mkly

mkly is a modern CLI framework designed with a relentless focus on user experience, ease of use, and expressiveness. It empowers developers to build CLI tools that greet users with friendly, clear, and beautiful interfaces.

Features

• UX First: Auto-generates beautiful, readable help pages and error messages.
• Expressive Parsing: Natural parsing of arguments and options.
• Rich Value Types: First-class support for Time, Size, Paths, and JSON.
• Modular & Composable: Easily build nested subcommands and reusable command modules.
• Type-Safe: Designed with TypeScript in mind for a robust development experience.
• Fast & Lightweight: Minimal overhead, perfect for tools of any size.

Installation

npm install mkly
# or
bun add mkly
# or
yarn add mkly

Usage

The examples directory contains several usage patterns. Here are key highlights.

Basic Command

Quickly define a CLI with commands, arguments, and actions.

import { CLI } from 'mkly';

const cli = new CLI('greeter', '1.0.0');

cli
  .command('greet')
  .description('Greets a person')
  .argument('name', { type: 'string' })
  .argument('age', { type: 'number' })
  .action((args) => {
    // args is typed based on definitions
    console.log(`Hello ${args.name}, you are ${args.age} years old`);
  });

cli.run();

Run it:

$ mycli greet "John Doe" 30
Hello John Doe, you are 30 years old

Options & Flags

Options can be defined with types, aliases, and default values. mkly handles the parsing and validation for you.

cli
  .command('build')
  .description('Builds the project')
  .option('minify', {
    type: 'boolean',
    alias: ['m', 'min'],
    defaultValue: false,
  })
  .option('target', {
    type: 'number',
    defaultValue: 18,
  })
  .action((_, opts) => {
    console.log('Options:', opts);
  });

Run it:

$ app build --minify -t 20
Options: { minify: true, target: 20 }

Supported Value Types

mkly comes with a powerful parser capable of handling various data types out of the box.

Type	Description	Valid Input Examples
boolean	Boolean flag	true, false, 1, 0, yes, no, on, off
string	Text string	"foo", bar
number	Numeric value	42, 3.14
choice	Set of allowed values	"red", "green", "blue"
path	File system path	./src, /etc/config
time	Duration or Date	5s, 1h30m, 2025-01-01
size	Digital storage size	10kb, 500mb, 1gb
json	JSON object	{"key": "value"}

Arrays: All types support array variants (e.g., stringArray, numberArray).

Time Type

The time type is incredibly flexible. It supports:

• Durations: 100ms, 5s, 10m, 1.5h, 2d, 1w, 1mo, 1y
• Compound Durations: 1h30m, 2d12h
• Dates: 2025-12-31, 2025-12-31 23:59 (parsed relative to now)

Size Type

The size type makes handling file sizes intuitive:

• Units: b, kb, mb, gb, tb, pb
• Values: 10kb (10240 bytes), 1.5gb, 500b

Nested Subcommands

Organize complex tools (like git) using nested subcommands.

const remote = cli.command('remote').description('Manage remotes');

remote.command('add')
  .argument('name', { type: 'string' })
  .argument('url', { type: 'string' })
  .action((args) => {
    console.log(`Adding remote ${args.name} -> ${args.url}`);
  });

remote.command('remove')
  .argument('name', { type: 'string' })
  .action((args) => {
    console.log(`Removing remote ${args.name}`);
  });

Running Examples

The repository includes a set of examples demonstrating different features. You can run them directly with Bun:

# Basic Hello World
bun examples/basic-hello.ts greet Parsa 25

# Options Demo
bun examples/options.ts build --minify --target 20

# Real World "Vite-like" CLI
bun examples/real-world.ts dev --port 8080

# Error Handling Demo
bun examples/errors.ts divide a 0

Contributors

Thanks to these amazing people:

License

MIT © Kkotero

Contributing

Issues and pull requests are welcome.

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