{"type":"object","required":["grant_type","auth_req_id"],"properties":{"grant_type":{"type":"string","description":"OAuth 2.0 grant type. For CIBA this is typically `urn:openid:params:grant-type:ciba`.","example":"urn:openid:params:grant-type:ciba"},"auth_req_id":{"type":"string","description":"Authentication request identifier returned by the backchannel-auth endpoint."}}}