Deprecated: Starts a Real Time Messaging session. Use rtm.connect instead.

Facts

Method access

HTTP
JavaScript
Python
Java
HTTP
GEThttps://slack.com/api/rtm.start
Bolt for Java
app.client().rtmStart
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Bolt for Python
app.client.rtm_start
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Content types

application/x-www-form-urlencoded
  • Rate limits

    Tier 1
  • Arguments

    ArgumentTypeDescription
    tokenRequired

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

    Examplexxxx-xxxxxxxxx-xxxx
    batch_presence_aware
    boolean

    Batch presence deliveries via subscription. Enabling changes the shape of presence_change events. See batch presence.

    Default: false

    Example1
    include_locale
    boolean

    Set this to true to receive the locale for users and channels. Defaults to false

    Exampletrue
    mpim_aware
    boolean

    Returns MPIMs to the client in the API response.

    Exampletrue
    no_latest
    boolean

    Exclude latest timestamps for channels, groups, mpims, and ims. Automatically sets no_unreads to 1

    Default: 0

    Example1
    no_unreads
    boolean

    Skip unread counts for each channel (improves performance).

    Exampletrue
    presence_sub
    boolean

    Only deliver presence events when requested by subscription. See presence subscriptions.

    Default: true

    Exampletrue
    simple_latest
    boolean

    Return timestamp only for latest message object of each channel (improves performance).

    Exampletrue

    Present arguments as parameters in application/x-www-form-urlencoded querystring or POST body. This method does not currently accept application/json.

    Example responses

    Common successful response

    Typical success response

    {
        "ok": true
    }
    Common error response

    Typical error response

    {
        "ok": false,
        "error": "invalid_auth"
    }

    DEPRECATED: Learn more about this method's deprecation.

    This method began a Real Time Messaging API session and reserved your application a specific URL with which to connect via websocket.

    It's user-centric and team-centric: your app connects as a specific user or bot user on a specific team. Many apps will find the Events API's subscription model more scalable when working against multiple teams.

    This method also returns a smorgasbord of data about the team, its channels, and members. Some times more information than can be provided in a timely or helpful manner.

    Please use rtm.connect instead, especially when connecting on behalf of an Enterprise Grid customer.

    Consult the RTM API documentation for full details on using the RTM API.

    The members array found in this and other methods will begin automatically truncating at 1,500 and eventually fewer results beginning December 1, 2017. As of March, 2018 the cap is 500. Please Use conversations.members to manage memberships instead. Read on to learn more.

    New Slack apps may not use any Real Time Messaging API method. Create a classic app and use the V1 Oauth flow to use RTM.

    For most applications, Socket Mode is a better way to communicate with Slack.

    Note that setting no_latest=1 will automatically set no_unreads=1.

    This method returns lots of data about the current state of a team, along with a WebSocket Message Server URL:

    {
        "ok": true,
        "url": "wss:\/\/wss-primary.slack.com\/websocket\/7I5yBpcvk",
    
        "self": {
            "id": "U023BECGF",
            "name": "bobby",
            "prefs": {
                ...
            },
            "created": 1402463766,
            "manual_presence": "active"
        },
        "team": {
            "id": "T024BE7LD",
            "name": "Example Team",
            "email_domain": "",
            "domain": "example",
            "icon": {
                ...
            },
            "msg_edit_window_mins": -1,
            "over_storage_limit": false
            "prefs": {
                ...
            },
            "plan": "std"
        },
        "users": [ ... ],
    
        "channels": [ ... ],
        "groups": [ ... ],
        "mpims": [ ... ],
        "ims": [ ... ],
    
        "bots": [ ... ],
    }
    

    The url property contains a WebSocket Message Server URL. Connecting to this URL will initiate a Real Time Messaging session. These URLs are only valid for 30 seconds, so connect quickly!

    The self property contains details on the authenticated user.

    The team property contains details on the authenticated user's team. If a team has not yet set a custom icon, the value of team.icon.image_default will be true.

    The users property contains a list of user objects, one for every member of the team. presence is no longer included for users. The list of users may truncate on especially long teams. Use Web API methods to retrieve information about users instead.

    The channels property is a list of channel objects, one for every channel visible to the authenticated user. For regular or administrator accounts this list will include every team channel. The is_member property indicates if the user is a member of this channel. If true then the channel object will also include the topic, purpose, member list and read-state related information. The latest, unread_count, and unread_count_display attributes have been removed from this method's response. See this changelog entry.

    The groups property is a list of group objects, one for every group the authenticated user is in.

    The mpims property is a list of mpims objects, one for every group the authenticated user is in. MPIMs are only returned to the client if mpim_aware is set when calling rtm.start. Otherwise, mpims are emulated using the groups API.

    The ims property is a list of IM objects, one for every direct message channel visible to the authenticated user.

    The bots property gives details of the integrations set up on this team.

    Errors

    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.

    ErrorDescription
    migration_in_progress

    Workspace is being migrated between servers. See the team_migration_started event documentation for details.

    rtm_connect_required

    rtm.start is deprecated. Please use rtm.connect instead of rtm.start. Read https://api.slack.com/changelog/2021-10-rtm-start-to-stop for more info.

    method_deprecated

    The method has been deprecated.

    not_authed

    No authentication token provided.

    invalid_auth

    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.

    account_inactive

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

    token_revoked

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

    token_expired

    Authentication token has expired

    no_permission

    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.

    org_login_required

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

    ekm_access_denied

    Administrators have suspended the ability to post a message.

    missing_scope

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

    not_allowed_token_type

    The token type used in this request is not allowed.

    deprecated_endpoint

    The endpoint has been deprecated.

    two_factor_setup_required

    Two factor setup is required.

    enterprise_is_restricted

    The method cannot be called from an Enterprise.

    invalid_arguments

    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.

    invalid_arg_name

    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.

    invalid_array_arg

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

    invalid_charset

    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.

    invalid_form_data

    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.

    invalid_post_type

    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.

    missing_post_type

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

    team_added_to_org

    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.

    ratelimited

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

    accesslimited

    Access to this method is limited on the current network

    request_timeout

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

    service_unavailable

    The service is temporarily unavailable

    fatal_error

    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.

    internal_error

    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.

    Warnings

    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.

    WarningDescription
    member_list_truncated

    A members array included in a channel object was truncated at 1500 results. Use conversations.members to retrieve all results.

    method_deprecated

    rtm.start is deprecated. Please use rtm.connect instead of rtm.start. Read https://api.slack.com/changelog/2021-10-rtm-start-to-stop for more info.

    missing_charset

    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.

    superfluous_charset

    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.

    Arguments

    Need a token? Create and install a Slack app to begin.
    This will make a real API request. Beware of using it with live workspaces.

    API response


    Submit your arguments to see the API response
    Deprecation notice
    rtm.start is deprecated and behavior for existing users will change on September 30, 2022.

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