Set the posting permissions for a public or private channel.


This API method can only be used on Enterprise Grid workspaces.


Method access

Bolt for Java
Powered by Bolt
Bolt for Python
Powered by Bolt
Bolt for JavaScript
Powered by Bolt

Content types

  • Rate limits

    Tier 3
  • Arguments

    Required arguments

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


    The channel to set the prefs for


    The prefs for this channel in a stringified JSON format.


    Usage info

    This Admin API method sets the posting permissions for a channel.

    This method allows you to adjust several conversation settings. To set any of these permissions, you'll use the prefs argument with some stringified JSON. Stringified JSON means JSON with white space removed and fields marked by single quotations. Since this argument won't contain more complex characters, you don't need to do further encoding.

    Calling this method requires that you β€” the user associated with your app's token β€” have permission to change conversation preferences. You can see or change the users who have permission in your Org’s Channel Management settings dashboard.

    Posting permissions

    To adjust who's allowed to post in a channel, use the who_can_post field inside your prefs argument:

    "prefs": "{'who_can_post':'type:admin,user:U1234'}"

    Inside your stringified JSON for who_can_post, you can specify who the permission applies to in a couple different ways:

    • By type: you can set posting permissions to include all admin users, or just any user in general. The user type is only honored when admin or org_admin is also provided.

    • By list of specific users who have the permission: user:U1234 for a single user or user:U1234,user:U5678 for multiple users. If you're specifying specific people, you can select up to 100 per channel. If you exceed that maximum, you may receive the could_not_set_channel_pref error.

    org_admin can only be used if the channel is an Org-Wide Channel, otherwise you may receive the invalid_value error.

    The can_thread field works exactly the same inside the prefs object, except that it determines who can respond in threads. You can pass both who_can_post and can_thread to the prefs argument in this method at the same time.


    "prefs": "{'who_can_post':'type:admin,user:U1234','can_thread':'type:user'}"

    In addition, while you cannot return to the original "empty" state of each of these fields when the channel is first created, you can always reset the channel to allow everyone to post by using the value ra:

    "prefs": "{'who_can_post':'type:ra','can_thread':'type:ra'}"

    Slack Connect

    In Slack Connect channels, the same fields and values are used by the channel owner (home workspace) to control who can post in a given channel, but they have slightly different meanings:

    • type:ra means that all home and away workspace members and guests can post.
    • type:regular means that only home workspace members can post, but away workspace members and home/away workspace guests cannot.
    • type:admin means that only home admins can post, but home/away workspace members or guests cannot.
    • type:org_admin means that only home org admins can post, but home/away workspace members or guests cannot.

    When listing individual users who can post in the channel, you are free to include user IDs of both home and away users.


    The can_huddle field determines if a huddle can be started in the channel.

    For example:

    "prefs": "{'can_huddle':'false'}"

    Channel mentions

    Channel mention restriction prefs enable_at_channel and enable_at_here can be used to place channel, here, and everyone mention restrictions in a channel.

    The enable_at_channel field determines if channel mentions can be used in a channel. The enable_at_here field determines if here mentions can be used in a channel. If these channel prefs have never been set before for a channel, then the relevant mention can be used in a channel. We require that both of these prefs remain synced so if you would like to set one of these prefs, you must also update the other pref, and they must be the same value. We do this because the everyone mention restriction in general channels is also controlled by these prefs.

    For example:

    "prefs": "{'enable_at_channel':'false', 'enable_at_here':'false'}"

    This admin scope is obtained through version two of the OAuth V2 flow, but there are a few additional requirements. The app requesting this scope must be installed by an Admin or Owner of an Enterprise Grid organization. Also, the app must be installed on the entire org, not on an individual workspace. See below for more details.

    If the app is installed by an Org Admin or Owner, ensure the Channel Management settings provide the appropriate permissions. In order to manage channels after they are created, you must update your token to enable permissions for Org Admins or Owners (not just the Primary Org Owner).

    Admin API endpoints reach across an entire Enterprise Grid organization, not individual workspaces.

    For a token to be imbued with admin scopes, it must be obtained from installing an app on the entire Grid org, not just a workspace within the organization.

    To configure and install an app supporting Admin API endpoints on your Enterprise Grid organization:

    1. Create a new Slack app. Your app will need to be able to handle a standard OAuth 2 flow.
    2. In the app's settings, select OAuth & Permissions from the left navigation. Scroll down to the section titled Scopes and add the admin.* scope you want. Click the green Save Changes button.
    3. In the app's settings, select Manage Distribution from the left navigation. Under the section titled Share Your App with Other Workspaces, make sure all four sections have the green check. Then click the green Activate Public Distribution button.
    4. Under the Share Your App with Your Workspace section, copy the Sharable URL and paste it into a browser to initiate the OAuth handshake that will install the app on your organization. You must be logged in as an Admin or Owner of your Enterprise Grid organization to install the app.
    5. Check the dropdown in the upper right of the installation screen to make sure you are installing the app on the organization, not an individual workspace within the organization. See the image below for a visual.
    6. Once your app completes the OAuth flow, you will be granted an OAuth token that can be used for calling Admin API methods for your organization.

    When installing an app to use an Admin API endpoint, be sure to install it on your Grid organization, not a workspace within the organization.

    Example responses

    Common successful response

    Typical success response

        "ok": true


    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.


    If setting channel mention restriction prefs, both mention prefs must be passed and they must be the same value.


    Value passed for channel was invalid.


    Value given for channel_id was a #general channel.


    Setting the preference or permission failed.


    Returned when you try to modify a default org wide channel.


    The Admin APIs feature is not enabled for this team.


    Value passed for the preferences are invalid


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


    The token provided is not associated with an org admin.


    A workspace preference prevents the authenticated user from archiving.


    Access to a resource specified in the request is denied.


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


    The endpoint has been deprecated.


    Administrators have suspended the ability to post a message.


    The method cannot be called from an Enterprise.


    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.


    This method cannot be called by a legacy bot.


    The method has been deprecated.


    The token type used in this request is not allowed.


    No authentication token provided.


    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.


    Authentication token has expired


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


    Two factor setup is required.


    Access to this method is limited on the current network


    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.


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


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


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


    The service is temporarily unavailable


    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.


    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.


    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.


    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