Anthropic has updated its terms of service to prohibit using Claude subscriptions - including the $20/month Pro plan and higher tiers - through third-party applications. The change cuts off users who were routing their Claude.ai account access through unofficial clients and wrappers instead of Anthropic's own products.
Boris Cherny, the engineer who built Claude Code (Anthropic's official command-line tool), addressed the policy publicly, explaining the company's reasoning. The short version: subscription pricing is designed around access through Anthropic's own interfaces, not as a general-purpose Claude access pass.
The users most affected are developers and power users who built workflows around unofficial Claude frontends. These tools typically worked by connecting to the Claude.ai web interface rather than the official API - a workaround that let people access Claude without paying separate API costs. Under the updated terms, those users must either use official Anthropic apps or sign up for API access, which bills by usage rather than a flat monthly rate.
For the vast majority of Claude subscribers, nothing changes. The Claude.ai web app, Claude for Desktop, and Claude Mobile all remain fully within the terms. Claude Code, as an official Anthropic product, is unaffected.
The economics explain the policy. Claude API calls are billed per token (roughly per word processed), while Pro and Max subscriptions offer high-volume usage within rate limits for a flat fee. Users doing heavy workloads through a $20/month subscription were getting dramatically better pricing than straight API billing would offer - and Anthropic is now closing that gap. Anyone who needs Claude access in custom environments should budget for API costs accordingly.