Usage info
The Conversations API method opens a direct message (DM) or a multi-person direct message (MPIM).
You can then send a message to the conversation using the chat.postMessage method.
Use the `conversations.create method instead for public or private channels.
Using the users parameter
Provide 1 to 8 user IDs in the users parameter to open or resume a conversation. Providing only 1 ID will create a direct message. Providing more than 1 will create a multi-person direct message (mpim).
Don’t include the ID of the user you’re calling conversations.open on behalf of – we do that for you.
If there are no conversations already in progress including that exact set of members, a new multi-person direct message conversation begins.
Subsequent calls to conversations.open with the same set of
users will return the already existing conversation.
Response
The response structure is altered by providing return_im parameter. When set to false, the default, just a conversation's ID is returned. When set to true, the entire conversation object is returned.