Stainless

Stainless is a developer platform that automates the creation of software development kits (SDKs), documentation, and MCP (Model Context Protocol) servers for your API. It takes your OpenAPI specification as input and outputs ready-to-use, idiomatic code libraries in languages like TypeScript, Python, Go, Java, Ruby, C#, and PHP. This removes the manual, repetitive work of building and maintaining client libraries and docs every time your API changes.

The tool works by deriving all its outputs from your OpenAPI spec, ensuring consistency. For developers, this means getting a polished, type-safe SDK that feels native to their programming language. For teams building AI agents, Stainless can generate an MCP server, which is a standardized way for agents like Claude to discover and use your API's capabilities. The focus is on providing a complete, high-quality interface layer between your API and the developers or automated systems that need to use it.

This tool is most useful for companies that offer a public API and want to improve the developer experience for their users. Engineering teams can save significant time on maintenance, while product teams can ensure their API is easily accessible to both human developers and the growing ecosystem of AI agents. It turns API specification into a functional, multi-language interface suite.