# CLI Creator

> Create command-line interface (CLI) tools following clig.dev best practices. Covers argument parsing, help text, error handling, output formatting, signals, and configuration. Supports Python (Click, Typer), Node.js (Commander), Go (Cobra), Rust (Clap), and Bash. Includes starter templates. DO NOT use for web applications, web servers, GUI apps, or long-running services.

- Skill: `eggboy/cli-creator` (Agent Skill, multi-file: 21 files)
- Install (CLI): `npx skillmds@latest add eggboy/cli-creator`
- Raw SKILL.md: https://api.skillmd.com/api/skills/eggboy/cli-creator/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: eggboy (https://skillmd.com/u/eggboy)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/eggboy/cli-creator

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# CLI Creator

Create excellent command-line interfaces following clig.dev best practices.

## Workflow

Determine the task type and follow the appropriate path:

**Creating a new CLI?** → Follow "New CLI" below
**Improving an existing CLI?** → Follow "Improve Existing CLI" below

### New CLI

1. Select language and framework (see table below)
2. Copy the corresponding starter template from `assets/templates/` into the user's project directory, rename to match the CLI name
3. Customize the template for the use case
4. Read the language-specific reference for advanced patterns (subcommands, progress bars, prompts)
5. Validate against [references/guidelines.md](references/guidelines.md)
6. For Bash scripts, run `shellcheck` to validate correctness

### Improve Existing CLI

1. Read [references/guidelines.md](references/guidelines.md) for clig.dev principles
2. Audit against the [compliance checklist](references/guidelines.md#compliance-checklist) — covers: help/usage, errors→stderr, stdin/stdout, signals/cleanup, `--json`/`--plain`, `NO_COLOR`, exit codes, secrets
3. Read the language-specific reference for implementation patterns
4. Apply fixes for identified gaps
5. For Bash scripts, run `shellcheck` to validate correctness

## Language and Framework Selection

| Language | Framework | Best For | Reference |
|----------|-----------|----------|-----------|
| Python | **Click** | General purpose, decorator-based | [references/python.md](references/python.md) |
| Python | **Typer** | Type-hint based, modern | [references/python.md](references/python.md) |
| Python | **argparse** | No dependencies, simple CLIs | [references/python.md](references/python.md) |
| Node.js | **Commander** | Most popular, clean API | [references/nodejs.md](references/nodejs.md) |
| Node.js | **yargs** | Feature-rich, complex CLIs | [references/nodejs.md](references/nodejs.md) |
| Go | **Cobra** | Industry standard (kubectl, hugo, gh) | [references/go.md](references/go.md) |
| Rust | **Clap** | Derive or builder API | [references/rust.md](references/rust.md) |
| Bash | **getopts** | Simple scripts, no dependencies | [references/bash.md](references/bash.md) |

## Starter Templates

Copy the appropriate template into the user's project, rename, and customize the processing logic:

- `assets/templates/python-click-template.py` — Python + Click (PEP 723, run with `uvx`)
- `assets/templates/nodejs-commander-template.js` — Node.js + Commander
- `assets/templates/go-cobra-template.go` — Go + Cobra
- `assets/templates/rust-clap-template.rs` — Rust + Clap
- `assets/templates/bash-template.sh` — Bash + getopts

All templates include: argument parsing, stdin/stdout support, error handling with exit codes, Ctrl+C handling, `--verbose` and `--json` flags, and `NO_COLOR` respect.

## Subcommand CLIs

For multi-command tools (`mycli init`, `mycli build`, `mycli deploy`), read the subcommand section in the language-specific reference:

- Python: Click `@click.group()` or Typer app with multiple `@app.command()`
- Node.js: Commander `.command()` or yargs `.command()`
- Go: Cobra `AddCommand()` tree
- Rust: Clap `#[derive(Subcommand)]` enum
- Bash: `case` dispatch on `$1` with per-command functions

## Reference Documentation

Read these as needed for detailed patterns and examples:

- **[references/guidelines.md](references/guidelines.md)** — Complete clig.dev principles: philosophy, help text structure, output formatting, error handling, arguments/flags, interactivity, configuration, environment variables, naming, signals, distribution, analytics
- **[references/python.md](references/python.md)** — Click, Typer, argparse: subcommands, progress bars, colors, stdin, JSON output, env vars, testing
- **[references/nodejs.md](references/nodejs.md)** — Commander, yargs: subcommands, chalk/ora, stdin, prompts, package.json setup, testing
- **[references/go.md](references/go.md)** — Cobra, urfave/cli, flag: subcommands, colors, progress, signal handling, cross-compilation
- **[references/rust.md](references/rust.md)** — Clap (derive + builder): subcommands, colored, indicatif, anyhow errors, testing with assert_cmd
- **[references/bash.md](references/bash.md)** — getopts: subcommands, colors, stdin, JSON with jq, signals, testing with bats-core, shellcheck