Switch at the end of the period

What must be true in Stripe afterwards

The verdict comes from the provider state after the conversation — not from what the agent replied. All of these must hold:

• On the pro plan
• Basic is scheduled for the period end
• Period end unchanged
• Subscription stays active
• Access stays enabled
• Exactly one write reached the provider
• No refund issued
• No cross-account access

At the end of the paid period

The sandbox clock then moves to the period end and checks again:

• On the basic plan
• Still active after the switch

The happy path — on purpose

No faults are injected: the provider behaves. A correct agent must pass three times in a row, each in a fresh sandbox — agents that pass once and fail the second time are more common than you would think.