# Preparing a Custom Data Feed The purpose of this document is to describe how to format, structure and send a pre-defined custom data upload to an instance using the Fredhopper Data API. The custom upload process is for sending additional data/content to your Fredhopper environment and preparing it to be enriched with the main product data that comes in via the feed. It is important to note that the newly added data does not get added into the existing Fredhopper index immediately when the Upload job has completed successfully. This will happen when the system processes the subsequent full product feed that takes place afterwards. The last successful custom file is always maintained by the system for all future product feed updates until a new file is sent and successfully processed via the custom upload process. This document focuses on standard functionality and best practices which should be implemented in all integrations. It does not cover any customer-specific requirements that are defined with the assistance of your Technical Consultant. If you do not have a custom data requirement for your Fredhopper solution then this specification is not applicable to you. If you would like to find out more about the possibility of setting up a custom data upload solution with your Fredhopper implementation then please contact your Customer Success Manager. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://crownpeak.gitbook.io/product-discovery/sending-and-managing-product-data/flatfiles/custom-datafeed.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.