format:setAlign

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Payload",
  "type": "object",
  "properties": {
    "sheet": {
      "description": "The sheet name.",
      "type": "string"
    },
    "range": {
      "description": "The target range, e.g. `{\"from\": \"A1\", \"to\": \"B3\"}`. May legitimately arrive \"backwards\", `from` below/right of `to`, normalized before use.",
      "$ref": "#/$defs/CellRange"
    },
    "value": {
      "description": "The horizontal alignment to set, or `null` for automatic, type-based: numbers and dates right, everything else left.",
      "anyOf": [
        {
          "$ref": "#/$defs/HAlign"
        },
        {
          "type": "null"
        }
      ]
    }
  },
  "required": [
    "sheet",
    "range"
  ],
  "$defs": {
    "CellRange": {
      "description": "An inclusive rectangle. `from`/`to` may be equal, a single cell.",
      "type": "object",
      "properties": {
        "from": {
          "description": "Top-left cell, e.g. `\"A1\"`.",
          "type": "string"
        },
        "to": {
          "description": "Bottom-right cell, e.g. `\"B3\"`.",
          "type": "string"
        }
      },
      "required": [
        "from",
        "to"
      ]
    },
    "HAlign": {
      "description": "Horizontal text alignment.",
      "oneOf": [
        {
          "description": "Hug the left edge of the cell box.",
          "type": "string",
          "const": "left"
        },
        {
          "description": "Centre within the cell box.",
          "type": "string",
          "const": "center"
        },
        {
          "description": "Hug the right edge of the cell box.",
          "type": "string",
          "const": "right"
        }
      ]
    }
  }
}