Open Application Programming Interface (OpenAPI) is a set of C language functions that enable you to create applications for accessing Ingres and non-Ingres databases.

It provides you with an alternative to using embedded SQL, which requires a preprocessor in addition to a C compiler. With OpenAPI, these C functions are called directly with normal function call facilities.

OpenAPI simplifies the task of developing applications when multiple interfaces, protocols, and environments are involved. It does this by providing a single interface for accessing data. You can concentrate on what data you want your application to access, rather than how it will access it.

OpenAPI provides an asynchronous method of writing applications. All OpenAPI operations are asynchronous in that a function call returns control to the application before its tasks are completed. When the tasks are completed, the function signals completion by invoking a callback function specified by the application. Thus, you can write an application as fully asynchronous, event-driven code. Alternatively, you can write synchronous code by using an OpenAPI feature that enables an application to wait for each OpenAPI function to complete its tasks.