OpenAPI Tooling working with WebAPI and APIM Notes

Editor.swagger.io is a great tool for building OAS files.  The Swagger editor is easy to use and has a preview for changes.

VS Code is a great IDE for working with OpenAPI  specification 2.0 and 3.0 files (also know and Swagger specification).  These 3 extensions are a good idea for working with a OpenAPI specification file.

Spotlight also has an editor which is nice.  Takes a little bit of getting use to, but make complex API design first easier.