This package contains a Go command line tool which converts JSON and YAML OpenAPI descriptions to and from equivalent Protocol Buffer representations. Protocol Buffers provide a language-neutral, platform-neutral, extensible mechanism for serializing structured data. gnostic's Protocol Buffer models for the OpenAPI Specification can be used to generate code that includes data structures with explicit fields for the elements of an OpenAPI description. This makes it possible for developers to work with OpenAPI descriptions in type-safe ways, which is particularly useful in strongly-typed languages like Go and Swift. gnostic reads OpenAPI descriptions into these generated data structures, reports errors, resolves internal dependencies, and writes the results in a binary form that can be used in any language that is supported by the Protocol Buffer tools. A plugin interface simplifies integration with API tools written in a variety of different languages, and when necessary, Protocol Buffer OpenAPI descriptions can be reexported as JSON or YAML. gnostic compilation code and OpenAPI Protocol Buffer models are automatically generated from an OpenAPI JSON Schema. Source code for the generator is in the generate-gnostic directory.