I have been able to successfully set up one time payments (which return Shipping and Payer information) and the majority of the Billing Plan/Billing Agreement functionality on my website using the paypalrestsdk (python in a django application).
After creating the Billing Plan, activating, then redirecting the user to the returned Redirect URL, I am given a token. I can then use that token to execute the Billing Agreement, which returns an id and a URL. When using that ID to retrieve information (https://developer.paypal.com/docs/api/#retrieve-an-agreement) about the Billing Agreement, I'm given some information about the Billing Agreement, but no information about the Payer [name, shipping address, email, etc].
Is this a known limitation of the REST API, or is there a known method to return shipping address and user information from a BillingAgreement after it's been created and Activated?