Payjoin V2 is asynchronous and introduces an expiration parameter after which sessions are no longer valid. The payjoin directory should dictate the length of time for which it is willing to maintain an open session and communicate that during session initialization. The expiration can then be communicated in the bip21 URI for the sender to stop attempts after expiration. The receiver should also stop after expiration.
Payjoin V2 is asynchronous and introduces an expiration parameter after which sessions are no longer valid. The payjoin directory should dictate the length of time for which it is willing to maintain an open session and communicate that during session initialization. The expiration can then be communicated in the bip21 URI for the sender to stop attempts after expiration. The receiver should also stop after expiration.