One protocol keeps Agent decisions interoperable

One message contract, not private conventions

What shared systems need

Shared refs, lifecycle, and validation keep meaning

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