Anthropic acquires Stainless on May 16, 2026 to integrate its tools for generating SDKs, CLIs, and MCP servers and improve how Claude agents connect to external software systems
Stainless has produced every official Anthropic SDK since the first Claude API releases, and the deal folds its toolchain directly into the developer platform.
First they came for openclaw and I did not do anything Then they came for opencode and I did not do anything
#1032Rohan Paul@ROHANPAUL_AIAnthropic just acquired Stainless to make Claude agents better at reaching real software systems through cleaner SDKs, CLIs, and MCP servers.
Shows again that better connectivity infrastructure will matter as much as better model intelligence once companies start asking agents to perform actual work.
Stainless has generated every official Anthropic SDK since the early Claude API days, which means Anthropic is buying a toolchain that already sits inside its developer platform.
#1410Dan Shipper 📧@DANSHIPPERAmazing!!
So proud of @RattrayAlex and honored to be a tiny investor
#1814Sarah Wang@SARAHDINGWANGCongrats @RattrayAlex , @StainlessAPI and @AnthropicAI! The mission of making APIs effortless for developers (and agents) is more important than ever
And big congrats to my amazing partner @JenniferHli who is on what I believe will be a generational run 🐐
Jennifer Li@JenniferHliHuge congratulations to @RattrayAlex and the @StainlessAPI team on the acquisition by @AnthropicAI. From our earliest conversations, what stood out about Stainless was the clarity of the mission: make APIs feel effortless for developers, by turning API design into great SDKs, docs, and tooling by default. It sounds simple until you appreciate how much craft sits behind it. True to its name, Stainless polished every detail developers only notice when they’re missing: type safety, idiomatic clients, versioning, reliability, to create an experience that just works. That kind of infrastructure compounds. As AI becomes more programmable and more deeply embedded in every product, the interface between developers and models matters enormously. Stainless built one of the defining developer infrastructure companies for that world. Proud to have been part of the journey, and excited to see what the team builds next with Anthropic. Congrats Alex, Mark, Daniella, Alex A, Mirole and the entire Stainless team!!
