You use the ListIdentifiers verb to get back the headers.

Let’s see an example request. To start we need to go to the “base” URL:

http://[ServerUrl]/oai/data/oai2_0

Now we specify the verb — which in this case is ListIdentifiers. So add ?verb=ListIdentifiers to the end of the previous URL to get this:

http://[ServerUrl]/oai/data/oai2_0?verb=ListIdentifiers

Here’s an example response: