Is the pricing paying for access to models, or is it expected that users must have their own subscriptions/API access to OpenAI/Anthropic/whichever model providers?

If the former, is there a non-paid option for people to bring their own model access? If the latter, what is the subscription pricing paying for? I am in favor of subscriptions for on-going services/costs, but in the absence of on-going costs, I'd prefer a pay-once option.