OpenAPI is a specification for describing APIs that can be written in either JSON or YAML formats. Older version of the specification only supported JSON format; however, the OpenAPIv3Spec also supports YAML which is the preferred format for this project.
The OpenAPI spec recommends the project use the filename openapi.yaml or openapi.json as the initial starting file. The examples might, however,use openapi.yml for consistency with other files here in order to compliment the examples provided by the OpenAPIv3Spec as well as the additional examples in the SwaggerTools.
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