Anthropic Acquires Stainless, the Company Developing Official SDK and MCP Server Tools

Anthropic has acquired Stainless, the maker of its official SDKs and MCP server tools.

The deal amount was not disclosed, and Stainless will phase out its hosted products over time.

Existing customers will keep ownership of the SDKs already generated from Stainless.

The acquisition tightens Anthropic’s control over core developer tooling for Claude and agent-building.

It may improve Anthropic’s ecosystem while making those tools less available to competitors.