We recommend against using the API unless you fully understand what the code does and implies and if you want to check up on changes every major release. Use the options instead, or submit a feature request if you can’t find what you need.
The SEO Framework
The SEO Framework is extensible, interpretable, and adjustable.
The Extension Manager
The Extension Manager is the epitome of extending The SEO Framework.
In the Extension Manager, the filters are used for debugging, and the actions are implemented for internal purposes only.
Some extensions in the Extension Manager have their own API.