You need a subscription to use Chai.
Once subscribed, you can either download it from here or compile your own binary from GitHub.
For Basic plan, it refers to a maximum of ~1,250,000 tokens.
For Pro plan, it refers to a maximum of either ~4,500,000 tokens, either 45 images, or a combination of both.
Usage for ChatGPT is measured in Tokens, as per OpenAI®'s method. A token is equivalent to ~0.75 words. As for images, they are billed by units. We use OpenAI®'s pricing as a base for ours, applying a tight margin on top that accounts for our infrastructure cost.
Given the nature of our service, once the account is used, we can not offer refunds. However, you can cancel your subscription anytime, and it will expire at the end of the billing cycle.