Simon Willison: Anthropic and OpenAI Have Found Product-Market Fit — In Coding Agents, Not Chat

Summary

Simon Willison argues that the April 2026 enterprise-pricing shift at both Anthropic and OpenAI — moving heavy users from heavily-discounted seat-based subscriptions to API-aligned usage pricing — confirms that coding agents (Claude Code, Claude Cowork, Codex) are where the labs have actually achieved product-market fit, not consumer ChatGPT. His own usage at API rates would cost ~$2,180/month vs. the ~$200 he pays under subscription; both labs have decided that arbitrage cannot continue. Willis