@type t() ::
  %ArchAstro.Types.ChannelPayloads.ApiChatChannel.ApiChatPostSimpleMessage.Response.Nested.MessageAttachmentsItem{
    content_type: String.t() | ArchAstro.Unset.t(),
    description: String.t() | ArchAstro.Unset.t(),
    filename: String.t() | ArchAstro.Unset.t(),
    height: integer() | ArchAstro.Unset.t(),
    id: String.t(),
    image_height: integer() | ArchAstro.Unset.t(),
    image_source:
      ArchAstro.Types.ChannelPayloads.ApiChatChannel.ApiChatPostSimpleMessage.Response.Nested.MessageAttachmentsItemImageSource.t()
      | ArchAstro.Unset.t(),
    image_url: String.t() | ArchAstro.Unset.t(),
    image_width: integer() | ArchAstro.Unset.t(),
    media_type: String.t() | ArchAstro.Unset.t(),
    name: String.t() | ArchAstro.Unset.t(),
    object: %{optional(String.t()) => ArchAstro.JSON.t()} | ArchAstro.Unset.t(),
    title: String.t() | ArchAstro.Unset.t(),
    type: String.t(),
    url: String.t() | ArchAstro.Unset.t(),
    variants:
      [
        ArchAstro.Types.ChannelPayloads.ApiChatChannel.ApiChatPostSimpleMessage.Response.Nested.MessageAttachmentsItemVariantsItem.t()
      ]
      | ArchAstro.Unset.t(),
    version: integer() | ArchAstro.Unset.t(),
    width: integer() | ArchAstro.Unset.t()
  }