1. Download the Java JAR (https://oss.sonatype.org/content/repositories/snapshots/org/...)

2. Rename the JAR as "openapi-generator-cli.jar"

3. Run the following command to generate a Dart API client for the Petstore API (https://raw.githubusercontent.com/OpenAPITools/openapi-gener...):

Mac/Linux:

- java -jar openapi-generator-cli.jar generate -g dart -i https://raw.githubusercontent.com/OpenAPITools/openapi-gener... -o /var/tmp/dart-api-client/

Windows:

- java -jar openapi-generator-cli.jar generate -g dart -i https://raw.githubusercontent.com/OpenAPITools/openapi-gener... -o C:\tmp\dart-api-client

Please give it a try and let us know if you've any feedback.