__xonsh__.shell.shell
# <xonsh.shells.ptk_shell.PromptToolkitShell>
__xonsh__.shell.shell.key_bindings
# <prompt_toolkit.key_binding.key_bindings._MergedKeyBindings>

@__xonsh__.shell.shell.key_bindings.add("c-f")
def _my_ctrl_f(event):
    pass
# AttributeError: '_MergedKeyBindings' object has no attribute 'add'
# Yes, because key_bindings are inside MergedKeyBindings

current_bindings = __xonsh__.shell.shell.key_bindings.registries[0]
@current_bindings.add("c-f")
def _my_ctrl_f(event):
    if not str(event.current_buffer.text):
        (buf := event.current_buffer).insert_text('echo F')
        buf.validate_and_handle()

# Ctrl+F
# echo F
# F

__xonsh__.shell.shell.key_bindings
# <prompt_toolkit.key_binding.key_bindings.KeyBindings>


@__xonsh__.shell.shell.key_bindings.add("c-f")
def _my_ctrl_f(event):
    if not str(event.current_buffer.text):
        (buf := event.current_buffer).insert_text('echo F')
        buf.validate_and_handle()

# Ctrl+F
# echo F
# F