Anthropic is acquiring Stainless, an SDK and developer tooling company, for reportedly over $300 million, as part of its broader strategy to control more of the AI technical stack. The deal is notable because Stainless currently generates SDKs used by Anthropic's rivals, including OpenAI and Google, and the platform is set to shut down on September 1, 2026, forcing those competitors to find alternatives. Analysts view the move as both offensive — giving Anthropic insight into competitor API development and dominance over integration tooling — and defensive, preventing rivals from gaining the same advantage.
