Un-pins an item from a channel.

Required Params

• channel - Channel where the item is pinned to.

Optional Params

• file - File to un-pin.
• file_comment - File comment to un-pin.
• timestamp - Timestamp of the message to un-pin.

Errors the API can return:

• bad_timestamp - Value passed for timestamp was invalid.
• file_comment_not_found - File comment specified by file_comment does not exist.
• file_not_found - File specified by file does not exist.
• message_not_found - Message specified by channel and timestamp does not exist.
• no_item_specified - One of file, file_comment, or timestamp was not specified.
• not_pinned - The specified item is not pinned to the channel.
• permission_denied - The user does not have permission to remove pins from the channel.