{
  "title": "Dataset Contract Gate",
  "tagline": "Quarantine invalid records and fail ingestion on explicit dataset rules.",
  "level": 2,
  "summary": "Define a small versioned data contract, check field types and bounds, find every row in duplicate groups, and export accepted records separately from quarantine. A CLI exit code gates ingestion while a source-line report explains failures.",
  "languageWhy": {
    "Python": "Standard dictionaries, numeric checks and JSONL IO make cross-row validation easy to inspect."
  },
  "prerequisiteProjects": [
    "dataset-split-auditor",
    "json-schema-output-guard"
  ],
  "id": "dataset-contract-gate",
  "languages": [
    "Python"
  ],
  "source": "core",
  "status": "ready",
  "hours": 8,
  "author": {
    "name": "AI Engineering from Scratch",
    "github": "rohitg00"
  },
  "prerequisites": [
    "Python 3.12+; dictionaries, lists and command-line IO"
  ],
  "youWillBuild": "accepted.jsonl, quarantine.jsonl, receipt.json and review.html",
  "skills": [
    "Validate an explicit quality contract",
    "Check each record without coercion",
    "Find all rows in a duplicate group",
    "Export partitions and enforce the dataset gate"
  ],
  "figures": true,
  "overviewFigure": "pj-dataset-contract-gate-1",
  "demo": {
    "cwd": "solution",
    "command": [
      "python3",
      "cli.py",
      "samples/input.jsonl",
      "--contract",
      "samples/contract.json",
      "--output",
      "demo-output"
    ]
  },
  "stages": [
    {
      "id": "01-validate-contract",
      "title": "Validate an explicit quality contract",
      "summary": "Require version=1 and a nonempty fields object.",
      "hours": 2,
      "language": "python",
      "difficulty": "starter",
      "concepts": [
        "validate an explicit quality contract"
      ],
      "figure": "pj-dataset-contract-gate-1"
    },
    {
      "id": "02-check-records",
      "title": "Check each record without coercion",
      "summary": "Consume a validated contract.",
      "hours": 2,
      "language": "python",
      "difficulty": "core",
      "concepts": [
        "check each record without coercion"
      ],
      "figure": "pj-dataset-contract-gate-2"
    },
    {
      "id": "03-check-uniqueness",
      "title": "Find all rows in a duplicate group",
      "summary": "For each unique column, index valid typed values to one-based input row numbers.",
      "hours": 2,
      "language": "python",
      "difficulty": "core",
      "concepts": [
        "find all rows in a duplicate group"
      ],
      "figure": "pj-dataset-contract-gate-3"
    },
    {
      "id": "04-quarantine-and-gate",
      "title": "Export partitions and enforce the dataset gate",
      "summary": "Return schema_version=1, passed, counts, dataset_issues, duplicates, accepted and quarantine.",
      "hours": 2,
      "language": "python",
      "difficulty": "core",
      "concepts": [
        "export partitions and enforce the dataset gate"
      ],
      "figure": "pj-dataset-contract-gate-4"
    }
  ],
  "demos": [
    {
      "gif": "media/run.gif",
      "poster": "media/run.png",
      "title": "Initialize and grade",
      "caption": "Recorded starter failure followed by every reference stage passing."
    },
    {
      "gif": "media/output.gif",
      "poster": "media/output.png",
      "title": "Inspect actual output",
      "caption": "Recorded interaction with the generated local interface. Run the documented command to inspect your own output."
    }
  ]
}