Casper uses OpenAI’s GPT models for AI output. If you have an OpenAI account, you can find your API keys here: https://platform.openai.com/account/api-keys
If you do not have an OpenAI API key yet, create an account first and then navigate to the above link to provision an API key.
Important: To use GPT-4 in Casper for custom document prompts, you must have API access to GPT-4. If you do not have access and are not on the waiting list, you can join that here: https://openai.com/waitlist/gpt-4-api