Introduction
SAP Internal and External APIs (OData and pure REST) must be published on the SAP Business Accelerator Hub. Here you will find all the information you need to start writing, editing, reviewing, validating, and publishing your APIs.
Guidelines
UA-90 Product Standard for API Document
Developer or Service Guides (API-related documentation)
Publishing APIs to SAP API Business Hub (Internal and Public APIs)
APIs and Events Portal (central portal for all API and Event guidelines)
API Documentation Consulting Service
API Overview for UA and Non-Developers - SAP eLearning Course