Our API does not currently support writing Free & Reduced data back to Aeries. That is a planned future enhancement.
Presently, we offer customers our NSLP Import process, which accepts a CSV file from the nutrition services vendor to import data into Aeries. Here is the related documentation: NSLP Manual and Scheduled Imports
Furthermore, if you continue to have questions about the Aeries API, I encourage you to join our vendor-focused Interfacing with Aeries forum on Google Groups: https://groups.google.com/forum/#!forum/interfacing-with-aeries.
We are integrating Aeries API with our database for one of our customers. They requested that we add the capability to send certain data from our database back to Aeries. I can't find any documentation on this, is this possible?