Event reference

The ob-event header tells you what kind of object changed and ob-action what happened to it. Each event has its own page with its actions, payload and examples.

Events

Event	Notifies you when
ORDER	A sales order is purchased, booked, refunded, cancelled, printed or relocated.
ITEM	A ticket is transferred, changes owner or is validated at access control.
MEMBERORDER	A membership or season-ticket order changes.
PREORDER	A purchase is abandoned before the payment.
EVENT_UPDATE	The configuration of an event changes.
SESSION_UPDATE	The configuration of a session changes.
CATALOG	The published catalog of an event, session or product changes.
PROMOTION	A promotion of an event changes.
CHANNEL	The configuration of a sales channel changes.
B2BBALANCE	A movement is registered on a B2B balance.

Subscriptions

A webhook only receives the event and action pairs it subscribes to, written as <EVENT>_<ACTION> in its configuration, for example ORDER_PURCHASE. Each event page lists the values to subscribe with and the entity that receives its notifications.

The ob-action header carries the action part of the subscription, with one exception: seat relocations arrive as ob-action: RELOCATE to webhooks subscribed to ORDER_PURCHASE.

Payload conventions

• Verify the signature on the raw body, exactly as received, before you parse it.
• Fields without a value are omitted rather than sent as null.
• Field names are not uniform across events (some are snake_case, others camelCase): use them exactly as documented.
• New fields may be added at any time. Ignore the fields you do not know and do not rely on their order.