A2A Extension

A2A is optional in GRP v0.1. Operators that support it publish an A2A Agent Card and declare the GRP extension URI:

https://groupresolutionprotocol.org/ext/grp/v1

The A2A binding is not a replacement for REST or MCP. It is an additional front door for A2A-fluent agents; multilateral semantics still live in the GRP room.

In practice: A2A reaches the room; GRP owns the shared state, mechanism run, and receipt. A participant agent MAY coordinate a low-stakes decision itself, but that is a lower-assurance pattern unless the result is submitted into a GRP room.

Read the normative binding at Specification: A2A binding.