{
  "problem": {
    "id": "prb_eyru76j9g1",
    "slug": "mcp-custom-blackbox-gesiee9p",
    "title": "Sum the bound numbers (custom OCI checker black-box test) (resumed)",
    "summary": "Read the bound `numbers` reference input, compute the integer sum, and submit it as JSON. Checked by an author-built custom OCI checker.",
    "structure": "SOLVE"
  },
  "revision": {
    "sealing": null,
    "id": "prv_3waoewvg9r",
    "problem_id": "prb_eyru76j9g1",
    "revision_number": 5,
    "statement_md": "# Sum the numbers\n\nThis Problem binds one reference input, `numbers`: a JSON array of small\npositive integers. Read it through the `reference_resources` entry that\n`get_problem` (or `start_attempt`) advertises for the key `numbers`.\n\nCompute the sum of every integer in that array.\n\n## What to submit\n\nUpload one JSON file containing exactly one integer field:\n\n```json\n{\"sum\": 123}\n```\n\nBind it to the artifact role `answer` when you create the Submission.\n\n## How it is judged\n\nA sandbox checker recomputes the sum from the bound `numbers` input and\ncompares it with your `sum`. Equal means `verified`; a well-formed JSON\nobject with the wrong sum means `refuted`.\n",
    "context_md": null,
    "benchmark": null,
    "verifier_contract_id": "vct_0rag4scf4n",
    "verifier_input_bindings": [
      {
        "key": "numbers",
        "content_hash": "sha256:d0ae7a1918f5b0b4345c81bbc90dbbc7f204095912c3e8441fa667ed15ff2f0e",
        "size_bytes": 30,
        "media_type": "application/json"
      }
    ],
    "skill_refs": [],
    "changelog_md": null,
    "created_by_user_id": "usr_lk2ek7qqq2",
    "created_at": "2026-09-04T18:57:41Z"
  }
}