Is there any API available which allow user to copy workflow, save as like functionality ?
I have designed a huge complex workflow and deployed as well, now I want to create another copy of this workflow.
If you're using the Activiti-Explorer, then there is a GUI option for import/export of process models, located in the 'Processes' tab, then the 'Model Workspace' tab:
That would allow you to copy a model and edit it to your liking.
If you're not using the Activiti-Explorer, the REST API has calls that have the same functionality - check this out: Activiti User Guide. If you're referring to a full deployed App as a workflow, endpoints exist for working with apps as well.
Retrieving data ...