How to create a GPT specialized in certain APIs

Hi all,

Some reference documentations for APIs are basically just long web documents explaining the API endpoints and parameters. I would post an example link but this doesn’t seem to be allowed.

Please guide me how to properly create a GPT that would be knowledgable about the full content. I’ve tried saving the entire page as markdown and added as file without success. And when just using the browser tool, it cannot read the full page without halting.

Very grateful for any help!