Microsoft has told engineers in one of its largest divisions to stop using an external AI coding assistant. The reason is simple. The bills grew too large. The software maker, which has invested roughly $13 billion in OpenAI and relies on generative AI for as much as 30 percent of its own code, is canceling licenses for Anthropic’s Claude Code across its Experiences and Devices group. That team builds Windows, Microsoft 365, Outlook, Teams and Surface hardware. Access ends June 30, the close of Microsoft’s fiscal year. Engineers will shift to the company’s own GitHub Copilot CLI, a less expensive in-house option. Yahoo Finance first detailed the move. But don’t mistake this for retreat. Claude models remain available inside Copilot. Microsoft’s broader partnership with Anthropic, including up to $5 billion in investment and Anthropic’s $30 billion Azure compute commitment, stays intact. The decision targets runaway token costs, not AI itself. The pattern repeats elsewhere.…