Abstract: An application programming interface for providing functionality between an program and a text checking engine that test words from the program for correctness. A preferred embodiment of the interface includes an input buffer communicating with the program to receive text from the program. An input buffer pointer is provided for addressing the text in the input buffer. The input buffer pointer is passed to the text checking engine, which preferably is part of the API. The text checking engine performs a text checking function requested by the program and provides information responsive to the requested function. A return buffer communicates with the text checking engine to receive the responsive information from the engine. The return buffer also communicates with the program to allow the program to retrieve the responsive information from the return buffer. Preferably, a clean bit is attached to each section of text checked if no errors are found in the section of text by the engine.