Codex AI usage cost analyzed for ChatGPT Pro

An analysis of a month of heavy AI coding agent usage reveals that paying per token at public API rates would have cost $745.16, compared to a $100 monthly subscription. The author argues that prompt caching is the primary reason the API remains affordable, reducing what would have been an $8,234.34 bill, though subscriptions are more cost-effective for heavy daily users who can tolerate usage limits. Open article →