textual

Textual Skill

Textual is a Python framework for building rich terminal user interfaces (TUIs). It provides a widget toolkit with CSS-based styling, an event system with message passing, reactive data binding, screen management, and async worker support.

When to Use This Skill

Use Textual when:

• Building interactive terminal applications
• Creating dashboards, forms, or data browsers in the terminal
• Need rich UI with layout, styling, and input handling
• Want CSS-like styling for terminal apps
• Building apps with multiple screens or modal dialogs

Architecture

App (application root)
 └── Screen (layered views, one active at a time)
      └── Widget (UI components, nested in a DOM tree)
           └── Child Widgets...

• App is the top-level container. It manages screens, themes, key bindings, and the event loop.
• Screen is a full-screen layer within the app. Screens stack; only the top screen is visible.
• Widget is a UI component. Widgets form a DOM tree, can have children, and are styled with CSS.

Creating an App

from textual.app import App, ComposeResult
from textual.widgets import Header, Footer, Static

class MyApp(App):
    """A minimal Textual application."""

    CSS = """
    Screen {
        align: center middle;
    }
    #greeting {
        width: 40;
        padding: 1 2;
        border: solid green;
        text-align: center;
    }
    """

    BINDINGS = [
        ("q", "quit", "Quit"),
        ("d", "toggle_dark", "Toggle dark mode"),
    ]

    def compose(self) -> ComposeResult:
        yield Header()
        yield Static("Hello, World!", id="greeting")
        yield Footer()

    def action_toggle_dark(self) -> None:
        self.theme = "textual-light" if self.theme == "textual-dark" else "textual-dark"

if __name__ == "__main__":
    MyApp().run()

App Class Variables

Variable	Type	Purpose
CSS	str	Inline CSS rules
CSS_PATH	str | list[str]	Path(s) to .tcss CSS files
BINDINGS	list[BindingType]	Key bindings
TITLE	str	App title (shown in Header)
SUB_TITLE	str	App subtitle
SCREENS	dict[str, Callable]	Named screen factories
MODES	dict[str, str | Callable]	App modes with base screens
COMMANDS	set[type[Provider]]	Command palette providers
ENABLE_COMMAND_PALETTE	bool	Enable command palette (default: True)