@type t() :: %Jido.Chat.Postable{
  ast: nil | nil | any(),
  attachments: [
    %Jido.Chat.Attachment{
      data: term(),
      duration: term(),
      filename: term(),
      height: term(),
      kind: term(),
      media_type: term(),
      metadata: term(),
      path: term(),
      size_bytes: term(),
      url: term(),
      width: term()
    }
  ],
  card: nil | nil | any(),
  fallback_text: nil | nil | binary(),
  files: [
    %Jido.Chat.FileUpload{
      data: term(),
      duration: term(),
      filename: term(),
      height: term(),
      kind: term(),
      media_type: term(),
      metadata: term(),
      path: term(),
      size_bytes: term(),
      url: term(),
      width: term()
    }
  ],
  kind: :raw | :markdown | :ast | :card | :text | :stream,
  markdown: nil | nil | binary(),
  metadata: map(),
  raw: nil | nil | any(),
  stream: nil | nil | any(),
  text: nil | nil | binary()
}