SMAPI (Shared Memory Application Programming Interface) is a cross-platform API that allows users to share their data between applications. This is done by creating an instance of the SMAPI class and configuring it to point to a specific memory location. This location is usually a section of the device's RAM, but it may also be a physical device such as a flash drive.

It allows users to share data between various applications, including desktop, mobile, and web applications. It is intended to be used by programs that need to exchange data with each other. It is an API that is designed to be used in a safe and secure way, and its functionality is limited to what is needed to support the exchange of data between two programs. It does not support the transfer of data between a program and the device's memory.

It was developed by SAPI, which is an application development company that specializes in creating cross-platform software, and is used by many of the world's largest software companies.