{"ok":true,"protocol":"picux-a2a","version":"0.1.0","transport":"external","envelope":{"required":["msgId","kind","fromAgent","toAgent","task","createdAt"],"optional":["caps","payload","traceId"],"schema":"schemas/protocols/a2a-envelope.schema.json"},"endpoints":{"contract":"/v1/a2a/contract","createEnvelope":"/v1/a2a/envelopes","listEnvelopes":"/v1/a2a/envelopes","getEnvelope":"/v1/a2a/envelopes/{msgId}","updateEnvelope":"/v1/a2a/envelopes/{msgId}/update"}}