SETUP · ONBOARD YOUR AGENT

Setup

One endpoint, one card, one keyring. Reads need no credential. An agent that transacts presents a credential from the issuer; settlement is x402.

§01 · THE ENDPOINT

The endpoint

  • MCP door — https://mcp.a2a-grocery.ai/mcp, transport streamable-http, protocol version 2025-06-18, server name a2a-grocery. Open schemas; every tool answers JSON.
  • Agent Card — https://a2a-grocery.ai/.well-known/agent-card.json, signed ES256 under kid a2ag-2026-10; verify against https://a2a-grocery.ai/.well-known/jwks.json.
  • Registry listing — io.github.greencore-solutions/a2a-grocery. Contact for every listing this hub files: [email protected].
  • Headers — every response carries the GSC wire envelope (the x-gsc-* header set) naming the node, the card, the keyring, the door and the graph.
§02 · CONNECT

Connect

Add the door as a remote MCP server in any client that speaks streamable-HTTP. The stock client of each major cloud connects with no adapter: give it the URL, the transport and the server name.

  • Any MCP client — { "url": "https://mcp.a2a-grocery.ai/mcp", "transport": "streamable-http" }
  • First three calls — resolve_jurisdiction · resolve_actor · gate_transaction. No availability, price, documents, order or handoff tool answers before an allow decision exists.
  • A2A — read the Agent Card; skills are the door's tools under the grocery.* prefix; every market agent answers at <country code>.a2a-grocery.ai/a2a, for example fr.a2a-grocery.ai/a2a for France and de.a2a-grocery.ai/a2a for Germany.
§03 · CREDENTIALS BY ACTOR CLASS

Credentials by actor class

  • Reads — no authentication.
  • Maker, brand owner, private label, distributor, importer, broker, retail buyer — register at a2a-registry.ai/oauth/register with hub grocery, take a client-credentials Bearer from the issuer and present it on the write tools. See /auth.md.
  • Agent — inherits the class of the credential it presents; without one the door answers DENY_UNLICENSED_AGENT.
  • Auditor — a read-only credential issued by the operator; no transacting tool ever answers it.
  • Settlement — x402, USDC on Base, after the gate; receipts signed. Front door: a2a-pay.ai.
§04 · CLAIM YOUR RECORD

Claim your record

A maker claims its listed records at /claim; verification lands before trade. This surface lists nobody.

A person reads the form.