# CLI Developer

Use when building CLI tools, implementing argument parsing, or adding interactive prompts.

- Repository: https://github.com/Jeffallan/claude-skills (12164 stars)
- Category: Design
- License: MIT
- Last updated: 2026-10-30
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add Jeffallan/claude-skills --skill cli-developer -g -a claude-code -y`
Codex: `npx skills add Jeffallan/claude-skills --skill cli-developer -g -a codex -y`
Cursor: `npx skills add Jeffallan/claude-skills --skill cli-developer -g -a cursor -y`
Gemini CLI: `npx skills add Jeffallan/claude-skills --skill cli-developer -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add Jeffallan/claude-skills`

## Description

Use when building CLI tools, implementing argument parsing, or adding interactive prompts. Invoke for parsing flags and subcommands, displaying progress bars and spinners, generating bash/zsh/fish completion scripts, CLI design, shell completions, and cross-platform terminal applications using commander, click, typer, or cobra.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# CLI Developer

## Core Workflow

1. **Analyze UX**, Identify user workflows, command hierarchy, common tasks. Validate by listing all commands and their expected `--help` output before writing code.
2. **Design commands**, Plan subcommands, flags, arguments, configuration. Confirm flag naming is consistent and no existing signatures are broken.
3. **Implement**, Build with the appropriate CLI framework for the language (see Reference Guide below). After wiring up commands, run `<cli> --help` to verify help text renders correctly and `<cli> --version` to confirm version output.
4. **Polish**, Add completions, help text, error messages, progress indicators. Verify TTY detection for color output and graceful SIGINT handling.
5. **Test**, Run cross-platform smoke tests; benchmark startup time (target: <50ms).

## Reference Guide

Load detailed guidance based on context:

| Topic | Reference | Load When |
|-------|-----------|-----------|
| Design Patterns | `references/design-patterns.md` | Subcommands, flags, config, architecture |
| Node.js CLIs | `references/node-cli.md` | commander, yargs, inquirer, chalk |
| Python CLIs | `references/python-cli.md` | click, typer, argparse, rich |
| Go CLIs | `references/go-cli.md` | cobra, viper, bubbletea |
| UX Patterns | `references/ux-patterns.md` | Progress bars, colors, help text |

## Quick-Start Example

### Node.js (commander)

```js
#!/usr/bin/env node
// npm install commander
const { program } = require('commander');

program
  .name('mytool')
  .description('Example CLI')
  .version('1.0.0');

program
  .command('greet <name>')
  .description('Greet a user')
  .option('-l, --loud', 'uppercase the greeting')
  .action((name, opts) => {
    const msg = `Hello, ${name}!`;
    console.log(opts.loud ? msg.toUpperCase() : msg);
  });

program.parse();
```

For Python (click/typer) and Go (cobra) quick-start examples, see `references/python-cli.md` and `references/go-cli.md`.

## Constraints

The rest: https://github.com/Jeffallan/claude-skills/blob/HEAD/skills/cli-developer/SKILL.md