Anthropic has acquired the dev tools startup used by OpenAI, Google, and Cloudflare

# Anthropic has acquired the dev tools startup used by OpenAI, Google, and Cloudflare | TechCrunch Source: [https://techcrunch.com/2026/05/18/anthropic-has-acquired-the-dev-tools-startup-used-by-openai-google-and-cloudflare/](https://techcrunch.com/2026/05/18/anthropic-has-acquired-the-dev-tools-startup-used-by-openai-google-and-cloudflare/) Anthropic announced Monday it has acquired Stainless, a startup founded by former Stripe engineer Alex Rattray whose software is widely used by rival AI labs, including OpenAI and Google\. Anthropic didn’t disclose terms of the deal\. However, The Information[reported](https://www.theinformation.com/articles/anthropic-talks-buy-developer-tools-startup-used-openai-google)last week that the company was in talks to acquire Stainless, which is backed by Sequoia Capital and Andreessen Horowitz, for more than $300 million\. The acquisition will take a key infrastructure supplier out of the hands of Anthropic’s competitors\. The company told TechCrunch it will wind down[all hosted Stainless products](https://www.stainless.com/blog/stainless-is-joining-anthropic/), including its SDK generator\. An Anthropic spokesperson said Stainless customers will still own the SDKs they’ve generated to date and have full rights to modify and extend them however they wish\. The New York\-based startup, founded in 2022, rose to prominence in the emerging AI industry for automating the creation and maintenance of software development kits, or SDKs — the libraries developers use to interact with APIs\. Rattray[developed software](https://techcrunch.com/2024/12/10/stainless-helps-build-sdks-for-openai-anthropic-and-meta/)that could take API specifications and turn them into production\-ready SDKs across multiple programming languages, including Python, TypeScript, Kotlin, Go, and Java\. It became a popular tool because the platform automatically updates the SDKs as APIs change and eliminated the time\-consuming process of manually maintaining them\. The technology is particularly valuable to[companies](https://www.stainless.com/customers/)like Anthropic, OpenAI, Google, Replicate, Runway, and Cloudflare that are building AI agents that can connect to external software and complete tasks on behalf of users\. Stainless’s SDK tools are an easy way to build and maintain those connections — but going forward, the tools will only be available to Anthropic, not its competitors\. According to Anthropic, Stainless software has powered the generation of every official Anthropic SDK since the earliest days of its API\. “I started Stainless because SDKs deserve as much care as the APIs they wrap,” Rattray said[in a press release](https://www.anthropic.com/news/anthropic-acquires-stainless)posted Monday\. “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\.” *When you purchase through links in our articles,[we may earn a small commission](https://techcrunch.com/techcrunch-affiliate-monetization-standards/)\. This doesn’t affect our editorial independence\.* Kirsten Korosec is a reporter and editor who has covered the future of transportation from EVs and autonomous vehicles to urban air mobility and in\-car tech for more than a decade\. She is currently the transportation editor at TechCrunch and co\-host of TechCrunch’s Equity podcast\. She is also co\-founder and co\-host of the podcast, “The Autonocast\.” She previously wrote for Fortune, The Verge, Bloomberg, MIT Technology Review and CBS Interactive\. You can contact or verify outreach from Kirsten by emailing[kirsten\.korosec@techcrunch\.com](mailto:[email protected])or via encrypted message at kkorosec\.07 on Signal\. [View Bio](https://techcrunch.com/author/kirsten-korosec/)