Access to library block and question ids

Hi,
I am trying to write an integration that will pre-create a default questionnaire for a client who can then add additional questions of their own. I have pre-built the default block with all the questions and saved to my library but I am struggling to find an API endpoint that will allow me to access the block_id of my library block in order to add it to the survey. Am I missing something or is the entire survey/block/question library missing from the API as a whole?

Thanks
Tim