Claude Pro costs $20/month. ChatGPT Plus costs $20/month. Claude Code doesn't require either.
That's the core insight behind a workflow a developer recently documented: run Claude Code - Anthropic's terminal-based coding assistant - on pay-per-use API pricing while keeping a ChatGPT Plus subscription for general tasks, skipping the flat Claude Pro fee entirely.
Claude Code authenticates through an API key from the Anthropic console rather than a Claude.ai account. That means you're billed by API tokens - small charges per piece of text processed - rather than a flat monthly subscription. For developers who already have ChatGPT Plus for writing, research, and general queries, this approach means paying for Claude Code only when you actually use it.
The math only works in your favor if your coding sessions are light to moderate. Developers running Claude Code continuously - multiple hours of active coding assistance per day - will likely exceed what a flat Claude Pro subscription would cost. The break-even point depends on how often you're running long, complex coding sessions versus occasional shorter ones.
Setup is simple: create an account at Anthropic's API console, generate a key, set it as an ANTHROPIC_API_KEY environment variable on your machine, then install Claude Code. The main practical difference from a subscription is rate limits, which are structured differently for API versus Pro accounts.
The underlying logic is sound for anyone managing monthly AI spend carefully. ChatGPT Plus and Claude Code serve different use cases well: ChatGPT's strengths lean toward versatility and breadth, while Claude's models currently outperform on complex coding work and long-document tasks. Covering both without doubling your subscription bill is a reasonable goal for developers who rely on both daily.