{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "form-layout-descriptor.schema.json",
  "title": "FormLayoutDescriptor",
  "description": "Describes the visual layout of a form (tabs > groups > field placements)",
  "type": "object",
  "properties": {
    "tabs": {
      "type": "array",
      "description": "Ordered list of tabs in the form",
      "minItems": 1,
      "items": {
        "type": "object",
        "properties": {
          "id": {
            "type": "string",
            "description": "Unique identifier for this tab",
            "minLength": 1
          },
          "title": {
            "type": "string",
            "description": "Display title for the tab",
            "minLength": 1
          },
          "isDefault": {
            "type": "boolean",
            "description": "Whether this is the default tab (cannot be deleted, receives orphaned fields)",
            "default": false
          },
          "groups": {
            "type": "array",
            "description": "Ordered list of groups within this tab",
            "minItems": 1,
            "items": {
              "type": "object",
              "properties": {
                "id": {
                  "type": "string",
                  "description": "Unique identifier for this group",
                  "minLength": 1
                },
                "title": {
                  "type": ["string", "null"],
                  "description": "Optional display title for the group"
                },
                "isDefault": {
                  "type": "boolean",
                  "description": "Whether this is the default group (cannot be deleted, receives orphaned fields)",
                  "default": false
                },
                "rows": {
                  "type": "array",
                  "description": "Ordered list of layout rows; each row contains one or more cells (fields placed side-by-side)",
                  "items": {
                    "type": "object",
                    "properties": {
                      "cells": {
                        "type": "array",
                        "description": "Fields placed side-by-side in this row (total colSpan should not exceed 4)",
                        "minItems": 1,
                        "items": {
                          "type": "object",
                          "properties": {
                            "fieldId": {
                              "type": "string",
                              "description": "Reference to a field id in the form's fields array",
                              "minLength": 1
                            },
                            "colSpan": {
                              "type": "integer",
                              "description": "Number of grid columns this field spans (1-4)",
                              "minimum": 1,
                              "maximum": 4,
                              "default": 4
                            },
                            "colStart": {
                              "type": "integer",
                              "description": "Starting grid column (1-4). Omit or null to auto-place after the previous cell.",
                              "minimum": 1,
                              "maximum": 4
                            }
                          },
                          "required": ["fieldId"],
                          "additionalProperties": false
                        }
                      }
                    },
                    "required": ["cells"],
                    "additionalProperties": false
                  }
                }
              },
              "required": ["id", "rows"],
              "additionalProperties": false
            }
          }
        },
        "required": ["id", "title", "groups"],
        "additionalProperties": false
      }
    }
  },
  "required": ["tabs"],
  "additionalProperties": false
}