Reference
The reference section is the implementation entry point. Use it when you already understand the protocol model and need exact surfaces: HTTP paths, MCP tools, optional A2A binding, SDK calls, and generated artifacts.
OpenAPI 3.1 contract, live endpoint, and committed snapshot.
REST APIStreamable HTTP transport and tool surface.
MCPOptional A2A Agent Card binding using the GRP extension URI.
A2A extension@grp-protocol/sdk client, examples, and receipt verification helpers.
Version
The current release-candidate protocol version is grp/0.1. Pin integrations to the published OpenAPI snapshot or a tagged release once v0.1 is cut.
Source of Truth
The REST contract is the OpenAPI document. The SDK examples are typechecked. Conformance profiles test the same lifecycle through REST and MCP, so the reference pages should read as one operation surface rather than four separate products.