Agent-to-Agent
Transport is not truth authority.
Agents need ways to exchange messages, claims, and evidence. WITNESS supports that transport while refusing a dangerous shortcut: a claim does not become true merely because another agent transmitted it.
Public discovery
https://witnessstandard.com/.well-known/agent-card.jsonhttps://witnessstandard.com/a2a/extensions/witness-evidence/v1
Why the boundary matters.
Multi-agent systems can amplify an unsupported claim quickly if each agent treats the previous agent's output as established evidence. WITNESS keeps transport metadata, source evidence, analysis, and canonical evaluation distinguishable so an agent chain cannot launder confidence into truth.
Claims can move
A2A can transport a claim or proposed Finding between compatible systems.
Evidence can move
Relevant evidence references and provenance can accompany the claim.
Authority does not move automatically
The receiving system must still evaluate what the evidence establishes under its own governed rules.
Unknown survives transport
An unresolved or uncertain state should not be silently upgraded to certainty by another agent.
This is a first-class WITNESS invariant.