Application programming interfaces (APIs) are machine-readable interfaces that allow interactions between multiple software, facilitating data use, access, and exchange. Scholars use web APIs, albeit in a limited way, as research sources and objects of criticism. This two-part series of guides offer an overview of the knowledge needed to collect data using APIs. This overview helps researchers and scholars understand the attitude they will need to adapt to become conceptually, technically, and empirically acquainted with APIs and the tools needed to communicate with and request data from them. Following this overview of the technicity perspective, this guide explains and defines the main characteristics of APIs, and introduces different types of web APIs. This guide will also present different ways of understanding and navigating API documentation, including using data retrieval software and verifying outputs. In Part 2 of this series, the guide will demonstrate possible ways to communicate with and access APIs, highlighting the main requirements to do that. Finally, the guide highlights aspects to consider before, during, and after data collection. Collectively these guides will help readers gain a technical and methodological understanding of how to collect data using APIs while illustrating key ethical considerations that may arise in the process.