchy of contexts.

When cli-kit parses the command line arguments, it will check each argument against the global context to see if the argument can be identified as a known command, option, or argument. If it finds a command, it adds the command's context to a stack and re-parses any unidentified arguments.

This allows you to create deep and dynamic hierarchies of commands, options, and arguments.

Pseudo-Terminal Support

cli-kit extensions can be native binary executables or other Node.js scripts. When the extension is a native executable, then it is executed using Node's spawn(). Note that spawned child processes do not have a TTY and thus things like prompting will not work.


class CLI

A CLI intance defines a global context for which you add commands, options, and arguments.

Extends Context > HookEmitter.


  • opts : Object (optional)

    Various options to initialize the CLI instance.

const cli = new CLI({
    // An array of argument definitions. They are parsed in the order they are defined.
    args: [
        // An argument can be as simple as its name. Wrapping the name with `<` and `>` signifies
        // that the argument is required.

        // To define an optional arguemnt, you can use `[` and `]`.

        // Or simply omit the brackets

        // For more options, you can specify an argument descriptor
            // The argument name. Follows the same rules as above.
            name: 'arg4',

            // The argument's description to show in the help output.
            desc: undefined,

            // When `true`, hides the argument from usage string in the help output.
            hidden: false,

            // When `true`, captures all subsequent argument values into an array
            multiple: false,

            // Overrides the brackets and forces the argument to be required or optional.
            required: false,

            // There are several built-in types. See the "types" section below for more info.
            type: 'string'

        // Adding `...` will capture all subsequent argument values into an array

    // Global flag to camel case property names derived from multi-word options/arguments.
    // Defaults to true, can be overwritten by the option/argument.
    camelCase: true,

    // An object of command names to command descriptors.
    commands: {
        'some-command': {
            // The action to perform when the command is parsed.
            action({ argv, _ }) {
                console.log('options:', argv);
                console.log('args:', _);

            // An array of alternate command names.
            aliases: [ 'another-command' ],

            // Command specific args. See `args` section above.
            args: [],

            // When `true`, camel case all option and argument names in the `argv` result.
            camelCase: true,

            // An object of subcommand names to subcommand descriptors.
            commands: {},

            // The command description.
            desc: undefined,

            // When `true`, hides the command from the help output.
            hidden: false,

            // An object of option formats to option descriptors. See the `options` section below.
            options: {},

            // The command name to display in the help output. Defaults to the command name.
            title: undefined

    // The default command `exec()` should run if no command was found during parsing.
    // If `help` is `true` and no default command is specified, it will default to displaying the
    // help screen. If you want help, but do not want to default to the help command, then set the
    // `defaultCommand` to `null`.
    defaultCommand: undefined,

    // The CLI description to print on the help screen between the usage and commands/options/args.
    desc: undefined,

    // Adds the `-h, --help` to the global flags and enables the auto-generated help screen.
    // Defaults to `true`.
    help: true,

    // The exit code to return when the help screen is displayed. This is useful if you want to
    // force the program to exit if `--help` is specified and the user is chaining commands together
    // or after displaying the help screen and prevent further execution in the CLI's promise chain.
    helpExitCode: undefined,

    // The name of the program used by the help screen to display the command's usage.
    // Defaults to "program".
    name: 'program',

    // An object of option formats to option descriptors or an array of sorted group names and
    // objects of option formats to option descriptors.
    options: {

    // The title for the top-level (or "Global") context. This title is displayed on the help screen
    // when displaying the list of options.
    title: 'Global',

    // When set, it will automatically wire up the `-v, --version` option. Upon calling with your
    // program with `--version`, it will display the version and exit with a success (zero) exit
    // code.
    version: null


Parses the command line args and executes a command, if found.

  • args : Array<String> (optional)

    An array of arguments. Each argument is expected to be a string.

    Defaults to process.argv.slice(2).

Returns a Promise that resolves an Arguments object. This object will contain the parsed options in argv and arguments in _.

    .then(({ argv, _ }) => {
        console.log('options:', argv);
        console.log('args:', _);

class Context

Base class for CLI and Command classes.

Extends HookEmitter.


Adds an argument to a CLI or Command.

  • arg : Argument, Object, or String.

    An argument descriptor. Either an Argument instance or an Object to pass into a Argument constructor.

    An argument requires a name.

Returns a reference to the CLI or Command.

// define a non-required argument "foo"

// define a non-required argument "wiz"

// define a required argument "pow"

    name: 'bar',
    type: 'int'

cli.argument(new Argument('baz'));

command(cmd, opts)

Adds a command to a CLI or Command.


option(optOrFormat, group, params)

Adds an option or group of options to a CLI or Command.


Who Uses cli-kit?