Compatibility policy

schema_version versions the public event envelope and its event-specific data contract.
Version 1 consumers should:

• ignore unknown object properties;
• tolerate new catalog event types they did not select;
• branch on type and schema_version;
• treat enum values they do not understand as unsupported data rather than a transport failure.

Oway can add optional fields without changing schema_version. Removing a field, changing its
meaning or type, or making an optional field required needs a new schema version. New event types
are added to the live catalog before they can be selected.

An endpoint stores explicit event type and schema selections. Oway does not silently switch an
endpoint to a breaking schema. Migration and sunset notices are published in the changelog with an
explicit support date; version 1 currently has no scheduled sunset.

Historical data updates do not automatically trigger webhook delivery. A retained event body is sent
again only through the documented retry or explicit replay paths, preserving its event ID.