Create an account with PayPal
Follow through all the steps to enable recieving payments
Visit the config page to review your progress
Log into PayPal developer site (create a session)
Navigate to sandbox acounts
Open the profile tab for the Business acount and take down the API creditentials
NB, that all sandbox apps share the app_id of "APP-80W284485P519543T"
Use the same receiver email as the test business account email
Make a "classic" API app, not the new REST API app.
NVP/SOAP API apps — NVP/SOAP APIs (formerly Classic API) app credentials, can be viewed and managed here. These APIs include Express Checkout, Website Payments Pro, Adaptive Payments, Adaptive Accounts, Mass Payments, the Button Manager API, the Permissions Service and the SOAP version of the Invoicing Service.
Log into PayPal developer site (create a session)
Navigate to the external classic app site
Click create a new app, fill out the form with minimal options, it will get auto-approved. (use documents and form sample from "bundle" directory)
Return to paypal.com, navigate to API access page
Write down the app's username, password, signature and app id
in /app/library/pay_pal.rb
create/update a config block with needed app information
all blocks share the API app's info, differ by receiver
receiver can be any email you have added to the managing account via email settings
Provided your code loads the correct PP setting blocks,
Navigate to pipeline checkout, pick PP and pay up
Log into PayPal and verify that you received the payments and that receiving emails are correct