chat.postMessage.md

This method posts a message to a public channel, private group, or IM channel.

Arguments

{ARGS}

Formatting

Messages are formatted as described in the formatting spec. You can specify values for parse and link_names to change formatting behavior.

The optional attachments argument should contain a JSON-encoded array of attachments. For more information, see the attachments spec.

By default links to media are unfurled, but links to text content are not. For more information on the differences and how to control this, see the the unfurling documentation.

Authorship

By default, the as_user parameter is set to false and messages are posted as bot_messages, with message authorship attributed to the default user name and icons associated with the Custom Integration or Slack App.

With as_user set to false, you may also provide a username to explicitly specify the bot user's identity for this message, along with icon_url or icon_emoji.

Set as_user to true and the authenticated user will appear as the author of the message, ignoring any values provided for username, icon_url, and icon_emoji. Posting as the authenticated user requires the client or chat:write:user scopes.

Channels

You must specify a public channel, private group, or an IM channel with the channel argument. Each one behaves slightly differently based on the authenticated user's permissions and additional arguments:

Post to a public channel

You can either pass the channel's name (#general) or encoded ID (C024BE91L), and the message will be posted to that channel. The channel's ID can be retrieved through the channels.list API method.

Post to a private group

As long as the authenticated user is a member of the private group, you can either pass the group's name (secret-group) or encoded ID (G012AC86C), and the message will be posted to that group. The private group's ID can be retrieved through the groups.list API method.

Post to an IM channel

Posting to an IM channel is a little more complex depending on the value of as_user.

• If as_user is false:
  • Pass a username (@chris) as the value of channel to post to that user's @slackbot channel as the bot.
  • Pass the IM channel's ID (D023BB3L2) as the value of channel to post to that IM channel as the bot. The IM channel's ID can be retrieved through the im.list API method.
• If as_user is true:
  • Pass the IM channel's ID (D023BB3L2) as the value of channel to post to that IM channel as the authenticated user. The IM channel's ID can be retrieved through the im.list API method.

Response

{
    "ok": true,
    "ts": "1405895017.000506",
    "channel": "C024BE91L",
    "message": {
        ...
    }
}

The response includes the timestamp (ts) and channel for the posted message. It also includes the complete message object, as it was parsed by our servers. This may differ from the provided arguments as our servers sanitize links, attachments and other properties.

Errors

{ERRORS}

Warnings

{WARNINGS}