It is difficult, in fact, to obtain the ID of the code you just uploaded.
You can start by [getting a list of code packages]{http://dev.iron.io/worker/reference/api/#list_code_packages},
but then you need to scan through the list to find the package you just uploaded.
The REST API has some inconsistencies that should get cleaned up.
Here is one example: POST Messages vs POST Codes
With IronMQ, when you add a message to a queue, the HTTP response includes the ID of the message.
With IronWorker, when you add new code, the HTTP response does not include the ID of the code.
There is no reason for the ID to be omitted.
It is difficult, in fact, to obtain the ID of the code you just uploaded. You can start by [getting a list of code packages]{http://dev.iron.io/worker/reference/api/#list_code_packages}, but then you need to scan through the list to find the package you just uploaded.
The fix? POST Codes should return the ID.