Stable identifier suitable for idempotency. Derived from the source notification
UUID where the store provides one (ASN v2 notificationUUID, RTDN message id);
otherwise hashed from the canonicalized payload.
Price in micros (1/1,000,000 of the currency unit) at event time, when available.
Matches Google Play's priceAmountMicros convention; iOS values are converted.
Cross-platform purchase identity used to correlate this event with an existing
purchase record. iOS: originalTransactionId. Android: purchaseToken.
Null for TestNotification events (Apple ASN v2 / Google RTDN test
payloads carry no transaction); always present for every other event type.
Original signed payload from the store. ASN v2 events expose the JWS string;
RTDN events expose the base64-decoded Pub/Sub message JSON. Provided so that
consumers can independently verify or extract platform-specific fields. kit
always validates this payload before emitting the event.