Welcome to the MES Stateful API
- Last UpdatedNov 06, 2025
- 2 minute read
This help shows you how to use the Manufacturing Execution System (MES) Client API within the System Platform Integrated Development Environment (IDE) to develop and customize System Platform scripts.
This help assumes you know how to use Microsoft Windows, including navigating menus, moving from application to application, and moving objects on the screen. If you need help with these tasks, see the Microsoft online help.
In some areas of System Platform, you can also right-click to open a menu. The items listed on this menu change, depending on where you are in the product. All items listed on this menu are available as items on the main menus.
MES includes Stateful and Stateless API wrappers.
Stateful API Wrapper
The stateful API is designed for client applications that allows users to log on to entities and make transactions. It contains various pop up methods for user interaction. Therefore, the stateful API must be used within a client application, such as System Platform graphics displayed within an InTouch application.
The stateful API requires a client session, which is created for each executable, to access the MES database.
The client session allows you to access zero or multiple entities to make transactions. It also maintains the current entity, current job for each entity, and other information in the MES database. This information is used while passing parameters to a method call of the stateful API.
Stateless API Wrapper
The stateless API is designed for more complex applications that require access to all the calls that are available in the MES application.
The stateless API maintains no information and provides direct access to calls through the middleware. There can be multiple sessions within one application or a common shared session across multiple applications. Since there is no information maintained in memory, the stateless API calls require more parameters than the corresponding stateful API call.
The stateless API supports multi threading. Therefore, the stateless API should be used in background applications such as System Platform Object scripting.
Note: The MES Stateless API will run on any CPU and is supported in both 32-bit and 64-bit applications.