Running custom defined WP-CLI commands without WordPress installation present

This may be helpful.

http://wp-cli.org/blog/how-wp-cli-loads-wordpress.html

This is what actually wp-cli tries.

$_SERVER['HTTP_HOST'] = 'example.com';
define('WP_ADMIN', true);
require('wordpress/wp-load.php');

You must have these WordPress files files and the database.
So the answer is NO unless you create hack.
I am not aware of any.

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If you pass:

$ wp make:a.txt --skip-wordpress
Error: This does not seem to be a WordPress install.
Pass --path=`path/to/wordpress` or run `wp core download`.

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wp --version
WP-CLI 0.23.1