Versioning and status

The version is in the path (/v1/). Within a version:

Change	Notice
A new route, a new optional field, a new event type, a new error_code	None. Ignore what you do not know
A breaking change to an available route	Never within v1. A v2 would run beside v1 for at least 12 months
A change to a preview route	30 days, in the changelog and by email to technical contacts
A planned route	Specified to design against; it answers 404 until it ships

Every operation in specs/openapi.yaml and every message in specs/asyncapi.yaml carries x-status. Write clients that tolerate unknown fields and unknown enum values.