cli-developer

name	cli-developer
description	Go CLI development with Cobra command hierarchy, Bubbletea interactive TUI, Lipgloss terminal styling, Charmbracelet ecosystem (Bubbles, Huh forms, Glamour markdown rendering), and shell completions. Use when building CLI tools, adding subcommands, creating interactive TUI, styling terminal output, or implementing shell completions.
license	MIT
metadata	{"author":"https://github.com/Jeffallan","version":"2.0.0","domain":"devops","triggers":"CLI, command-line, cobra, bubbletea, lipgloss, charmbracelet, huh, glamour, terminal, TUI, shell completions","role":"specialist","scope":"implementation","output-format":"code","related-skills":"architecture-designer, cloud-architect"}

CLI Developer

Core Workflow

1. Analyze — Understand user workflows, input sources (flags, env, config files), and output expectations (human vs machine)
2. Design — Plan command hierarchy, flag inheritance, and interaction patterns (interactive prompts vs non-interactive flags)
3. Implement — Build with Cobra for commands and Charmbracelet (Bubbletea, Bubbles, Huh, Lipgloss, Glamour) for interactive TUI and styled output
4. Polish — Add shell completions, error handling, help text, and TTY detection for graceful degradation
5. Test — Verify cross-platform (Windows, macOS, Linux), interactive and non-interactive modes, piped input/output, and signal handling

Quick-Start Examples

Cobra Root Command + Subcommand

package main

import (
	"fmt"
	"os"

	"github.com/spf13/cobra"
)

var verbose bool

var rootCmd = &cobra.Command{
	Use:   "myctl",
	Short: "Manage resources from the terminal",
	PersistentPreRunE: func(
		cmd *cobra.Command, args []string,
	) error {
		// Shared setup: load config, init logger.
		return nil
	},
}

var listCmd = &cobra.Command{
	Use:   "list",
	Short: "List all resources",
	Args:  cobra.NoArgs,
	RunE: func(
		cmd *cobra.Command, args []string,
	) error {
		if verbose {
			fmt.Fprintln(os.Stderr, "fetching resources...")
		}
		fmt.Println("resource-1\nresource-2")
		return nil
	},
}

func init() {
	rootCmd.PersistentFlags().BoolVarP(
		&verbose, "verbose", "v", false,
		"enable verbose output",
	)
	rootCmd.AddCommand(listCmd)
}

func main() {
	if err := rootCmd.Execute(); err != nil {
		os.Exit(1)
	}
}

Bubbletea Interactive List Selector

package main

import (
	"fmt"
	"os"

	tea "github.com/charmbracelet/bubbletea"
)

type model struct {
	choices  []string
	cursor   int
	selected int
}

func initialModel() model {
	return model{
		choices:  []string{"Deploy", "Rollback", "Status"},
		selected: -1,
	}
}

func (m model) Init() tea.Cmd { return nil }

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.String() {
		case "ctrl+c", "q":
			return m, tea.Quit
		case "up", "k":
			if m.cursor > 0 {
				m.cursor--
			}
		case "down", "j":
			if m.cursor < len(m.choices)-1 {
				m.cursor++
			}
		case "enter":
			m.selected = m.cursor
			return m, tea.Quit
		}
	}
	return m, nil
}

func (m model) View() string {
	s := "Pick an action:\n\n"
	for i, choice := range m.choices {
		cursor := "  "
		if m.cursor == i {
			cursor = "> "
		}
		s += cursor + choice + "\n"
	}
	s += "\nPress q to quit.\n"
	return s
}

func main() {
	p := tea.NewProgram(initialModel())
	finalModel, err := p.Run()
	if err != nil {
		fmt.Fprintf(os.Stderr, "error: %v\n", err)
		os.Exit(1)
	}
	m := finalModel.(model)
	if m.selected >= 0 {
		fmt.Println("Selected:", m.choices[m.selected])
	}
}

Lipgloss Styled Output

package main

import (
	"fmt"

	"github.com/charmbracelet/lipgloss"
)

func main() {
	banner := lipgloss.NewStyle().
		Bold(true).
		Foreground(lipgloss.Color("205")).
		Background(lipgloss.Color("235")).
		Padding(1, 3).
		Border(lipgloss.RoundedBorder()).
		BorderForeground(lipgloss.Color("62")).
		Render("myctl v1.0.0 — ready")

	fmt.Println(banner)
}

Reference Guide

Load detailed guidance based on context:

Topic	Reference	Load When
Go CLI	references/go-cli.md	Cobra, Bubbletea, Charmbracelet
Design Patterns	references/design-patterns.md	Command hierarchy, config, output format
UX Patterns	references/ux-patterns.md	TTY detection, signals, completions

Constraints

MUST DO

• Keep startup time under 50ms
• Support --help and --version flags
• Handle Ctrl+C gracefully via context
• Validate input early with cobra.ExactArgs / cobra.NoArgs
• Support both interactive and non-interactive modes
• Test cross-platform (Windows, macOS, Linux)
• Use Charmbracelet ecosystem for interactive TUI
• Log diagnostics to stderr, not stdout

MUST NOT DO

• Apply colors when output is not a terminal (TTY detection required)
• Hardcode paths — use os.UserConfigDir() and XDG
• Block the Bubbletea update loop on network or file I/O — run it in a tea.Cmd instead
• Skip shell completions
• Mix stdout data with stderr diagnostics