set_layer_text

{
  "type": "object",
  "properties": {
    "elementId": {
      "type": "string",
      "description": "Text layer id, text.<id>."
    },
    "text": {
      "type": "string",
      "description": "The text to render. Newlines are honoured as hard line breaks."
    },
    "text_size": {
      "type": "number",
      "description": "Font size in px."
    },
    "font_family": {
      "type": "string",
      "description": "Google Fonts family name, e.g. \"Anton\"."
    },
    "text_color": {
      "type": "string",
      "description": "Text fill colour as #rrggbb."
    },
    "font_weight": {
      "type": "number",
      "description": "Font weight 100..900 (400 regular, 700 bold, 800 black). Default 400; the canvas synthesizes weights a static font doesn't ship."
    },
    "font_style": {
      "type": "string",
      "enum": [
        "normal",
        "italic"
      ],
      "description": "Italic toggle. Default normal."
    },
    "text_transform": {
      "type": "string",
      "enum": [
        "none",
        "uppercase",
        "lowercase"
      ],
      "description": "Case transform applied before layout. Default none."
    },
    "letter_spacing": {
      "type": "number",
      "description": "Tracking between glyphs in px; may be negative. Default 0."
    },
    "curve": {
      "type": "number",
      "description": "Curve the text onto an arc, in degrees of total sweep. 0 = straight (default). POSITIVE = a SMILE (⌣, ends rise); NEGATIVE = an ARCH (⌒, rainbow). Clamped ±135. A tasteful smile is ~+60. Applies to a SINGLE line — multi-line text is joined to one line while curved (the stored text is untouched, so curve:0 restores it)."
    },
    "line_height": {
      "type": "number",
      "description": "Line height as a multiple of font size (1.2 = 120%)."
    },
    "text_align": {
      "type": "string",
      "enum": [
        "left",
        "center",
        "right"
      ],
      "description": "Horizontal alignment of each line. Default center."
    },
    "text_autofit": {
      "type": "string",
      "enum": [
        "fit",
        "shrink",
        "wrap",
        "hug"
      ],
      "description": "How text fits its box. \"hug\" (default for new layers): hold text_size FIXED and DERIVE the box from the measured text plus padding, honouring the literal newlines you pass — the box shrink-wraps the exact content and grows/shrinks live as the text changes, so it can never re-wrap differently between the editor preview and the export (bake your own \"\\n\" breaks; pair with set_text_background for a rounded caption box). \"wrap\": hold text_size FIXED in a fixed-size box and only word-wrap (hard-breaking a single over-wide word), never resize. \"fit\": ignore text_size and auto-size the font BOTH ways (grow and shrink) to the largest size whose wrapped block fills the box — resizing the box resizes the text. \"shrink\" (legacy): word-wrap then auto-shrink the font from text_size until the block fits; never grows."
    },
    "text_valign": {
      "type": "string",
      "enum": [
        "top",
        "middle",
        "bottom"
      ],
      "description": "Vertical alignment of the text block within its box. \"middle\" (default) centres it; \"bottom\" pins it to the box floor so extra wrapped lines grow upward from a fixed baseline (captions use this so a wrapped line doesn't shift the others); \"top\" pins the ceiling."
    },
    "stroke_width": {
      "type": "number",
      "description": "Outline width in px (0 = no outline)."
    },
    "stroke_color": {
      "type": "string",
      "description": "Outline colour as #rrggbb. Defaults to white when a width is set."
    },
    "text_shadow": {
      "type": [
        "object",
        "null"
      ],
      "description": "Drop shadow { offsetX, offsetY, blur, color }; color is any CSS colour (rgba allowed). null clears it.",
      "properties": {
        "offsetX": {
          "type": "number"
        },
        "offsetY": {
          "type": "number"
        },
        "blur": {
          "type": "number"
        },
        "color": {
          "type": "string"
        }
      }
    },
    "decorations": {
      "type": [
        "object",
        "null"
      ],
      "description": "Per-character underline / strikethrough. { underline?: [{start,end}], strikethrough?: [{start,end}] } — each a list of half-open character ranges [start,end) (UTF-16 offsets) into `text`. E.g. underline the first word of \"Big news\": underline:[{start:0,end:3}]. Ranges are normalized (sorted + merged). null clears all decorations; editing `text` in the SAME call re-indexes existing ranges against the new text. Not rendered on curved text.",
      "properties": {
        "underline": {
          "type": "array",
          "items": {
            "type": "object",
            "properties": {
              "start": {
                "type": "number"
              },
              "end": {
                "type": "number"
              }
            }
          }
        },
        "strikethrough": {
          "type": "array",
          "items": {
            "type": "object",
            "properties": {
              "start": {
                "type": "number"
              },
              "end": {
                "type": "number"
              }
            }
          }
        }
      }
    },
    "projectId": {
      "type": "string",
      "description": "Opaque project id (a v4 UUID, from list_projects/create_project). Selects which existing project this call mutates."
    },
    "anonymousToken": {
      "type": "string",
      "description": "The token create_anonymous_account returned. This connection has no Morpha key, so every call carries it."
    }
  },
  "required": [
    "elementId",
    "projectId",
    "anonymousToken"
  ]
}