{
  "lesson": "16-mcp-security-oauth-2-1",
  "title": "MCP Authorization: CIMD, Issuer Binding, PKCE, and Step-Up",
  "questions": [
    {
      "stage": "pre",
      "question": "Which mechanism is preferred for new MCP OAuth client enrollment in 2026-07-28?",
      "options": [
        "An access token in the URL",
        "Mcp-Session-Id",
        "Client ID Metadata Documents",
        "Dynamic Client Registration"
      ],
      "correct": 2,
      "explanation": "CIMD is preferred; DCR is deprecated and retained as a compatibility path."
    },
    {
      "stage": "check",
      "question": "What application_type should a desktop client with a loopback redirect declare during DCR fallback?",
      "options": [
        "web",
        "stateless",
        "native",
        "confidential"
      ],
      "correct": 2,
      "explanation": "Desktop, mobile, command-line, and loopback clients are native applications."
    },
    {
      "stage": "check",
      "question": "What must a client do with an authorization response iss value?",
      "options": [
        "Normalize it and compare hostnames",
        "Store it as clientInfo",
        "Ignore it after PKCE succeeds",
        "Compare it exactly with the recorded issuer before using the response"
      ],
      "correct": 3,
      "explanation": "RFC 9207 issuer checking prevents authorization response mix-up between issuers."
    },
    {
      "stage": "check",
      "question": "How should a client key issuer-minted OAuth credentials and access tokens?",
      "options": [
        "Issuer-minted credentials by issuer and tokens by issuer plus resource",
        "All registrations and tokens under one global client name",
        "By the server display name only",
        "By protocol session identifier"
      ],
      "correct": 0,
      "explanation": "Issuer and resource keys prevent minted credentials from crossing security authorities or audiences. A self-hosted CIMD URL remains portable."
    },
    {
      "stage": "post",
      "question": "A resource returns 403 with scope notes:delete. What is the correct next step?",
      "options": [
        "Add notes:delete locally without authorization",
        "Explain the scope, obtain consent, authorize for it, then retry with a new request id",
        "Send the MCP token to a downstream API",
        "Reuse the current token and ignore the challenge"
      ],
      "correct": 1,
      "explanation": "Step-up obtains a newly authorized token before retrying the operation."
    },
    {
      "stage": "post",
      "question": "What is the RFC 9728 metadata URL for the MCP resource https://notes.example.com/mcp?",
      "options": [
        "https://notes.example.com/.well-known/oauth-protected-resource/mcp",
        "https://auth.example.com/.well-known/oauth-protected-resource",
        "https://notes.example.com/.well-known/oauth-protected-resource",
        "https://notes.example.com/mcp/.well-known/oauth-protected-resource"
      ],
      "correct": 0,
      "explanation": "RFC 9728 preserves the protected resource path after the well-known segment, so the /mcp suffix is required."
    }
  ]
}