Method carried out at a computer system, the computer system including a runtime environment that can request dynamic access to application program interfaces (APIs), the runtime environment providing dynamic access requests with a default visibility into application program interfaces (APIs) based on application program interface type, the API type being selected from a group comprising internal, private and public, the method providing a consumer with specified visibility into an application programming interface, the method comprising: executing executable code in the runtime environment, the executable code derived from application code; during execution of the executable code: receiving a dynamic call from a consumer to execute a portion of the executable code, the portion of the executable code derived from a portion of the application code that refers to an application program interface within a library; accessing a runtime default visibility into the application program interface based on the type of the application program interface; accessing any attributes applied to the application program interface, attributes applied to the application program interface indicative of a desire by the author of application program interface to alter the runtime default visibility into the application program interface; accessing any attributes applied to the portion of the application code that refers to the application program interface, attributes applied to the portion of the application code indicative of a desire by the author of the application code to provide visibility into the application program interface to a lesser extent than indicated by the runtime default visibility as altered by any attributes applied to the application program interface; determining a calculated visibility into the application program interface based on the runtime default visibility into the application program interface, any attributes applied to the an application program interface, and any attributes applied to the portion of the application code that refers to the application program interface; and providing the dynamic call with visibility into the application program interface in accordance with the calculated visibility. executing executable code in the runtime environment, the executable code derived from application code; during execution of the executable code: receiving a dynamic call from a consumer to execute a portion of the executable code, the portion of the executable code derived from a portion of the application code that refers to an application program interface within a library; accessing a runtime default visibility into the application program interface based on the type of the application program interface; accessing any attributes applied to the application program interface, attributes applied to the application program interface indicative of a desire by the author of application program interface to alter the runtime default visibility into the application program interface; accessing any attributes applied to the portion of the application code that refers to the application program interface, attributes applied to the portion of the application code indicative of a desire by the author of the application code to provide visibility into the application program interface to a lesser extent than indicated by the runtime default visibility as altered by any attributes applied to the application program interface; determining a calculated visibility into the application program interface based on the runtime default visibility into the application program interface, any attributes applied to the an application program interface, and any attributes applied to the portion of the application code that refers to the application program interface; and providing the dynamic call with visibility into the application program interface in accordance with the calculated visibility. receiving a dynamic call from a consumer to execute a portion of the executable code, the portion of the executable code derived from a portion of the application code that refers to an application program interface within a library; accessing a runtime default visibility into the application program interface based on the type of the application program interface; accessing any attributes applied to the application program interface, attributes applied to the application program interface indicative of a desire by the author of application program interface to alter the runtime default visibility into the application program interface; accessing any attributes applied to the portion of the application code that refers to the application program interface, attributes applied to the portion of the application code indicative of a desire by the author of the application code to provide visibility into the application program interface to a lesser extent than indicated by the runtime default visibility as altered by any attributes applied to the application program interface; determining a calculated visibility into the application program interface based on the runtime default visibility into the application program interface, any attributes applied to the an application program interface, and any attributes applied to the portion of the application code that refers to the application program interface; and providing the dynamic call with visibility into the application program interface in accordance with the calculated visibility.