TagInputField.js tags xtype

CQ includes this:

http://localhost:4502/libs/cq/tagging/widgets/source/widgets/TagInputField.js

So you can configure it like this:

new CQ.tagging.TagInputField({
    namespaces: ["foo", "default", "bar] //search only these namespaces
    , tagsBasePath: "/content/mytags" //do NOT do this. TagManager always searches from /etc/tags anyways
    , suggestMinChars: 1 //auto complete starts from one character input (default 3)
});

cq:ClientLibraryFolder debug

To have individual javascript to be included instead of one javascript:

http://localhost:4502/system/console/configMgr/com.day.cq.widget.impl.HtmlLibraryManagerImpl

Check Debug