OneStepSmarter

Billing state cannot be whichever webhook arrived most recently. OneStepSmarter re-reads current Stripe truth before applying events that could regress a paid invoice or overwrite a newer subscription state.

The same hardening stopped an open, unattempted renewal invoice from being treated as a payment failure and prevented a completed learner checkout from being superseded by a newer checkout.

For a past-due learner, the retry flow pays the exact existing Stripe invoice. It does not create a Checkout Session or replacement subscription. Operation claims make duplicate retries converge on one logical attempt.

Cancellation is previewed from authoritative Stripe state before confirmation. A stale legacy cancellation endpoint fails closed and forces the client into the newer review-and-confirm flow instead of performing a destructive action under old assumptions.

A previous 1.5-second race could let the teacher tab close without proving that the class end was durable. The hardened flow records the end state first; a failed write leaves the page open with a retryable error.

Unexpected LiveKit disconnects request a fresh join token for recovery instead of assuming the old session is still valid.

Assignment and assessment publication creates an immutable event snapshot, confirms the teacher immediately, then fans out asynchronously in bounded work.

Delivery claims are keyed by publication event, recipient, channel and learner. Parents can receive in-app and email notifications, learners receive in-app notifications, transient email failures retry on a bounded schedule, and a later republish permanently supersedes stale queued work.