Most OpenAPI specs are “mostly right,” but small inconsistencies can break generated SDKs. This post explains when OpenAPI Overlays are enough—and how Stainless Transforms handle harder fixes like schema deduplication, structural renames, and language-aware naming without modifying the upstream spec.

Learn how to maximize the growth potential of your API and minimize your costs at the same time.

A practical guide for API platform teams deciding between hand-written SDKs and generators like Stainless. It breaks down when generation wins (HTTP-heavy, multi-language, spec-driven clients), when custom code is better (logic-first libraries), and why a hybrid approach often delivers the best developer experience.

Stainless preview builds solve the biggest problem blocking API development at scale: engineers can't see how their OpenAPI changes affect SDKs until after they ship. Now you and your team can see exact SDK diffs and test locally without leaving your pull request.

Ruby SDK and Terraform provider generators are now generally available, along with major upgrades to MCP, TypeScript, Go, and Java. Our free tier is also expanded to support up to 5 SDKs.

You can now generate MCP servers for free using your OpenAPI spec.