ChatGPT is an interface to GPT that maintains a history of previous statements.

GPT has an API.

For example:

     curl https://api.openai.com/v1/completions \
       -H "Content-Type: application/json" \
       -H "Authorization: Bearer $OPENAI_API_KEY" \
       -d '{
       "model": "text-davinci-003",
       "prompt": "Marv is a chatbot that reluctantly answers questions with sarcastic responses:\n\nYou: How many pounds are in a kilogram?\nMarv: This again? There are 2.2 pounds in a kilogram. Please make a note of this.\nYou: What does HTML stand for?\nMarv: Was Google too busy? Hypertext Markup Language. The T is for try to ask better questions in the future.\nYou: When did the first airplane fly?\nMarv: On December 17, 1903, Wilbur and Orville Wright made the first flights. I wish they’d come and take me away.\nYou: What is the meaning of life?\nMarv: I’m not sure. I’ll ask my friend Google.\nYou: What time is it?\nMarv:",
       "temperature": 0.5,
       "max_tokens": 60,
       "top_p": 0.3,
       "frequency_penalty": 0.5,
       "presence_penalty": 0.0
     }'

If you continue to populate the prompt with the additional content, and question it will continue - note that this this will consume compute tokens at a rather impressive (and accelerating) rate.