{
  "desc": "Change the topic of a conversation. The calling user must be a member of the conversation. Not all conversation types may have a purpose set.",

  "args": {
    "channel": {
      "example" : "G1234567890",
      "required": true,
      "desc"    : "Conversation to set the purpose of."
    },
    "topic": {
      "example" : "Apply topically for best effects",
      "required": true,
      "desc"    : "The new topic string. Does not support formatting or linkification."
    }
  },

  "errors": {
    "channel_not_found": "Value passed for `channel` was invalid",
    "not_in_channel": "Authenticated user is not in the channel.",
    "is_archived": "Channel has been archived",
    "too_long": "Topic was longer than 250 characters.",
    "user_is_restricted": "This method cannot be called by a restricted user or single channel guest.",
    "method_not_supported_for_channel_type": "This type of conversation cannot be used with this method."
  }
}