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.

Impact on the AI Ecosystem

The acquisition will take a key infrastructure supplier out of the hands of Anthropic’s competitors. According to the company, they plan to wind down all hosted Stainless products [https://www.stainless.com/blog/stainless-is-joining-anthropic/], including its SDK generator. An Anthropic spokesperson mentioned that Stainless customers will still own the SDKs they’ve generated so far and have full rights to modify and extend them as they wish.

Stainless, based in New York and founded in 2022, quickly rose to prominence in the AI industry for automating the creation and maintenance of software development kits (SDKs) — essential libraries that developers use to interact with APIs. Rattray designed software [https://techcrunch.com/2024/12/10/stainless-helps-build-sdks-for-openai-anthropic-and-meta/] capable of transforming API specifications into production-ready SDKs across several programming languages, including Python, TypeScript, Kotlin, Go, and Java. Since the platform automatically updates SDKs as APIs evolve, it has eliminated the time-consuming process of manual updates.

Future of Stainless within Anthropic

This technology is especially valuable for companies [https://www.stainless.com/customers/] like Anthropic, OpenAI, Google, Replicate, Runway, and Cloudflare, which are building AI agents that connect to external software to perform tasks for users. Stainless’s SDK tools provided an efficient solution to build and maintain those connections. Going forward, however, the tools will be exclusive to Anthropic and unavailable to competitors.

Anthropic confirmed that Stainless software has powered the generation of every official Anthropic SDK since the beginning of its API. “I started Stainless because SDKs deserve as much care as the APIs they wrap,” Rattray stated in a press release [https://www.anthropic.com/news/anthropic-acquires-stainless] posted Monday. He emphasized that Anthropic was one of the first teams to collaborate with them. Reflecting on the developer community’s achievements on Claude, Rattray noted that merging their teams felt like a natural and easy decision. He added that the Stainless team will continue working on the projects they are passionate about, focusing on the platform where their contribution matters most.

Tags: Anthropic, Stainless, AI development tools, SDK automation, OpenAI, technology acquisition