We haven't yet rolled out memory for GPTs. When it is rolled out, builders will be able to enable their GPTs to have a memory. The end-user will need to have Memory on to engage with the GPT.

Please note that ChatGPT and GPTs each have their own unique memories based on your interactions with them.

Memory is not shared between GPTs and other GPTs or ChatGPT. Memories, like chats, with GPTs are not shared with GPT builders.