Anthropic revealed on Monday that it has acquired Stainless, a startup by former Stripe engineer Alex Rattray, whose software is widely utilized by competing AI labs, such as OpenAI and Google.
Anthropic did not reveal the terms of the acquisition. Previously, The Information reported that Anthropic was negotiating to buy Stainless, which is backed by Sequoia Capital and Andreessen Horowitz, for over $300 million.
This acquisition removes a crucial infrastructure provider from the reach of Anthropic’s competitors. The company informed TechCrunch that it will discontinue all hosted Stainless products, including its SDK generator. An Anthropic spokesperson assured that existing Stainless customers will retain ownership of the SDKs they have generated so far, with full rights to modify and extend them as they see fit.
Founded in 2022 in New York, Stainless gained prominence in the AI industry by automating the creation and maintenance of software development kits (SDKs), which developers use to engage with APIs.
Rattray developed software capable of taking API specifications and creating production-ready SDKs in various programming languages, such as Python, TypeScript, Kotlin, Go, and Java. The platform gained popularity for its ability to automatically update SDKs as APIs evolved, eliminating the need for time-consuming manual upkeep.
The technology holds particular value for companies like Anthropic, OpenAI, Google, Replicate, Runway, and Cloudflare that are developing AI agents capable of interacting with external software and executing tasks for users. While Stainless’s SDK tools have been an easy way to build and maintain those connections, these tools will now only be accessible to Anthropic, excluding its rivals.
Anthropic noted that Stainless software has been instrumental in generating every official Anthropic SDK since their API’s inception.
“I started Stainless because SDKs deserve as much care as the APIs they wrap,” Rattray stated in a press release on Monday. “Anthropic was one of the first teams to support this vision. Observing what developers have built on Claude over the years made uniting our teams an obvious choice. We can continue doing the work we love on the platform where it matters most.”