Anthropic acquires dev tools startup used by OpenAI, Google
▼ Summary
– Anthropic acquired Stainless, a startup founded by Alex Rattray, for over $300 million; Stainless’s SDK tools were used by rivals like OpenAI and Google.
– Anthropic will shut down all hosted Stainless products, including its SDK generator, but customers retain ownership and rights to their generated SDKs.
– Stainless software automates the creation and maintenance of SDKs from API specifications across languages like Python, TypeScript, and Go.
– The technology is valuable for building AI agents that connect to external software; after the acquisition, it will be exclusive to Anthropic.
– Stainless has powered all official Anthropic SDKs since the company’s early API days, and founder Rattray cited this partnership as a reason for the deal.
Anthropic has officially acquired Stainless, a developer tools startup whose software has been instrumental for rivals like OpenAI and Google. The deal, announced Monday, marks a strategic move to bring a key infrastructure provider in-house, though financial terms were not disclosed.
Reports from The Information last week indicated that Anthropic was in talks to purchase the company, backed by Sequoia Capital and Andreessen Horowitz, for over $300 million. With the acquisition now finalized, Anthropic plans to shut down all hosted Stainless products, including its SDK generator. However, an Anthropic spokesperson confirmed that existing customers will retain ownership of the SDKs they have already generated and retain full rights to modify and extend them.
Founded in 2022 by former Stripe engineer Alex Rattray, the New York-based startup quickly became a vital player in the AI ecosystem. Its core technology automates the creation and maintenance of software development kits (SDKs),the libraries developers rely on to interact with APIs. Rattray’s software takes API specifications and transforms them into production-ready SDKs across multiple programming languages, including Python, TypeScript, Kotlin, Go, and Java. The platform’s ability to automatically update SDKs as APIs evolve eliminated the tedious manual upkeep that previously slowed development.
This technology is especially critical for companies building AI agents that must connect to external software and perform tasks on behalf of users. Anthropic, OpenAI, Google, Replicate, Runway, and Cloudflare all relied on Stainless to build and maintain those connections. Going forward, those tools will be exclusive to Anthropic, effectively cutting off competitors from a key infrastructure supplier.
According to Anthropic, Stainless software has powered every official Anthropic SDK since the earliest days of its API. Rattray expressed enthusiasm about the merger, stating, “I started Stainless because SDKs deserve as much care as the APIs they wrap. Anthropic was one of the first teams to bet on this with us. 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.”
(Source: TechCrunch)
