# auth.md — gsc-marketplace.ai (GreenCore Solutions Corp.)

## Posture

Everything on this surface is **open and free by design** — no authentication, no payment, no 402 challenge. Discovery endpoints (/.well-known/*) are public. The MCP endpoint (https://mcp.gsc-marketplace.ai/mcp) serves all eleven read tools openly. x402 is declared as a capability (`x-gsc-x402: ready`) and carries no terms.

Anything that creates obligation — an RFQ, terms, a purchase order — leaves this surface through one of the two doors and is human-signed.

## Protected resource

- Resource: https://gsc-marketplace.ai
- Protected Resource Metadata: [/.well-known/oauth-protected-resource](/.well-known/oauth-protected-resource)
- Authorization server (Microsoft Entra): https://login.microsoftonline.com/54939635-2f2e-465a-8526-a907cb3c8ebd/v2.0
- AS metadata mirror: [/.well-known/oauth-authorization-server](/.well-known/oauth-authorization-server)
- Bearer tokens are presented in the Authorization header.

## Agent registration (self-contained flow)

- **Agent audience:** marketplace and retail sourcing agents, and the operators integrating them with GSC-Marketplace and the CPG Knowledge Graph.
- **Registration endpoint:** https://gsc-navigator.ai/ — the GSC Trading Desk (the humans' channel, informed by Navigator). Intake on this surface (POST https://formspree.io/f/mppannbj with fields name, email, message) — human-reviewed by the GSC Trading Desk. There is no self-serve dynamic client registration; every registration is human-reviewed.
- **Agents' channel:** Instant Messaging — https://x-gsi.ai/ingest → https://mcp.cpghumanintheloop.ai/mcp (tools: submit_rfq, check_rfq_status, request_terms, escalate). Typed, identified, ticketed, human-signed.
- **Supported method — verified email:** GSC verifies the operator's email, then provisions credentials after review.
- **Credential use:** GSC issues **Microsoft Entra OAuth 2.0 client credentials** (client_credentials grant against the issuer above); present the access token as a **Bearer token in the Authorization header**. Revocation on request via the same endpoint.

```json
{
  "agent_auth": {
    "skill": "https://gsc-marketplace.ai/auth.md",
    "register_uri": "https://gsc-navigator.ai/",
    "identity_types_supported": [
      "identity_assertion"
    ],
    "identity_assertion": {
      "assertion_types_supported": [
        "verified_email"
      ],
      "credential_types_supported": [
        "oauth2_client_credentials"
      ]
    },
    "claim_uri": "https://gsc-navigator.ai/"
  }
}
```

Operator: GreenCore Solutions Corp. · D-U-N-S 24-336-6774 · Microsoft AI Cloud Partner.