Request
Response
Fields
The gateway leaves
documentationUrl, iconUrl, signatures, and
capabilities.extendedAgentCard unset. An unset field is dropped from the JSON
entirely rather than serialized as null, so test for the key rather than
comparing against null.
The security scheme
One HTTP Bearer scheme covers both credential kinds the gateway accepts: a platform JWT (eyJ…) or a service-principal API key (ak-…). Both arrive on
Authorization: Bearer and are disambiguated by prefix.
See Authentication for the admission rules.
Extensions
Both declared extensions are optional and take effect only when you negotiate them by sending theA2A-Extensions request header.
Without negotiation, payloads for these extensions are not tagged with their
extension URI.
GetExtendedAgentCard
The GetExtendedAgentCard JSON-RPC method returns the same card this
endpoint serves. There is no distinct extended card.