3 API Protocol Types: Their Differences and When To Use Each

APIs (Application Programming Interfaces) serve as crucial communication layers between applications, allowing them to interact within a connected infrastructure. There are four major types of web APIs—open, internal, partner, and composite—each suited for different levels of access, security, and functionality. Open APIs are publicly accessible and encourage integration, internal APIs are used within organizations for secure communication, partner APIs are restricted to authorized clients, and composite APIs streamline operations by connecting multiple APIs. Alongside these, three main API protocols—REST, RPC, and SOAP—facilitate the technical communication process, each with distinct advantages and limitations. REST is flexible, transmitting data in various formats, RPC is fast and client-server oriented, while SOAP is simple and broad but prone to errors. Understanding these elements is essential for modern development, as APIs significantly enhance developer experience by simplifying the integration process. Additionally, APIs are distinct from web services and SDKs, offering specialized functions for web connectivity and software development, respectively. As real-time communication becomes increasingly vital, platforms like Stream provide robust API solutions for chat and activity feeds, helping build dynamic, interactive applications.