The names of all LayGO API functions begin with the prefix lgo_ to indicate their source as the LayGO API. The body of the function name is designed to state in 2 or 3 words exactly what the function does. For instance, lgo_InitializeStack() is called to initialize the stack. The words which compose the function name are always spelled out completely to avoid cryptic abbreviations and to improve the readability of code and to make it self-documenting.

C function prototypes for all core API functions are found in laygo.h. Prototypes for auxiliary functions are found in laygomsg.h. All type and macro definitions used by the API are found in laygodef.h.

All API functions return non-negative values to indicate successful completion and negative values to indicate failure. (See API Error Codes for a detailed discussion of individual error codes).