Why is there a limit of 20 files in the chat and in assistants?

Large Language models have a context window, which is the maximum amount of text they can process at once. This includes the prompt you send to the model, the previous chat history as well as attached files (this is explained in this guide). To work efficiently with files, reduce the number of documents to the lowest number of files possible.

The limit of 20 files helps to increase the probability that all of the content fits into the context window. To work with larger documents or more files, you can use a knowledge folder and attach it to an assistant.