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swaggeropenapi

How to convert OpenAPI 2.0 to OpenAPI 3.0?

I have some API definitions in OpenAPI 2.0 format, but my tooling requires OpenAPI 3.0 format. How do I convert OpenAPI 2.0 to OpenAPI 3.0? Ideally I want to be able to script the process to avoid manual copying and pasting.

Solution

  • Swagger Editor

    Paste your OpenAPI 2.0 definition into https://editor.swagger.io and select Edit > Convert to OpenAPI 3 from the menu.

    Swagger Editor conversion from OpenAPI 2.0 to OpenAPI 3.0

    Swagger Converter

    Converts OpenAPI 2.0 and Swagger 1.x definitions to OpenAPI 3.0.

    https://converter.swagger.io/api/convert?url=OAS2_YAML_OR_JSON_URL

    This gives you JSON. If you want YAML, send the request with the Accept: application/yaml header:

    curl "https://converter.swagger.io/api/convert?url=OAS2_YAML_OR_JSON_URL" -H "Accept: application/yaml" -o ./openapi.yaml

    API docs: https://converter.swagger.io

    GitHub repo: https://github.com/swagger-api/swagger-converter

    Swagger Codegen version 3.x

    Can also convert OpenAPI 2.0 and Swagger 1.x definitions to OpenAPI 3.0. Swagger Codegen has a CLI version, Maven plugin, Docker images.

    Here's an example using the command-line version (you can download the latest JAR from Maven Central). Write the entire command on one line. Use openapi-yaml to get YAML or openapi to get JSON.

    java -jar swagger-codegen-cli-3.0.19.jar generate
     -l openapi-yaml
     -i https://petstore.swagger.io/v2/swagger.yaml
     -o OUT_DIR

    GitHub repo: https://github.com/swagger-api/swagger-codegen