> While ChatGPT is able to remember what the user has said earlier in the conversation, there is a limit to how much information it can retain. The model is able to reference up to approximately 3000 words (or 4000 tokens) from the current conversation - any information beyond that is not stored.
This implies ChatGPT has a 4000 token maximum prompt and prior prompts in a given web session are inserted into the current prompt, most recent to oldest (probably with some sort of time context like "previously, user asked:"), up to 4000 tokens.
Their API calls on the site have references to previous message ids, which makes me expect they're doing something similar.