Anthropic acquires SDK startup Stainless to boost agent connectivity
Stainless built every official Anthropic SDK since day one—now they're joining the team.
Anthropic announced the acquisition of Stainless, a leader in SDK and MCP server tooling founded in 2022. Stainless turns a single API specification into high-performance, language-native SDKs for TypeScript, Python, Go, Java, Kotlin, and more. The company has generated every official Anthropic SDK since the earliest days of the Claude API, and hundreds of businesses rely on its tooling to build libraries, CLIs, and connectors for developers and AI agents. Anthropic's Head of Platform Engineering, Katelyn Lesse, emphasized that agents are only as useful as what they can connect to, and bringing Stainless in-house will advance Claude's ability to reach data and tools.
Stainless CEO Alex Rattray noted that the team will continue doing the work they love on the platform where it matters most. The acquisition aligns with Anthropic's push for agent connectivity via the Model Context Protocol (MCP), which enables AI models to interact with external systems. By combining Stainless's SDK expertise with Anthropic's MCP infrastructure, the Claude Platform aims to set a new standard for developer experience and agent capabilities. This move comes alongside other major partnerships, including a $200 million deal with the Gates Foundation and a rollout of Claude at PwC, signaling Anthropic's aggressive expansion into enterprise AI agents.
- Stainless generates SDKs in TypeScript, Python, Go, Java, and Kotlin from a single API spec, ensuring native performance.
- Every official Anthropic SDK has been built using Stainless since the Claude API launched in 2023.
- The acquisition enhances Claude's agent connectivity by integrating Stainless's MCP server tooling with Anthropic's platform.
Why It Matters
As AI shifts from answering to acting, agents need robust connectivity—Stainless gives Anthropic the tooling to scale that.