vCenter Orchestrator’s REST API allows not only to start and monitor workflows, but also manage the content of your vCO server. With the Packages manager of the API it’s for example possible to import workflow packages via the API. Example to do exactly this via command line using curl:
curl --form "name=file" --form "file=@de.vcoportal.someTest.package" -X POST -u vcoadmin:vcoadmin -k https://172.16.96.130:8281/vco/api/packages
…with de.vcoportal.someTestPackage is the full filename of the package to upload.
See more details in the API reference documentation on https://your-vco-server:8281/vco/api/docs