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im type

An IM object contains information about a direct message channel.

{
    "id": "D024BFF1M",
    "is_im": true,
    "user": "U024BE7LH",
    "created": 1360782804,
    "is_user_deleted": false
},

Each direct message channel is between two users. One of these users is always the calling user, the other is indicated by the user property. is_user_deleted will be true if the other user's account has been disabled.

created is a unix timestamp.

Some API methods will include extra state information for the channel. is_open shows if the DM channel is open. last_read is the timestamp for the last message the calling user has read in this channel. unread_count is a count of messages that the calling user has yet to read. latest is the latest message in the channel.