One protocol keeps Agent decisions interoperable
One message contract, not private conventions
What shared systems need
Shared refs, lifecycle, and validation keep meaning
RequirementPurposeProtocol roleResult
Shared envelope
Parse the same action
Action Card and challenge structure stay recognizable
Readable
Shared lifecycle
Place the action
Named states and transitions preserve workflow context
Contextual
Shared validation
Check the same rules
Compatible checks reject invalid participation
Conformant
Boundary clarity
Shared contract, independent outcomes
Shared grammar
Systems read messages under one contract
Product differences remain
Relay, Agents, and Protocol keep separate roles
Outcomes can differ
Compatibility makes decisions interpretable