https://click.palletsprojects.com/en/8.1.x/changes/#version-8-1-3

Changes
Version 8.1.3

Released 2022-04-28

    Use verbose form of typing.Callable for @command and @group. #2255

    Show error when attempting to create an option with multiple=True, is_flag=True. Use count instead. #2246

Version 8.1.2

Released 2022-03-31

    Fix error message for readable path check that was mixed up with the executable check. #2236

    Restore parameter order for Path, placing the executable parameter at the end. It is recommended to use keyword arguments instead of positional arguments. #2235

Version 8.1.1

Released 2022-03-30

    Fix an issue with decorator typing that caused type checking to report that a command was not callable. #2227

Version 8.1.0

Released 2022-03-28

    Drop support for Python 3.6. #2129

    Remove previously deprecated code. #2130

        Group.resultcallback is renamed to result_callback.

        autocompletion parameter to Command is renamed to shell_complete.

        get_terminal_size is removed, use shutil.get_terminal_size instead.

        get_os_args is removed, use sys.argv[1:] instead.

    Rely on PEP 538 and PEP 540 to handle selecting UTF-8 encoding instead of ASCII. Click’s locale encoding detection is removed. #2198

    Single options boolean flags with show_default=True only show the default if it is True. #1971

    The command and group decorators can be applied with or without parentheses. #1359

    The Path type can check whether the target is executable. #1961

    Command.show_default overrides Context.show_default, instead of the other way around. #1963

    Parameter decorators and @group handles cls=None the same as not passing cls. @option handles help=None the same as not passing help. #1959

    A flag option with required=True requires that the flag is passed instead of choosing the implicit default value. #1978

    Indentation in help text passed to Option and Command is cleaned the same as using the @option and @command decorators does. A command’s epilog and short_help are also processed. #1985

    Store unprocessed Command.help, epilog and short_help strings. Processing is only done when formatting help text for output. #2149

    Allow empty str input for prompt() when confirmation_prompt=True and default="". #2157

    Windows glob pattern expansion doesn’t fail if a value is an invalid pattern. #2195

    It’s possible to pass a list of params to @command. Any params defined with decorators are appended to the passed params. #2131.

    @command decorator is annotated as returning the correct type if a cls argument is used. #2211

    A Group with invoke_without_command=True and chain=False will invoke its result callback with the group function’s return value. #2124

    to_info_dict will not fail if a ParamType doesn’t define a name. #2168

    Shell completion prioritizes option values with option prefixes over new options. #2040

    Options that get an environment variable value using autoenvvar_prefix treat an empty value as None, consistent with a direct envvar. #2146

Version 8.0.4

Released 2022-02-18

    open_file recognizes Path("-") as a standard stream, the same as the string "-". #2106

    The option and argument decorators preserve the type annotation of the decorated function. #2155

    A callable default value can customize its help text by overriding __str__ instead of always showing (dynamic). #2099

    Fix a typo in the Bash completion script that affected file and directory completion. If this script was generated by a previous version, it should be regenerated. #2163

    Fix typing for echo and secho file argument. #2174, #2185