How to get task external form definition to render it by my own?

[zloy]

I can get a task <b>formKey</b> which contains a form definition file uploaded in zip archive as a part of process definition.

So I requested  <tt>form/form-data?taskId=95166</tt> and got

<ruby>
{"formKey"=>"handle_request.yaml", "deploymentId"=>"93951", "processDefinitionId"=>nil, "processDefinitionUrl"=>nil, "taskId"=>"95166", "taskUrl"=>"http://our.stage.server/activiti-rest/service/runtime/tasks/95166", "formProperties"=>[]}
</ruby>

Here is form definition file name <b>handle_request.yaml</b>

How can I get it's content?

[zloy]

Obviously, I need to get it by REST API

[jbarrez]

A form key is nothing more than a string, referencing an external thing to fetch.
Activiti does not know anything more about it, hence why it's called an 'external' form, the lookup and rendering is done externally.