{
  "$schema": "https://json-structure.org/meta/core/v0/#",
  "$id": "https://raw.githubusercontent.com/api-evangelist/new-york-public-library-whats-on-the-menu/refs/heads/main/json-structure/new-york-public-library-whats-on-the-menu-dataset-structure.json",
  "name": "NyplWhatsOnTheMenuDataset",
  "description": "Structural layout of the New York Public Library 'What's on the Menu?' open dataset. The dataset is distributed as four related CSV tables (Menu, MenuPage, MenuItem, Dish) packaged in a gzip archive on Amazon S3. This JSON Structure documents the four entity types, their fields, and the foreign-key relationships that join them.",
  "type": "object",
  "properties": {
    "menus": {
      "type": "array",
      "description": "Menu.csv — one row per digitized physical menu object.",
      "items": { "type": { "$ref": "#/definitions/Menu" } }
    },
    "menuPages": {
      "type": "array",
      "description": "MenuPage.csv — one row per digitized page; child of Menu.",
      "items": { "type": { "$ref": "#/definitions/MenuPage" } }
    },
    "menuItems": {
      "type": "array",
      "description": "MenuItem.csv — one row per transcribed dish-on-page line item; links MenuPage and Dish.",
      "items": { "type": { "$ref": "#/definitions/MenuItem" } }
    },
    "dishes": {
      "type": "array",
      "description": "Dish.csv — one row per normalized/deduplicated dish with appearance and price statistics.",
      "items": { "type": { "$ref": "#/definitions/Dish" } }
    }
  },
  "definitions": {
    "Menu": {
      "type": "object",
      "description": "A single historical menu. Root of the hierarchy.",
      "properties": {
        "id": { "type": "uint32", "description": "Primary key." },
        "name": { "type": "string" },
        "sponsor": { "type": "string" },
        "event": { "type": "string" },
        "venue": { "type": "string" },
        "place": { "type": "string" },
        "physical_description": { "type": "string" },
        "occasion": { "type": "string" },
        "notes": { "type": "string" },
        "call_number": { "type": "string", "description": "NYPL catalog call number." },
        "keywords": { "type": "string" },
        "language": { "type": "string" },
        "date": { "type": "string", "description": "Issue/use date; precision varies." },
        "location": { "type": "string" },
        "location_type": { "type": "string" },
        "currency": { "type": "string" },
        "currency_symbol": { "type": "string" },
        "status": { "type": "string", "description": "Transcription status: complete, under review, to transcribe." },
        "page_count": { "type": "uint16" },
        "dish_count": { "type": "uint16" }
      },
      "required": ["id"]
    },
    "MenuPage": {
      "type": "object",
      "description": "A digitized page of a Menu.",
      "properties": {
        "id": { "type": "uint32", "description": "Primary key." },
        "menu_id": { "type": "uint32", "description": "Foreign key -> Menu.id." },
        "page_number": { "type": "uint16" },
        "image_id": { "type": "string", "description": "NYPL Digital Collections image id." },
        "full_height": { "type": "uint16" },
        "full_width": { "type": "uint16" },
        "uuid": { "type": "uuid" }
      },
      "required": ["id", "menu_id"]
    },
    "MenuItem": {
      "type": "object",
      "description": "A transcribed line item positioning a Dish on a MenuPage.",
      "properties": {
        "id": { "type": "uint32", "description": "Primary key." },
        "menu_page_id": { "type": "uint32", "description": "Foreign key -> MenuPage.id." },
        "dish_id": { "type": "uint32", "description": "Foreign key -> Dish.id." },
        "price": { "type": "decimal", "precision": 12, "scale": 3 },
        "high_price": { "type": "decimal", "precision": 12, "scale": 3 },
        "xpos": { "type": "double", "description": "Normalized x position (0..1) on the page image." },
        "ypos": { "type": "double", "description": "Normalized y position (0..1) on the page image." },
        "created_at": { "type": "datetime" },
        "updated_at": { "type": "datetime" }
      },
      "required": ["id", "menu_page_id"]
    },
    "Dish": {
      "type": "object",
      "description": "A normalized dish aggregating all MenuItem occurrences of the same name.",
      "properties": {
        "id": { "type": "uint32", "description": "Primary key." },
        "name": { "type": "string" },
        "description": { "type": "string" },
        "menus_appeared": { "type": "uint32" },
        "times_appeared": { "type": "int32" },
        "first_appeared": { "type": "uint16", "description": "Earliest appearance year; 0 = unknown." },
        "last_appeared": { "type": "uint16", "description": "Latest appearance year; 0 = unknown." },
        "lowest_price": { "type": "decimal", "precision": 12, "scale": 3 },
        "highest_price": { "type": "decimal", "precision": 12, "scale": 3 }
      },
      "required": ["id", "name"]
    }
  },
  "x-relationships": [
    { "from": "MenuPage.menu_id", "to": "Menu.id", "cardinality": "many-to-one" },
    { "from": "MenuItem.menu_page_id", "to": "MenuPage.id", "cardinality": "many-to-one" },
    { "from": "MenuItem.dish_id", "to": "Dish.id", "cardinality": "many-to-one" }
  ]
}