Opens or resumes a direct message or multi-person direct message.


Method URL:
Preferred HTTP method:POST
Accepted content types:application/x-www-form-urlencoded, application/json
Rate limiting:Tier 3
Works with:
Token typeRequired scope(s)
botchannels:manage  groups:write  im:write  mpim:write 
userchannels:write  groups:write  im:write  mpim:write 
classic botbot

This Conversations API method's required scopes depend on the type of channel-like object you're working with. To use the method, you'll need at least one of the channels:, groups:, im: or mpim: scopes corresponding to the conversation type you're working with.

This Conversations API method opens a multi-person direct message or just a 1:1 direct message.

Use conversations.create for public or private channels.

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 will create an mpim. Don’t include the ID of the user you’re calling 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 with the same set of users will return the already existing conversation.



Authentication token bearing required scopes. Tokens should be passed as an HTTP Authorization header or alternatively, as a POST parameter.


Resume a conversation by supplying an im or mpim's ID. Or provide the users field instead.


Boolean, indicates you want the full IM channel definition in the response.


Comma separated lists of users. If only one user is included, this creates a 1:1 DM. The ordering of the users is preserved whenever a multi-person direct message is returned. Supply a channel when not supplying users.


This method supports application/json via HTTP POST. Present your token in your request's Authorization header. Learn more.


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.

Common successful response

Typical success response

    "ok": true,
    "channel": {
        "id": "D069C7QFK"
Alternate response

Passing return_im will expand the response to include more info about a conversation

    "ok": true,
    "no_op": true,
    "already_open": true,
    "channel": {
        "id": "D069C7QFK",
        "created": 1460147748,
        "is_im": true,
        "is_org_shared": false,
        "user": "U069C7QF3",
        "last_read": "0000000000.000000",
        "latest": null,
        "unread_count": 0,
        "unread_count_display": 0,
        "is_open": true,
        "priority": 0
Common error response

Typical error response

    "ok": false,
    "error": "channel_not_found"


This table lists the expected errors that this method could return. However, other errors can be returned in the case where the service is down or other unexpected factors affect processing. Callers should always check the value of the ok params in the response.


Value passed for channel was invalid.


Value(s) passed for users was invalid.


The calling user is restricted from seeing the requested user.


A specified user has been disabled.


Missing users in request


Needs at least 2 users to open


Needs at most 8 users to open


This type of conversation cannot be used with this method.


To message people from multiple organizations, those organizations must be in at least one channel together.


The token used is not granted the specific scope permissions required to complete this request.


The token used is not granted the specific workspace access required to complete this request.


No authentication token provided.


Some aspect of authentication cannot be validated. Either the provided token is invalid or the request originates from an IP address disallowed from making the request.


Authentication token is for a deleted user or workspace when using a bot token.


Authentication token is for a deleted user or workspace or the app has been removed when using a user token.


The workspace token used in this request does not have the permissions necessary to complete the request. Make sure your app is a member of the conversation it's attempting to post a message to.


The workspace is undergoing an enterprise migration and will not be available until migration is complete.


Administrators have suspended the ability to post a message.


The token type used in this request is not allowed.


The method has been deprecated.


The endpoint has been deprecated.


Two factor setup is required.


The method cannot be called from an Enterprise.


The method was either called with invalid arguments or some detail about the arguments passed are invalid, which is more likely when using complex arguments like blocks or attachments.


The method was passed an argument whose name falls outside the bounds of accepted or expected values. This includes very long names and names with non-alphanumeric characters other than _. If you get this error, it is typically an indication that you have made a very malformed API call.


The method was passed an array as an argument. Please only input valid strings.


The method was called via a POST request, but the charset specified in the Content-Type header was invalid. Valid charset names are: utf-8 iso-8859-1.


The method was called via a POST request with Content-Type application/x-www-form-urlencoded or multipart/form-data, but the form data was either missing or syntactically invalid.


The method was called via a POST request, but the specified Content-Type was invalid. Valid types are: application/json application/x-www-form-urlencoded multipart/form-data text/plain.


The method was called via a POST request and included a data payload, but the request did not include a Content-Type header.


The workspace associated with your request is currently undergoing migration to an Enterprise Organization. Web API and other platform operations will be intermittently unavailable until the transition is complete.


The request has been ratelimited. Refer to the Retry-After header for when to retry the request.


Access to this method is limited on the current network


The method was called via a POST request, but the POST data was either missing or truncated.


The service is temporarily unavailable


The server could not complete your operation(s) without encountering a catastrophic error. It's possible some aspect of the operation succeeded before the error was raised.


The server could not complete your operation(s) without encountering an error, likely due to a transient issue on our end. It's possible some aspect of the operation succeeded before the error was raised.


This table lists the expected warnings that this method will return. However, other warnings can be returned in the case where the service is experiencing unexpected trouble.


Slack did nothing when serving this request but it did not fail.


The conversation was already open so Slack did nothing.


The method was called via a POST request, and recommended practice for the specified Content-Type is to include a charset parameter. However, no charset was present. Specifically, non-form-data content types (e.g. text/plain) are the ones for which charset is recommended.


The method was called via a POST request, and the specified Content-Type is not defined to understand the charset parameter. However, charset was in fact present. Specifically, form-data content types (e.g. multipart/form-data) are the ones for which charset is superfluous.

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