Anthropic acquires Stainless, a developer tools company founded in 2022, to expand Claude’s ability to connect with external systems and APIs. The acquisition integrates Stainless’s SDK and MCP server tooling into Anthropic’s platform infrastructure.
Stainless has generated every official Anthropic SDK since the company’s API launch. The tooling automates the creation of software development kits across TypeScript, Python, Go, Java, Kotlin, and additional languages. Hundreds of companies use Stainless to build SDKs, command-line interfaces, and Model Context Protocol servers that enable developers and artificial intelligence agents to interact with APIs.
Why Anthropic Acquires Stainless Now
The shift in AI architecture from models that answer questions to agents that perform actions requires reliable system connectivity. Agents can only operate as effectively as the tools and data sources they can access. MCP, Anthropic’s protocol for agent connectivity, benefits from deeper integration with SDK tooling that Stainless provides.
“Agents are only as useful as what they can connect to. We’re excited to bring the Stainless team into Anthropic to advance Claude’s ability to connect to data and tools.”
Katelyn Lesse, Head of Platform Engineering at Anthropic
Stainless Leadership on SDK Development
Stainless founder and CEO Alex Rattray stated that SDK quality deserves attention equal to the APIs they support. Anthropic was among the first organizations to prioritize this approach with Stainless from the beginning. The founder noted that observing developer work built on Claude over recent years made the team integration a natural fit.
“We have been watching what developers have built on Claude over the last few years, which made bringing our teams together an easy decision. The team gets to keep doing the work we love, on the platform where it matters most.”
Alex Rattray, Founder and CEO of Stainless
Impact on Developer Experience
The acquisition combines two teams focused on developer tools and AI agent connectivity. By consolidating Stainless’s SDK generation technology with Anthropic’s MCP framework, the Claude Platform aims to advance how agents interface with external systems, databases, and third-party services.
Stainless SDKs are designed for speed, reliability, and native language integration. The acquisition enables Anthropic to embed these capabilities directly into Claude’s ecosystem, reducing friction for developers building agent applications.
Future of Agent Connectivity
Anthropic created MCP to standardize how agents connect to tools and data sources. The integration of Stainless strengthens this protocol by providing production-grade SDK generation at scale. Developers using Claude can now access improved tooling for building agents that reliably interact with APIs and external systems.
