Rich text input

A formatted text field, with Slack's formatting toolbar, that reports a rich_text value.

rich_text_input collects text and hands it back as a rich_text block, the same structure Slack uses for a message composed in its own WYSIWYG editor. It’s an input-block-only element: it doesn’t appear in an actions block or as a section accessory, and, like file_input, Slack only supports it in modals, not Home tabs.

Fields

Examples

With an initial value

initial_value takes a full rich_text block, the same shape you’d get back from the element itself, not a plain string.

Sizing the field

min_lines sets the field’s starting height; max_lines (8 by default) caps how tall it grows before it scrolls.

Interactivity

Typing calls onAction with the current content wrapped as a rich_text block, under rich_text_value:

{
  "type": "rich_text_input",
  "action_id": "notes_input",
  "block_id": "notes",
  "action_ts": "1706000000.000100",
  "rich_text_value": {
    "type": "rich_text",
    "elements": [
      {
        "type": "rich_text_section",
        "elements": [{ "type": "text", "text": "Fixed the login redirect loop." }]
      }
    ]
  }
}

Reading the value

Every edit (and the initial value, if any) is written to state.values as { type, rich_text_value }:

{
  "notes": {
    "notes_input": {
      "type": "rich_text_input",
      "rich_text_value": {
        "type": "rich_text",
        "elements": [
          {
            "type": "rich_text_section",
            "elements": [{ "type": "text", "text": "Fixed the login redirect loop." }]
          }
        ]
      }
    }
  }
}

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