Stripe webhooks

Endpoint: POST /v1/webhooks/stripe — raw body required for signature verification (stripe-signature + webhook secret). No session auth on this route.

Handled events

Event	Behavior
checkout.session.completed	If payment_status === paid, resolve org + pack from session metadata, grant credits from the server catalogue (creates lot + purchase ledger). Duplicate session id is ignored (idempotent).
checkout.session.async_payment_succeeded	Same grant path as above for async payment methods that complete later.

All other event types — acknowledged with success; no credit changes.

Outcomes

• Unpaid or pending session on a handled event → success response, no grant.
• Paid session with missing org/pack metadata → error so Stripe retries.
• Invalid signature → validation error (not a retry loop for bad clients).
• Successful handling (including duplicates and ignored types) → 200 so Stripe stops retrying.

Credits granted use pack size from the catalogue, not client-supplied amounts alone.