Get Rally Hierarchical Requirement snapshot for a given revision

[Dario Griffo]

Using the Rally Rest Api I'm trying to get a Hierarchical Requirement at a given point in time, like I request the User Story now.
I know how to get the Hierarchical Requirement

https://rally1.rallydev.com/slm/webservice/v2.0/HierarchicalRequirement/‹ObjectID›/

I know how to get the revisions

https://rally1.rallydev.com/slm/webservice/v2.0/RevisionHistory/‹ObjectID›

Now with this, I have all the history of revisions (Created [rev 0], Name changed [rev 1], etc [rev ..], BLOCKED [rev N -1], UNBLOCKED [rev N])

Let's say I want to see the FULL Hierarchical Requirement at rev 2 (with the new name) or the FULL Hierarchical Requirement at rev N-1, when it was blocked, but I want to get it like if I was doing
https://rally1.rallydev.com/slm/webservice/v2.0/HierarchicalRequirement/‹ObjectID›/

Is there a way to get these snapshots?

[Sagi Gabay]

Hi Dario.

Our Lookback API is best suited for this purpose. Essentially most changes to a work item (such as a user story) create a snapshot that keeps track of what had changed. The Lookback API allows you to examine these snapshots based on all sorts of filters such as at a given time stamp, in a time range and other filtering options. I have included the link to the Lookback API and so please go over it to learn how to use it. If you have any more specific question - let us know.

Thanks,
Sagi