{
  "lesson": "30-mcp-registry-supply-chain-and-drift",
  "title": "MCP Registry Supply Chain: Admission, Drift, and Rollback",
  "questions": [
    {
      "stage": "pre",
      "question": "What does successful publication in an MCP Registry establish for a production gateway?",
      "options": [
        "The record passed Registry publication controls, while local runtime admission is still required",
        "The live endpoint exactly matches the published package",
        "The newest version should immediately replace every older route",
        "The server is safe for every principal"
      ],
      "correct": 0,
      "explanation": "Registry publication establishes publication facts. Artifact, runtime, authorization, and local approval checks remain separate."
    },
    {
      "stage": "check",
      "question": "Which namespace comparison rejects com.exampleevil/tool when the verified namespace is com.example?",
      "options": [
        "Check whether the whole name starts with com.example",
        "Search for the substring example",
        "Split at the slash and compare the namespace segment exactly",
        "Trust the namespace written inside server.json"
      ],
      "correct": 2,
      "explanation": "An exact segment comparison preserves the namespace boundary and uses authority supplied by a trusted verifier."
    },
    {
      "stage": "check",
      "question": "A live server adds a new tool while its Registry record and package coordinate stay unchanged. Which evidence detects this?",
      "options": [
        "A fresh normalized descriptor digest compared with the admitted toolset pin",
        "The Registry publication timestamp",
        "The namespace authentication method",
        "The semantic version string alone"
      ],
      "correct": 0,
      "explanation": "Live descriptor pinning detects behavior drift that publication metadata and package coordinates cannot show."
    },
    {
      "stage": "check",
      "question": "What should happen when an admitted Registry version changes from active to deprecated?",
      "options": [
        "Quarantine it from new routing and retain the historical admission evidence",
        "Rewrite the published record back to active",
        "Delete all evidence so clients cannot discover it",
        "Ignore status because package ownership was already verified"
      ],
      "correct": 0,
      "explanation": "Status is operational input. Quarantine stops new use while retained evidence supports audit and rollback analysis."
    },
    {
      "stage": "post",
      "question": "Which target is eligible for an automatic rollback?",
      "options": [
        "Any version whose name sorts before the candidate",
        "A previously admitted pin that is active under policy, healthy, and not quarantined",
        "The version marked latest, even if it was never reviewed",
        "A deleted Registry version with a familiar package name"
      ],
      "correct": 1,
      "explanation": "Rollback restores a known admissible route. It does not bypass current status, health, or quarantine checks."
    },
    {
      "stage": "post",
      "question": "Why should admission ledger heads be anchored in a separate trust domain?",
      "options": [
        "It makes artifact digests unnecessary",
        "It lets publishers set Registry-managed status",
        "It converts mutable version ranges into exact pins",
        "A local hash chain detects edits, while a separate anchor makes a complete local rewrite detectable"
      ],
      "correct": 3,
      "explanation": "An attacker who can rewrite the whole local ledger can recompute its chain. An external signed or write-once anchor exposes that rewrite."
    }
  ]
}