SKILL.md


name: charm-huh description: "Build interactive terminal forms and prompts in Go with huh - input, select, confirm, multiselect, validation, theming. Use when building Go terminal forms, huh, interactive Go prompts, or form fields with validation. NOT for shell script prompts (use gum)."

charmbracelet/huh

Interactive terminal forms and prompts for Go. Built on Bubble Tea.

Import: charm.land/huh/v2

Quick Start

package main

import (
    "fmt"
    "log"

    "charm.land/huh/v2"
)

func main() {
    var name string
    var confirm bool

    err := huh.NewForm(
        huh.NewGroup(
            huh.NewInput().
                Title("What's your name?").
                Value(&name).
                Validate(huh.ValidateNotEmpty()),
            huh.NewConfirm().
                Title("Ready?").
                Value(&confirm),
        ),
    ).Run()
    if err != nil {
        log.Fatal(err)
    }
    fmt.Printf("Hello, %s!\n", name)
}

Single field shorthand (no Form/Group wrapper needed):

var name string
huh.NewInput().Title("Name?").Value(&name).Run()

Core API

Architecture

Form > Group (pages) > Field (inputs)

Groups are displayed one at a time. The form advances to the next group when all fields in the current group pass validation.

Form

form := huh.NewForm(groups...*Group) *Form

Key methods:

Method Purpose
.Run() Block and run the form
.RunWithContext(ctx) Run with context (supports cancellation)
.WithTheme(theme) Set theme
.WithWidth(w) / .WithHeight(h) Set dimensions
.WithAccessible(bool) Screen reader mode
.WithShowHelp(bool) Toggle help bar
.WithShowErrors(bool) Toggle error display
.WithTimeout(duration) Auto-cancel after duration
.WithLayout(layout) Set group layout
.WithKeyMap(keymap) Custom keybindings
.WithOutput(w) / .WithInput(r) Custom IO

Retrieve values by key after completion:

form.GetString("key")
form.GetInt("key")
form.GetBool("key")
form.Get("key") // any

Form states: huh.StateNormal, huh.StateCompleted, huh.StateAborted

Errors: huh.ErrUserAborted (ctrl+c), huh.ErrTimeout

Group

group := huh.NewGroup(fields ...Field) *Group
Method Purpose
.Title(s) / .Description(s) Group header
.WithHide(bool) Skip this group
.WithHideFunc(func() bool) Conditionally skip group
.WithShowHelp(bool) Toggle help for group

Field Types

Every field supports: .Title(s), .Description(s), .Key(s), .Value(&v), .Validate(fn), .Run().

Dynamic variants exist for most properties: .TitleFunc(fn, binding), .DescriptionFunc(fn, binding), etc.

Input

Single line text. Type: string.

huh.NewInput().
    Title("Email").
    Placeholder("you@example.com").
    Prompt("> ").
    CharLimit(100).
    Suggestions([]string{"gmail.com", "outlook.com"}).
    EchoMode(huh.EchoModePassword). // or EchoModeNone
    Inline(true). // title and input on same line
    Validate(huh.ValidateNotEmpty()).
    Value(&email)

Text

Multi-line textarea. Type: string.

huh.NewText().
    Title("Description").
    Lines(5).
    CharLimit(500).
    Placeholder("Enter details...").
    ShowLineNumbers(true).
    Editor("vim"). // external editor support (ctrl+e)
    EditorExtension("md").
    ExternalEditor(false). // disable external editor
    Value(&description)

Select

Pick one from a list. Generic: Select[T comparable].

huh.NewSelect[string]().
    Title("Country").
    Options(
        huh.NewOption("United States", "US"),
        huh.NewOption("Canada", "CA"),
    ).
    Height(8).      // scrollable if options exceed height
    Inline(true).   // horizontal left/right navigation
    Filtering(true). // start with filter active
    Value(&country)

Shorthand for simple options:

Options(huh.NewOptions("Warrior", "Mage", "Rogue")...)

MultiSelect

Pick zero or more. Generic: MultiSelect[T comparable].

huh.NewMultiSelect[string]().
    Title("Toppings").
    Options(
        huh.NewOption("Lettuce", "lettuce").Selected(true),
        huh.NewOption("Tomato", "tomato"),
        huh.NewOption("Cheese", "cheese"),
    ).
    Limit(3).
    Height(6).
    Filterable(false). // disable "/" filter
    Value(&toppings)

Space to toggle, a to select all (when no limit), / to filter.

Confirm

Yes/No. Type: bool.

huh.NewConfirm().
    Title("Continue?").
    Affirmative("Yes!").
    Negative("No way").
    Inline(true).
    Value(&ok)

Keys: h/l or left/right to toggle, y to accept, n to reject.

Note

Display-only. Not interactive by default (auto-skipped).

huh.NewNote().
    Title("Welcome").
    Description("This form collects your _preferences_.").
    Height(10).
    Next(true).        // show a "Next" button, makes it interactive
    NextLabel("Continue")

Description supports basic markdown: _italic_, *bold*, `code`.

Common Patterns

Multi-Step Forms

Groups act as pages. Users navigate forward/back between them.

huh.NewForm(
    huh.NewGroup(/* step 1 fields */).Title("Step 1"),
    huh.NewGroup(/* step 2 fields */).Title("Step 2"),
    huh.NewGroup(/* step 3 fields */).Title("Step 3"),
).Run()

Conditional Groups

Hide groups based on previous answers:

var wantExtras bool

huh.NewForm(
    huh.NewGroup(
        huh.NewConfirm().Title("Want extras?").Value(&wantExtras),
    ),
    huh.NewGroup(
        huh.NewInput().Title("Extra details").Value(&details),
    ).WithHideFunc(func() bool { return !wantExtras }),
).Run()

Dynamic Fields

Use *Func variants to recompute properties when bindings change. Pass a pointer to the bound variable.

var country string

huh.NewSelect[string]().
    Value(&state).
    TitleFunc(func() string {
        if country == "Canada" { return "Province" }
        return "State"
    }, &country).
    OptionsFunc(func() []huh.Option[string] {
        return huh.NewOptions(statesByCountry[country]...)
    }, &country)

The binding (&country) tells huh when to recompute. Results are cached per binding hash.

Validation

Built-in validators:

huh.ValidateNotEmpty()
huh.ValidateMinLength(3)
huh.ValidateMaxLength(100)
huh.ValidateLength(3, 100)  // min and max
huh.ValidateOneOf("a", "b", "c")

Custom validation:

.Validate(func(s string) error {
    if !strings.Contains(s, "@") {
        return fmt.Errorf("must be a valid email")
    }
    return nil
})

Validation runs on blur (when leaving a field). Forms block progression if any field in the current group has errors.

Theming

Built-in themes: ThemeCharm (default), ThemeDracula, ThemeCatppuccin, ThemeBase16, ThemeDefault.

form.WithTheme(huh.ThemeFunc(huh.ThemeDracula))

Custom theme - implement the Theme interface:

type Theme interface {
    Theme(isDark bool) *Styles
}

Or use ThemeFunc:

form.WithTheme(huh.ThemeFunc(func(isDark bool) *huh.Styles {
    s := huh.ThemeCharm(isDark) // start from a base
    s.Focused.Title = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("212"))
    return s
}))

Layouts

form.WithLayout(huh.LayoutDefault)         // one group at a time (default)
form.WithLayout(huh.LayoutStack)           // all groups stacked vertically
form.WithLayout(huh.LayoutColumns(2))      // groups in 2 columns
form.WithLayout(huh.LayoutGrid(2, 3))      // 2 rows, 3 columns

Accessibility

accessible := os.Getenv("ACCESSIBLE") != ""
form.WithAccessible(accessible)

When TERM=dumb, accessible mode activates automatically. Replaces TUI with plain text prompts. Timeout is not supported in accessible mode.

Spinner

Separate package for loading indicators after form submission:

import "charm.land/huh/v2/spinner"

err := spinner.New().
    Title("Processing...").
    Action(func() { /* do work */ }).
    Run()

Or with context:

go doWork()
spinner.New().Title("Working...").Context(ctx).Run()

Integration: Standalone vs Bubble Tea

Standalone

Call .Run() on a form or individual field. Blocks until complete.

form.Run()
// or
huh.NewInput().Title("Name?").Value(&name).Run()

Embedded in Bubble Tea

*huh.Form implements tea.Model. Use it as a component in your Bubble Tea app.

type Model struct {
    form *huh.Form
}

func NewModel() Model {
    return Model{
        form: huh.NewForm(
            huh.NewGroup(
                huh.NewSelect[string]().
                    Key("class").
                    Options(huh.NewOptions("Warrior", "Mage", "Rogue")...).
                    Title("Choose your class"),
            ),
        ),
    }
}

func (m Model) Init() tea.Cmd {
    return m.form.Init()
}

func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
    form, cmd := m.form.Update(msg)
    if f, ok := form.(*huh.Form); ok {
        m.form = f
    }

    if m.form.State == huh.StateCompleted {
        return m, tea.Quit
    }
    return m, cmd
}

func (m Model) View() string {
    if m.form.State == huh.StateCompleted {
        return fmt.Sprintf("You picked: %s", m.form.GetString("class"))
    }
    return m.form.View()
}

Key differences when embedded:

  • Do NOT call .Run(), use Init/Update/View cycle instead
  • Set SubmitCmd and CancelCmd if you want custom behavior on form completion
  • Use .Key("name") on fields, retrieve with form.GetString("name")
  • Check form.State to know when the form is done
  • Type assert the Update result: form.(*huh.Form)

Navigation methods available for programmatic control:

  • form.NextGroup(), form.PrevGroup()
  • form.NextField(), form.PrevField()
  • form.GetFocusedField()

Common Mistakes

  1. Forgetting .Value(&v) - Without it, answers go nowhere. The field uses an internal EmbeddedAccessor that you cannot read after form completes unless you use .Key() + form.GetString().

  2. Using .Run() inside Bubble Tea - Never call .Run() on an embedded form. Use the Init/Update/View pattern.

  3. Missing type parameter on Select/MultiSelect - huh.NewSelect[string]() not huh.NewSelect(). The generic parameter determines the option value type.

  4. Dynamic binding without pointer - TitleFunc(fn, country) will not work. Must be TitleFunc(fn, &country) with a pointer so huh can detect changes.

  5. Timeout in accessible mode - WithTimeout() returns ErrTimeoutUnsupported in accessible mode. Guard it.

  6. Not handling ErrUserAborted - form.Run() returns huh.ErrUserAborted when user presses ctrl+c. Always check the error.

  7. Form outputs to stderr - By default, the TUI renders to stderr (stdout stays clean for piping). Use .WithOutput(os.Stdout) to change.

Checklist

  • Import charm.land/huh/v2
  • Every field that stores data has .Value(&var) or .Key("name")
  • Custom validators return nil on success, error on failure
  • Dynamic fields use *Func variants with pointer bindings
  • Accessible mode handled via env var or config flag
  • ErrUserAborted handled after .Run()
  • Embedded forms use Init/Update/View, not .Run()
  • Form state checked via form.State == huh.StateCompleted