SETUP · CONNECT AN AGENT

Setup

One endpoint, one card, one keyring. The door is a stateless streamable-HTTP Model Context Protocol (MCP) server; the Agent-to-Agent (A2A) party is described by the signed Agent Card. 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-cosmetics.ai/mcp, transport streamable-http, protocol version 2025-06-18, server name a2a-cosmetics. Open schemas; every tool answers JSON.
Agent Card — https://a2a-cosmetics.ai/.well-known/agent-card.json, signed ES256 under kid a2ac-2026-09; verify against https://a2a-cosmetics.ai/.well-known/jwks.json.
Registry listing — io.github.greencore-solutions/a2a-cosmetics. Contact for every listing this hub files: the mcp mailbox on this domain, on the card.
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-cosmetics.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 twenty tools under the cosmetics.* prefix; the handoff skill is cosmetics.a2a_handoff; every market agent answers at <country code>.a2a-cosmetics.ai/a2a, for example us.a2a-cosmetics.ai/a2a and fr.a2a-cosmetics.ai/a2a.

§03 · CREDENTIALS BY ACTOR CLASS

Credentials by actor class

Reads — no authentication.
Brand, manufacturer, retailer, distributor — register at a2a-registry.ai/oauth/register, take a client-credentials Bearer from the issuer and present it on the transacting 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 brand claims its listed records at /claim; verification lands before trade. This surface lists nobody.

The form is the only human door on this surface. Machine contact is on the Agent Card and in the headers.