page_messages.md

Channel messages

Channel messages are sent to a channel, IM or Group, delivered from several sources:

• Sent by the message server, over the websocket.
• Returned via calls to channel.history, im.history or group.history.
• Returned as the latest message for channels/ims/groups, during login or joining.

Messages

The most simple message is regular text from a user:

{
	"type": "message",
	"ts": "1358878749.000002",
	"user": "U2147483828",
	"text": "hi"
}

Other messages that need to be displayed in some way will have the following structure:

{
	"type": "message",
	"ts": "1358878749.000002",
	"subtype": "something",
	"text": "hi",
	...more...
}

They are structured in this way so that clients can either support them fully (by having distinct behavior for each different subtype) or can fallback to a simple mode by just showing the text of the message. Note that these messages do not come from a user. Message text is typically automatically generated to explain the event, but a full client will format this information specially. The message text supports the usual user, channel and URL escaping.

Messages may optionally include attachments for display of structured data.

Messages that are part of a channel's history, but should not be displayed to the user, have a special hidden flag. These messages include records of edits and deletes and other 'invisible' metadata.

{
	"type": "message",
	"ts": "1358878749.000002",
	"subtype": "message_changed",
	"hidden": true,
	...more...
}

Invisible message subtypes

The contents of a message changed

{
	"type": "message",
	"subtype": "message_changed",
	"hidden": true,
	"channel": "C2147483705",
	"ts": "1358878755.000001",
	"message": {
		"type": "message",
		"user": "U2147483697",
		"text": "Hello, world!",
		"ts": "1355517523.000005",
		"edited": {
			"user": "U2147483697",
			"ts": "1358878755.000001"
		}
	}
}

A message was removed

{
	"type": "message",
	"subtype": "message_deleted",
	"hidden": true,
	"channel": "C2147483705",
	"ts": "1358878755.000001"
	"deleted_ts": "1358878749.000002"
}

Visible message subtypes

New member has been joined to a channel

{
	"type": "message",
	"subtype": "channel_join",
	"ts": "1358877458.000011",
	"user": "U2147483828",
	"text": "<@U2147483828|cal> has joined the channel"
}

Existing member has left a channel

{
	"type": "message",
	"subtype": "channel_leave",
	"ts": "1358877455.000010",
	"user": "U2147483828",
	"text": "<@U2147483828|cal> has left the channel"
}

Channel topic change

{
	"type": "message",
	"subtype": "channel_topic",
	"ts": "1358877455.000010",
	"user": "U2147483828",
	"topic": "hello world",
	"text": "<@U2147483828|cal> set the channel topic: hello world"
}

Channel purpose change

{
	"type": "message",
	"subtype": "channel_purpose",
	"ts": "1358877455.000010",
	"user": "U2147483828",
	"purpose": "whatever",
	"text": "<@U2147483828|cal> set the channel purpose: whatever"
}

"Bot" messages

{
	"type": "message",
	"subtype": "bot_message",
	"ts": "1358877455.000010",
	"text": "[SlackClientSpec/master] added presence to users for login message - Cal Henderson 
		(https://github.com/tinyspeck/SlackClientSpec/commit/82276fd02393e0571c38289ab887ed84f92a9519)",
	"bot_id": "BB12033", // optional bot id that defines the name and icons to use for this message
	"username": "github", // optional name for the bot to "speak" as, should only be used if `bot_id` is not present
	"icons": {} // optional hash of icons to use for displaying the bot (overrides what is set in `bot_id`)
}

File shared with channel

{
	"type": "message",
	"subtype": "file_share",
	"ts": "1358877455.000010",
	"text": "<@cal> uploaded a file: <https:...7.png|7.png>",
	"file": {...},
	"user": "U2147483697",
	"upload": true
}

Comment on a file

{
	"type": "message",
	"subtype": "file_comment",
	"ts": "1361482916.000003",
	"text": "<@cal> commented on a file: ...",
	"file": {},
	"comment": {}
}

Channel archived

{
	"type": "message",
	"subtype": "channel_archive",
	"ts": "1361482916.000003",
	"text": "<U1234|@cal> archived the channel",
	"user": "U1234",
	"members": ["U1234", "U5678", ...]
}

Channel un-archived

{
	"type": "message",
	"subtype": "channel_unarchive",
	"ts": "1361482916.000003",
	"text": "<U1234|@cal> un-archived the channel",
	"user": "U1234"
}

The following subtypes for groups take exactly the same format as their channel_* equivalents:

• group_join
• group_leave
• group_topic
• group_purpose
• group_archive (does not contain a members array)
• group_unarchive