# User-defined functions
The abbreviation UDF stands for user-defined function. With this concept, users are able to upload custom code and have it executed e.g. for every pixel of a scene, allowing custom calculations on server-side data.
UDFs are currently developed and evaluated outside of the core API. More information regarding the current draft for UDFs can be found in a separate repository (opens new window). There is additional documentation available for the UDF Framework (opens new window) and the UDF API (opens new window).