Software development kits (SDKs) are crucial tools for developers, simplifying the process of building applications using specific products or platforms. Despite this, many tech vendors only provide APIs—protocols enabling software to communicate—leaving developers to build everything from scratch using API documentation.
Stainless, a platform founded by Alex Rattray, aims to bridge this gap by using a compiler to automatically generate SDKs from APIs. The tool supports multiple programming languages, including Python, TypeScript, Kotlin, and Go. As APIs evolve, Stainless can manage updates, versioning, and changelogs, making integration faster and more efficient.
Unlike the traditional approach, where vendors manually create libraries for different programming languages, Stainless leverages AI to produce an initial configuration for SDKs. Development teams can then customize the output, eliminating inconsistencies and outdated libraries. This approach speeds up integration and reduces maintenance overhead.
Rattray, who gained experience working on developer tools at Stripe, highlights the transformative potential of APIs in a world where AI tools are increasingly accessible. He believes APIs will soon become the primary interface for most users, making robust API tools essential for businesses.
Stainless stands out in a competitive field, which includes alternatives like LibLab and OpenAPI Generator, by delivering higher-quality code outputs. This "polished" output has attracted high-profile clients, including OpenAI, Anthropic, Meta, and Cloudflare. Today, Stainless serves hundreds of paying customers, with its SDKs downloaded millions of times weekly.
The platform offers a free option for publishing a single SDK, while businesses requiring multiple SDKs pay between $250 per month and $30,000 annually. Stainless has achieved significant milestones, including nearing profitability with annual recurring revenue of $1 million.
To accelerate growth, Stainless raised $25 million in Series A funding, bringing its total funding to $35 million. The company plans to expand its 20-person team and broaden its offerings to become a comprehensive platform for all API-related needs.
With this innovative approach, Stainless is redefining how developers interact with APIs, enabling faster, more efficient integration while setting a new standard for SDK generation.
