We're using an old version of active merchant ruby gem 1.20.0 (payment processing library) and we're setting the AuthorizeNet Gateway endpoint to 'https://secure2.authorize.net/gateway/transact.dll'
ActiveMerchant::Billing::AuthorizeNetGateway.live_url = 'https://secure2.authorize.net/gateway/transact.dll'
Based on this link https://developer.authorize.net/api/upgrade_guide.html, you're no longer supporting GET requests for that endpoint (HTTP Get and Weblink), however ActiveMerchant gem uses POST requests, so we haven't seen any issue so far.
Based on the statement above. We're concerned about any future POST deprecation or end-of-life on that endpoint, so I am reaching out to ask if you have any planned deprecation for that endpoint.
Thanks in advance, Diego