The make real site uses OpenAI’s new GPT-4 with Vision model, which is currently in preview. Applications make requests to OpenAI’s API (”hey gpt4, is this photo a hot dog or not?”) and OpenAI responds back with the model’s results (”nope, sorry”).
In order to make money and keep the GPUs spinning, OpenAI charges for each request it handles. For this to work, each request must be sent along with an “API Key” that identifies who is making the request, so that OpenAI can charge the right person.