We (Speakeasy) recently open-sourced the OpenAPI library we use to generate SDKs and Terraform providers.

We built this because we found existing Go libraries struggled with the "sharp edges" of OpenAPI—specifically dynamic types (polymorphic fields) and complex reference architectures (circular refs/remote files).

This library uses Go generics to maintain strict type safety without losing flexibility and includes native support for the new Arazzo (workflows) and Overlay specifications.

Code is here: https://github.com/speakeasy-api/openapi