class Layout | None = None, style: BaseStyle | None = None, include_default_pygments_style: FilterOrBool = True, style_transformation: StyleTransformation | None = None, key_bindings: KeyBindingsBase | None = None, clipboard: Clipboard | None = None, full_screen: bool = False, color_depth: ColorDepth | Callable[[], ColorDepth | None] | None = None, mouse_support: FilterOrBool = False, enable_page_navigation_bindings: None | FilterOrBool = None, paste_mode: FilterOrBool = False, editing_mode: EditingMode = EditingMode.EMACS, erase_when_done: bool = False, reverse_vi_search_direction: FilterOrBool = False, min_redraw_interval: float | int | None = None, max_render_postpone_time: float | int | None = 0.01, refresh_interval: float | None = None, terminal_size_polling_interval: float | None = 0.5, cursor: AnyCursorShapeConfig = None, on_reset: ApplicationEventHandler[_AppResult] | None = None, on_invalidate: ApplicationEventHandler[_AppResult] | None = None, before_render: ApplicationEventHandler[_AppResult] | None = None, after_render: ApplicationEventHandler[_AppResult] | None = None, input: Input | None = None, output: Output | None = None)

The main Application class! This glues everything together.

  • layout – A Layout instance.

  • key_bindingsKeyBindingsBase instance for the key bindings.

  • clipboardClipboard to use.

  • full_screen – When True, run the application on the alternate screen buffer.

  • color_depth – Any ColorDepth value, a callable that returns a ColorDepth or None for default.

  • erase_when_done – (bool) Clear the application output when it finishes.

  • reverse_vi_search_direction – Normally, in Vi mode, a ‘/’ searches forward and a ‘?’ searches backward. In Readline mode, this is usually reversed.

  • min_redraw_interval

    Number of seconds to wait between redraws. Use this for applications where invalidate is called a lot. This could cause a lot of terminal output, which some terminals are not able to process.

    None means that every invalidate will be scheduled right away (which is usually fine).

    When one invalidate is called, but a scheduled redraw of a previous invalidate call has not been executed yet, nothing will happen in any case.

  • max_render_postpone_time – When there is high CPU (a lot of other scheduled calls), postpone the rendering max x seconds. ‘0’ means: don’t postpone. ‘.5’ means: try to draw at least twice a second.

  • refresh_interval – Automatically invalidate the UI every so many seconds. When None (the default), only invalidate when invalidate has been called.

  • terminal_size_polling_interval – Poll the terminal size every so many seconds. Useful if the applications runs in a thread other then then main thread where SIGWINCH can’t be handled, or on Windows.


  • mouse_support – (Filter or boolean). When True, enable mouse support.

  • paste_modeFilter or boolean.

  • editing_modeEditingMode.

  • enable_page_navigation_bindings – When True, enable the page navigation key bindings. These include both Emacs and Vi bindings like page-up, page-down and so on to scroll through pages. Mostly useful for creating an editor or other full screen applications. Probably, you don’t want this for the implementation of a REPL. By default, this is enabled if full_screen is set.

Callbacks (all of these should accept an Application object as input.)

  • on_reset – Called during reset.

  • on_invalidate – Called when the UI has been invalidated.

  • before_render – Called right before rendering.

  • after_render – Called right after rendering.

I/O: (Note that the preferred way to change the input/output is by creating an AppSession with the required input/output objects. If you need multiple applications running at the same time, you have to create a separate AppSession using a with create_app_session(): block.

  • inputInput instance.

  • outputOutput instance. (Probably Vt100_Output or Win32Output.)


app = Application(…)

# Or await app.run_async()