We've added ASP.NET 3.0 Core preview 4 support to OpenAPI Generator (https://github.com/OpenAPITools/openapi-generator). To generate the server stub given an OpenAPI/Swagger specification file, please follow 3 simple steps below:<p>1. Download the Java JAR (https://oss.sonatype.org/content/repositories/snapshots/org/openapitools/openapi-generator-cli/4.0.3-SNAPSHOT/openapi-generator-cli-4.0.3-20190703.014526-54.jar)<p>2. Rename the JAR as "openapi-generator-cli.jar"<p>3. Run the following command to generate a C# API client for the Petstore API (https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator/src/test/resources/2_0/petstore.yaml):<p>- Mac/Linux:<p>java -jar openapi-generator-cli.jar generate -g aspnetcore -i https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator/src/test/resources/2_0/petstore.yaml -o /var/tmp/aspnetcore/ --additional-properties aspnetCoreVersion=3.0<p>- Windows:<p>java -jar openapi-generator-cli.jar generate -g aspnetcore -i https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator/src/test/resources/2_0/petstore.yaml -o C:\tmp\aspnetcore --additional-properties aspnetCoreVersion=3.0<p>If you've any feedback, please let us know by creating a ticket (https://github.com/OpenAPITools/openapi-generator/issues/new)<p>Thanks for the contribution by Amit Joshi.