There are many plug-ins to to generate OpenAPI/Swagger spec from annotations in the source code. For C#, please try https://github.com/domaindrivendev/Swashbuc

There are many plug-ins to to generate OpenAPI/Swagger spec from annotations in the source code. For C#, please try https://github.com/domaindrivendev/Swashbuckle https://github.com/domaindrivendev/Swashbuckle For PHP, please try https://github.com/zircote/swagger-php https://github.com/zircote/swagger-php For other langauges, just do a google search on "{lang} swagger" and you will probably find something useful.