Bash Complete

New in version 2.0.

As of Click 2.0, there is built-in support for Bash completion for any Click script. There are certain restrictions on when this completion is available, but for the most part it should just work.


Bash completion is only available if a script has been installed properly, and not executed through the python command. For information about how to do that, see Setuptools Integration. Also, Click currently only supports completion for Bash.

Currently, Bash completion is an internal feature that is not customizable. This might be relaxed in future versions.

What it Completes

Generally, the Bash completion support will complete subcommands and parameters. Subcommands are always listed whereas parameters only if at least a dash has been provided. Example:

$ repo <TAB><TAB>
clone    commit   copy     delete   setuser
$ repo clone -<TAB><TAB>
--deep     --help     --rev      --shallow  -r


In order to activate Bash completion, you need to inform Bash that completion is available for your script, and how. Any Click application automatically provides support for that. The general way this works is through a magic environment variable called _<PROG_NAME>_COMPLETE, where <PROG_NAME> is your application executable name in uppercase with dashes replaced by underscores.

If your tool is called foo-bar, then the magic variable is called _FOO_BAR_COMPLETE. By exporting it with the source value it will spit out the activation script which can be trivally activated.

For instance, to enable Bash completion for your foo-bar script, this is what you would need to put into your .bashrc:

eval "$(_FOO_BAR_COMPLETE=source foo-bar)"

From this point onwards, your script will have Bash completion enabled.

Activation Script

The above activation example will always invoke your application on startup. This might be slowing down the shell activation time significantly if you have many applications. Alternatively, you could also ship a file with the contents of that, which is what Git and other systems are doing.

This can be easily accomplished:

_FOO_BAR_COMPLETE=source foo-bar >

And then you would put this into your bashrc instead:

. /path/to/