A: Publisher supplies article + visitor context
B: Register missing item and check, or check known item
C: Valid access decision received? (decision)
D: Withhold protected content; show unavailable state
E: allow (decision)
F: Deliver authorized content; show unlocked view
G: Withhold protected content; show access prompt
A → B
B → C
C → D: No: request error or missing/malformed decision
C → E: Yes
E → F: true
E → G: false