Anthropic buys SDK and MCP tooling startup Stainless to expand Claude’s ability to connect with apps, data, and developer tools

Anthropic is acquiring Stainless, a startup that generates SDKs, CLIs, and MCP servers from API specs. Stainless has produced Anthropic’s official SDKs since the early days of its API and supports languages including TypeScript, Python, Go, Java, and Kotlin.

The deal reflects the shift from chatbots toward AI agents that can take action across external systems. By owning more of the developer tooling layer, Anthropic can make Claude easier to integrate and potentially strengthen MCP as a standard for agent connectivity.

Anthropic acquires Stainless