twinstance is a command line tool included with TiddlyWebWiki that is used to create a new instance. It takes a single argument: the name of the directory in which you would like the new instance to be created. The tool creates that directory and places within a basic tiddlywebconfig.py file and populates a store with the basics needed to get a hosted TiddlyWiki up and running.

Take note that if twinstance is run in a directory that already has a tiddlywebconfig.py in it, the config settings of that tiddlywebconfig.py can impact the created instance, notably where data is stored. This behavior can be a bit confusing but is intentional: It provides a building block for enabling scripted instance builds. For more discussion see this issue.

The parent tiddlywebconfig.py does not impact the tiddlywebconfig.py that is written into the newly created instance. If you have set a custom store in the parent config, you will also need to set it in the instance config.

See also: How do I create an instance using a different store?