> For clean Markdown content of this page, append .md to this URL. For the complete documentation index, see https://buildwithfern.com/learn/llms.txt. # Overview ## Docs - [What is an API definition?](https://buildwithfern.com/learn/api-definitions/overview/what-is-an-api-definition.md): Describes the contract between the API provider and API consumer - [Project structure](https://buildwithfern.com/learn/api-definitions/overview/project-structure.md): Describes the Fern folder structure