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Schema

.erd.json is the editor's document format. It is what editor.value returns, what setInitialValue() accepts, and what the JSON export writes — read this page if you need to generate, validate, or migrate a document outside the editor.

TypeScript​

ERDEditorSchemaV3​

type ERDEditorSchemaV3 = {
  $schema: 'https://raw.githubusercontent.com/dineug/erd-editor/main/json-schema/schema.json';
  version: '3.0.0';
  settings: Settings;
  doc: Doc;
  collections: {
    tableEntities: Record<string, Table>;
    tableColumnEntities: Record<string, Column>;
    relationshipEntities: Record<string, Relationship>;
    indexEntities: Record<string, Index>;
    indexColumnEntities: Record<string, IndexColumn>;
    memoEntities: Record<string, Memo>;
  };
};

Settings​

type Settings = {
  width: number;
  height: number;
  scrollTop: number; // legacy, read once to migrate
  scrollLeft: number; // legacy, read once to migrate
  originX: number;
  originY: number;
  zoomLevel: number;
  show: number; // Constants: Show
  database: number; // Constants: Database
  databaseName: string;
  canvasType: string; // Constants: CanvasType
  language: number; // Constants: Language
  tableNameCase: number; // Constants: NameCase
  columnNameCase: number; // Constants: NameCase
  bracketType: number; // Constants: BracketType
  relationshipDataTypeSync: boolean;
  relationshipOptimization: boolean;
  columnOrder: number[]; // Constants: ColumnType
  maxWidthComment: number;
  ignoreSaveSettings: number; // Constants: SaveSettingType
};

// Constants
const CanvasType = {
  ERD: 'ERD',
  visualization: '@dineug/erd-editor/builtin-visualization',
  schemaSQL: '@dineug/erd-editor/builtin-schema-sql',
  generatorCode: '@dineug/erd-editor/builtin-generator-code',
  settings: 'settings',
} as const;

const Show = {
  tableComment: 1,
  columnComment: 2,
  columnDataType: 4,
  columnDefault: 8,
  columnAutoIncrement: 16,
  columnPrimaryKey: 32,
  columnUnique: 64,
  columnNotNull: 128,
  relationship: 256,
} as const;

const ColumnType = {
  columnName: 1,
  columnDataType: 2,
  columnNotNull: 4,
  columnUnique: 8,
  columnAutoIncrement: 16,
  columnDefault: 32,
  columnComment: 64,
} as const;

const Database = {
  MariaDB: 1,
  MSSQL: 2,
  MySQL: 4,
  Oracle: 8,
  PostgreSQL: 16,
  SQLite: 32,
  Databricks: 64,
  Snowflake: 128,
} as const;

const Language = {
  GraphQL: 1,
  csharp: 2,
  Java: 4,
  Kotlin: 8,
  TypeScript: 16,
  JPA: 32,
  Scala: 64,
  Go: 128,
  SQLAlchemy: 256,
  TypeORM: 512,
  Sequelize: 1024,
  Drizzle: 2048,
  DBML: 4096,
  AML: 8192,
} as const;

const NameCase = {
  none: 1,
  camelCase: 2,
  pascalCase: 4,
  snakeCase: 8,
} as const;

const BracketType = {
  none: 1,
  doubleQuote: 2,
  singleQuote: 4,
  backtick: 8,
} as const;

const SaveSettingType = {
  scroll: 1,
  zoomLevel: 2,
} as const;

originX and originY are the view: the screen point scene (0, 0) lands on.
scrollTop and scrollLeft are the legacy pair every editor before 3.6.0 reads. The parser reads them once, and only when a document carries no origin, to derive originX and originY from them; nothing writes them any more. A document saved here therefore opens in an older editor where that editor last left it, rather than where this one saved it.
width and height are the legacy canvas size. The canvas is unbounded, so nothing sets them any longer; they are still written, at their defaults, for an older editor to read.
zoomLevel runs from 0.1 to 1.5. A document saved past 1 opens at 1 in an editor before 3.5.0.

canvasType is the tab a document opens on. A document saved on the Visualization tab holds '@dineug/erd-editor/builtin-visualization' but not whether Graph or Flow mode was showing, and a newly created editor shows that tab in Graph mode.
None of Flow mode's own state is serialized — its placement, zoom, pan, row display and focused tables stay in the editor — so originX, originY and zoomLevel always describe the ERD canvas.

show and ignoreSaveSettings are bitmasks — OR the flags together.
columnOrder is an array holding all seven ColumnType values, in display order.
database, language, tableNameCase, columnNameCase and bracketType each hold exactly one value, and the JSON Schema rejects a combined value.

Database and Language are append-only. A saved document stores the number, so a new vendor or code-generation target takes the next bit instead of a slot in the middle.

Doc​

type Doc = {
  tableIds: string[];
  relationshipIds: string[];
  indexIds: string[];
  memoIds: string[];
};

EntityType​

Every entity in collections carries a meta object.

type EntityMeta = {
  updateAt: number;
  createAt: number;
};

type EntityType<T> = T & {
  meta: EntityMeta;
};

Collection: tableEntities​

type Table = EntityType<{
  id: string;
  name: string;
  comment: string;
  columnIds: string[];
  seqColumnIds: string[];
  ui: TableUI;
}>;

type TableUI = {
  x: number;
  y: number;
  zIndex: number;
  widthName: number;
  widthComment: number;
  color: string;
};

Collection: tableColumnEntities​

type Column = EntityType<{
  id: string;
  tableId: string;
  name: string;
  comment: string;
  dataType: string;
  default: string;
  options: number; // Constants: ColumnOption
  ui: ColumnUI;
}>;

type ColumnUI = {
  keys: number; // Constants: ColumnUIKey
  widthName: number;
  widthComment: number;
  widthDataType: number;
  widthDefault: number;
};

// Constants
const ColumnOption = {
  autoIncrement: 1,
  primaryKey: 2,
  unique: 4,
  notNull: 8,
} as const;

const ColumnUIKey = {
  primaryKey: 1,
  foreignKey: 2,
} as const;

Collection: relationshipEntities​

type Relationship = EntityType<{
  id: string;
  identification: boolean;
  relationshipType: number; // Constants: RelationshipType
  startRelationshipType: number; // Constants: StartRelationshipType
  start: RelationshipPoint;
  end: RelationshipPoint;
}>;

type RelationshipPoint = {
  tableId: string;
  columnIds: string[];
  x: number;
  y: number;
  direction: number; // Constants: Direction
};

// Constants
const RelationshipType = {
  ZeroOne: 2,
  ZeroN: 4,
  OneOnly: 8,
  OneN: 16,
} as const;

const StartRelationshipType = {
  ring: 1,
  dash: 2,
} as const;

const Direction = {
  left: 1,
  right: 2,
  top: 4,
  bottom: 8,
} as const;

Collection: indexEntities​

type Index = EntityType<{
  id: string;
  name: string;
  tableId: string;
  indexColumnIds: string[];
  seqIndexColumnIds: string[];
  unique: boolean;
}>;

Collection: indexColumnEntities​

type IndexColumn = EntityType<{
  id: string;
  indexId: string;
  columnId: string;
  orderType: number; // Constants: OrderType
}>;

// Constants
const OrderType = {
  ASC: 1,
  DESC: 2,
} as const;

Collection: memoEntities​

type Memo = EntityType<{
  id: string;
  value: string;
  ui: MemoUI;
}>;

type MemoUI = {
  x: number;
  y: number;
  width: number;
  height: number;
  zIndex: number;
  color: string;
};

JSON Schema​

The canonical schema file is published at json-schema/schema.json and can be referenced directly with $schema.

{
  "$schema": "https://raw.githubusercontent.com/dineug/erd-editor/main/json-schema/schema.json",
  "version": "3.0.0"
}

Put $schema at the top of an .erd.json file and editors that understand JSON Schema, such as VS Code, validate the document and autocomplete its fields as you edit.

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://raw.githubusercontent.com/dineug/erd-editor/main/json-schema/schema.json",
  "title": "erd-editor schema",
  "description": "Entity-Relationship Diagram Editor Schema",
  "type": "object",
  "properties": {
    "$schema": {
      "type": "string"
    },
    "version": {
      "description": "Version of the schema",
      "const": "3.0.0"
    },
    "settings": {
      "$ref": "#/$defs/settings"
    },
    "doc": {
      "$ref": "#/$defs/doc"
    },
    "collections": {
      "type": "object",
      "properties": {
        "tableEntities": {
          "$ref": "#/$defs/tableEntities"
        },
        "tableColumnEntities": {
          "$ref": "#/$defs/tableColumnEntities"
        },
        "relationshipEntities": {
          "$ref": "#/$defs/relationshipEntities"
        },
        "indexEntities": {
          "$ref": "#/$defs/indexEntities"
        },
        "indexColumnEntities": {
          "$ref": "#/$defs/indexColumnEntities"
        },
        "memoEntities": {
          "$ref": "#/$defs/memoEntities"
        }
      },
      "required": [
        "tableEntities",
        "tableColumnEntities",
        "relationshipEntities",
        "indexEntities",
        "indexColumnEntities",
        "memoEntities"
      ]
    }
  },
  "required": ["version", "settings", "doc", "collections"],
  "$defs": {
    "settings": {
      "type": "object",
      "properties": {
        "width": {
          "type": "number",
          "minimum": 2000,
          "maximum": 20000
        },
        "height": {
          "type": "number",
          "minimum": 2000,
          "maximum": 20000
        },
        "scrollTop": {
          "type": "number"
        },
        "scrollLeft": {
          "type": "number"
        },
        "originX": {
          "type": "number"
        },
        "originY": {
          "type": "number"
        },
        "zoomLevel": {
          "type": "number",
          "minimum": 0.1,
          "maximum": 1.5
        },
        "show": {
          "description": "bit value (tableComment: 1) | (columnComment: 2) | (columnDataType: 4) | (columnDefault: 8) | (columnAutoIncrement: 16) | (columnPrimaryKey: 32) | (columnUnique: 64) | (columnNotNull: 128) | (relationship: 256)",
          "type": "integer"
        },
        "database": {
          "description": "bit value (MariaDB: 1) | (MSSQL: 2) | (MySQL: 4) | (Oracle: 8) | (PostgreSQL: 16) | (SQLite: 32) | (Databricks: 64) | (Snowflake: 128)",
          "type": "integer",
          "enum": [1, 2, 4, 8, 16, 32, 64, 128]
        },
        "databaseName": {
          "type": "string"
        },
        "canvasType": {
          "enum": [
            "ERD",
            "@dineug/erd-editor/builtin-visualization",
            "@dineug/erd-editor/builtin-schema-sql",
            "@dineug/erd-editor/builtin-generator-code",
            "settings"
          ]
        },
        "language": {
          "description": "bit value (GraphQL: 1) | (csharp: 2) | (Java: 4) | (Kotlin: 8) | (TypeScript: 16) | (JPA: 32) | (Scala: 64) | (Go: 128) | (SQLAlchemy: 256) | (TypeORM: 512) | (Sequelize: 1024) | (Drizzle: 2048) | (DBML: 4096) | (AML: 8192)",
          "type": "integer",
          "enum": [1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192]
        },
        "tableNameCase": {
          "description": "bit value (none: 1) | (camelCase: 2) | (pascalCase: 4) | (snakeCase: 8)",
          "type": "integer",
          "enum": [1, 2, 4, 8]
        },
        "columnNameCase": {
          "description": "bit value (none: 1) | (camelCase: 2) | (pascalCase: 4) | (snakeCase: 8)",
          "type": "integer",
          "enum": [1, 2, 4, 8]
        },
        "bracketType": {
          "description": "bit value (none: 1) | (doubleQuote: 2) | (singleQuote: 4) | (backtick: 8)",
          "type": "integer",
          "enum": [1, 2, 4, 8]
        },
        "relationshipDataTypeSync": {
          "type": "boolean"
        },
        "relationshipOptimization": {
          "type": "boolean"
        },
        "columnOrder": {
          "description": "bit value (columnName: 1) | (columnDataType: 2) | (columnNotNull: 4) | (columnUnique: 8) | (columnAutoIncrement: 16) | (columnDefault: 32) | (columnComment: 64)",
          "type": "array",
          "prefixItems": [
            { "type": "integer" },
            { "type": "integer" },
            { "type": "integer" },
            { "type": "integer" },
            { "type": "integer" },
            { "type": "integer" },
            { "type": "integer" }
          ],
          "minItems": 7,
          "maxItems": 7
        },
        "maxWidthComment": {
          "type": "integer"
        },
        "ignoreSaveSettings": {
          "description": "bit value (scroll: 1) | (zoomLevel: 2)",
          "type": "integer"
        }
      },
      "required": [
        "width",
        "height",
        "scrollTop",
        "scrollLeft",
        "zoomLevel",
        "show",
        "canvasType",
        "language",
        "tableNameCase",
        "columnNameCase",
        "bracketType",
        "relationshipDataTypeSync",
        "relationshipOptimization",
        "columnOrder",
        "maxWidthComment"
      ]
    },
    "doc": {
      "type": "object",
      "properties": {
        "tableIds": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "relationshipIds": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "indexIds": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "memoIds": {
          "type": "array",
          "items": {
            "type": "string"
          }
        }
      }
    },
    "tableEntities": {
      "type": "object",
      "additionalProperties": {
        "type": "object",
        "properties": {
          "id": {
            "type": "string"
          },
          "name": {
            "type": "string"
          },
          "comment": {
            "type": "string"
          },
          "columnIds": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "seqColumnIds": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "ui": {
            "type": "object",
            "properties": {
              "x": {
                "type": "number"
              },
              "y": {
                "type": "number"
              },
              "zIndex": {
                "type": "number"
              },
              "widthName": {
                "type": "number"
              },
              "widthComment": {
                "type": "number"
              },
              "color": {
                "type": "string"
              }
            },
            "required": [
              "x",
              "y",
              "zIndex",
              "widthName",
              "widthComment",
              "color"
            ]
          },
          "meta": {
            "$ref": "#/$defs/EntityMeta"
          }
        },
        "required": [
          "id",
          "name",
          "comment",
          "columnIds",
          "seqColumnIds",
          "ui",
          "meta"
        ]
      }
    },
    "tableColumnEntities": {
      "type": "object",
      "additionalProperties": {
        "type": "object",
        "properties": {
          "id": {
            "type": "string"
          },
          "tableId": {
            "type": "string"
          },
          "name": {
            "type": "string"
          },
          "comment": {
            "type": "string"
          },
          "dataType": {
            "type": "string"
          },
          "default": {
            "type": "string"
          },
          "options": {
            "description": "bit value (autoIncrement: 1) | (primaryKey: 2) | (unique: 4) | (notNull: 8)",
            "type": "integer"
          },
          "ui": {
            "type": "object",
            "properties": {
              "keys": {
                "description": "bit value (primaryKey: 1) | (foreignKey: 2)",
                "type": "integer"
              },
              "widthName": {
                "type": "number"
              },
              "widthComment": {
                "type": "number"
              },
              "widthDataType": {
                "type": "number"
              },
              "widthDefault": {
                "type": "number"
              }
            },
            "required": [
              "keys",
              "widthName",
              "widthComment",
              "widthDataType",
              "widthDefault"
            ]
          },
          "meta": {
            "$ref": "#/$defs/EntityMeta"
          }
        },
        "required": [
          "id",
          "tableId",
          "name",
          "comment",
          "dataType",
          "default",
          "options",
          "ui",
          "meta"
        ]
      }
    },
    "relationshipEntities": {
      "type": "object",
      "additionalProperties": {
        "type": "object",
        "properties": {
          "id": {
            "type": "string"
          },
          "identification": {
            "type": "boolean"
          },
          "relationshipType": {
            "description": "bit value (ZeroOne: 2) | (ZeroN: 4) | (OneOnly: 8) | (OneN: 16)",
            "type": "integer"
          },
          "startRelationshipType": {
            "description": "bit value (ring: 1) | (dash: 2)",
            "type": "integer"
          },
          "start": {
            "$ref": "#/$defs/RelationshipPoint"
          },
          "end": {
            "$ref": "#/$defs/RelationshipPoint"
          },
          "meta": {
            "$ref": "#/$defs/EntityMeta"
          }
        },
        "required": [
          "id",
          "identification",
          "relationshipType",
          "startRelationshipType",
          "start",
          "end",
          "meta"
        ]
      }
    },
    "indexEntities": {
      "type": "object",
      "additionalProperties": {
        "type": "object",
        "properties": {
          "id": {
            "type": "string"
          },
          "name": {
            "type": "string"
          },
          "tableId": {
            "type": "string"
          },
          "indexColumnIds": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "seqIndexColumnIds": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "unique": {
            "type": "boolean"
          },
          "meta": {
            "$ref": "#/$defs/EntityMeta"
          }
        },
        "required": [
          "id",
          "name",
          "tableId",
          "indexColumnIds",
          "seqIndexColumnIds",
          "unique",
          "meta"
        ]
      }
    },
    "indexColumnEntities": {
      "type": "object",
      "additionalProperties": {
        "type": "object",
        "properties": {
          "id": {
            "type": "string"
          },
          "indexId": {
            "type": "string"
          },
          "columnId": {
            "type": "string"
          },
          "orderType": {
            "description": "bit value (ASC: 1) | (DESC: 2)",
            "type": "integer"
          },
          "meta": {
            "$ref": "#/$defs/EntityMeta"
          }
        },
        "required": ["id", "indexId", "columnId", "orderType", "meta"]
      }
    },
    "memoEntities": {
      "type": "object",
      "additionalProperties": {
        "type": "object",
        "properties": {
          "id": {
            "type": "string"
          },
          "value": {
            "type": "string"
          },
          "ui": {
            "type": "object",
            "properties": {
              "x": {
                "type": "number"
              },
              "y": {
                "type": "number"
              },
              "zIndex": {
                "type": "number"
              },
              "width": {
                "type": "number"
              },
              "height": {
                "type": "number"
              },
              "color": {
                "type": "string"
              }
            },
            "required": ["x", "y", "zIndex", "width", "height", "color"]
          },
          "meta": {
            "$ref": "#/$defs/EntityMeta"
          }
        },
        "required": ["id", "value", "ui", "meta"]
      }
    },
    "EntityMeta": {
      "type": "object",
      "properties": {
        "updateAt": {
          "type": "integer"
        },
        "createAt": {
          "type": "integer"
        }
      },
      "required": ["updateAt", "createAt"]
    },
    "RelationshipPoint": {
      "type": "object",
      "properties": {
        "tableId": {
          "type": "string"
        },
        "columnIds": {
          "type": "array",
          "items": {
            "type": "string"
          }
        },
        "x": {
          "type": "number"
        },
        "y": {
          "type": "number"
        },
        "direction": {
          "description": "bit value (left: 1) | (right: 2) | (top: 4) | (bottom: 8)",
          "type": "integer"
        }
      },
      "required": ["tableId", "columnIds", "x", "y", "direction"]
    }
  }
}