The Stella API is divided into 2 sections: Context Methods and REST API.
For Context Methods, you can access the methods when you are designing the flow of your chatbot. For example, you can call
this.upsertDataToDataSource inside you pre-actions or post-actions to insert or update the data in your datasource. This is very useful when you want to fully customize your chatbot flow.
For REST API, you can call the methods through standard HTTP request and Stella will return corresponding HTTP response code and data you want.